Bycatch of Asteroidea from shrimp trawl fishery in the southwestern Atlantic Ocean ­ Brazil

Shrimp trawling is considered a significant negative impact on the marine ecosystem, especially on the benthic community. Sea stars (Echinodermata: Asteroidea) are one of the most affected groups by unintentional catches. This study was performed at the Santana Archipelago, a Marine Protected Area in the northern region of Rio de Janeiro State, between 2008-2009. Sea stars accidentally caught by trawling were collected during open and closed season of the shrimp fisheries (Xiphopenaeus kroyeri) at depths of 5-60 m. A generalized linear zero-inflated model was applied to test for differences in capture between fishing seasons and depths. A total of 158 sea star specimens were captured. These specimens were identified as Asterina stellifera, Astropecten acutiradiatus, Astropecten brasiliensis, Astropecten cingulatus, Luidia alternata alternata, Luidia clathrata, Luidia ludwigi scotti, Luidia senegalensis. The sea stars A. brasiliensis and L. senegalensis are currently considered as vulnerable species in the Brazilian official list of threatened species. The higher capture of sea stars was shown in deepest areas, and there was no significant difference in the number of specimens between seasons. This is the first study about asteroids accidentally captured by shrimp trawling.(AU)

Locomotion and righting behavior of sea stars: a study case on the bat star Asterina stellifera (Asterinidae) / Comportamiento de locomoción y enderezamiento en estrellas de mar: un caso de estudio sobre la estrella Asterina stellifera (Asterinidae)

Introduction: The locomotion behavior of an organism involves the integration of aspects like body symmetry, sensory and locomotor systems. Furthermore, various ecological factors seem to be related to locomotion characteristics, such as foraging strategy, migration trends, response to predators and competitors, and environmental stress. Objective: To analyze locomotion and the influence of body symmetry in the crawling and righting movements of the sea star Asterina stellifera. Methods: We carried out laboratory experiments in aquariums in the presence/absence of water current and on a horizontal and vertical surface. Results: The speed is similar to speed in other species of similar size. Both the speed and linearity of displacement were independent of individual body size. A water current leads to faster crawling and straight paths, but there is no rheotaxis: streams do not affect locomotion. Speed and linearity of displacement were independent of individual body size. The displacement pattern described here may be an adaptation of organisms that present dense populations in communities with high prey abundance, as is the case of A. stellifera. Conclusions: Like other asteroids, this species did not show an Anterior/Posterior plane of symmetry during locomotion, or righting movement: it does not tend to bilaterality.

Introducción: El comportamiento de locomoción de un organismo implica la integración de aspectos como la simetría corporal, los sistemas sensorial y locomotor. Además, varios factores ecológicos parecen estar relacionados con las características de la locomoción, como la estrategia de alimentación, las tendencias migratorias, la respuesta a los depredadores y competidores y el estrés ambiental. Objetivo: Analizar el patrón general de locomoción y la influencia de la simetría corporal en la locomoción y enderezamiento de la estrella de mar Asterina stellifera. Métodos: Realizamos experimentos de laboratorio en acuarios en presencia / ausencia de corriente de agua y en superficie horizontal y vertical. Resultados: La velocidad es similar a la velocidad en otras especies de tamaño similar. Tanto la velocidad como la linealidad del desplazamiento fueron independientes del tamaño corporal individual. Una corriente de agua conduce a una velocidad de desplazamiento mayor y a trayectorias más rectas, pero no hay reotaxis: una corriente de agua no afecta el patrón de locomoción. La velocidad y la linealidad del desplazamiento fueron independientes del tamaño corporal individual. El patrón de desplazamiento aquí descrito puede ser una adaptación de organismos que presentan densas poblaciones en comunidades con alta abundancia de presas, como es el caso de A. stellifera. Conclusiones: Al igual que otros asteroides, esta especie no mostró un plano de simetría Anterior / Posterior durante la locomoción o el movimiento de enderezamiento: no tiende a la bilateralidad.

Population size structure and abnormalities in the number of rays of the Sea Star Pentaceraster cumingi (Valvatida: Oreasteridae) in Bahía Chamela, Mexican Pacific / Estructura de tallas poblacional y anormalidades en el número de radios de la estrella de mar Pentaceraster cumingi (Valvatida: Oreasteridae) en Bahía Chamela, Pacífico mexicano

Introduction: The Panamic Cushion Star Pentaceraster cumingi is widely distributed along the Tropical Eastern Pacific. This species strictly produces only five arms, but sometimes, this number varies or show another kind of abnormality. Objective: We aimed to evaluate the population size structure and abnormalities occurrence in the radial pattern of P. cumingi in Bahía Chamela, Jalisco, Mexico. Methods: The population was monitored along four years (2016-2019), in two seasonal periods (warm and cold). During fieldwork, a random sample of individuals was collected. Every starfish was measured, weighted, and evaluated to identify any abnormality on its radial pattern. Results: The highest density of P. cumingi was found in October 2019 (2.03 ± 0.05 ind/m-2), the lower in March 2017 (0.66 ± 0.13 ind/m-2). A total of 849 individuals were collected. For 5-armed starfishes, the average length was 123.8 ± 15.2 mm and the average weight of 326.0 ± 62.4 g. The most frequent length classes ranged from 110 to 120 mm. Of the total of individuals sampled 0.82 % had four arms, 1.06 % six, and 1.41 % had one bifurcated arm. Conclusions: There were differences in the population density and size structure of P. cumingi between seasons. The main causes of abnormalities in the starfish could be due to the changes that occur during larval metamorphosis or by an abnormal regeneration of the arms after a predation attempt.

Introducción: La Estrella Cojín Pentaceraster cumingi está ampliamente distribuida a lo largo del Pacífico Oriental Tropical. Esta especie produce estrictamente cinco brazos, pero en algunas ocasiones el número puede ser menor o mayor de cinco, o mostrar otro tipo de anormalidad. Objetivo: Evaluar la estructura de tallas poblacional y la presencia de anormalidades en el patrón radial de P. cumingi en la Bahía Chamela, Jalisco, México. Métodos: La población fue monitoreada a lo largo de cuatro años (2016-2019), durante dos periodos estacionales (cálido y templado). Durante el trabajo de campo se recolectó una muestra aleatoria de individuos. Cada estrella de mar fue medida, pesada y revisada para identificar alguna anormalidad en el patrón radial. Resultados: La mayor densidad de individuos se encontró en octubre de 2019 (2.03 ± 0.05 ind/m-2), la menor en marzo de 2017 (0.66 ± 0.13 ind/m-2). Un total de 849 individuos fueron recolectados. Para las estrellas de mar con 5 brazos, la longitud promedio fue de 123.8 ± 15.2 mm y el peso promedio de 326.0 ± 62.4 g. La clase de talla más frecuente varió entre 110 y 120 mm. Del total de individuos muestreados el 0.82 % tuvieron cuatro brazos, el 1.06 % con seis, y el 1.41 % tuvieron un brazo bifurcado. Conclusiones: Se encontraron diferencias en la densidad poblacional y en la estructura de tallas de P. cumingi entre estaciones. Las principales causas de anormalidades en la estrella de mar pueden ser debidas a los cambios que ocurren durante la metamorfosis de las larvas o por una regeneración anormal de los brazos a causa de la depredación.

A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico / Revisión de literatura de Ophiuroidea (Echinodermata) de las costas del Pacífico de México

Abstract Despite the important effort of knowing the Ophiuroidea diversity in the Mexican Pacific, some mistakes in the taxonomic nomenclature have pervaded through time. In order to clarify the latter, a checklist based on literature review of brittle stars from the Mexican Pacific is provided. We reviewed a total of 105 references that in total summarized 125 species of brittle stars from the Mexican Pacific (112) and the Gulf of California (97), belonging to two orders, 16 families and 50 genera. These records are higher than those reported on previous studies carried out in the area. México is the country with the highest number of brittle stars reported in the Tropical Eastern Pacific; this may be due to its exceptional oceanographic conditions, location and coastline extension. However, a total of 27 species reported in the literature were considered doubtful due to their general distributions and were not included in the checklist. Of the reported species, 35 have their type locality in the Mexican Pacific, corroborating the importance of the country in the Tropical Eastern Pacific in terms of Echinodermata diversity. Rev. Biol. Trop. 63 (Suppl. 2): 37-47. Epub 2015 June 01.

Resumen A pesar del importante esfuerzo en el conocimiento de la diversidad de ofiuroideos del Pacífico mexicano, algunos errores en la nomenclatura taxonómica han perseverado a través del tiempo. Con el objetivo de clarificar lo anterior, se provee una lista de especies de ofiuroideos del Pacífico Mexicano, basada en la revisión de literatura. Se revisó un total de 105 referencias que en total suman 125 especies pertenecientes a dos órdenes, 16 familias y 50 géneros de ofiuros del Pacífico Mexicano (112) y el Golfo de California (97). Estos reportes son mayores que otros estudios llevados a cabo en el área. México es el país con el mayor número de ofiuros reportados en el Pacífico Oriental Tropical; esto puede deberse a su excepcional condición oceanográfica, ubicación y extensión de línea de costa. Un total de 27 de las especies reportadas en la literatura fueron consideradas dudosas de acuerdo distribución geográfica por lo que no fueron incluidas en la lista. 35 especies poseen su localidad tipo en el Pacífico Mexicano, corroborando la importancia de México en el Pacífico Oriental Tropical en términos de diversidad de equinodermos.

Checklist of echinoderms (Echinodermata) from the Southern Mexican Pacific: a historical review / Listado de los equinodermos (Echinodermata) del Pacífico sur de México: una revisón histórica

Resumen Los equinodermos del Pacífico Sur mexicano han sido estudiados por tres siglos, sin embargo discrepancias en la nomenclatura de algunas especies han prevalecido a través del tiempo. El objetivo de este trabajo es presentar la primera lista de especies actualizada de todos los nombres válidos y sinonimias, así como una revisión histórica del estudio de los equinodermos en el Pacífico Sur mexicano. La lista de especies se basa en una exhaustiva búsqueda de registros de literatura y de especímenes depositados en colecciones de referencia. Existen 162 especies válidas de equinodermos en el Pacífico Sur mexicano incluidas en 96 géneros, 54 familias y 20 órdenes. El estado de Guerrero presentó 135 especies, Oaxaca, 94 y Chiapas, 15. Se actualizó la lista de especies y se añadieron cinco nuevos registros de especies (Microphiopholis platydisca, Ophiostigma tenue, Arbacia stellata, Thyone bidentata, Chiridota rigida) para el Pacífico Sur mexicano y uno para el Pacífico mexicano (Encope laevis). Esta lista de especies incrementa el número de especies para el área de estudio, sin embargo, los estudios sugieren que aún existen más especies por ser descubiertas.

Abstract The echinoderms of the Southern Mexican Pacific have been studied for three centuries, but discrepancies in the nomenclature of some species have pervaded through time. The objective of this work is to present the first updated checklist of all valid species and synonyms, and a historical review of the study of the echinoderms of the Southern Mexican Pacific is also presented. The checklist is based on an exhaustive published literature search and records of specimens deposited in museum and curated reference collections. There are 162 species of echinoderms in the Southern Mexican Pacific from 96 genera, 54 families and 20 orders. The State of Guerrero presented a total of 135 species, Oaxaca 94 and Chiapas 15. We updated the list and added five new records of the species (Microphiopholis platydisca, Ophiostigma tenue, Arbacia stellata, Thyone bidentata, Chiridota rigida) for the Southern Mexican Pacific and one for the Mexican Pacific (Encope laevis). This checklist expands the number of species known for the study area; nevertheless studies suggest that still more species are yet to be discovered. Rev. Biol. Trop. 63 (Suppl. 2): 87-114. Epub 2015 June 01.

Fossil Asterozoa (Echinodermata) of Argentina / Fósiles de Asterozoa (Echinodermata) de Argentina

Abstract Thefossil Asterozoa of Argentina have received scant attention. Marine rocks of Early Devonian-Late Miocene age yield ten species of Asterozoa (four Asteroidea and six Ophiuroidea), including the new Neogene record of Astropecten sp. presently introduced. Due to homonymy, Marginix nomen novum is proposed as a substitution of Marginura (Ophiuroidea, Encrinasteridae). Rev. Biol. Trop. 63 (Suppl. 2): 1-6. Epub 2015 June 01.

Resumen Se registran 10 especies de Asterozoa fósiles de Argentina (cuatro Asteroidea y seis Ophiuroidea), desde el Devónico Temprano hasta el Mioceno Tardío, incluyendo un nuevo registro de Astropecten sp. Por homonimia, Marginix nomen novum es propuesto para sustituir a Marginura (Ophiuroidea, Encrinasteridae).

From baby to adult: ontogenetic series of nine species of Ophiuroidea from Atlantic Southwestern / De bebé a adulto: serie ontogenética de nueve especies de Ophiuroidea del Atlántico sudoccidental

Abstract The post-metamorphic stage is essential in the life history of marine invertebrates. During this period, animals are more vulnerable and suffer high mortality, which influences the distribution and abundance of adult populations. It is also during this period that major morphological changes happen in the individuals, complicating their taxonomic identification. The juvenile ophiuroids dominate the meiofauna in certain times of the year and at some places. However, they are ignored by most ecological studies due to identification difficulties. Here we describe the ontogeny of nine deep-sea species from the Southeast and South regions of Brazil, with the first record of morphological modifications for eight of them. Most organisms were collected 60 to 800 m deep, between December 1997, January, 1998 and March, 1998, during the REVIZEE-Score South / Benthos program. We also included additional material from the Zoology Museum of Unicamp (ZUEC). For descriptions and identifications of the different stages, the specimens were dried and photographed. The juveniles were identified by "backwards" process through the growth series of adults to smaller individuals, a backwards method that was successful in previous studies. Some individuals were mounted on aluminum stubs for scanning electron microscopy. The species were: Ophiacantha pentacrinus (Ophiacanthidae), Ophiomastus satelitae, Ophiomusium acuferum, Ophiomusium eburneum, Ophiomisidium tommasii, Ophiura ljungmani, Ophiura clemens (Ophiuridae), Amphiura complanata (Amphiuridae) and Ophiothrix rathbuni (Ophiotrichidae). Many species could be identified since their most juvenile stage. Some structures remain almost unaltered during the whole life. Rev. Biol. Trop. 63 (Suppl. 2): 361-381. Epub 2015 June 01.

Resumen La etapa post-metamórfica es esencial en la historia de vida de los invertebrados marinos. Durante este período, los animales son más vulnerables y sufren una elevada mortalidad, que influye en la distribución y abundancia de las poblaciones de los adultos. También es durante este período cuando grandes cambios morfológicos ocurren en los individuos, lo que complica su identificación taxonómica. Los ofiuroideos juveniles son el componente principal para la mayor parte de la composición de la meiofauna en ciertas épocas del año y en algunos lugares. Sin embargo, son ignorados por la mayoría de los estudios ecológicos debido a las dificultades de identificación. De esta manera, la descripción de las fases juveniles presenta mayor importancia, sobre todo en estudios relacionados con la dinámica poblacional y de composición de fauna. Este trabajo tiene como objetivo describir la ontogenia de nueve especies de aguas profundas de las regiones Sudeste y Sur de Brasil, siendo el primer registro en la literatura sobre cambios morfológicos -a partir del crecimiento- para ocho de ellos. La mayoría de los organismos se tomaron en el intervalo de 60 a 800 m de profundidad, entre diciembre de 1997, enero de 1998 y marzo de 1998, durante el programa REVIZEE Sur-Score / Bentos. También se incluyen en este estudio material adicional del Museo de Zoología de la Unicamp (ZUEC). Para las identificaciones y descripciones de las diferentes etapas, las muestras se secaron y fueron fotografiadas. Los juveniles fueron identificados por "al revés" el proceso de crecimiento a través de la serie desde adultos hasta los individuos de menores tallas, una metodología exitosa en estudios anteriores. Las especies seleccionadas para la descripción de la serie de crecimiento fueron escogidas de acuerdo a su abundancia relativa en diferentes etapas de desarrollo. Algunos individuos fueron montados en tacos de aluminio para la microscopía electrónica de barrido. Las especies se estudiadas fueron: Ophiacantha pentacrinus (Ophiacanthidae), Ophiomastus satelitae, Ophiomusium acuferum, Ophiomusium eburneum, Ophiomisidium tommasii, Ophiura ljungmani, Ophiura clemens (Ophiuridae), Amphiura complanata (Amphiuridae) y Ophiothrix rathbuni (Ophiotrichidae). El análisis del desarrollo post-metamórfico de los individuos reveló que muchas especies podrían ser identificadas desde sus etapas más juveniles, sobre todo a partir de caracteres morfológicos externos. Este estudio nos permite sostener que algunas estructuras permanecen casi inalteradas durante toda la vida del organismo, mientras que otras están sujetas a transformaciones. De este modo, se contribuye al conocimiento más amplio de algunas especies de ofiuroideos, con relación a la caracterización de sus diferentes etapas de desarrollo.

Tooth microstructure and feeding biology of the brittle star Ophioplocus januarii (Echinodermata: Ophiuroidea) from northern Patagonia, Argentina / Microestructura dental y biología alimentaria del Ophioplocus januarii (Echinodermata: Ophiuroidea) del norte de Patagonia, Argentina

Abstract Ophioplocus januarii is a common brittle star on soft and hard substrates along the Argentinian and Brazilian coasts. Based on stomach contents, tooth microstructure and field observations we identified its food. Opposed to previous suggestions, O. januarii appears to be a microphagous species feeding on macroalgal fragments (found in 60.0 % of the analyzed stomachs with content), plant debris (28.0 %), animal cuticle structures (13.0 %), and unidentifiable material (30.7 %). Less frequent items found were foraminiferans, ostracods, an amphipod, a juvenile bivalve, and other crustaceans. Electronic microscope revealed digested material, diatoms and small crustacean appendices. Thus, O. januarii is an omnivorous species, feeding mainly on algae, complemented opportunistically with other items. Suspension feeding was observed in the field. It has an fenestrated arrangement intermediate between the previously described uniform and compound teeth. Rev. Biol. Trop. 63 (Suppl. 2): 353-360. Epub 2015 June 01.

Resumen El ofiuroideo Ophioplocus januarii se distribuye a lo largo de las costas de Argentina y Brasil, encontrándose tanto en substratos duros como blandos. En base al análisis de contenidos estomacales y la microestructura de los dientes, junto a observaciones de campo, se describe el comportamiento alimentario de esta especie. Opuesto a suposiciones previas, O. januarii es una especie micrófaga que se alimenta de fragmentos de macroalgas (encontrados en el 60.0 % de los estómagos analizados que presentaban contenido), detritos vegetales (28.0 %), estructuras cuticulares animales (13.0 %) y material inidentificable (30.7 %). Menos frecuente, se encontraron foraminíferos, ostrácodos, un anfípodo, un bivalvo juvenil y otros crustáceos. Pequeñas porciones del material inidentificable fueron analizadas en el microscopio electrónico de barrido, resultando ser material digerido, diatomeas y pequeños apéndices de crustáceos. Así, O. januarii es una especie omnívora, que se alimenta principalmente de algas, complementando su dieta de manera oportunista con otros ítems. Las observaciones de campo revelaron alimentación suspensívora. El análisis de la microestructura del estereoma del diente resultó en un arreglo del tipo fenestrado intermedio, que se encuentra entre los dos tipos de arreglos descriptos hasta ahora, los dientes de tipo uniforme y los compuestos. De estos últimos, el primero ha sido encontrado en especies macrófagas mientras que el segundo se corresponde a ofiuroideos micrófagos. En el presente trabajo, se propone la existencia de un nuevo tipo de arreglo intermedio en la matriz dental de los ofiuroideos.

Actividad antibacteriana y antifúngica de la estrella de mar Oreaster reticulatus (Valvatida: Oreasteridae) y de los erizos de mar Mellita quinquiesperforata (Clypeasteroida: Mellitidae) y Diadema antillarum (Diadematoida: Diadematidae) del Caribe Colombiano / Antibacterial and antifungal activity of the starfish Oreaster reticulatus (Valvatida: Oreasteridae) and the sea urchins Mellita quinquiesperforata (Clypeasteroida: Mellitidae) and Diadema antillarum (Diadematoida: Diadematidae) from the Colombian Caribbean

Resumen Como organismos bentónicos, estrellas de mar y erizos de mar están constantemente expuestos a un gran número de bacterias, hongos y virus, algunos de ellos potencialmente dañinos. Para sobrevivir, estos equinodermos dependen de su sistema inmunológico, que ha desarrollado una serie de compuestos que actúan como estrategias de defensa antimicrobianos. En este trabajo se evaluaron las actividades antibacteriana y antifúngica de los extractos metanólicos de la estrella de mar Oreaster reticulatus y de los erizos de mar Mellita quinquiesperforata y Diadema antillarum recolectados en el Caribe Cordobés, frente a las bacterias Escherichia coli, Staphylococcus aureus y Klebsiella pneumoniae, y frente a los hongos fitopatógenos Fusarium sp., Scleortium sp., y Rhizoctonia sp. Los resultados obtenidos mostraron que O. reticulatus y D. antillarum, son organismos capaces de producir compuestos con capacidad antibiótica generando inhibición bacteriana a bajas concentraciones (< 100 µg / ml), mientras que M. quinquiesperforata no presentó inhibición a ninguna de la concentraciones evaluadas. Específicamente, la cepa de S. aureus fue la que presentó mayor susceptibilidad frente a los extractos evaluados, es decir, los metabolitos producidos por los equinodermos inhiben con mayor facilidad las bacterias Gram +. Por su parte, solo el extracto de diclorometano de D. antillarum presentó inhibición frente a Fusarium sp., con porcentajes de inhibición de 78.2 % y 56.5 % a concentraciones de 2 000 y 100 µg / ml. Se encontró que las cepas de los hongos Sclerotium sp. y Rhizoctonia sp., presentaron resistencia frente a todos los.extractos de los organismos estudiados, con excepción del extracto de diclorometano de D. antillarum.

Abstract As benthic organisms, sea stars and sea urchins are constantly exposed to a large number of bacteria, fungi and viruses, some of them potentially harmful. To survive, these echinoderms depend on their immune system, which has developed a number of compounds which act as antimicrobial defense strategies. In this work, the antibacterial and antifungal activities of the extracts of the starfish Oreaster reticulatus and sea urchins Diadema antillarum and Mellita quinquiesperforata collected in the Caribbean Cordobés were evaluated against the bacteria Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae and against the phytopathogenic fungi Fusarium sp., Scleortium sp., and Rhizoctonia sp. Our results show that O. reticulatus and D. antillarum produce compounds producing bacterial inhibition at low concentrations (< 100 μg / ml), while, M. quinquiesperforata extracts showed no inhibition at any of the concentrations tested. Specifically, the strain of S. aureus was the one with greater susceptibility to the extracts evaluated, i.e. the metabolites produced by echinoderms inhibit more easily gram + bacteria. Only the D. antillarum dichloromethane affected Fusarium sp. with inhibition of 78.2 % and 56.5 % at concentrations of 2 000 and 100 μg / ml. Strains of the fungi Sclerotium sp. and Rhizoctonia sp. had resistance to all extracts. Rev. Biol. Trop. 63 (Suppl. 2): 329-337. Epub 2015 June 01.

Regeneration rate after fission in the fissiparous sea star Allostichaster capensis (Asteroidea) / Tasa de regeneración luego de la fisión en la estrella de mar fisipara Allostichaster capensis (Asteroidea)

Abstract Many studies have focused on the regeneration rate of arms in Asteroidea but no studies have focused on the regeneration rate after fission. Allostichaster capensis is a fissiparous sea star with a wide range of distribution. In Golfo Nuevo (42°46'49'' S - 64°59' 26'' W) sea stars undergo fission every spring and summer and regenerate the rest of the year. To analyze the regeneration rate, we conducted an experiment with sea stars collected just before fission. After sea stars underwent fission, the length of the three non-regenerating and the three regenerating arms were measured weekly. The arm length (regenerating and non-regenerating) was used in non-Linear Mixed Effect models in order to account for within-individual correlation in different models. The regenerating arms regenerate according to a Quadratic model, while the non-regenerating arms regenerate according to a linear model. In the regenerating arms, the regeneration rate was estimated to be 0.1 mm.week-1 and in the non-regenerating arms, the growth rate was 0.004 mm.week -1. Sea stars regenerate ca. 20 % of the arm in one month, and it takes about 5 months to be completely regenerated. At the beginning, the regeneration rate is fast generating the growth of the arms, once the pyloric caeca and gonads are present inside the arms the regeneration rate slows down probably due to allocation to gametes and pyloric caeca and arms. The factors that regulate the regeneration rate are unknown. However, food availability and energy storage seem to play an important role. Rev. Biol. Trop. 63 (Suppl. 2): 321-328. Epub 2015 June 01.

Resumen Numerosos estudios se han enfocado en estudiar la tasa de regeneración de brazos en Asteroidea, sin embargo ninguno se han centrado en la tasa de regeneración después del proceso de fisión. Allostichaster capensis es una estrella de mar fisípara con un amplio rango de distribución. En el Golfo Nuevo (42°46'49'' S - 64°59'26'' W) las estrellas de mar se fisionan cada primavera y verano y se regeneran durante el resto del año. Para analizar la tasa de regeneración, se realizó un experimento con estrellas de mar colectadas justo antes de la fisión. Después de estrellas de mar se fisionaron, se midió la longitud de los tres brazos en regeneración y de los tres brazos originales semanalmente. Se utilizaron modelos no lineales de efectos mixtos para analizar la correlación dentro de individuos del largo de los brazos (regenerados y que no regeneran). Los brazos en regeneración, regeneraron sus brazos de acuerdo con un modelo cuadrático, mientras que los brazos originales ajustaron a un modelo lineal. En los brazos de regeneración se estimó que la tasa de regeneración era de 0.1 mm/ semana; mientras que en los brazos originales, la tasa de crecimiento fue de 0.004 mm/semana. Las estrellas de mar se regeneran un 20 % aproximadamente del brazo en un mes, y tardan alrededor de cinco meses en estar completamente regenerado. Al principio, la alta tasa de regeneración genera el crecimiento rápido de los brazos en longitud, una vez que el ciego pilórico y las gónadas están presentes en el interior de los brazos; la tasa de regeneración disminuye, probablemente debido a la asignación de energía en la producción de gametas, en el ciego pilórico y en los brazos. Los factores que regulan la tasa de regeneración son desconocidos. Sin embargo, la disponibilidad de alimentos y el almacenamiento de energía parecen jugar un papel importante.

Histological analysis after arm tip amputation in the brittle star Ophioplocus januarii (Echinodermata: Ophiuroidea) / Análisis histológico luego de la amputación de las puntas de los brazos en Ophioplocus januarii (Echinodermata: Ophiuroidea)

Abstract Wound healing in the arm tip after amputation in the brittle star Ophioplocus januarii was examined in San José gulf, Argentina, to observe histological and morphological changes. The process of wound healing is described and compared with other brittle stars species. This process in O. januarii involves the closure of the wound, the repair of the tissue damage and posterior formation of a presumptive stalked blastema by undifferentiated cells, sclerocytes and presumptive blastemic cells. The sclerocytes are the most abundant cell type due to this cells are crucial to the future skeleton regeneration. The results found in this study support the results found in others brittle stars Rev. Biol. Trop. 63 (Suppl. 2): 297-308. Epub 2015 June 01.

Resumen Se examinaron los cambios histológicos y morfológicos producidos en la punta del brazo de la ofiura Ophioplocus januarii luego de su amputación. En el presente trabajo se describe el proceso de cicatrización de la herida y se lo compara con otras especies de la misma Clase. Este proceso en O. januarii involucra el cierre de la herida, la reparación del tejido dañado y la posterior formación de un presunto blastema formado por células indiferenciadas, esclerocitos y presuntas células blastémicas. Los esclerocitos son las células más abundantes debido a que estas células son cruciales para la regeneración del esqueleto. Los resultados encontrados en este estudio apoyan los resultados que se encuentran en otras estrellas frágiles.

Anti-inflammatory components of the Vietnamese starfish Protoreaster nodosus

BACKGROUND: In the present study, we examined the inhibitory effects of a methanolic extract, dichloromethane fraction, water layer, and polyhydroxylated sterols (1-4) isolated from the Vietnamese starfish Protoreaster nodosus on pro-inflammatory cytokine (IL-12 p40, IL-6, and TNF-α) production in LPS-stimulated bone marrow-derived dendritic cells (BMDCs) using enzyme-linked immunosorbent assays (ELISA). RESULTS: The methanolic extract and dichloromethane fraction exerted potent inhibitory effects on the production of all three pro-inflammatory cytokines, with IC50 values ranging from 0.60 ± 0.01 to 26.19 ± 0.64 µg/mL. Four highly pure steroid derivatives (1-4) were isolated from the dichloromethane fraction and water layer of P. nodosus. Potent inhibitory activities were also observed for (25S)5α-cholestane-3ß,4ß,6α,7α,8ß,15α,16ß,26-octol (3) on the production of IL-12 p40 and IL-6 (IC50s = 3.11 ± 0.08 and 1.35 ± 0.03 µM), and for (25S) 5α-cholestane-3ß,6α,8ß,15α,16ß,26-hexol (1) and (25S)5α-cholestane-3ß,6α,7α,8ß,15α,16ß,26-heptol (2) on the production of IL-12 p40 (IC50s = 0.01 ± 0.00 and and 1.02 ± 0.01 µM). Moreover, nodososide (4) exhibited moderate inhibitory effects on IL-12 p40 and IL-6 production. CONCLUSION: This is the first report of the anti-inflammatory activity from the starfish P. nodosus. The main finding of this study is the identification oxygenated steroid derivatives from P. nodosus with potent anti-inflammatory activities that may be developed as therapeutic agents for inflammatory diseases.

Seasonal variation in body size and diet of the sea star Astropecten marginatus (Paxillosida, Astropectinidae) off coast of Paraná, Southern Brazil / Variaciones estacionales en el tamaño corporal y dieta de la estrella de mar Astropecten marginatus (Paxillosida, Astropectinidae) frente a la costa de Paraná, sur de Brasil

The sea star Astropecten marginatus has a neotropical distribution and is a highly abundant and frequent species in shrimp trawling by-catchin many places along the Brazilian coast. This has caused its threat to extinction and in addition, its bio-ecological aspects are poorly known. Thus, the main objective of this study was to analyze the seasonal variations of population length structure and feeding habits of the sea stars A. marginatus inhabiting off state of Paraná, Southern Brazil. The analyzed specimens were collected in February (summer), April (fall), June (winter) and October (spring) of 2008 from shrimp by-catch trawling. In the laboratory, each individual had its length measured and then weighed on an analytical scale. Afterwards, the stomach contents of 10 individuals of each of two most frequent length classes were seasonally analyzed. The relative frequency and abundance for each prey category was determined and, then combined into an index of alimentary importance. A total of 994 individuals of A. marginatus were collected with length ranging from 7.0 to 56.2mm, but most individuals were in the 20.1-25mm length classes. Individuals larger than 40mm were only collected in the spring while a few recruits (<10mm) were found in fall and winter. The total weight of individuals ranged from 0.1 to 15.3g and the weight-length relationships showed a negative allometric growth (b<2.54). Regarding its food consumption, this sea star explored eleven food items, with cumaceans and mollusks as the most frequent items. High frequency of empty stomach was recorded at fall. Seasonal differences in the amount explored preys and ingested items as well as in the prey composition were also observed. Higher amount of explored prey categories and ingested items were recorded at winter-spring than summer-fall periods. Predominance in prey category changed from gastropods (summer and fall) to cumaceans (winter and spring). The importance of gastropods as main prey category at summer and fall should be carefully considered since it was coincidently observed with high frequency of empty stomach and low amount of ingested items. The observed seasonal differences in feeding behavior pattern were mainly associated to low prey availability and to changes in the sea star feeding rates, and probably reflected in some biological traits such as small body size of the population inhabiting waters off the Paraná coast, Southern Brazil.

La estrella de mar Astropecten marginatus presenta una distribución neotropical y debido a su abundancia es frecuente encontrarla como captura incidental durante actividades de pesca de arrastre; actividad por la cual se encuentra amenazada en muchos lugares a lo largo de la costa brasileña. En este estudio se analizaron las variaciones estacionales de la estructura de la población y se determinaron los principales componentes de la dieta de A. marginatus frente a la costa de Paraná, sur de Brasil. Las muestras analizadas provinieron de las capturas de la pesca de arrastre recogidas en febrero (verano), abril (otoño), junio (invierno) y octubre (primavera) 2008. De cada individuo se midió la longitud y se pesó, posteriormente se analizó el contenido estomacal de 10 organismos de cada una de las dos clases de talla más frecuentes por cada temporada. Se analizaron 994 ejemplares de A. marginatus, los cuales presentaron una longitud que varió entre 7.0-56.2mm, con mayor frecuencia de individuos entre 20.1-25mm. Los organismos mayores (>40mm) se encontraron solamente en la primavera, mientras aquellos con talla inferior a los 10mm se obtuvieron durante el otoño y el invierno. El peso de los individuos se mantuvo entre los 0.1-15.3g. La relación entre el peso y talla mostró un crecimiento alométrico negativo (b<2.54). En cuanto a la dieta, esta especie consumió un total de once presas, de las cuales los cumáceos y moluscos fueron los grupos más consumidos. Una mayor cantidad de presas exploradas se registró en el invierno-primavera de los períodos de verano-otoño. El predominio de la presa cambió de gasterópodos (verano y otoño) a cumáceos (invierno y primavera). Las diferencias estacionales en el patrón de alimentación podrían estar asociadas a una baja disponibilidad de presas y a los cambios en las tasas de alimentación, lo cual se ve reflejado en algunos rasgos biológicos, como el pequeño tamaño del cuerpo esta población.

Hemolytic activity of venom from crown-of-thorns starfish Acanthaster planci spines

Background : The crown-of-thorns starfish Acanthaster planci is a venomous species from Taiwan whose venom provokes strong hemolytic activity. To understand the hemolytic properties of A. planci venom, samples were collected from A. planci spines in the Penghu Islands, dialyzed with distilled water, and lyophilized into A. planci spine venom (ASV) powder. Results : Both crude venom and ASV cause 50% hemolysis at a concentration of 20 μg/mL. The highest hemolytic activity of ASV was measured at pH 7.0-7.4; ASV-dependent hemolysis was sharply reduced when the pH was lower than 3 or greater than 8. There was almost no hemolytic activity when the Cu2+ concentration was increased to 10 mM. Furthermore, incubation at 100°C for 30 to 60 minutes sharply decreased the hemolytic activity of ASV. After treatment with the protease α-chymotrypsin, the glycoside hydrolase cellulase, and the membrane component cholesterin, the hemolytic activity of ASV was significantly inhibited. Conclusions : The results of this study provide fundamental information about A. planci spine venom. The hemolytic activity was affected by pH, temperature, metal ions, EDTA, cholesterin, proteases, and glycoside hydrolases. ASV hemolysis was inhibited by Cu2+, cholesterin, α-chymotrypsin, and cellulose, factors that might prevent the hemolytic activity of venom and provide the medical treatment for sting.(AU)

Distribución, densidad y estructura de talla de Oreaster reticulatus y Luidia senegalensis (Echinodermata: Asteroidea) en isla de Cubagua, Venezuela / Distribution, density an size structure of Oreaster reticulatus and Luidia senegalensis (Echinodermata: Asteroidea) in Cubagua Island, Venezuela

There is limited biological information about the starfish Oreaster reticulatus and the nine-armed starfish Luidia senegalensis in Venezuelan waters. These species are currently considered threatened in many localities of the Caribbean, Brazil and Colombia. Therefore, the aim of this study was to describe their population density, size distribution and population structure in Cubagua Island. During 2008, 52 stations located around the island were evaluated using band transects of 50m2. Each organism was counted and measured (maximum radius), and its size was compared to the maturity length reported in the literature. The results for O. reticulatus include: 167.3ind./ha; 33% juveniles and 67% adults; average size of 10.7±5cm (range: 2.2-21cm); a wide distribution around the island, with higher densities in the Eastern and Southwest areas. The 50% of the specimens were found in seagrass beds, 25% in sand, 16% in areas covered by decomposed seaweeds, 9% in oyster beds and 1% coralline patches. The densities of O. reticulatus were higher than those reported in the Caribbean, Panama and Puerto Rico, but lower than Venezuelan National Parks: Mochima and Morrocoy; as well as in the Virgin Islands and Belize. For L. senegalensis we found an average density of 40ind./ha; 95% exceeded the reported size at maturity, with mean length of 12cm±3.5cm (range: 3.5-22.3cm); they were found only in 15% of the stations of which 92.5% were sandy bottoms and the other 7.5% oyster beds. The degree of aggregation of L. senegalensis was greater than O. reticulatus, with an estimated k of 0.06. However, it was not possible to compare the densities of L. senegalensis with any other study. For both species is recommended to carry out reproductive studies and to monitor their population densities to infer temporal variations.

Las estrellas de mar: Oreaster reticulatus y Luidia senegalensis, han sido objeto de escasos estudios en aguas venezolanas. Actualmente son consideradas especies amenazadas en diversas zonas del Caribe, Brasil y Colombia. Por esto, se planteó como objetivo generar información sobre su densidad poblacional, distribución y estructura de talla en los alrededores de la isla de Cubagua. Para ello, durante el año 2008, se realizaron cuatro transectas bandas de 50m2 cada una, en 52 estaciones ubicadas alrededor de la isla. Entre los resultados obtenidos para O. reticulatus destacan: 167.3ind/ha, un 33% inmaduros y 67% adultos con un promedio de tallas de 10.7±5cm (rango: 2.2-21cm); una amplia distribución en los alrededores de la isla, con mayores densidades en la zona este y suroeste. Luidia senegalensis mostró una densidad promedio de 40ind/ha, 95% superaba la talla de madurez reportada, con talla promedio de 12cm±3.5cm (rango: 3.5-22.3cm). Se recomienda realizar estudios de reproducción, así como monitoreos de sus densidades poblacionales que permitan inferir sus variaciones temporales.

Distribución, parámetros poblacionales y dieta de Astropecten marginatus (Asteroidea: Astropectinidae) en el Atlántico venezolano

Distribution, population parameters, and diet of Astropecten marginatus (Asteroidea: Astropectinidae) in the Venezuelan Atlantic coast. Astropecten marginatus is a sea star widely distributed in Northern and Eastern South America, found on sandy and muddy bottoms, in shallow and deep waters. To describe some of its ecological characteristics, we calculated it spatial-temporal distribution, population parameters (based on size and weight) and diet in the Orinoco Delta ecoregion (Venezuela). The ecoregion was divided in three sections: Golfo de Paria, Boca de Serpiente and Plataforma Deltana. Samples for the rainy and dry seasons came from megabenthos surveys of the "Línea Base Ambiental Plataforma Deltana (LBAPD)" and "Corocoro Fase I (CFI)" projects. The collected sea stars were measured, weighted and dissected by the oral side to extract their stomach and identify the preys consumed. A total of 570 sea stars were collected in LBAPD project and 306 in CFI one. The highest densities were found during the dry season in almost all sections. In LBAPD project the highest density was in "Plataforma Deltana" section (0.007±0.022ind/m² in dry season and 0.014±0.06ind/m² in rainy season) and in the CFI project the densities in "Golfo de Paria" section were 0.705±0.829ind/m² in rainy season and 1.027±1.107ind/m² in dry season. The most frequent size range was 3.1-4.6cm. The highest biomass was found in "Golfo de Paria" section (7.581±0.018mg/m² in dry season and 0.005±6.542x10-06mg/m² in rainy season for 2004-2005 and 3.979±4.024mg/m² in dry season; and 3.117±3.137mg/m² in rainy season for 2006). A linear relationship was found between the sea star size and its weight but no relationship was observed between its size and the depth where it was collected. Mollusks are dominant in the sea star diet (47.4% in abundance). The diet in any of the sections, seasons or between projects or size class was heterogeneous, using multivariate ordinations (MDS) and SIMPER analysis and there was no difference in the prey number or food elements that a sea star can eat. Although A. marginatus has been described as a predator, in this study were also inferred scavenger and detritivorous habits. Rev. Biol. Trop. 59 (1): 53-69. Epub 2011 March 01.

Astropecten marginatus Gray 1840 presenta una amplia distribución en el norte y este de sur América, encontrándose en fondos arenosos y fangosos de aguas someras y profundas. Se determinó su distribución, parámetros poblacionales tales como: talla, peso y dieta, de los ejemplares provenientes de los muestreos de megabentos de los proyectos LBAPD y CFI en las épocas de lluvia y sequía en la ecorregión Delta del Orinoco, Venezuela. Se dividió la ecorregión en tres sectores: Golfo de Paria, Boca de Serpiente y Plataforma Deltana. Las estrellas fueron medidas, pesadas y se extrajo su estómago para la determinación de las presas. Las mayores densidades se encontraron en época de sequía en Golfo de Paria (2006) y en época de lluvia en Plataforma Deltana (2005). El intervalo de tallas más frecuente fue 3.1-4.6cm. La mayor biomasa se encontró en Golfo de Paria en época de sequía. No se observaron relaciones entre el tamaño de la estrella y la profundidad de muestreo. Existe una dominancia de los moluscos en la dieta, a pesar de tener una alimentación heterogénea. Se observó que aparte de la depredación, también pueden presentar comportamientos carroñeros y detritívoros.

First record and impact of the crown-of-thorns starfish, Acanthaster planci (Spinulosida: Acanthasteridae) on corals of Malpelo Island, Colombian Pacific

The crown-of-thorns starfish, Acanthaster planci, is a major coral predator widely distributed in the Indo-Pacific region, where population outbreaks have caused dramatic impacts on coral reefs. In the Tropical Eastern Pacific (TEP) A. planci occurs at low population densities; it has been significantly abundant only in Panama and Cocos Island. We have recently found two individuals of A. planci at Malpelo Island, a small oceanic island with significant coral communities located off the Colombian Pacific coast. The recent discovery of A. planci at Malpelo is significant in light of recent reports of its increased frequency of observation at Cocos Island and occurrence at the Galapagos Islands. The individuals found at Malpelo have been repeatedly sighted since 2004, actively feeding on nine species of coral. Although densities of A. planci are low at Malpelo and other oceanic islands of the TEP, these islands may act as stepping stones for the colonization of other coral reef areas in the region. However, the low densities of A. planci suggest that it currently poses no threat to coral reefs in the TEP. Rev. Biol. Trop. 58 (Suppl. 1): 139-143. Epub 2010 May 01.

La estrella de mar corona de espinas Acanthaster planci, es un importante depredador de coral ampliamente distribuido en la región del Indo-Pacifico, donde explosiones poblacionales han causado dramáticos impactos sobre los arrecifes coralinos. En el Pacifico Oriental Tropical (POT) A. planci ocurre con densidades poblacionales bajas; solamente en Panamá e Isla de Cocos su abundancia ha sido significativa. Nosotros encontramos recientemente al menos dos individuos de A. planci en la Isla de Malpelo, una pequeña isla oceánica con comunidades coralinas importantes localizada en el Pacífico Colombiano. El hallazgo de A. planci en Malpelo es significativo a la luz de reportes recientes de un incremento en su frecuencia de observación en Isla de Cocos y su registro en Galápagos. Los individuos encontrados en Malpelo han sido repetidamente observados alimentándose activamente de nueve especies de coral desde 2004. Aunque las densidades de A. planci son bajas en Malpelo y otras islas oceánicas del POT, éstas pueden actuar como trampolín de dispersión para la colonización de otras áreas arrecifales en la región. Sin embargo, las bajas densidades de A. planci sugieren que actualmente ella no representa amenaza alguna para los arrecifes del POT.

On some toxinological aspects of the starfish Stellaster equestris (Retzius, 1805)

Whole-body extracts in methanol were obtained from the starfish Stellaster equestris. The crude toxin was fractionated stepwise using diethylaminoethyl (DEAE) cellulose column chromatography. The crude toxin was lethal to male albino mice at a dose of 1.00 mL (containing 531.0 µg/mL protein) when injected intraperitoneally (IP) but the toxicity was abolished in all cases except one upon fractionation. The crude toxin and all the adsorbed fractions exhibited potent hemolytic activity on chicken, goat and human blood. However, group B human erythrocytes were resistant to lysis by all fractions and group O by most of the fractions. Paw edema in mice was caused by the crude toxin and all fractions. Pheniramine maleate and piroxicam blocked the toxicity when administered earlier than, or along with, the crude or fractionated toxins but not when administered after the envenomation. Pretreatment with either of these drugs also blocked edema formation.(AU)

Estructura de las asociaciones de las estrellas de mar (Asteroidea) en arrecifes rocosos del Golfo de California, México / Sea star (Asteroidea) association structures on the rocky reef in the Gulf of California, Mexico

Sea stars are invertebrates that play relevant roles in rocky and coral reefs: they occupy different levels in food webs and may act as top predators. There are numerous studies on taxonomy and biogeography of the class in the eastern tropical Pacific, but information about the attributes and composition of its assemblages is scant. The objectives of this study were the examination and comparison of asteroid community structure from four regions of the Gulf of California, Mexico, characterized by the presence of rocky reefs, and the search for possible associations between pairs of species. In August 2004 we visited four locations in the western gulf: Bahia de Los Angeles (29 degrees N), Santa Rosalia (27 degrees N), Loreto (26 degrees N) and La Paz (24 degrees N), and censuses sea stars using 50 m2 belt transects (N=93). Abundance and species richness was estimated, as well as diversity (H'), evenness (J') and taxonomic distinctness (delta*); then, all variables were compared among regions with analysis of variance. In addition, an ordination analysis was run looking for groups of locations with similar faunistic composition. Our results showed that Loreto Bay had the highest richness and abundance of asteroids, probably because it presents a large number of habitats and multiple food sources; these conditions seem to favor the occurrence of rare species and of detritivores. However, there were no significant interregional differences among ecological indices, nor we detected groups of locations singled out because of its species composition. Thus, community structure of sea stars in rocky areas of the Gulf of California is quite homogeneous and do not change with latitude. This is a consequence of the fact that all regions under analysis had the species Phataria unifascialis and Pharia pyramidatus as dominant in number. There were significant positive associations between three pairs of species: apparently competition is not particularly relevant to control sea star community structure in the Gulf.

Oceanographic conditions and diversity of sea stars (Echinodermata: Asteroidea) in the Gulf of California, México

Species richness is one of the best indicators of biodiversity. However, there are few investigations on concordance of diversity patterns and environmental settings for marine regions. The objectives of this study were to correlate species richness of shallow water (< 200 m deep) sea stars with key oceanographic factors in the Gulf of California, México, and to predict species richness of Asteroidea using multiple regressions. In these analyses the Gulf was divided into nine sections of one degree in latitude (from 23-31 degrees N), at each section we recorded: continental shelf area (at 100 and 200 m depth), temperature mean and range at three depth levels (0, 60 and 120 m), thermocline depth, surface nutrient concentrations (nitrates, phosphates and silicates), surface photosynthetic pigment concentration, and integrated productivity. Sea star species richness at each latitudinal section was estimated from literature data, new collections and museum records. Species were assigned to one of the following feeding guilds: predators of small mobile invertebrates (I), detritivores (D), predators of colonial organisms (C), generalist carnivores (G), and planktivores (P). There are 47 shallow water asteroid species in the Gulf of California (16 I, 15 D, eight C, six G, one P and one not assigned). Total species richness and guild species richness showed strong latitudinal attenuation patterns and were higher in the southernmost Gulf, an area characterized by a narrow shelf, high temperature, and low nutrient concentrations. Species diversity for each guild was correlated to a set of oceanographic parameters: temperature, nitrate concentration, and integrated productivity were linked to richness in must cases. We detected that nutrients and surface pigments always presented negative relationships with species richness, indicating that productive environments limit asteroid diversity in the study area. Finally, the postulated regression models to estimate species richness from oceanographic data were significant and highly precise. We conclude that species richness of Asteroidea in the Gulf of California is related to oceanographic conditions and can be estimated from regional oceanographic information