The role of spine length in crustacean and fish associations with echinoids at Los Cabos, Baja California Sur, Mexico / El papel de la longitud de la espina en la asociación de crustáceos y peces con equinoideos en Los Cabos, Baja California Sur, México

Introduction: Echinoids (sea urchins) provide shelter for a variety of facultative or obligatory ectosymbionts. Objective: To evaluate the hypothesis that decapods and fishes prefer to associate with echinoid individuals and species that have longer spines. Methods: We visually studied the frequency of decapod crustaceans and fishes associated with echinoids in shallow water (< 4 m) and deeper water (5-20 m) at Los Cabos, Baja California Sur, Mexico, during 1-6 January 2019. Results: We inspected 1 058 echinoids of six species. Five decapod species associated with three species of echinoids. When compared with other echinoid species, in shallow water, decapods associated 5.1 times more often with the longest-spined echinoid Diadema mexicanum (7.0 times more decapods per individual D. mexicanum); in deeper water, association frequency was similar for all echinoid species. Fourteen fish species associated with four echinoid species. In shallow water, fishes associated 2.6 times more with D. mexicanum (4.5 times more fishes per individual). There was no preferred echinoid species in deeper water. Longer-spined D. mexicanum had more decapods and fishes. Associations were more frequent in shallow water. Multiple individuals and species of decapods and fish often associated together with a single D. mexicanum. The decapod that presumably is Tuleariocaris holthuisi showed a possible obligatory association with one of the equinoids (D. mexicanum); the other decapods and all fish species are facultative associates. Conclusion: Our results support the hypothesis that decapods and fishes associate most frequently with echinoids with the longest spines, presumably to reduce the risk of predation.

Introducción: Los equinoideos (erizos de mar) brindan refugio a una variedad de ectosimbiontes facultativos u obligatorios. Objetivo: Evaluar la hipótesis de que los decápodos y los peces prefieren asociarse con individuos y especies de equinoideos con espinas más largas. Métodos: Estudiamos visualmente la frecuencia de crustáceos decápodos y peces asociados con equinoideos en aguas poco profundas (< 4 m) y aguas más profundas (5-20 m) en Los Cabos, Baja California Sur, México, del 1-6 de enero 2019. Resultados: Examinamos 1 058 equinoideos de seis especies. Cinco especies de decápodos se asociaron con tres especies de equinoideos. Al comparar con otras especies de equinoideos, en aguas poco profundas, los decápodos se asociaron 5.1 veces más frecuentemente con la especie de equinoideo de espinas más largas, Diadema mexicanum (7.0 veces más decápodos por individuo en D. mexicanum); en aguas más profundas, la frecuencia fue similar para todas las especies de equinoideos. Catorce especies de peces se asociaron con 4 especies de equinoideos. En aguas poco profundas, los peces se asociaron 2.6 veces más con D. mexicanum (4.5 veces más peces por individuo). No hubo preferencia por una especie de equinoideo en aguas más profundas. Individuos de D. mexicanum con espinas largas tuvieron más asociación con decápodos y peces. Las asociaciones se dieron con mayor frecuencia en aguas poco profundas. Múltiples individuos y especies de decápodos y peces a menudo se asociaron con un solo D. mexicanum. Un decápodo que presumiblemente es Tuleariocaris holthuisi mostró una posible asociación obligatoria con uno de los equinoideos (D. mexicanum); las otras especies de decápodos y todas las especies de peces presentaron asociaciones facultativas. Conclusión: Nuestros resultados apoyan la hipótesis de que los decápodos y los peces se asociaron con mayor frecuencia con los equinoideos con las espinas más largas, presumiblemente para reducir el riesgo de depredación.

Reproductive aspects of Grapsus grapsus (Decapoda: Grapsidae) on islands of the southeastern Gulf of California / Aspectos reproductivos de Grapsus grapsus (Decapoda: Grapsidae) en islas del sureste del Golfo de California

ABSTRACT Objective. The sex ratio, proportion of ovigerous females, length at sexual maturity and fecundity of Grapsus grapsus crabs in the Lobos, Venados and Pajaros islands (southeastern Gulf of California) were analyzed. Materials and methods. Sampling was conducted monthly between March 2011 and February 2012, during the night at low tide. Thirty crabs were collected in a quadrant (25 m2) at each sampling site on each island. cw (mm) and w (g) were determined. The sex ratio and size at sexual maturity (cw50%) were estimated, and for ovigerous females, embryonic stages and fecundity (gravimetric method) were determined. Results. The sex ratio (M:F) was 1:1.3. The average size at sexual maturity (cw50%) was 34.9 mm. The majority of females were ovigerous (71.3%), and 48% of the embryos of ovigerous females were at the red-orange phase. Egg diameter ranged from 1.1 to 5 µm, with an average of 2.05 µm. The mean fecundity was 24339.3 eggs. The maximum and minimum weight of ovigerous females was 69.9 and 15.2 g. Conclusions. The studied characteristics of sex ratio, proportion of ovigerous females, length at sexual maturity and fecundity of G. grapsus, indicate the effective administration and management of this resource in this area.

RESUMEN Objetivo. Se analizó la proporción de sexos, hembras ovígeras, talla de primera madurez sexual y fecundidad del cangrejo roca Grapsus grapsus en islas Lobos, Venados y Pájaros (sureste del Golfo de California). Material y métodos. Los muestreos fueron mensuales entre marzo 2011 y febrero 2012, las colectas fueron nocturnas durante la bajamar, se obtuvieron en un cuadrante (25 m2) por isla 30 organismos al azar, se les determinó el AN (mm) y PT (g). Se estimó la proporción de sexos y talla de primera madurez sexual (AN50%), se analizaron en hembras grávidas, las fases embrionarias y la fecundidad (método gravimétrico). Resultados. La proporción de M:H fue 1:1.3. La talla media de primera madurez fue AN50% 34.9 mm. Es evidente la presencia de hembras ovígeras (71.3%) y todas las fases embrionarias, la fase rojo-naranja fue la mayor representada en 48%. La variación del diámetro del huevo fue 1.1 a 5 µm y el promedio de 3.05 µm. La fecundidad media fue 24339.3 cigotos. El máximo y mínimo peso de hembras ovígeras fue 69.9 y 15.2 g, respectivamente. Conclusiones. Con base a las características biológicas del recurso tales como la proporción de sexos, hembras ovígeras, talla de primera madurez sexual y fecundidad en la población de G. grapsus, representa un efecto favorable en su posterior administración y manejo de este recurso en esta zona.

Incidence of hepatitis A and hepatitis E viruses and norovirus and rotavirus in fish and shrimp samples caught from the Persian Gulf / [Incidência de vírus da hepatite A e hepatite E e norovírus e rotavírus em amostras de peixes e camarões capturados no Golfo Pérsico]

Foodborne viruses including hepatitis A virus (HAV), norovirus (NoV), rotavirus (RoV) and hepatitis E virus (HEV) are easily transmitted through contaminated seafoods. The current research was done to assess the incidence of RoV, NoV GI and GII,hAV and hEV in fish and shrimp samples caught from the Persian Gulf, Iran. Three-hundred and twenty fish and shrimp samples were collected. The presence of foodborne viruses were assessed by the real-time PCR. Forty-nine out of 320 (15.31%) fish and shrimp samples were positive for foodborne viruses. Distribution of hAV, NoV GI and NoV GII amongst all studied samples were 0.93%, 5.93% and 8.43%, respectively. hEV and RoV viruses were not found in studied samples. Parastromateus niger and Scomberomorus commerson fish and Penaeus monodon shrimp were the most frequently contaminated samples. Simultaneous incidence of hAV and NoV GI and hAV and NoV GII were 0.31% and 0.93%, respectively. Distribution of foodborne viruses in samples collected through spring, summer, autumn and winter seasons were 14.28%, 9.33%, 11.76% and 24.44%, respectively. Findings revealed that the incidence of foodborne viruses was significantly associated with seafood species and also season of sampling.(AU)

Vírus transmitidos por alimentos, incluindo hepatite A (HAV), norovírus (NoV), rotavírus (RoV) e hepatite E (HEV) são facilmente transmitidos através de frutos do mar contaminados. Esta pesquisa foi realizada para avaliar a incidência de RoV, NoV GI e GII, hAV e hEV em amostras de peixes e camarões capturadas no Golfo Pérsico, Irã. Foram coletadas 300 amostras de peixes e camarões. A presença de vírus transmitidos por alimentos foi avaliada por PCR em tempo real. Quarenta e nove das 320 amostras de peixes e camarões (15,31%) foram positivas para vírus transmitidos por alimentos. A distribuição de hAV, NoV GI e NoV GII entre as amostras estudadas foi 0,93%, 5,93% e 8,43%, respectivamente. Os vírus hEV e RoV não foram encontrados nas amostras estudadas. Os peixes Parastromateus niger e Scomberomorus commerson e o camarão Penaeus monodon foram as amostras mais frequentemente contaminadas. A incidência simultânea de hAV e NoV GI, e hAV e NoV GII foi de 0,31% e 0,93%, respectivamente. A distribuição dos vírus transmitidos por alimentos nas amostras coletadas na primavera, verão, outono e inverno foi de 14,28%, 9,33%, 11,76% e 24,44%, respectivamente. Os resultados demonstram que a incidência de vírus transmitidos por alimentos foi significativamente associada às espécies de frutos do mar e também à época da amostragem.(AU)

Áreas en riesgo de invasión por Procambarus clarkii (Decapoda: Cambaridae) un cangrejo de río introducido en Colombia / Areas at risk of invasion by Procambarus clarkii (Decapoda: Cambaridae) a crayfish introduced in Colombia

Introducción: El proceso de invasión biológica es una de las mayores amenazas a la biodiversidad y ecosistemas, con actuales y potenciales impactos en la salud pública y conservación. Procambarus clarkii es un crustáceo decápodo, originario del sur de Estados Unidos y noreste de México, que puede adaptarse a diferentes condiciones ambientales debido a su plasticidad ecológica. Objetivo: Se caracterizó el nicho ecológico fundamental existente de Procambarus clarkii con el fin de predecir las áreas con idoneidad ambiental para el potencial establecimiento de la especie en Suramérica y Colombia. Métodos: Usamos modelos de nichos ecológicos calibrados en el área nativa, elaborados con el algoritmo Maxent, basados en datos de presencia extraídos de GBIF y variables hidroclimáticas de ecosistemas acuáticos a una resolución de 1 km2. Resultados: En Suramérica el modelo indicó un potencial geográfico amplio de invasión mostrando áreas ambientalmente idóneas para la presencia y expansión hacia Colombia, Venezuela, Perú, Ecuador, Brasil, Guyana, Surinam, Bolivia, Uruguay, Argentina, Paraguay y Chile. En Colombia, el modelo predijo que las áreas idóneas se ubican principalmente en el norte y oriente, incluidos diversos ecosistemas, como: bosques tropicales, bosques basales, bosques riparios y sabanas. La especie tiene una alta posibilidad de expandirse hacia áreas de distribución de latitudes bajas, ocupando zonas hacia la parte norte de la región Caribe colombiana, en departamentos de Magdalena, Cesar, Córdoba y Atlántico. También se predijo áreas con idoneidad ambiental en el oriente de Colombia, hacia la extensión de la planicie oriental de la Orinoquia, una región de baja altitud en: Arauca, Casanare, Meta y Vichada. Conclusión: En este estudio se aplican modelos de nichos ecológicos, que puede ser de interés en la planeación de estrategias o la creación de planes de manejo, como sistemas de alerta temprana para evitar el establecimiento de esta especie.

Introduction: Biological invasions are a major threat to biodiversity and ecosystems, with current and potential impacts on public health and conservation. Procambarus clarkii is a decapod crustacean, native to the Southern United States and Northeastern Mexico, which may adapt to different environmental conditions due to its ecological plasticity. Objective: The existing fundamental ecological niche of Procambarus clarkii was characterized in order to predict areas with environmental suitability for the potential establishment of the species in South America and Colombia. Methods: We used models of calibrated ecological niches in the native area, elaborated with the Maxent algorithm, based on occurrence data extracted from GBIF and hydroclimatic variables of aquatic ecosystems at a resolution of 1 km2. Results: The model indicated a wide geographic area for invasion potential in South America, predicting environmentally suitable areas for the presence and expansion towards Colombia, Venezuela, Peru, Ecuador, Brazil, Guyana, Surinam, Bolivia, Uruguay, Argentina, Paraguay and Chile. In Colombia, suitable areas predicted by the model are located mainly in the North and East of the country, spanning a diversity of ecosystems, such as tropical forests, basal forests, riparian forests and savannas. The species has a high possibility of expanding into low latitude distribution areas, occupying areas towards the Northern part of the Colombian Caribbean region, in the departments of Magdalena, Cesar, Cordoba and Atlántico. Suitability areas environmental were also predicted in Eastern Colombia, towards the extension of the Eastern plain of the Orinoquia, a low altitude region in Arauca, Casanare, Meta and Vichada. Conclusion: This study applies ecological niche models, which may be of interest in the planning of strategies or the creation of management plans, such as early warning systems that prevent the establishment of this species.

Crustáceos (Decapoda y Stomatopoda) del R.V. Skimmer y R.V. Victor Hensen en el Golfo de Nicoya, Pacífico, Costa Rica / Crustaceans (Decapoda and Stomatopoda) from the R.V. Skimmer and R.V. Victor Hensen in the Gulf of Nicoya, Pacific, Costa Rica

Resumen El acceso a datos actualizados, sobre los nombres y distribución de las especies de crustáceos presentes en un área en particular, es un primer paso para evaluar cambios debidos a factores locales, regionales o globales, como la sobrepesca, la contaminación y el cambio climático. Los datos en este estudio están basados en las expediciones de los buques de investigación Skimmer (20 estaciones, 1979-1980) y Victor Hensen (1993-1994, 12 estaciones) en el estuario del Golfo de Nicoya. Los crustáceos fueron recolectados mediante redes de arrastre tipo Otter (Skimmer, malla 3.5 cm) y por tipos Otter y Beam (V. Hensen, mallas de 2.5 cm y 1.9 cm) a profundidades entre 10 y 228 m. Datos en dos estudios posteriores aportaron información para una zona de entre-mareas en la región superior del Golfo y para estaciones en la boca del estuario, lo que incrementa el ámbito de profundidad de 0 a 350 m. Se revisaron las publicaciones originales y se hicieron 32 actualizaciones de los nombres de las especies con base en la literatura reciente y en la página de red World Register of Marine Species (WORMS). El total de especies para ambas expediciones fue de 131, del que 119 fueron decápodos y 12 fueron estomatópodos. Los datos en los otros dos estudios, así como la revisión de las colecciones en el Museo de Zoología de la Universidad de Costa Rica, incrementó en 43 el número de registros, para un total de 174 especies en los sedimentos del estuario. Para el Skimmer el número mínimo de especies en una estación fue de cuatro (tres estaciones) y el máximo de 27, con un promedio de 12.3 especies / estación. Para el V. Hensen el mínimo de especies en una estación fue de ocho, con un máximo de 27 y un promedio de 17 especies / estación. Las especies presentes en 50 % o más de las 20 estaciones de la expedición del Skimmer, fueron: Callinectes arcuatus, Rimapenaeus faoe, Penaeus brevirostris, Achelous asper y Hepatus kossmanni. Para la expedición del V. Hensen las especies presentes en más del 50 % de las 12 estaciones, fueron: A. asper, Sicyonia disdorsalis, S. picta y Persephona subovata. Durante el estudio del Skimmer, un total de 15 especies fueron encontradas en solo una estación, mientras que para el V. Hensen el número fue de 26. Se digitalizaron dos matrices de datos de presencia-ausencia de las especies en las estaciones y con base en los nombres actualizados de las especies recolectadas por el Skimmer (57 especies x 20 estaciones) y V. Hensen (82 especies x 12 estaciones) se les aplicó un Análisis No Métrico Dimensional de Escala (NMDS) para obtener una distribución de las estaciones en un espacio bi-dimensional. Los resultados revelaron unos grupos heterogéneos de estaciones. Algunos sub-grupos de tres o cuatro estaciones concuerdan con su proximidad geográfica. Las cuatro estaciones del V. Hensen en la boca del estuario a profundidades mayores a los 60 m fueron separadas más claramente de las otras, y podrían indicar una transición, desde aguas estuarinas hacia aguas profundas, en la composición de la fauna de crustáceos. Evaluaciones futuras de la diversidad de crustáceos del Golfo de Nicoya deben de considerar la amplia distribución espacial de algunas especies y la restringida de otras. La variabilidad temporal es también importante en el estuario, tal como lo evidenció la oscilación de la población de Pinnixulala valerii en un periodo de tres años.(AU)

Abstract The access to updated data on the names of the crustacean species and their distribution in a given area is a first step to evaluate changes due to local, regional and global factors such as overfishing, pollution, and climatic change. Data in this study are based on the expeditions of the RV Skimmer (20 stations, 1979-1980) and RV Victor Hensen (1993-1994, 12 stations) in the Gulf of Nicoya estuary. The crustaceans were collected by means of an Otter trawl (Skimmer, mesh 3.5 cm) and by Otter and Beam trawls (V. Hensen, mesh 2.5 cm and 1.0 cm, respectively) at depths from 10 m to 228 m. Data from two later studies were also included, one from an intertidal flat in the upper Gulf and the other from stations at the mouth of the estuary, which expand the depth range from 0 to 350 m. The list of species in the original publications were updated and 32 corrections were made based on recent literature and the web page, World Register of Marine Species (WORMS). The total number of species for both surveys was 131, of which 119 were decapods and 12 were stomatopods. Data from the other two studies and from the crustacean collection deposited at the University of Costa Rica Zoology Museum added 43 records for a total of 174 species collected in sediments from the estuary. For the Skimmer, the minimum number of species found in one station was four (three stations) and the maximum was 27, with an average of 12.3 species / station. For the V. Hensen, the minimum of species found in one station was eight, with a maximm of 27 and an average of 17 species / station. The species present in 50 % or more of the 20 stations of the Skimmer expedition, were: Callinectes arcuatus, Rimapenaeus faoe, Penaeus brevirostris, Achelous asper and Hepatus kossmanni. For the V. Hensen expedition, the species present in 50 % or more of the 12 stations, were: A. asper, Sicyonia disdorsalis, S. picta, and Persephona subovata. During the Skimmer survey a total of 15 species were found at only one station, while for the V. Hensen the number was 26. Two presence-absence matrices based on the updated names of the crustaceans collected by the Skimmer (57 species x 20 stations) and V. Hensen (82 species x 12 stations) were analyzed by Non Metric Dimensional Scaling (NMDS) to display the distribution of stations in a two-dimensional space. The results revealed heterogeneous groups of stations. Several sub-groups of two or three stations agreed with their geographical proximity. The four V. Hensen stations, located at the mouth of the estuary at depths greater than 60 m, were separated more clearly from the others and may indicate a transition, from estuarine to deep waters, in the composition of the crustacean fauna. Future evaluations of the crustacean diversity of the Gulf of Nicoya must take into account the wide spatial distribution of some species and the patchy distribution of others. Temporal variability is also important in the estuary as evidenced by the population oscilallations of Pinnixulala valerii over a three year period.(AU)

Weight-length relationships of six shrimp species caught off the Madeira Archipelago, Northeastern Atlantic / Relações peso-comprimento de seis espécies de camarão capturados ao largo do arquipélago da Madeira, Atlântico Nordeste

Abstract Length and weight relationships and descriptive statistics are reported for six shrimp species caught off the Madeira archipelago between 1983 and 2014 using bottom and floating traps from depths ranging from 50 to 1,300 m. The parameter b ranged between 2.36 for Plesionika ensis and 2.97 for Plesionika williamsi. All species showed a pattern of negative allometric growth. To the authors' knowledge all weight-length relationships presented herein are recorded for the first time from the Madeira area, and in the cases of Ligur ensiferus and Plesionika ensis are the first references worldwide.

Resumo As relações peso-comprimento e a estatística descritiva foram estimadas para seis espécies de camarões, capturados ao largo do arquipélago da Madeira, entre 1983 e 2014, usando armadilhas de fundo e alvoradas entre os 50 e 1.300 metros de profundidade. O parâmetro b variou entre 2,36 para Plesionika ensis e 2,97 para Plesionika williamsi. Todas as espécies evidenciaram um padrão de crescimento alométrico negativo. De acordo com o conhecimento dos autores, todas as relações peso-comprimento são aqui apresentadas pela primeira vez para a área da Madeira e no caso de Ligur ensiferus e Plesionika ensis são a primeira referência mundial.

Distribution and abundance of freshwater decapods in an Atlantic rainforest catchment with a dammed future / Distribuição e abundância de decápodes de água doce e sua associação com variáveis ambientais em uma bacia hidrográfica de Mata Atlântica que será represada

Abstract Variations in physical characteristics along the course of a river influence habitat availability which reflects in species distribution. Knowledge of ecology and diversity of lotic species is important for evaluating how river ecosystems will respond to environmental impacts. Freshwater decapods are a group of high ecological and economic importance, but the knowledge about factors influencing their distribution is scarce in Brazil. We performed a survey of decapods to describe their abundance and distribution as well as to study their relationships with stream physical variables and especially their association with different substrates types. We studied 23 sites located in 15 tributaries of Guapiaçú River, RJ, where we collected decapods in different substrates types and measured a set of physical variables. We found five decapods species, including amphidromous and non-amphidromous shrimps and crabs. Decapods were strongly associated with leaf-litter substrates and their abundance was related to a multivariate axis describing longitudinal changes in stream characteristics. We concluded that decapods occurring in the Guapiaçú catchment inhabit mainly small streams with preserved riparian forests where they find shelter and potential prey of invertebrates. The ongoing project to build a dam on the Guapiaçú River will have negative consequences to migrating shrimps and we strongly recommend that mitigating actions, such the construction of structures to allow the passage of migrating fauna, should be taken.

Resumo Variações nas características físicas de um rio ao longo do seu curso influenciam a disponibilidade de habitas e dessa forma a distribuição de espécies. O conhecimento sobre a ecologia e diversidade de espécies lóticas é importante para avaliar como esses ecossistemas responderão a impactos ambientais. Decápodes de água doce são um grupo de grande importância ecológica e econômica, contudo o conhecimento sobre fatores influenciando sua distribuição ainda é escasso no Brasil. Nós realizamos um levantamento de decápodes para descrever sua abundância e distribuição, bem como estudar sua relação com características físicas dos rios, especialmente sua associação com tipos diferentes de substrato. Nós estudamos 23 localidades distribuídas em 15 rios tributários do Rio Guapiaçú, RJ, onde coletamos decápodas em diferentes tipos de substratos e medimos um conjunto de variáveis físicas. Nós encontramos cinco espécies de decápodas incluindo camarões anfídromos e não anfídromos e caranguejos. Esses organismos foram fortemente associados a substratos de folhiço alóctone e sua abundância foi relacionada com um eixo PCA que descreve as mudanças nas características físicas longo do curso do rio. Nós concluímos que os decápodas que ocorrem na bacia do Rio Guapiaçú habitam principalmente pequenos córregos com mata ciliar preservada, onde podem encontrar abrigo e um potencial campo de caça onde predam invertebrados. O projeto atualmente em curso para a construção de uma represa no Rio Guapiaçú irá afetar negativamente a fauna de camarões anfídromos, assim nós recomendamos fortemente que ações mitigadoras, como a construção de estruturas para permitir a passagem da fauna migrante sejam tomadas.

Method of capture and population structure of Aegla georginae Santos and Jara, 2013 (Decapoda: Anomura: Aeglidae) in a tributary of the Ibicuí River in southern Brazil / Método de captura e estrutura populacional de Aegla georginae Santos and Jara, 2013 (Decapoda: Anomura: Aeglidae) em um afluente do rio Ibicuí no sul do Brasil

Abstract In the current study, we investigated population aspects of Aegla georginae in the Ibicuí River Basin by considering different capture methods and the implication of these data in the analysis of population dynamics. We sampled 1774 individuals: 1259 males (21 and 97 juveniles and 1029 and 113 adults in trap and handnet, respectively), 512 females (05 and 140 juveniles, 184 and 64 adults, and 81 and 38 ovigerous in trap and handnet, respectively) and 03 unsexed individuals (02 and 01 in trap and handnet, respectively). The frequency distribution in size classes shows a bimodal model for both sexes. The carapace length (CL) in males and females varied from 3.11 to 26.00 and 3.73 to 22.36 mm, respectively. Males presented significantly larger sizes than females. The relative abundance between males and females was significantly different from 1:1 with more males than females in most sampling periods (p < 0.05) when considering the grouped data (handnet + trap) and trap captures, but followed the expected ratio in most months when considering individuals sampled only with handnet (p > 0.05). Juveniles were recorded in all seasons, and reproduction occurs throughout the year. The population structure is similar to the model known for aeglids, and the capture methods affected the analysis of A. georginae, where the grouped data and trap captures presented greater abundance of individuals than handnet and males predominate in the larger size classes, and females in the intermediary size classes. Therefore, an integrated view of the capture methods is the best model for studying the population dynamics of aeglids.

Resumo No presente estudo, nós investigamos aspectos populacionais de Aegla georginae na Bacia do rio Ibicuí e consideramos a implicação de diferentes métodos de captura na análise dos dados de dinâmica populacional. Foram amostrados 1774 indivíduos: 1259 machos (21 e 97 juvenis e 1028 e 113 adultos em armadilhas e rede de mão, respectivamente), e 512 fêmeas (05 e 140 juvenis, 184 e 64 adultos, e 81 e 38 ovígeras em armadilhas e rede de mão, respectivamente) e 03 não-sexados (2 e 1 em armadilhas e rede de mão, respectivamente). A distribuição de frequência nas classes de tamanho mostrou um modelo bimodal para ambos os sexos. O comprimento da carapaça (CC) em machos e fêmeas variou de 3,11 a 26,00 e 3,73 a 22,36 mm, respectivamente. Machos apresentaram-se significativamente maiores que as fêmeas. A abundância relativa entre machos e fêmeas foi diferente significativamente de 1:1 com mais machos do que fêmeas na maioria dos períodos amostrados (p < 0,05) quando considerados os dados agrupados (rede de mão + armadilhas) e somente armadilhas, mas seguiu a razão esperada na maioria dos meses quando considerados apenas os indivíduos capturados com rede de mão (p > 0,05). Juvenis foram registrados em todas as estações do ano e a reprodução ocorreu durante todo o ano. A estrutura populacional é similar ao modelo conhecido para eglídeos e os métodos de captura afetam a análise para A. georginae, onde os dados agrupados e as capturas por armadilha apresentaram maior abundância de indivíduos do que rede de mão e machos predominando nas classes de tamanho mais altas e fêmeas nas classes de tamanho intermediárias. Portanto, uma visão integrativa dos métodos de captura é o melhor modelo para estudar a dinâmica populacional de eglídeos.

Influencia de la proporción sexual y del ambiente en la tasa de crecimiento poblacional de Callinectes bellicosus (Decapoda: Portunidae) del Golfo de California / Sex ratio and environmental influence on population growth rate of Callinectes bellicosus (Decapoda: Portunidae) in the Gulf of California

ResumenPara la jaiba café (Callinectes bellicosus) capturada en Sonora, México dentro del Golfo de California desde 1986, durante 20 años se ha observado una tendencia decreciente en la biomasa. Se estimaron las tasas de crecimiento poblacional (r) y proporción de sexos de C. bellicosus además de tres parámetros que describen su hábitat: temperatura del mar, extensión de humedales y tamaño del hábitat en cuatro zonas a lo largo de la costa de Sonora. La proporción de sexos se estimó de 25 556 jaibas muestreadas de las capturas comerciales en los años 19982002 y 2012; la temperatura media en el período de desove (mayo-agosto) se generó a partir de sensores remotos en los mismos años; la cobertura de humedales se obtuvo de reportes publicados; y el tamaño del hábitat se estimó como la superficie de pesca. Para cada zona se estimó r mediante un método desarrollado para situaciones de escasa información utilizando las capturas comerciales (t) de 1986 a 2013. Con los datos de las cuatro zonas se desarrollaron modelos de regresión lineal simple y múltiple para evaluar las sensibilidades teóricas de r a variaciones en la proporción de sexos y en los parámetros ambientales. Los machos dominaron (68.8 %) sobre las hembras en el período de estudio en las cuatro zonas; un análisis de conglomerados identificó dos grupos de acuerdo a la proporción de sexos: un grupo norteño con las zonas 1 y 2, y otro sureño con las zonas 3 y 4. Los valores de r fueron diferentes en las cuatro zonas (P<0.001) igual que la proporción de sexos (P=0.037); no se encontraron diferencias en la temperatura entre los años considerados en el estudio (P>0.995). Tanto los datos estimados como los análisis de sensibilidad sugieren que r dependen directa y positivamente de la proporción de hembras de jaiba y el tamaño de los humedales. Por lo anterior planteamos la hipótesis de que la pesca excesiva de hembras es la causa del descenso de la biomasa de jaiba café en Sonora, y concluimos que es conveniente implementar refugios pesqueros dentro de humedales costeros para proteger las hembras en el período de desove.

Abstract:The brown swimming crab (Callinectesbellicosus) is an economically important species in the Gulf of California, and its fishing activity, held in Sonora from 1986, has been affected by a 20-year declining trend in its biomass. With the aim to understand the possible reasons of this species population changes along time, we estimated population growth rate (r) and sex ratio of C. bellicosus, and combined them with three parameters describing its habitat: sea temperature, wetland extension and habitat size in four areas along the coast of Sonora. For this, monthly mean sex ratio was estimated from crabs samples obtained from commercial catches during 1998-2002 and 2012; mean sea surface temperature for the spawning period (May-August) were derived from remote sensors for the same years; while wetland coverages were obtained from published reports, and habitat size was estimated as the fishing surface. For each area, r was estimated using a method developed for limited data situations using commercial landings (t) from 1986-2013. With data from the four areas, simple and multiple linear regression models were developed to ascertain theoretical sensitivities of r to variations in sex ratio and environmental parameters. A total of 24 556 crabs were sampled; males dominated (68.8 %) over females during the study period and in all areas; a cluster analysis identified two groups according to sex ratio: a Northern group with zones 1 and 2, and a Southern group with zones 3 and 4. r values were different in all zones (P<0.001) as was sex ratio (P=0.037); no differences in temperature were identified within the study years (P>0.995). Both the estimated data and sensitivity analyses suggest the existence of a direct and positive dependence of r on the proportion of female crabs and wetland size. We hypothesize that excess fishing of females caused the declining biomass trend of the brown swimming crab in Sonora, and concluded on the convenience of implementing harvest refugia inside coastal wetlands to protect females during the spawning season. Rev. Biol. Trop. 64 (3): 1259-1271. Epub 2016 September 01.

Analysis of food habits of skate Rioraja agassizii (Elasmobranchii, Rajidae) from southern Brazil / Análise quantitativa dos hábitos alimentares da raia Rioraja agassizii (Elasmobranchii, Rajidae) do Sudeste e Sul do Brasil

Abstract Catches and exports of skate Rioraja agassizii place this species as “vulnerable to extinction” on the IUCN Red List; therefore, biological and ecological knowledge becomes an important instrument for its conservation control. This study described and quantified the diet composition of R. agassizii by means of stomach analysis contents in the periods 2005-2006 and 2012-2013. We analyzed and quantified stomach contents in terms of abundance (%N), weight (%M), frequency of occurrence (% FO), and index of relative importance (IRI). The results showed differences in the food rates between the periods. However, the groups of food items were the same: Teleostei fish, decapods, and mollusks. In 2005-2006, the diet consisted mainly of shrimp, however, in 2012-2013 it consisted of fish, followed by decapods, especially shrimps. The differences in diets may be attributed to shrimp abundance, which do not characterize a change in the eating habits in 2012-2013, because, in addition to fish, shrimps were also important food sources. The presence of a certain prey is more related to its availability rather than the feeding preference of skate. The amount of ingested items is associated to biological and environmental factors, so that further studies relating diet with capture area, seasonality, depth, and other factors should be conducted.

Resumo A raia-santa, Rioraja agassizii é uma espécie endêmica da qual pouco se conhece sobre sua biologia e ecologia, o que a leva a ser classificada como “vulnerável a extinção”. O objetivo foi identificar e quantificar a composição da dieta alimentar da R. agassizii através da análise do conteúdo estomacal de exemplares capturados nos períodos de 2005-2006 e 2012-2013. Foram analisados os conteúdos alimentares e quantificados em abundância (N%), peso (M%), frequência de ocorrência (FO%) e índice de importância relativa (IRI) de cada item. Os resultados mostraram que em 2012-13 a dieta foi composta por peixes, seguido de decápodes, especialmente camarões, entretanto em 2005-06 foi composta basicamente por camarões. A diferença nas dietas não quer dizer que os hábitos alimentares mudaram, pois em 2012-13 além dos peixes, os camarões também foram classificados como maior importância alimentar. Considerando que a quantidade e variedade dos itens ingeridos está relacionada, principalmente, a fatores ambientais são necessários mais estudos que relacionem áreas de captura, sazonalidade e profundidade.

Evaluación del crecimiento de Callinectes sapidus (Decapoda: Portunidae) con métodos basados en talla, Tamaulipas, México / Evaluation of the growth of Callinectes sapidus (Decapoda: Portunidae) by the use of lengthbased methods based on size in Tamaulipas, Mexico

ResumenLa captura de la jaiba azul (Callinectes sapidus) es una de las principales del Estado de Tamaulipas, México, tanto por su volumen y precio de venta, como por la generación de empleo, pero se cuenta con escasa información de sus características biológicas. El objetivo del presente estudio fue evaluar los parámetros de crecimiento de la jaiba azul, estableciendo el método más adecuado para realizarlo. Se estimó la frecuencia de tallas de 17 814 jaibas de muestreos realizados de enero a junio 2009, provenientes de la captura comercial de trece localidades, comprendidas en cuatro lagunas costeras: Laguna El Barril, Laguna Madre, Laguna de Morales y Laguna de San Andrés. Los parámetros de crecimiento se estimaron usando los métodos indirectos ELEFAN, PROJMAT y SLCA en combinación con la técnica jackknife para establecer la incertidumbre de las estimaciones inherentes a cada método. Los parámetros de crecimiento L∞ y k se unificaron para efectos comparativos mediante el índice de crecimiento phi prima (Φ’). Con una moda de 110 mm, el intervalo de longitud de caparazón varió entre 60 y 205 mm. Los valores de los parámetros de crecimiento variaron de acuerdo al método utilizado. Utilizando SLCA, L∞ varió entre 259 y 260 mm y k osciló entre 0.749 y 0.750/año; con PROJMAT, L∞ registró valores entre 205 y 260 mm y k fluctuó entre 0.550 y 0.740/año, y con ELEFAN, L∞ osciló entre 156 y 215 mm y k varió entre 0.479 y 0.848/año. Las estimaciones mediante jackknife detectaron nula variabilidad en Φ’ entre localidades y diferencias significativas entre métodos. Los rangos de valores de Φ’ estimados por SLCA y PROJMAT (4.70 a 4.71 y 4.66 a 4.70, respectivamente) se ubicaron en el rango reportado por la literatura (4.201-4.798), mientras que ELEFAN aportó valores significativamente menores (3.87 a 4.27). Los métodos SLCA y PROJMAT en combinación con la técnica jackknife, resultaron ser los más adecuados para estimar los parámetros de crecimiento de C. sapidus.

AbstractThe capture blue crab (Callinectes sapidus) is one of the major fisheries of the state of Tamaulipas, Mexico; both in volume and selling price, as well as employment generation, but there is little information on its biological characteristics. The aim of this study was to evaluate the growth parameters of the blue crab, establishing the most appropriate method. We estimated the length frequency of 17 814 crabs from commercial catch of thirteen locations, including four coastal lagoons. The lagoons were El Barril, Madre, Morales and San Andrés from Tamaulipas, State. Growth parameters were evaluated using indirect methods ELEFAN, PROJMAT and SLCA in combination with the jackknife technique to establish the uncertainty of estimates inherent in each method. The growth parameters L∞ and k were consolidated for purposes of comparison with the growth index phi prime (Φ’). With a mode of 110 mm, the interval carapace length varied between 60 and 205 mm. The values of the growth parameters varied according to the method used. Using SLCA, L∞ varied between 259 and 260 mm and k ranged between 0.749 and 0.750 /year; with PROJMAT, L∞ recorded values between 205 and 260 mm, k fluctuated between 0.550 and 0.740/year, and with ELEFAN, L∞ ranged between 156 and 215 mm and k varied between 0.479 and 0.848/year. Estimates by jackknife detected no variability in Φ’ between locations and significant differences between methods. The ranges of values of Φ’ and PROJMAT estimated SLCA (4.70 to 4.71 and 4.66 to 4.70, respectively) were in the range reported in the literature (4.201-4.798), while lower values ELEFAN contributed significantly (3.87 to 4.27). The SLCA and PROJMAT methods in combination with the jackknife technique, proved to be the most suitable to estimate the growth parameters of C. sapidus. Rev. Biol. Trop. 64 (2): 821-836. Epub 2016 June 01.

Morfogeometría del caparazón del cangrejo Damithrax spinosissimus (Decapoda: Mithracidae) en tres islas del Caribe suroccidental / Morfogeometry shell crab Damithrax spinosissimus (Decapoda: Mithracidae) on three islands in the southwestern Caribbean

ResumenEl cangrejo rey del Caribe Damithrax spinosissimus es un recurso pesquero catalogado en estado de vulnerabilidad y de cuya biología se conoce muy poco. Su distribución agregada en mosaico y la gran heterogeneidad ambiental dada por las características oceanográficas, paisajísticas y ecológicas del Caribe, pueden propiciar a que exista variabilidad fenotípica en función de la procedencia geográfica de los individuos. Por esta razón, el objetivo de esta investigación fue determinar si existe variabilidad morfogeométrica en los caparazones de ejemplares procedentes de tres islas del Caribe suroccidental: Providencia, Rosario y San Bernardo. La primera de ellas con una influencia netamente oceánica y las dos siguientes, cercanas al continente, con mayor influencia de las dinámicas costeras. Para ello se capturaron y fotografiaron 276 individuos: 103 hembras ovadas y 173 machos, sobre los cuales se realizaron análisis morfogeométricos, tomando 12 puntos anatómicos de referencia (Landmarks) en una de las mitades del caparazón. Las diferencias de tamaño entre sexos y entre orígenes geográficos se contrastaron mediante comparaciones pareadas de Fisher, el efecto alométrico se estimó mediante Análisis de Regresión Multivariada y el modelo de pendientes alométricas mediante Análisis Multivariado de Covarianza. La conformación promedio entre sexos y entre orígenes geográficos se computó de las deformaciones relativas, obtenidas mediante análisis de componentes principales; asimismo, las distancias Euclidianas entre las conformaciones promedio se utilizaron para construir un árbol con base en el algoritmo de Neighbour- Joining con una significancia calculada sobre 10 000 permutaciones. Los resultados mostraron diferencias en el tamaño y conformación del caparazón entre sexos y entre las tres islas, siendo más evidentes las diferencias en Providencia. Estos resultados pueden ser explicados de manera no excluyente por diferencias genéticas y plasticidad fenotípica debida a la heterogeneidad ambiental del sector. Este estudio, primero en su clase, es un aporte al conocimiento de la especie y de él se concluye que deberían existir estrategias de manejo diferentes para las tres islas.

AbstractThe Caribbean King Crab, Damithrax spinosissimus is a fishery resource, but few biological studies are available. Its patchy distribution, and the high environmental heterogeneity due to the oceanographic, landscape, and ecological characteristics of the Caribbean Sea, can favor the phenotypic variability according to the geographic origin. For this reason, the objective of our study was to determine morphometic variability in the carapace of the crabs from three Southwestern Caribbean islands: Providence, Rosario and San Bernardo. The former has an oceanic influence, whereas the two latter islands, which are closer to the mainland, have more influence of the coastal dynamic. A total of 276 individuals from the three islands were captured and photographed: 103 females and 173 males; their variation was analyzed from 12 anatomical landmarks marked on one half of the carapace. The differences in the carapace size were calculated using a Fisher’s pairwise comparison; the allometric effect was calculated by Multivariate Regression Analysis; and the Allometric model via Multivariate Analysis of Covariance. The average shape was calculated from the relative wraps RW obtained through PCA analysis; and the Euclidian distances between the shape averages, were used to construct a tree using the Neighbour-Joining algorithm over 10 000 permutations. The results showed significant differences in the size and shape of the carapace between sexes and among the three islands. The differences in the shape of the crabs from Providencia were significantly greater than those found between the crabs of Rosario and San Bernardo. These results can be explained inclusively due to the genetic differences and phenotypic plasticity, due to environmental heterogeneity of the sector. This study, the first of its kind, is a contribution to the knowledge of the species. We concluded that different management strategies should be differently adopted in each of the three studied islands. Rev. Biol. Trop. 64 (2): 667-681. Epub 2016 June 01.

New records of the striped cleaner shrimp Lysmata grabhami (Gordon, 1935) from Brazil, Southwestern Atlantic / Novos registros do camarão limpador Lysmata grabhami (Gordon, 1935) no Brasil, Atlântico Sul Ocidental

Abstract New records for Lysmata grabhami (Gordon, 1935) in Brazilian waters are presented. Four adult individuals from coastal waters off the city of Vitória, Espírito Santo coast and one adult from Trindade Island were collected during scuba diving in depths between 20-40 meters. These two records represent the southernmost published finding of this species in the Atlantic and the record for Vitória, Espirito Santo is the first from Brazilian coastal waters.

Resumo Novos registros de ocorrência de Lysmata grabhami (Gordon, 1935) em águas brasileiras são apresentados. Quatro indivíduos foram coletados próximo à costa da cidade de Vitória, Espírito Santo, e um na Ilha da Trindade, por mergulhadores autônomos em profundidades entre 20-40 metros. O presente registro é a ocorrência mais meridional conhecida para esta espécie no Atlântico e o registro em Vitória é o primeiro para águas costeiras brasileiras.

Population structure of the red mangrove crab, Goniopsis cruentata (Decapoda: Grapsidae) under different fishery impacts: Implications for resource management / Estructura de la población del cangrejo rojo de manglar, Goniopsis cruentata (Decapoda: Grapsidae) bajo diferentes impactos de pesca: Implicaciones para la gestión de los recursos

The red mangrove crab, Goniopsis cruentata, influences the recruitment and composition of plant species in the mangrove ecosystem and it is an important fishery resource. Nevertheless, no current management and conservation plans are available for this species for the Brazilian coast. This investigation evaluated the population structure and reproductive biology in populations of G. cruentata under contrasting fishery pressures. The sampling program was carried out in two mangroves, Vaza-Barris and Sergipe River, from January through December 2011. Crabs from both mangroves were randomly collected by a professional fisherman during daytime low tide periods, using a fishing rod baited with pieces of a locally abundant gastropod, Pugilina morio, during 20min/area (catch per unit effort). Monthly measurements of air, sediment surface layer and water temperatures were obtained with a digital thermometer and salinity with an optical refractometer. Both crab populations were compared concerning their abundance, body size, sex ratio, size at onset of sexual maturity and fecundity (FI). Abiotic factors (air, water and mud temperature; and salinity) showed no significant differences between sampling localities. A total of 4 370 crabs were sampled, 2 829 from the Sergipe River and 1 541 from the Vaza-Barris River. The abundance and body size of crabs were compared between mangroves, and statistically significant differences were found. The sex ratio for both populations differed from the expected 1:1 ratio, and a significant deviation in favor of juvenile males was obtained, while adults showed a bias toward females. The estimated size at onset of sexual maturity for both sexes was similar in both populations. However, the populations differed significantly in the number and volume of eggs: a higher FI was obtained in females from the Sergipe River, while a higher egg volume was observed in females from the Vaza-Barris River mangrove. These results indicated a tendency to decrease the body size, the abundance of crabs and the reproductive potential of the species, with higher fishing intensities, reinforcing the need to develop a management plan as well as to establish conservation units for G. cruentata in the Northeastern Brazilian coast. Habitat loss in conjunction with long-term overfishing can have irreversible consequences, which can impact not only the populations of commercially exploited crabs, but the dynamics of virtually the entire mangrove ecosystem.

El cangrejo rojo Goniopsis cruentata influye en el reclutamiento y la composición de especies vegetales del ecosistema manglar y es un importante recurso pesquero. Sin embargo hasta la fecha, no se han desarrollado planes de manejo y conservación para esta especie en Brasil. La presente investigación evaluó la estructura poblacional y la biología reproductiva de las poblaciones de G. cruentata expuestas a diferentes presiones de pesca. El muestreo se realizó en dos manglares, Río Sergipe y Río Vaza-Barris entre enero y diciembre 2011. En ambos manglares, los animales fueron recolectados de día durante la marea baja por un pescador profesional, utilizando una caña de pescar con carnada del gasterópodo Pugilina morio, durante 20min/área (captura por unidad de esfuerzo, CPUE). Mensualmente con un termómetro digital se registró la temperatura del aire, agua y capa superficial del sedimento, mientras que la salinidad fue cuantificada utilizando un refractómetro óptico. Las poblaciones fueron comparadas en su abundancia, tamaño corporal, proporción de sexos, talla de primera madurez sexual y fecundidad. Los factores abióticos(temperatura del aire, agua y sedimento y la salinidad) no mostraron diferencias significativas entre ambos sitios de muestreo. Se recolectaron un total de 4 370 cangrejos; 2 829 en el río Sergipe y 1 541 en Vaza-Barris. Se registraron diferencias significativas entre los manglares con respecto a la abundancia y el tamaño corporal de los animales. La proporción de sexos de ambas poblaciones difirió de la relación 1:1 esperada y se obtuvo una desviación significativa en favor de machos jóvenes, mientras que los adultos mostraron una tendencia hacia las hembras. A su vez, las poblaciones difirieron significativamente en el número de huevos, con un mayor IF para las hembras del manglar del río Sergipe. El volumen de los huevos también mostró diferencias significativas entre ambas poblaciones. Estos resultados indican que la alta intensidad de pesca podría estar afectando dichos parámetros, lo que refuerza la necesidad de desarrollar un plan de manejo y la creación de unidades de conservación para G. cruentata en la costa noreste de Brasil. La pérdida del hábitat junto con la sobrepesca a largo plazo, pueden tener consecuencias irreversibles, que afectan no sólo a las poblaciones de cangrejos de importancia comercial, sino también la dinámica del ecosistema de manglar.

Inversión reproductiva de Aratus pisonii (Decapoda: Sesarmidae): diferencias entre hábitats y análisis de rutas / Reproductive investment of Aratus pisonii (Decapoda: Sesarmidae): differences among habitats and path analysis

Aratus pisonii is an abundant Neotropical mangrove crab that forages on fresh leaf tissue in the canopy and lives in a wide spectrum of habitats. It presents great plasticity in some aspects of its life history becoming an excellent subject for comparative studies. The purpose of this study was to investigate possible reproductive variations among populations of this crab in mangroves with different levels of structural development, and explore the direct and indirect effects of environmental variables on reproductive investment. The study was conducted during the rainy season of 2003 and 2004, in North Western Venezuela. Fecundity (number of eggs/female), dry weight of egg mass (PSH) and egg quality (C/Neggs) were evaluated in five populations of this species, in mangroves under different environmental conditions (estuarine, marine, hypersaline) and diverse degrees of structural development (arboreal, arbustive, scrub). Reproductive output (Ro) was obtained by the ratio Ro=PSH/dry body weight (PSC); other estimations of Ro were tested: Ro1=PSH/carapace length (CL), Ro2=fecundity/CL. A path analysis was used to explore causal relationships between environmental and morphological variables and reproductive investment (PSH, fecundity). Fecundity ranged from 6 463±831 eggs (Mean±SE) in the hypersaline arbustive mangrove to a maximum of 24 584±2 393 eggs in estuarine arboreal mangrove, which presents the greatest structural development. The reproductive output of females showed significant differences among mangroves, with the highest values of Ro1, Ro2 in the estuarine mangrove females. The results of the path analysis indicated a multicausal effect of morphological and environmental variables; in particular, the salinity showed the greatest influence on fecundity and PSH. The condition of the estuarine mangrove forests with lower salinity and higher structural development involving higher quality of mangrove leaves and a wider range of potential resources, may explain the higher reproductive output of females observed in this habitat. Rev. Biol. Trop. 63 (2): 385-399. Epub 2015 June 01.

Aratus pisonii es un cangrejo abundante de los manglares del Neotrópico, que forrajea sobre el tejido foliar fresco del dosel y vive en una amplia variedad de hábitats. Presenta una gran plasticidad en algunos aspectos de su historia de vida, convirtiéndose en un excelente sujeto para estudios comparativos. El propósito de este estudio fue investigar las posibles variaciones reproductivas entre las poblaciones de este cangrejo en manglares con diferentes niveles de desarrollo estructural, y explorar los efectos directos e indirectos de las variables ambientales sobre la inversión reproductiva. El estudio se realizó durante la temporada de lluvias 2003 y 2004, en la región Noroccidental de Venezuela. Se evaluaron la fecundidad (número de huevos/hembra), el peso seco de la masa de huevos (PSH) y la calidad del huevo (C/Nhuevos) en cinco poblaciones de esta especie, que viven en manglares bajo diferentes condiciones ambientales (estuarinos, marinos, hipersalinos) y diferente grados de desarrollo estructural (arbóreo, arbustivo, achaparrado). El rendimiento reproductivo (Ro) se obtuvo por la relación Ro=PSH/peso seco del cuerpo (PSC); se probaron otras estimaciones de Ro: Ro1=PSH/longitud del caparazón (LC), Ro2=fecundidad/LC. Se utilizó un análisis de rutas para explorar las relaciones causales entre las variables ambientales y morfológicas con la inversión reproductiva (PSH, fecundidad). La fecundidad varió de 6 463±831 huevos (media±ES) en el manglar arbustivo hipersalino, hasta un máximo de 24 584±2 393 huevos en el manglar arbóreo estuarino, que presentó el mayor desarrollo estructural. El rendimiento reproductivo de las hembras mostró diferencias significativas entre manglares, encontrándose los más altos valores de Ro1, Ro2 en las hembras de manglar estuarino. Los resultados del análisis de rutas indicaron un efecto multicausal de variables morfológicas y ambientales; en particular, la salinidad mostró la mayor influencia sobre la fecundidad y el PSH. La condición del manglar estuarino con menor salinidad y mayor desarrollo estructural, que de acuerdo con estudios anteriores supone una mayor calidad de las hojas de mangle y una mayor variedad de recursos potenciales, puede explicar la mayor inversión reproductiva observada en las hembras de este hábitat.

Distribution of the Planktonic Shrimp Lucifer (Thompson, 1829) (Decapoda, Sergestoidea) off the Amazon / Distribuição do camarão planctônico Lucifer (Thompson, 1829) (Decapoda, Sergestoidea) na plataforma continental amazônica

Lucifer faxoni (BORRADAILE, 1915) and L. typus (EDWARDS, 1837) are species first identified in the neritic and oceanic waters off the Amazon. Samplings were made aboard the vessel “Antares” at 22 stations in July and August, 2001 with a bongo net (500-µm mesh size). Hydrological data were taken simultaneously for comparative purposes. L. faxoni was present at thirteen of the fourteen neritic stations analysed, as well as at five of the eight oceanic stations. L. typus was present at three of the fourteen neritic stations and in one of the eight oceanic stations. The highest density of L. faxoni in the neritic province was 7,000 ind.m–3 (St. 82) and 159 ind.m–3 (St. 75) in the oceanic area. For L. typus, the highest density observed was 41 ind.m–3 (St. 64) in the neritic province. In the oceanic province, the highest single density value was recorded at station 75 (5 ind.m–3). Overall, L. faxoni typically presented the highest densities.

Lucifer faxoni (BORRADAILE, 1915) e L. typus (EDWARDS, 1837) são espécies identificadas pela primeira vez nas águas neríticas e oceânicas da Amazônia. As coletas foram realizadas a bordo do navio “Antares” em 22 estações em julho e agosto de 2001, com uma rede bongô (500 µm). Dados hidrológicos foram tomados simultaneamente para fins comparativos. L. faxoni esteve presente em 13 das 14 estações neríticas analisadas, bem como em 5 das 8 estações oceânicas. L. typus esteve presente em 3 das 14 estações neríticas e em 1 das 8 estações oceânicas. A maior densidade de L. faxoni na província nerítica foi de 7.000 ind.m–3 (estação 82) e 159 ind.m–3 (estação 75) na área oceânica. Para L. typus, a maior densidade observada foi de 41 ind.m–3 (estação 64), na província nerítica. Na província oceânica, o maior valor de densidade foi registrado na estação 75 (5 ind.m–3). No geral, L. faxoni tipicamente apresentou as maiores densidades.

Evaluación in vivo del efecto cicatrizante de un gel a base de quitosano obtenido de exoesqueleto de camarón blanco Litopenaeus vannamei / Healing effect of a chitosan-based gel obtained from the exoskeleton of white shrimp Litopenaeus vannamei and its evaluation in vivo

En México alrededor del 62 % de la población sufre de accidentes causantes de alteraciones en la piel como quemaduras, heridas y diabetes principalmente. Para atender esta problemática, se propone el uso de un gel de quitosano, obtenido del exoesqueleto de camarón ya que presenta actividad antimicrobiana e inmunológica acelerando la cicatrización. Se evaluó el efecto sinérgico sobre la velocidad de cicatrización, aplicándolo en heridas de 1 cm2 infringidas a 48 ratones albinos, agrupados en cuatro tratamientos; Quitosano 0.15 y 0.30 %, producto cicatrizante (Ketanserina al 2 %) y blanco (testigos sin tratamiento). El tiempo para la cicatrización sin tratamiento y el producto comercial fue 14 días, teniendo el control un efecto cicatrizante del 0 %, mientras que los geles de quitosano 0.15 y 0.30 % cicatrizaron en 7 días (P> 0.05) con efecto cicatrizante del 58 % para el quitosano 0.15 y 64 % para el quitosano 0.30.

Skin problems in Mexico have steadily increased (62 %) by burns, wounds and diabetes mainly. To solve this problem, chitosan can be implemented; this polysaccharide has an antimicrobial and immunology activity against bacteria and fungi, accelerating healing. Therefore, synergistic effect of chitosan gel on the rate of healing, obtained from the exoskeleton of shrimp, that was evaluated. This was tested by applying it 1 cm2 of inflicted wounds of 48 albino mice, of 45 days old and between 23 to 26 g of weight, during 14 days, and grouped into four treatments: 1) 0.15 % chitosan 2) 0.30 % chitosan, 3) commercial product 2 % Ketanserin and 4) A batch of untreated controls. The time required for healing without treatment was 14 days and with the utilization of 0.30 % chitosan gel was achieved in 7 days (P> 0.05) with the healing effect 58 % for the chitosan 0.15 and 64 % for chitosan 0.30.

Actividad antibacteriana de soluciones acidas de quitosano obtenido de exoesqueleto de camarón / Antibacterial activity of chitosan acid solutions obtained from shrimp exoskeleton

El trabajo tuvo como objetivo evaluar la actividad antibacteriana in vitro de soluciones ácidas de quitosano obtenido a partir del exoesqueleto de camarón, sobre siete bacterias patógenas, cinco de las cuales corresponden a patógenas de humanos (Enterococcus faecalis ATCC 29212, Escherichia coli UDS, Pseudomonas aeruginosa ATCC 27853, Klebsiella oxytoca ATCC 43863 y K. oxytoca ATCC 43086) y las fitopatógenas (Pectobacterium sp UDS y Burkholderia glumae 320012-CIAT). Concentraciones de soluciones de quitosano de 1.0, 1.5, 2.0, 2.5, 3.0 y 3.5 % (v/v) disuelto en ácido acético de 1.0, 1.5, 2.0 % (v/v) fueron preparadas; a partir de estas concentraciones, mediante la técnica de Kirby-Bauer se evaluó la actividad antibacteriana in vitro. Los resultados de actividad antimicrobiana mostraron diferencias altamente significativas entre la especie de bacteria y los tratamientos de quitosano. Las bacterias P. aeruginosa, E. coli, K. oxytoca (ATCC 43086 y ATCC 43863) fueron las más susceptibles a los tratamientos, mientras que E. faecalis, Pectobacterium sp y B. glumae mostraron resistencia. Los tratamientos T3, T4, T5, T7, T8, T9 en donde las concentraciones de quitosano estuvieron por encima a las del ácido acético, se presentaron mayores valores medios de actividad de antimicrobiana en mm y aumentó este valor para los tratamientos T9 (5.8095 mm), T8 (6.00 mm) para y T9 (5.8095 mm), donde las concentraciones de quitosano de 2.5 y 3.5%, disuelta en ácido acético fueron igual a 2%. Los resultados de este estudio en el Caribe Colombiano permitirán a futuro el reaprovechamiento del exoesqueleto de camarón como fuente de quitosano como un compuesto potencial frente al manejo al problema de salud pública ocasionada por las enfermedades bacterianas.

The work was to evaluate the in vitro antibacterial activity of chitosan obtained from exoskeleton of shrimp, on seven pathogenic bacteria, five of which corresponded to human pathogenic strain (ATCC 29212 Enterococcus faecalis, Escherichia coli UDS, Pseudomonas aeruginosa ATCC 27853, Klebsiella oxytoca, K. oxytoca ATCC 43863 and ATCC 43086) and two phytopathogenic strain (Pectobacterium sp UDS and Burkholderia glumae 320012-CIAT). Solution of chitosan of 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5% (v/v) dissolved in 1.0, 1.5, 2.0% (v / v) acetic acid was prepared and from these is by diffusion through the Kirby-Bauer technique was evaluated for antibacterial activity in vitro. The results of the antimicrobial activity showed significant differences between the species of bacteria and chitosan treatments evaluated. P. aeruginosa, E. coli and K. oxytoca (ATCC 43086 and ATCC 43863) were the most susceptible to the treatments, while E. faecalis, B. glumae and Pectobacterium sp were resistant. The treatments T3, T4, T5, T7, T8, T9, where chitosan concentrations were above the acetic acid, showed higher mean mm antimicrobial activity and this value increased to T9 treatments (5.8095 mm ), T8 (6.00 mm) and T9 (5.8095 mm), where chitosan concentrations 2.5 and 3.5% solution in acetic acid was equal to 2%. The results of this study in the Colombian Caribbean enable future reuse of the exoskeleton of shrimp as a source of chitosan as a potential compound against handling the public health problem caused by bacterial diseases.

Do omnivorous shrimp influence mayfly nymph life history traits in a tropical island stream?

Interspecific interactions can play an important role in determining habitat selection and resource use between competing species. We examined interactions between an omnivorous shrimp and a grazing mayfly, two co-dominant taxa found in Puerto Rican headwater streams, to assess how predator presence may influence mayfly resource use and instantaneous growth in a tropical rainforest ecosystem. We conducted a series of behavioral and growth experiments to determine the effects of the freshwater shrimp, Xiphocaris elongata, on the growth rate and resource selection of mayfly nymphs in the family Leptophlebiidae. For resource choice assessments, we conducted a series of five day laboratory experiments where mayflies were given access to two resource substrate choices (cobble vs. leaves) in the presence or absence of shrimp. To assess for the effects of shrimp on mayfly fitness, we measured mayfly growth in laboratory aquaria after five days using four treatments (cobble, leaves, cobble + leaves, no resource) in the presence or absence of shrimp. In resource choice experiments, mayflies showed preference for cobble over leaf substrata (p<0.05) regardless of the presence of shrimps, however, the preference for cobble was significantly greater when shrimp were present in the leaf habitat. In growth experiments, there were no statistical differences in mayfly growth in the presence or absence of shrimp (p=0.07). However, we measured increased mayfly nymph growth in the absence of predators and when both cobble and leaves were available. Our results suggest that interspecific interactions between these taxa could potentially influence organic matter resource dynamics (e.g., leaf litter processing and export) in Puerto Rican streams. Rev. Biol. Trop. 62 (Suppl. 2): 41-51. Epub 2014 April 01.

Las relaciones interespecíficas pueden jugar un papel importante en la determinación del uso de recursos y selección de hábitat entre especies que compiten. Hemos examinado las interacciones entre un camarón omnívoro y un efemeróptero que se alimenta de vegetación , dos taxones codominantes en las partes altas de arroyos de Puerto Rico, para evaluar el efecto de los depredadores en el uso de recursos del efemeróptero y el crecimiento instantáneo en un ecosistema de selva tropical. Examinamos experimentalmente el efecto del camarón Xiphocaris elongata sobre la tasa de crecimiento y selección de recursos en ninfas efemerópteras (Leptophlebiidae). Hicimos experimentos de laboratorio de 5 días, dando a los efemerópteros acceso a dos opciones de sustrato (piedrecillas u hojas) en presencia o ausencia del camarón. Para evaluar los efectos sobre el crecimiento probamos cuatro tratamientos (piedrecillas, hojas , piedrecillas + hojas, sin ambas), en presencia o ausencia del camarón. Los efemerópteros prefirieron las piedrecillas a las hojas ( p < 0,05 ) independientemente de la presencia de los camarones. Esta preferencia fue mayor cuando junto a las hojas había camarones. Los camarones no afectaron el crecimiento de los efemerópteros (p = 0,07). Las ninfas efemerópteras crecieron mejor sin camarones y en acuarios con piedrecillas y hojas. Nuestros resultados sugieren que las interacciones interespecíficas entre estos animales podrían influir en la dinámica de la materia orgánica (por ejemplo, procesamiento de la hojarasca y su exportación) en los arroyos puertoriqueños.

Effects of insect and decapod exclusion and leaf litter species identity on breakdown rates in a tropical headwater stream

High species richness of tropical riparian trees influences the diversity of organic detritus entering streams, creating temporal variability in litter quantity and quality. We examined the influence of species of riparian plants and macroinvertebrate exclusion on leaf-litter breakdown in a headwater stream in the Luquillo Mountains of Puerto Rico. Leaf litter of Dacryodes excelsa (Burseraceae), Guarea guidonia (Meliaceae), Cecropia scheberiana (Moraceae), Manilkara bidentata (Sapotaceae), and Prestoea acuminata (Palmae) were incubated in litter bags in a pool of Quebrada Prieta. Fine mesh bags were used to exclude macroinvertebrates during leaf breakdown, and coarse mesh bags allowed access to decapod crustaceans (juvenile shrimps and crabs) and aquatic insects (mainly mayflies, chironomids, and caddisflies). D. excelsa and G. guidonia (in coarse- and fine-mesh bags) had significantly higher breakdown rates than C. scheberiana, M. bidentata, and P. acuminata. Breakdown rates were significantly faster in coarse-mesh bag treatments for all leaf types, thus indicating a positive contribution of macroinvertebrates in leaf litter breakdown in this headwater stream. After 42 days of incubation, densities of total invertebrates, mayflies and caddisflies, were higher in bags with D. excelsa and G. guidonia, and lower in P. acuminata, C. scheberiana y M. bidentata. Decay rates were positively correlated to insect densities. Our study highlights the importance of leaf identity and macroinvertebrate exclusion on the process of leaf litter breakdown in tropical headwater streams. Rev. Biol. Trop. 62 (Suppl. 2): 143-154. Epub 2014 April 01.

La gran variedad de especies vegetales junto a los ríos tropicales afecta la diversidad de detritos orgánicos que llegan a los arroyos, creando variaciones temporales en cantidad y calidad de hojarasca. Examinamos la influencia de las especies vegetales y de la exclusión de macroinvertebrados sobre la descomposición de hojarasca en la parte alta de un arroyo en las montañas Luquillo de Puerto Rico. Incubamos hojarasca de Dacryodes excelsa (Burseraceae), Guarea guidonia (Meliaceae), Cecropia scheberiana (Moraceae), Manilkara bidentata (Sapotaceae) y Prestoea acuminata (Palmae) en bolsas descomposición que colocamos en una poza de Quebrada Prieta. Usamos bolsas de malla fina para excluir los macroinvertebrados y de malla gruesa para permitir la entrada a crustáceos decápodos (camarones y cangrejos jóvenes) e insectos acuáticos (principalmente efemerópteros, quironómidos y tricópteros). D. excelsa y G. guidonia (en ambos tipos de malla) tuvieron tasas de descomposición más altas que C. scheberiana, M. bidentata y P. acuminata. La descomposición fue más rápida para todas las especies de hoja con la malla gruesa, resaltando el papel de los descomponedores en este hábitat. Tras 42 días de esta incubación, las densidades totales de invertebrados, efemerópteros y tricópteros fueron mayores en las bolsas con hojas de D. excelsa y G. guidonia, e inferiores en P. acuminata, C. scheberiana y M. bidentata. A mayor densidad de insectos hubo mayor tasa de descomposición. Nuestros resultados indican la importancia de la especie de las hojas y de la presencia de macroinvertebrados en el proceso de descomposición de hojarasca en partes altas de arroyos tropicales.