Invertebrate colonization on artificial substrates in a coral reef at Gorgona Island, Colombian Pacific Ocean / Colonización de invertebrados sobre sustratos artificiales en un arrecife de coral en la Isla Gorgona, Océano Pacífico colombiano

Habitat colonization is a fundamental process in marine population dinamics and community ecology. Marine invertebrate colonization of artificial hard substrates and its spatial variation was studied over the course of one year at La Azufrada coral reef, Gorgona Island, Colombia. Five sets of artificial plates (terracotta and ceramic) were deployed parallel to the bottom in each of three reef zones (backreef, flat and slope). Plates were recovered after 12 months of their installation. The community that developed on the artificial substrate plates was composed of 24 taxa, among which corals were remarkably absent. Species richness on plates did not differ between reef zones, type of plate material or plate surfaces. The resulting community was dominated by barnacles (Balanus trigonus) with a mean density of 26 787.8 (±47 301.0) individuals/m² (mean±1S.D.). The density of this species was significantly higher on plates deployed on the reef slope than on the reef flat or back reef, and was lower on the upper than on the lower or lateral surfaces of plates. The dominance of B. trigonus on artificial plates during this experiment suggests a possible synergistic effect between its reproductive traits and competitive ability for space, which prevents the successful recruitment of other reef organisms such as corals. Rev. Biol. Trop. 62 (Suppl. 1): 161-168. Epub 2014 February 01.

La colonización de hábitat disponible es un proceso fundamental de la ecología de poblaciones y comunidades de organismos marinos. La colonización sobre sustratos artificiales por invertebrados y su variación espacial fue estudiada por un año en el arrecife coralino de La Azufrada, Isla Gorgona (Colombia). Cinco juegos de baldosas (terracota y grés) fueron dispuestos en tres zonas arrecifales (trasarrecife, planicie y talud). Las baldosas fueron recuperadas y examinadas después de 12 meses posteriores a su instalación. La comunidad desarrollada estuvo compuesta por 24 taxa siendo notable la ausencia de corales. No se encontraron diferencias en la riqueza de especies entre las zonas arrecifales, los materiales utilizados y las superficies de las baldosas. Las baldosas fueron dominadas por cirripedios (Balanus trigonus) con una densidad de 26 787.8 (±47 301.0) ind/m² (media±1D.E). La densidad de esta especie fue significativamente más alta en el talud y menor en las superficies superiores. La dominancia de B. trigonus durante el experimento sugiere un posible efecto sinérgico entre sus características reproductivas y su habilidad competitiva por el espacio evitando que otros organismos, como los corales, recluten exitosamente.

Genealogical approaches to the temporal origins of the Central American gap: Speciation and divergence in Pacific Chthamalus (Sessilia: Chthamalidae)

A large section of the tropical Eastern Pacific coastline is nearly devoid of reef or consolidated habitat, and is known as the Central American Gap as it is associated with a biogeographic transition in fish and invertebrate species. We analyze phylogeographic data for intertidal barnacles (Chthamalus) to identify relevant temporal patterns that describe the origins of this biogeographic transition (the Mexican-Panamic Transition Zone). These contrasts of populations on either side of the transition zone include two pairs of closely related species (C. panamensis and C. hedgecocki; C. southwardorum and a Southern form of C. southwardorum), as well as gene flow data within one species (C. panamensis) that currently is found on both sides of the boundary between provinces. Using sequence data from a prior phylogenetic study, we used traditional (net nucleotide divergence) measures as well as coalescent analyses that incorporate the isolation-migration model to identify the likely time of separation between Northern and Southern taxa in two species pairs. A total of 67 individuals were sequenced at two mitochondrial (cytochrome c oxidase I, 16S) and one nuclear (elongation factor 1-alpha) gene regions. Our analyses indicate that the regional isolation of these intertidal barnacles occurred approximately 315-400kya, with subsequent expansion of C. panamensis from the Southern region into the North much more recently. There are insufficient survey data to conclusively document the absence of species from this group within the Central American Gap region near the Gulf of Tehuantepec. However, appropriate habitat is quite sparse in this region and other environmental factors, including upwelling and water temperature, are likely to be associated with isolation of many species in the Mexican and Panamic provinces sensu stricto. Some taxa may maintain gene flow across this region, but very few genetic studies have been completed on such taxa. Until further work is done, distinguishing between prior hypotheses of a faunal gap, or a faunal transition zone, is somewhat speculative. Additional taxonomic revision will be necessary in Chthamalus but is beyond the scope of this paper.

La taxonomía del complejo de especies de cirripedios (Chthamalus) se ha confundido en la literatura desde hace casi 30 años, por lo tanto analizamos datos de su filogeografía para identificar modelos temporales relevantes que describan los orígenes de la zona de transición entre las provincias Mexicana y Panameña. Estos contrastes de poblaciones a ambos lados de la zona de transición incluyen a dos pares de especies estrechamente relacionadas, así como datos de flujo de genes dentro de una especie que actualmente es encontrada en ambos lados del límite entre provincias. Usando datos de secuencia de un estudio previo de filogenética, usamos medidas tradicionales, así como análisis de coalescencia que incorporan el modelo de migración y aislamiento para identificar el tiempo probable de la separación entre los taxa del norte y del sur en dos pares de especies. Nuestros análisis indican que el aislamiento regional de estos ciripedios ocurrió aproximadamente hace 315-400 mil años, con una extensión subsecuente de Chthamalus panamensis de la región del sur hacia el norte mucho más reciente. No hay datos suficientes para documentar conclusivamente la ausencia de especies de este grupo dentro de la región de Centro América cerca del Golfo de Tehuantepec. Sin embargo, el hábitat apropiado es bastante escaso en esta región y otros factores ambientales, incluyendo corrientes y temperatura acuática, probablemente están relacionados con el aislamiento de muchas especies en estas provincias. Algunos taxa pueden mantener el flujo de genes a través de esta región, pero muy pocos estudios genéticos han sido realizados en tales taxa. Hasta que no se desarrollen trabajos adicionales, la distinción entre hipótesis previas de un gap faunal o de una zona de transición faunal es algo especulativo.

Coliform accumulation in Amphibalanus amphitrite (Darwin, 1854) (Cirripedia) and its use as an organic pollution bioindicator in the estuarine area of Recife, Pernambuco, Brazil / Acumulação de coliformes em Amphibalanus amphitrite (Darwin, 1854) (Cirripedia) e seu uso como bioindicador de poluição orgânica na área estuarina do Recife, Pernambuco, Brazil

Samples of water and barnacles Amphibalanus amphitrite were collected from Recife, Brazil, to assess if it accumulates total (TC) and thermotolerant coliforms (TTC) related with sewage pollution. The Most Probable Number (MPN) values and the standard procedures for examination of shellfish were used. Comparatively with the water samples, the highest coliform values came from the barnacles, with TC values ranging from < 3.0 × 10³ to > 2.4 × 10(6) MPN.g-1, and TTC ranging from > 2.4 × 10³ to 2.9 × 10(5) MPN.g-1. Barnacles accumulate the TC Ewingella americana, and the TTC Escherichia coli, Enterobacter gergoviae, Enterobacter aerogenes, and Enterobacter sakazakii. The results provided an indication of the level of organic contamination at the sampling locations and that this species could be a good organic pollution bioindicator.

Amostras de água e cirrípedes Amphibalanus amphitrite foram coletados em Recife, Brasil, para avaliar se estes acumulam coliformes totais (CT) e termo-tolerantes (TTC) relacionados à poluição por esgoto doméstico. Foram utilizados os valores de Números Mais Prováveis (NMP) e os procedimentos padrões para exame de bivalves. Comparativamente às amostras de água, os valores mais altos de coliformes foram dos cirrípedes, com valores de TC variando de < 3,0 × 10³ a > 2,4 × 10(6) NMP.g-1, e TTC variando de > 2,4 × 10³ a 2,9 × 10(5) NMP.g-1. Os cirrípedes acumularam TC Ewingella americana e TTC Escherichia coli, Enterobacter gergoviae, Enterobacter aerogenes e Enterobacter sakazakii. Os resultados proveram uma indicação de que há contaminação orgânica nas localidades de amostras e que esta espécie pode ser um bioindicador bom de poluição orgânica.

Effects of human trampling on a rocky shore fauna on the Sao Paulo coast, southeastern Brazil / Impactos do pisoteio humano na fauna de um costão rochoso do litoral de São Paulo, no sudeste brasileiro

Increased tourist activity in coastal regions demands management strategies to reduce impacts on rocky shores. The highly populated coastal areas in southeastern Brazil are an example of degradation caused by development of industry and tourism. Among different shore impacts, trampling has been intensively studied, and may represent a significant source of stress for intertidal fauna. A randomised blocks design was applied to experimentally study the effects of two different trampling intensities on richness, diversity, density and biomass of the rocky shore fauna of Obuseiro beach, Guarujá, southeastern Brazil. Blocks were distributed in two portions of the intertidal zone, dominated respectively by Chthamalus bisinuatus (Cirripedia) and Isognomon bicolor (Bivalvia). Blocks were trampled over three months, simulating the vacation period in Brazil and were monitored for the following nine months. Results indicate that Chthamalus bisinuatus is vulnerable to trampling impacts. Richness, diversity and turn-over index tended to be higher in trampled plots four months after trampling ceased. In general, results agree with previous trampling studies, suggesting that even low intensities of trampling may cause some impact on intertidal communities. Management strategies should include isolation of sensitive areas, construction of boardwalks, visitor education and monitoring programmes. In Brazil, additional data obtained from experimental studies are necessary in order to achieve a better understanding of trampling impacts on rocky shore communities.

O aumento da atividade turística em áreas costeiras nas últimas décadas faz necessária a adoção de estratégias de manejo para reduzir os impactos gerados às comunidades de costões rochosos. A região costeira do sudeste brasileiro possui bons exemplos de degradação causada pelo turismo e desenvolvimento industrial. Dentre os diferentes distúrbios causados pela visitação, o pisoteio têm sido estudado de forma intensa e pode representar uma fonte significativa de impactos para as comunidades da zona entre-marés. Neste projeto, foi aplicado um desenho de blocos randômicos para se avaliar experimentalmente os efeitos de duas intensidades de pisoteio na riqueza, diversidade, densidade, recobrimento e biomassa da fauna de um costão situado na praia do Obuseiro, no município do Guarujá, São Paulo, Brasil. Os blocos foram alocados em dois povoamentos diferentes, dominados respectivamente por Chthamalus bisinuatus (Cirripedia) e Isognomon bicolor (Bivalvia). O pisoteio foi aplicado durante três meses, simulando a temporada de férias no Brasil, e os blocos foram monitorados nos nove meses seguintes. Os resultados indicaram que Chthamalus bisinuatus é vulnerável aos impactos do pisoteio. Os índices de riqueza, diversidade e turnover apresentaram uma tendência ao aumento nas áreas pisoteadas quatro meses após o término do pisoteio. No geral, os resultados concordam com estudos anteriores e sugerem que mesmo baixas intensidades do distúrbio podem causar impacto às comunidades bentônicas. Estratégias de manejo devem envolver o isolamento de áreas sensíveis, a construção de passarelas, a educação dos visitantes e o monitoramento das comunidades impactadas. No Brasil, a realização de maior quantidade de estudos experimentais é necessária para a melhor compreensão dos impactos do pisoteio nas comunidades de costões rochosos.

Zonación vertical del macrobentos de sustratos sólidos del estuario del río Massangana, Bahía de Suape, Pernambuco, Brasil / Vertical zonation of the hard substrata macrofauna of the Massangana River estuary, Suape Bay (Pernambuco, Brazil)

The estuarine area of the Massangana River (Pernambuco, Brazil) undergoes several kinds of interventions as a result of the activities of the Suape Industrial and Harbor Complex, which could affect local biotic communities. Thus, this study aimed to verify the composition of the benthic macrofauna of hard substrates regarding their vertical distribution in order to support the future biomonitoring of possible changes in this complex. The invertebrates found in an area of 519 m² were collected and their distribution on the biogenic and abiogenic substrates was described. A total of 79 species were found, primarily in the mangroves and distributed in three intertidal zones: a Chthamaletum, which comprised the intertidal and upper shore, the balanid zone, with barnacles and oysters in the mid intertidal, and the Bostrychietum, in the lowest region. In general, this matched the Brazilian and international vertical distribution patterns for mangrove invertebrates. The presence of rocky substrate and the area's high salinity made possible the occurrence of 28 species- including the coral Siderastrea stellata - in an estuarine area. The enlarged distribution of the bivalve Isognomon alatus, the barnacle Amphibalanus reticulatus, and the bryozoans Biflustra savartii, Bowerbankia gracilis, and Conopeum reticulum on the Brazilian coast can be explained by the proximity to the Port of Suape, which allows for passive transportation on ships. The scattered distribution of the fouling organisms among the substrates and the absence of characteristic animals of this ecosystem (such as the mussels) suggest that the environment is already undergoing some stress due to the diverse human interventions occurring in this area.

El área estuarina del río Massangana (Pernambuco, Brasil) está sujeta a diversas intervenciones antropomórficas resultantes de las actividades del Complejo Industrial y Portuario de Suape, que pueden afectar las comunidades bióticas. Con esa perspectiva, este estudio tuvo como finalidad verificar la composición de la macrofauna bentónica de los sustratos sólidos, en su gradiente de distribución vertical, que sirva de referencia para futuros monitoreos biológicos relacionados a los cambios que pueden ocurrir en el complejo portuario. Se colectaron los invertebrados presentes en un área de 519 m² y su distribución en los sustratos biogénicos y abiogénicos es mostrada en el siguiente trabajo. Fueron encontradas 79 especies presentes principalmente en los mangles y distribuidas en tres zonas del intermareal: Chthamaletum, delimitando el supralitoral, "zona balanoide", conteniendo cirripedios y ostras, en la región intermareal media, y el Bostrychietum, en la región inferior. Esta distribución coincidió en forma general, con el patrón brasileño e internacional de distribución vertical de los invertebrados de manglares. La presencia de sustrato rocoso y la alta salinidad posibilitó la aparición de 28 especies, incluyendo el coral Siderastrea stellata en un área estuarina. La ampliación de la distribución en el litoral brasileño del bivalvo Isognomon alatus, del cirripedio Amphibalanus reticulatus y de los briozoos Biflustra savartii, Bowerbankia gracilis y Conopeum reticulum fue justificada por la proximidad con el Puerto de Suape, facilitada por el transporte pasivo en las embarcaciones. La distribución esparcida de los organismos incrustantes en los sustratos y la ausencia de animales característicos de este ecosistema, como los mejillones, muestran señales de que el ambiente ya sufre algún estrés, resultado de las diversas intervenciones antropomórficas que están aconteciendo.

Comparative growth of the intertidal barnacle Tetraclita stalactifera (Thoracica: Tetraclitidae) in sites influenced by upwelling and tropical conditions at the Cabo Frio region, Brazil

El crecimiento del cirripedio intermareal Tetraclita stalactifera fue comparado en dos sitios influenciados por condiciones de resurgencia y tropicales en la región del Cabo Frio, Brasil. La hipótesis fue que el crecimiento es más grande en el sitio con más elevada producción. En esta región, cinco cuadrantes de 10 x 10 cm fueron raspados en el intermareal de las costas rocosas, en cada una de estas localidades, para estudiar el crecimiento de T. stalactifera desde el reclutamiento hasta finalizar el experimento o la muerte del individuo. El diámetro de la base de T. stalactifera fue medido para 18 individuos en el sitio tropical (Ponta da Fortaleza) y 22 en el sitio de resurgencia (Ponta da Cabeza) por medio de fotografías digitalizadas y el software ImageTool. Los resultados observados mostraron una mayor tasa de crecimiento en el área bajo la influencia tropical (0.07 mm/día) que en el área bajo influencia de resurgencia (0.06 mm/día). La localización del sitio, periodo de resurgencia o periodo del asentamiento no afectaron las tasas de crecimiento. Otros efectos o interacciones sinérgicas como la temperatura y la disponibilidad de alimento pueden afectar el crecimiento de esta especie en la región.

Growth of the intertidal barnacle Tetraclita stalactifera was compared in two sites under upwelling and tropical influence at Cabo Frio region, Brazil. The hypothesis was that growth is higher at sites with an enhanced productivity. Five quadrates of 10 x 10 cm were cleared in an intertidal zone of each site to follow growth from recruitment and onwards. Base diameters were measured for 18 individuals at the tropical site (Ponta da Fortaleza) and 22 at the upwelling site (Ponta da Cabeça) using digitalized photos and ImageTool software. Mean growth rates were 0.07 mm/day at the tropical site and 0.06 mm/day at the site under upwelling influence. No effect of location, upwelling season or settlement time was found on barnacle growth rates. Other factors or synergic interactions such as temperature and food availability could influence T. stalactifera growth.

Contaminação mercurial em pescado capturado na lagoa Rodrigo de Freitas – Rio de Janeiro, Brasil / Mercuric contamination of the fish inside Rodrigo de Freitas lagoon – Rio de Janeiro, Brazil

O objetivo deste estudo foi avaliar o grau de contaminação mercurial em alguns representantes da biota aquática desteecossistema. Foram analisados 24 exemplares de acará (Geophagus brasiliensis), 18 de tainha (Mugil sp.), 18 de robalo(Centropomus sp.), 10 de siris (Callinectes sp.) e 10 pools de cracas (Balanus sp.). Para a determinação da concentração demercúrio total, utilizou-se o analisador Bacharach Coleman, modelo MAS-50 B, baseado na técnica de espectrofotometria deabsorção atômica por arraste de vapor a frio. O tratamento constou de uma análise descritiva simples e comparação dasmédias de concentração de Hg Total obtidos em cada porção estudada por análise de variância e pelo teste não-paramétricode Friedman, com objetivo de comparar a magnitude das variações. Outra análise estatística utilizada para interpretação dosresultados foi o Coeficiente de Correlação de Pearson, onde foi medido o grau de correlação entre duas variáveis. Os teoresmédios encontrados foram 0,015 mg.g-1 (0,001-0,105) nos exemplares de acará; 0,011 mg.g-1 (0,002-0,063) nas tainhas; 0,025mg.g-1 (0,015-0,041) nos robalos; 0,023 mg.g-1 (0,012-0,056) nos siris; e 0,057 mg.g-1 (0,042-0,075) nas cracas. Não foi encontradacorrelação entre o teor de Hg e tamanho e/ou peso das amostras em nenhum organismo estudado. Embora os valoresobtidos estejam abaixo do limite máximo permitido pela legislação brasileira, de 0,5 ppm e 1,0 ppm para predadores, é deextrema importância a monitorização dos teores de Hg na lagoa. Desta forma, os resultados servem de subsídios para umaação dos órgãos da saúde pública quanto à liberação ou não do consumo de pescado deste ecossistema.

The objective of this study was to evaluate the degree of mercury contamination in some organisms from this ecosystem. Assampling, it had been used 24 units of “acarᔠ(Geophagus brasiliensis), 18 of “tainha” (Mugil sp.), 18 of “robalo” (Centropomussp.), 10 of crabs (Callinectes sp.) and 10 pools of barnacles (Balanus sp.). The analytical methodology for the determination ofthe total mercury concentration was using Bacharach Coleman Model MAS-50B employing cold vapor atomic absorptionspectrometry, which results are presented in micrograms of mercury per grams of sample (µg.g-1). The statistical treatment ofthe results consisted of a simple descriptive analysis and comparison of concentration of Total Hg in each portion studied byanalysis of variance and by Friedman test with objective of compare the magnitude of the variations. The coefficient of correlationbetween the variables was measured as well. The mean values obtained were 0.015mg.g-1 (0.001-0.105) in “acará”; 0.011mg.g-1(0.002-0.063) in “tainha”; 0.025 mg.g-1 (0.015-0.041) in “robalo”; 0.023 mg.g-1 (0.012-0.056) in crabs; and 0.057 mg.g-1 (0.042-0.075) in barnacle. There was not correlation between size/weight and the mercury concentration in neither studied organisms.Although the total mercury determined was bellow the allowed limit for human consumption established by Brazilian legislation,of 0,5 mg.g-1and 1,0 mg.g-1 to predators fish it is so much important to monitoring mercury values in the studied lagoon.Consequently, the results can supply an action of the public health agencies related to eating or not fishes from this ecosystem.

Gregarine Cephaloidophora communis mawrodiadi, 1908 in the barnacle Euraphia rhyzophorae, Oliveira, 1940 from Brazil

The gregarine Cephaloidophora communis was observed for the first time in Brazil in the barnacles Euraphia rhyzophorae collected in Angra dos Reis, Rio de Janeiro, Brazil, between 1990 and 1996. Histological studies showed growth phases of the parasite in specific parts of the digestive system. The intracellular forms occurred in the vacuoles of the intestinal cells. Syzygy was frequent, and the most common form following syzygy was cylindrical, with a single membrane. The cytoplasm of the gregarines was always irregular, dense, and occasionally presenting a dark stoch area