Brazilian Miocene crabs I. Taxonomic review of Cyclocancer tuberculatus Beurlen, 1958 and Hepatella amazonica Beurlen, 1958 (Pancrustacea, Decapoda, Brachyura)

In describing Cyclocancer to accommodate his new species C. tuberculatus, Beurlen highlighted that his new genus was a cancroid intermediate in form between Atelecyclus and Cancer, but with enough characters to be placed in a new genus. Examination of C. tuberculatus type material revealed that Cyclocancer is a junior synonym of Hepatus. Therefore, C. tuberculatus is herein transferred into Hepatus as H. beurleni nomen novum because H. tuberculatus (Beurlen, 1958) is a junior homonym of H. tuberculatusSaussure (1858), a junior synonym of Hepatus pudibundus (Herbst, 1785). Miohepatus gen. nov., comb. nov. is proposed here to accommodate Hepatella amazonica Beurlen from the Pirabas Formation, Neogene, Pará, Brazil, based on new morphological evidence from the type material.(AU)

Linking fish and crustacean taxonomic composition with seasonal contrasts in the soft-bottom intertidal zone / Ligação da composição taxonômica de peixes e crustáceos com contrastes sazonais na zona intertidal de fundo macio

The primary objective of this study was to investigate the seasonal fish and crustacean variations concerning taxonomic composition, species richness, and diversity in sandy beach habitat. For this purpose, we investigated the Sonmiani Hor lagoon area during four distinct seasons, i.e., northeast (NE) monsoon, pre-monsoon, south-west (SW) monsoon, and post-monsoon for one year. During each haul, the net was pulled about 100m along the beach in 0.5m depth. The results showed a strong linear correlation between the diversity index and equitability in fishes (r = 0.978). The diversity index was strong negatively correlated with the abundance and biomass (r = -0.978, -0.972, respectively). The physical attributes like sea surface water temperature and salinity showed a strong negative effect on species assemblages (r = -0.981 and -0.943, respectively). The mean air and water temperature illustrated approximately 3°C difference during NE and pre-monsoon seasons. However, salinity, pH, and electrical conductivity did not show any significant seasonal variabilities. Under the ecological indices, the fish species displayed higher diversity (H = 3.19) during SW monsoon, whereas the lowest diversity was observed during pre-monsoon (H = 1.58). The equitability and species richness, however, remained more noticeable during SW monsoon (J = 0.81). The total number of individuals of fish and crustaceans reached 4799 with 3813 fish individuals and 986 individuals of crustaceans. A total of 27 families of fish while five crustacean families comprising of 30 genera and 38 fish species while ten genera and 17 species of crustaceans were recorded. Liza subviridis displayed the highest abundance among the sampled fish species. In conclusion, fish species constituted a significant part of the coastal fauna in the study area. The seasonal variations displayed distinct variations in fish species composition and diversity.(AU)

O objetivo principal deste estudo foi investigar as variações sazonais de peixes e crustáceos em relação à composição taxonômica, riqueza de espécies e diversidade no habitat de praias arenosas. Para esse fim, investigamos a área da lagoa Sonmiani Hor durante quatro estações distintas, ou seja, monção nordeste (NE), pré-monção, monção sudoeste (SW) e pós-monção, por um ano. Durante cada transporte, a rede foi puxada cerca de 100 m ao longo da praia, a 0,5 m de profundidade. Os resultados mostraram uma forte correlação linear entre o índice de diversidade e a equitabilidade de peixes (r = 0,978). O índice de diversidade apresentou forte correlação negativa com a abundância e a biomassa (r = -0,978 e -0,972, respectivamente). Os atributos físicos, como temperatura da água da superfície do mar e salinidade, apresentaram forte efeito negativo sobre o conjunto de espécies (r = -0,981 e -0,943, respectivamente). A temperatura média do ar e da água teve uma diferença de aproximadamente 3 °C durante a monção NE e a pré-monção. No entanto, salinidade, pH e condutividade elétrica não apresentaram variabilidade sazonal significativa. A respeito dos índices ecológicos, as espécies de peixes apresentaram maior diversidade (H = 3,19) durante a monção SW, enquanto a menor diversidade observada foi na pré-monção (H = 1,58). A equitabilidade e a riqueza de espécies, no entanto, permaneceram mais perceptíveis durante a monção SW (J = 0,81). O número total de peixes e crustáceos foi de 4.799, com 3.813 peixes e 986 crustáceos. Foram registradas 27 famílias de peixes e 5 famílias de crustáceos, com 30 gêneros e 38 espécies de peixes, além de 10 gêneros e 17 espécies de crustáceos. Liza subviridis apresentou a maior abundância entre as espécies de peixes amostradas. Em conclusão, as espécies de peixes constituíram uma parte significativa da fauna costeira na área de estudo. As variações sazonais apresentaram variações distintas na composição e diversidade das espécies de peixes.(AU)

Macrocrustaceans associated with reefs of Phragmatopoma caudata Krøyer in Mörch, 1863 (Polychaeta: Sabellariidae) and rocky shore in the Northeastern Brazil

Ecosystem engineering species create, modify, and/or maintain the characteristics of the environment. The polychaete Phragmatopoma caudata builds large sand reefs in the intertidal region of the Brazilian coast with high structural complexity, favoring the increase of diversity and interactions among the species associated. However, there are no studies concerning the association of polychaetes with crustacean macrofauna in the northeastern Brazil ecoregion, leaving an information gap on baseline biodiversity. Our aim was to analyze the effect of P. caudata colonies (PC) on the local diversity of macrocrustaceans compared to the rocky shore (RS) microhabitat. Monthly collections were carried out in low tide from September 2015 to August 2016 on 10 × 10 m quadrants for fauna and environmental variables (temperature and salinity) samples. In each microhabitat, the capture effort was two hours by two researchers. We collected 3,390 individuals, 60% associated with the colonies of PC and 40% with the RS. The PC obtained higher Shannon diversity, Pielou evenness and species richness coupled with milder water temperature and salinity conditions (minor air exposure during tide), compared to the RS that obtained greater species dominance and more extreme abiotic conditions (major air exposure). The Porcellanidae family stood out because all its species were highly abundant and had high occurrence in the colonies. The tropical Brazil porcelain crab Pachycheles greeleyi was dominant in both microhabitats (major dominance in PC). The structural complexity in the reefs of PC promoted higher availability of niches for the species, as more shelter for the resident species and refugium for temporary species with preference for more complex microhabitats. Conservation managers should prioritize the health of these colonies and subsequent species that constitute important ecosystemic and fishery resources.(AU)

Yet another record of Scylla serrata Forsskal, 1775 (Crustacea: Decapoda: Portunidae) from the western Atlantic

The Indo-Pacific edible swimming crab Scylla serrata is reported here for the fifth time from the western Atlantic including a failed attempt of introduction to Florida for aquaculture purposes in the years 1960’s. The species had been recorded from Brazil in the early 1980’s and in 2011 and from the Caribbean coast of Colombia in 2013. The capture of a third specimen in southeastern Brazil on 24 August 2020 is discussed here. On all occasions individuals found in Brazil were adults captured alive near port areas. The occurrence of S. serrata in disparate time periods in the western Atlantic (1983, 2011, 2013 and 2020) is regarded as an indication of low inoculation pressure.

Yet another record of Scylla serrata Forsskal, 1775 (Crustacea: Decapoda: Portunidae) from the western Atlantic

The Indo-Pacific edible swimming crab Scylla serrata is reported here for the fifth time from the western Atlantic including a failed attempt of introduction to Florida for aquaculture purposes in the years 1960s. The species had been recorded from Brazil in the early 1980s and in 2011 and from the Caribbean coast of Colombia in 2013. The capture of a third specimen in southeastern Brazil on 24 August 2020 is discussed here. On all occasions individuals found in Brazil were adults captured alive near port areas. The occurrence of S. serrata in disparate time periods in the western Atlantic (1983, 2011, 2013 and 2020) is regarded as an indication of low inoculation pressure.(AU)

Discovery of the mud shrimp genus Anacalliax de Saint Laurent, 1973 (Decapoda: Callianassidae) in the Brazilian coast

Previously known only from Argentina and Uruguay, Anacalliax argentinensis is herein reported for the first time from Rio de Janeiro, representing the first occurrence of genus Anacalliax in the Brazilian coast and the northernmost record of the species in the Atlantic Ocean. Morphological variations on the third maxilliped and first pereopods are discussed based in our material.

First record of the genus Eumunida Smith, 1883 (Crustacea, Decapoda, Eumunididae) from the southwestern Atlantic, with the description of a new species

Eumunida picta Smith, 1883, was considered for over a century an amphi-Atlantic species and the only representative of the genus in the Atlantic Ocean, until being split into three species: E. picta sensu stricto (from the northwestern Atlantic), E. bella de Saint Laurent & Macpherson, 1990 and E. squamifera de Saint Laurent & Macpherson, 1990 (from the northeastern and southeastern Atlantic, respectively). Eumunida is now expanded to include a new species, E. notialis, from off the Brazilian coast. Hence, this is the first record of Eumunida and Eumunididae from the southwestern Atlantic. The new species differs from all its Atlantic counterparts in having (1) four hepatic spines; (2) two carapace inframarginal spines; (3) the distal end of the antennal acicle nearly reaching to the articulation between fourth and fifth antennal segments; and (4) the anterolateral spine of the second pleonal tergite obsolete.

Discovery of the mud shrimp genus Anacalliax de Saint Laurent, 1973 (Decapoda: Callianassidae) in the Brazilian coast

Previously known only from Argentina and Uruguay, Anacalliax argentinensis is herein reported for the first time from Rio de Janeiro, representing the first occurrence of genus Anacalliax in the Brazilian coast and the northernmost record of the species in the Atlantic Ocean. Morphological variations on the third maxilliped and first pereopods are discussed based in our material.(AU)

First record of the genus Eumunida Smith, 1883 (Crustacea, Decapoda, Eumunididae) from the southwestern Atlantic, with the description of a new species

Eumunida picta Smith, 1883, was considered for over a century an amphi-Atlantic species and the only representative of the genus in the Atlantic Ocean, until being split into three species: E. picta sensu stricto (from the northwestern Atlantic), E. bella de Saint Laurent & Macpherson, 1990 and E. squamifera de Saint Laurent & Macpherson, 1990 (from the northeastern and southeastern Atlantic, respectively). Eumunida is now expanded to include a new species, E. notialis, from off the Brazilian coast. Hence, this is the first record of Eumunida and Eumunididae from the southwestern Atlantic. The new species differs from all its Atlantic counterparts in having (1) four hepatic spines; (2) two carapace inframarginal spines; (3) the distal end of the antennal acicle nearly reaching to the articulation between fourth and fifth antennal segments; and (4) the anterolateral spine of the second pleonal tergite obsolete.(AU)

Composition and abundance of decapod crustaceans in mixed seagrass meadows in the Paraguaná Peninsula, Venezuela / Composición y abundancia de crustáceos decápodos en praderas mixtas de hierbas marinas en la península de Paraguaná, Venezuela

Thalassia testudinum y Halodule wrigthii son las hierbas marinas dominantes en el Caribe, siendo comunes en costas someras, tanto en monocultivos como en cultivos mixtos. Entre la macrofauna asociada a estas comunidades, los crustáceos son considerados esenciales para el funcionamiento del ecosistema. Sin embargo, el conocimiento sobre la comunidad de crustáceos decápodos asociada a praderas mixtas de T. testudinum y H. wrigthii es escaso, en particular fuera de zonas protegidas. En este trabajo presentamos ocho nuevas especies de decápodos para la Península de Paraguaná (estado Falcón, Venezuela) asociados a praderas mixtas de hierbas marinas: Achelous tumidulus Stimpson, 1871, Alpheus floridanus Kingsley, 1878, Chorinus heros (Herbst, 1790), Clibanarius antillensis (Stimpson, 1859), Clibanarius sclopetarius (Herbst, 1796), Latreutes parvulus (Stimpson, 1866), Panopeus occidentalis Saussure, 1857, y Processa fimbriata Manning & Chace, 1971. Estos registros representan extensiones de hábitat y completan brechas en la distribución geográfica de las especies a lo largo de la costa septentrional de Sudamérica. Diferencias estadísticas en la abundancia y composición de las especies de decápodos fueron posiblemente causadas por la acción conjunta de cobertura y heterogeneidad de las praderas. Las especies más influyentes en la comunidad son típicas para el Caribe; no obstante, la abundancia de Penaeus schmitti Burkenroad, 1936 juveniles fue notable, puesto que raramente han sido encontrados en estos hábitats. Este hallazgo resalta el rol de áreas no protegidas como hábitats de cría para especies de importancia comercial. Nuestros resultados muestran que las praderas de hierbas marinas en la Península de Paraguaná reflejan un buen estado en comparación con otras zonas del Caribe, y representan un hábitat importante para el mantenimiento de las poblaciones de crustáceos.(AU)

Thalassia testudinum and Halodule wrigthii are the dominant seagrasses in the Caribbean, being common across shallow shorelines, either as monospecific or as intermixed meadows. Among the macrofauna associated with these beds, crustaceans are considered essential for the whole ecosystem functioning. However, knowledge about the associated community of decapod crustaceans in assemblages of T. testudinum and H. wrigthii is still scarce, particularly outside of protected areas. Here we report eight new decapod species for the Paraguaná Peninsula (Falcón State, Venezuela) in association with intermixed seagrass beds: Achelous tumidulus Stimpson, 1871, Alpheus aff. floridanus Kingsley, 1878, Chorinus heros (Herbst, 1790), Clibanarius antillensis (Stimpson, 1859), Clibanarius sclopetarius (Herbst, 1796), Latreutes parvulus (Stimpson, 1866), Panopeus occidentalis Saussure, 1857, and Processa fimbriata Manning & Chace, 1971. These records represent habitat extensions and fill gaps in the geographical distribution of the species along the northern coast of South America. Furthermore, we found that statistical differences in decapod species abundance and composition are likely to be caused by the joint action of coverage and heterogeneity of the beds. Our results indicate that typical Caribbean species were the most influential in the community; nevertheless, the abundance of juvenile Penaeus schmitti Burkenroad, 1936 was notable, since they have rarely been found in these habitats. This finding highlights the role of non-protected areas as nursery habitats for economically important species. Our results show that seagrass meadows in the Paraguaná Peninsula reflect overall good health when compared to other Caribbean zones, representing an important habitat for the maintenance of crustacean populations.(AU)

Composition and abundance of decapod crustaceans in mixed seagrass meadows in the Paraguaná Peninsula, Venezuela / Composición y abundancia de crustáceos decápodos en praderas mixtas de hierbas marinas en la península de Paraguaná, Venezuela

Thalassia testudinum y Halodule wrigthii son las hierbas marinas dominantes en el Caribe, siendo comunes en costas someras, tanto en monocultivos como en cultivos mixtos. Entre la macrofauna asociada a estas comunidades, los crustáceos son considerados esenciales para el funcionamiento del ecosistema. Sin embargo, el conocimiento sobre la comunidad de crustáceos decápodos asociada a praderas mixtas de T. testudinum y H. wrigthii es escaso, en particular fuera de zonas protegidas. En este trabajo presentamos ocho nuevas especies de decápodos para la Península de Paraguaná (estado Falcón, Venezuela) asociados a praderas mixtas de hierbas marinas: Achelous tumidulus Stimpson, 1871, Alpheus floridanus Kingsley, 1878, Chorinus heros (Herbst, 1790), Clibanarius antillensis (Stimpson, 1859), Clibanarius sclopetarius (Herbst, 1796), Latreutes parvulus (Stimpson, 1866), Panopeus occidentalis Saussure, 1857, y Processa fimbriata Manning & Chace, 1971. Estos registros representan extensiones de hábitat y completan brechas en la distribución geográfica de las especies a lo largo de la costa septentrional de Sudamérica. Diferencias estadísticas en la abundancia y composición de las especies de decápodos fueron posiblemente causadas por la acción conjunta de cobertura y heterogeneidad de las praderas. Las especies más influyentes en la comunidad son típicas para el Caribe; no obstante, la abundancia de Penaeus schmitti Burkenroad, 1936 juveniles fue notable, puesto que raramente han sido encontrados en estos hábitats. Este hallazgo resalta el rol de áreas no protegidas como hábitats de cría para especies de importancia comercial. Nuestros resultados muestran que las praderas de hierbas marinas en la Península de Paraguaná reflejan un buen estado en comparación con otras zonas del Caribe, y representan un hábitat importante para el mantenimiento de las poblaciones de crustáceos.

Thalassia testudinum and Halodule wrigthii are the dominant seagrasses in the Caribbean, being common across shallow shorelines, either as monospecific or as intermixed meadows. Among the macrofauna associated with these beds, crustaceans are considered essential for the whole ecosystem functioning. However, knowledge about the associated community of decapod crustaceans in assemblages of T. testudinum and H. wrigthii is still scarce, particularly outside of protected areas. Here we report eight new decapod species for the Paraguaná Peninsula (Falcón State, Venezuela) in association with intermixed seagrass beds: Achelous tumidulus Stimpson, 1871, Alpheus aff. floridanus Kingsley, 1878, Chorinus heros (Herbst, 1790), Clibanarius antillensis (Stimpson, 1859), Clibanarius sclopetarius (Herbst, 1796), Latreutes parvulus (Stimpson, 1866), Panopeus occidentalis Saussure, 1857, and Processa fimbriata Manning & Chace, 1971. These records represent habitat extensions and fill gaps in the geographical distribution of the species along the northern coast of South America. Furthermore, we found that statistical differences in decapod species abundance and composition are likely to be caused by the joint action of coverage and heterogeneity of the beds. Our results indicate that typical Caribbean species were the most influential in the community; nevertheless, the abundance of juvenile Penaeus schmitti Burkenroad, 1936 was notable, since they have rarely been found in these habitats. This finding highlights the role of non-protected areas as nursery habitats for economically important species. Our results show that seagrass meadows in the Paraguaná Peninsula reflect overall good health when compared to other Caribbean zones, representing an important habitat for the maintenance of crustacean populations.

Spatial distribution and egg production in squat lobsters (Decapoda: Munididae, Munidopsidae) from the collection of the Museu de Zoologia of the Universidade de São Paulo, Brazil

Se examinó la distribución espacial y la producción de huevos de langostillas depositados en la colección del Museu de Zoologia de la Universidade de São Paulo (MZUSP), Brasil. Para ello, se analizaron 1.346 ejemplares, de los cuales 169 correspondieron a hembras ovígeras. Las hembras ovígeras estuvieron distribuidas en diez especies de Munididae y tres de Munidopsidae. Once de las trece especies estudiadas se distribuyeron en la costa brasilera, mientras que dos en otras regiones marinas. El análisis de la distribución batimétrica reveló la presencia de cuatro especies de langostillas sobre la plataforma continental ( 200 m: M. spinifrons, M. pusilla, M. irrasa, M. flinti), dos en la primera franja del talud continental (200-500 m: Munida forceps, A. longipes) y cinco distribuidas entre 500 y 1048 m de profundidad (M. erinacea, M. constricta, M. valida, M. microphthalma, M. transtridens). En general, las especies de Munididae produjeron una alta cantidad de huevos (554 ± 619 huevos) de pequeño tamaño (0,48 ± 0,120 mm) comparado con las especies de Munidopsidae (13 ± 10 huevos; 1,12 ± 0,337 mm, respectivamente). Esta tendencia es consistente con la filogenia de ambos clados cuyo origen en común se refleja en similitudes morfológicas tanto en las formas larvales como en las adultas, pero no así en la estrategia reproductiva que claramente separa las especies pertenecientes a estas familias. Nuestros resultados también demuestran que el tamaño del huevo en langostillas está correlacionado con la profundidad, sugiriendo una estrecha relación entre el hábitat y la duración del desarrollo larval de estas especies.(AU)

Spatial distribution and egg production of squat lobsters is examined from specimens deposited in the collection of the Museu de Zoologia of the Universidade de São Paulo (MZUSP), Brazil. A total of 1,346 specimens of squat lobsters were analyzed, out of which 169 were ovigerous females. Ovigerous females contained ten species of Munididae (n = 165) and three of Munidopsidae (n = 4). Eleven of the thirteen studied species were distributed along the Brazilian coast, while two of the remaining species in other marine regions. The analysis of bathymetric distribution revealed the presence of four species on the continental shelf ( 200 m depth: M. spinifrons, M. pusilla, M. irrasa, M. flinti), two on the first layer of the continental slope (200-500 m: Munida forceps, A. longipes) and five distributed between 500 and 1,048 m (M. erinacea, M. constricta, M. valida, M. microphthalma, M. transtridens). Overall, species belonging to Munididae produced a higher number of eggs (554 ± 619 eggs) but of minor size (0.48 ± 0.120 mm) than species of Munidopsidae (13 ± 10 eggs; 1.12 ± 0.337 mm, respectively). Such tendency is consistent with the phylogeny of both clades whose common origin is reflected in morphological similarities both in larval and adult forms, but not in terms of the reproductive strategy that clearly separates the species belonging to these families. Results also demonstrated that egg size in squat lobsters is strongly associated with depth, which suggests the strong influence of habitat on the duration of larval development of these species.(AU)

Spatial distribution and egg production in squat lobsters (Decapoda: Munididae, Munidopsidae) from the collection of the Museu de Zoologia of the Universidade de São Paulo, Brazil

Se examinó la distribución espacial y la producción de huevos de langostillas depositados en la colección del Museu de Zoologia de la Universidade de São Paulo (MZUSP), Brasil. Para ello, se analizaron 1.346 ejemplares, de los cuales 169 correspondieron a hembras ovígeras. Las hembras ovígeras estuvieron distribuidas en diez especies de Munididae y tres de Munidopsidae. Once de las trece especies estudiadas se distribuyeron en la costa brasilera, mientras que dos en otras regiones marinas. El análisis de la distribución batimétrica reveló la presencia de cuatro especies de langostillas sobre la plataforma continental ( 200 m: M. spinifrons, M. pusilla, M. irrasa, M. flinti), dos en la primera franja del talud continental (200-500 m: Munida forceps, A. longipes) y cinco distribuidas entre 500 y 1048 m de profundidad (M. erinacea, M. constricta, M. valida, M. microphthalma, M. transtridens). En general, las especies de Munididae produjeron una alta cantidad de huevos (554 ± 619 huevos) de pequeño tamaño (0,48 ± 0,120 mm) comparado con las especies de Munidopsidae (13 ± 10 huevos; 1,12 ± 0,337 mm, respectivamente). Esta tendencia es consistente con la filogenia de ambos clados cuyo origen en común se refleja en similitudes morfológicas tanto en las formas larvales como en las adultas, pero no así en la estrategia reproductiva que claramente separa las especies pertenecientes a estas familias. Nuestros resultados también demuestran que el tamaño del huevo en langostillas está correlacionado con la profundidad, sugiriendo una estrecha relación entre el hábitat y la duración del desarrollo larval de estas especies.

Spatial distribution and egg production of squat lobsters is examined from specimens deposited in the collection of the Museu de Zoologia of the Universidade de São Paulo (MZUSP), Brazil. A total of 1,346 specimens of squat lobsters were analyzed, out of which 169 were ovigerous females. Ovigerous females contained ten species of Munididae (n = 165) and three of Munidopsidae (n = 4). Eleven of the thirteen studied species were distributed along the Brazilian coast, while two of the remaining species in other marine regions. The analysis of bathymetric distribution revealed the presence of four species on the continental shelf ( 200 m depth: M. spinifrons, M. pusilla, M. irrasa, M. flinti), two on the first layer of the continental slope (200-500 m: Munida forceps, A. longipes) and five distributed between 500 and 1,048 m (M. erinacea, M. constricta, M. valida, M. microphthalma, M. transtridens). Overall, species belonging to Munididae produced a higher number of eggs (554 ± 619 eggs) but of minor size (0.48 ± 0.120 mm) than species of Munidopsidae (13 ± 10 eggs; 1.12 ± 0.337 mm, respectively). Such tendency is consistent with the phylogeny of both clades whose common origin is reflected in morphological similarities both in larval and adult forms, but not in terms of the reproductive strategy that clearly separates the species belonging to these families. Results also demonstrated that egg size in squat lobsters is strongly associated with depth, which suggests the strong influence of habitat on the duration of larval development of these species.

The first finding of Ostrea cf. puelchana (Bivalvia) living as epibiont on Callinectes exasperates (Decapoda) / Primeiro registro de Ostrea cf. puelchana (Bivalvia) vivendo como epibionte sobre Callinectes exasperates (Decapoda)

This paper describes the epibiosis of Ostrea cf. puelchana on Callinectes exasperatus (Gerstaecker, 1856), both collected from the estuary of the Paraíba River, in the state of Paraíba, northeastern Brazil. The basibiont crab was captured using a trap installed in mangrove area at a depth of about 2 meters. The oyster was closely attached to the left side of dorsal carapace covering most of the epibranchial, mesobranchial and metabranchial regions. Possible advantages and disadvantages for both the epibiont and the basibiont are discussed. We believe that young O. cf. puelchana may avoid a variety of potential predators due to the considerable movement capacity of C. exasperatus and may also serve as a small protective shield for the basibiont. However, the oyster, which is a bivalve with an epifaunal lifestyle, is likely to be negatively affected, mainly due to burrowing activity of the crab. This is the first record of epibiosis between bivalves of the genus Ostrea Linnaeus, 1758 and crabs of the genus Callinectes Stimpson, 1860.(AU)

O presente estudo descreve a epibiose de Ostrea cf. puelchana sobre Callinectes exasperatus(Gerstaecker, 1856), ambos coletados no estuário do Rio Paraíba, no estado da Paraíba, nordeste do Brasil.O caranguejo basibionte foi capturado usando uma armadilha instalada em área de mangue em cerca de 2metros de profundidade. A ostra estava fixada sobre o lado esquerdo da carapaça dorsal cobrindo grandeparte das regiões epibranquial, mesobranquial e metabranquial. Possíveis vantagens e desvantagens paraambos epibionte e basibionte são discutidas. O espécime jovem de O. cf. puelchana pode evitar umavariedade de predadores potenciais devido à considerável capacidade de deslocamento de C. exasperatus, aomesmo tempo, essa espécie pode atuar como um escudo protetor para o basibionte. Entretanto, o ostreídeopossui um estilo de vida epifaunal, podendo ser afetado de forma negativa, principalmente devido àatividade de escavação do caranguejo. Este é o primeiro registro de epibiose entre bivalves do gênero OstreaLinnaeus, 1758 e caranguejos do gênero Callinectes Stimpson, 1860.(AU)

Description of ten additional ossicles in the foregut of the freshwater crabs Sylviocarcinus pictus and Valdivia serrata (Decapoda: Trichodactylidae)

The morphology of stomach ossicles of decapod crustaceans provides valuable information on their phylogeny and biology. We herein described ten new ossicles in the foreguts of two trichodactylid crabs, Sylviocarcinus pictus (H. Milne-Edwards, 1853) and Valdivia serrata White, 1847, in addition to previously described 38 ossicles, which are also recognized and listed. Five specimens each of S. pictus and V. serrata were selected for morphological analysis of gastric ossicles. The stomachs were obtained after removing the carapace, and they were fixed in 10% formalin for 24 hours. After this procedure, the stomachs were immersed in a solution of 10% Potassium Hydroxide (KOH) and heated to 100 °C during 60 minutes for tissue maceration. At this point, the clean skeletons were colored by adding 1% Alizarin Red to the KOH solution in order to facilitate visualization of the internal structures such as the setae and ossicles. The ten new ossicles are: dorsomedial cardiac plate; dorsolateral cardiac plate; suprapectineal lateral ossicle; inferior cardiac valve; lateral mesopyloric ossicle; ampullary roof-medium portion ossicle; process of the ampullary roof-upper portion; lateral-inferior post-ampullary plate; pleuro-pyloric valves ossicle; and lateral pleuro-pyloric plate. Some ossicles are thin plates that together with the main ossicles assist in the structure and support of the stomach, which are similar in the two species studied herein. The current knowledge on gastric ossicles will be useful in establishing taxonomic characters, which can evaluate phylogenetic relationships among brachyuran crabs.

Description of ten additional ossicles in the foregut of the freshwater crabs Sylviocarcinus pictus and Valdivia serrata (Decapoda: Trichodactylidae)

The morphology of stomach ossicles of decapod crustaceans provides valuable information on their phylogeny and biology. We herein described ten new ossicles in the foreguts of two trichodactylid crabs, Sylviocarcinus pictus (H. Milne-Edwards, 1853) and Valdivia serrata White, 1847, in addition to previously described 38 ossicles, which are also recognized and listed. Five specimens each of S. pictus and V. serrata were selected for morphological analysis of gastric ossicles. The stomachs were obtained after removing the carapace, and they were fixed in 10% formalin for 24 hours. After this procedure, the stomachs were immersed in a solution of 10% Potassium Hydroxide (KOH) and heated to 100 °C during 60 minutes for tissue maceration. At this point, the clean skeletons were colored by adding 1% Alizarin Red to the KOH solution in order to facilitate visualization of the internal structures such as the setae and ossicles. The ten new ossicles are: dorsomedial cardiac plate; dorsolateral cardiac plate; suprapectineal lateral ossicle; inferior cardiac valve; lateral mesopyloric ossicle; ampullary roof-medium portion ossicle; process of the ampullary roof-upper portion; lateral-inferior post-ampullary plate; pleuro-pyloric valves ossicle; and lateral pleuro-pyloric plate. Some ossicles are thin plates that together with the main ossicles assist in the structure and support of the stomach, which are similar in the two species studied herein. The current knowledge on gastric ossicles will be useful in establishing taxonomic characters, which can evaluate phylogenetic relationships among brachyuran crabs.(AU)

Towards a review of the decapod crustacea from the remote oceanic archipelago of Trindade and Martin Vaz, south Atlantic Ocean: new records and notes on ecology and zoogeography

The remoteness of the Trindade and Martin Vaz young volcanic archipelago (TMV) raises questions about the source of its marine benthic fauna and levels of endemism. Addressing these questions requires a comprehensive knowledge of the taxonomic composition of the marine fauna of the islands. A five-year survey in the shallow marine waters (up to 30 m) and a literature review on the data published for TMV have been conducted to document the biodiversity of the benthic fauna. Here we report on ten new records of decapod crustaceans from TMV: Gnathophyllum americanum and Thor amboinensis are circumtropical in distribution, whereas Stenopus hispidus, Gnathophylloides mineri and Parribacus antarcticus are disjunct circumtropical species as their distribution in the Atlantic Ocean is limited eastwardly to TMV or Ascension Island (S. hispidus), therefore, do not extending into the eastern Atlantic. Gnathophyllum circellum and Thor manningi are western Atlantic species, with G. circellum previously known only from the Caribbean Sea. Pontonia manningi, Tuleariocaris neglecta and Enoplometopus antillensis are amphi-Atlantic in distribution. Two of the above species are recorded from the southwestern Atlantic for the first time: Gnathophyllum circellum and Tuleariocaris neglecta. These new records corroborate that the marine benthic invertebrate fauna of the TMV archipelago is actually a [...]

O grande isolamento geográfico do jovem arquipélago vulcânico Trindade e Martin Vaz (TMV) suscita questionamentos sobre a origem e os níveis de endemismo de sua fauna. Entretanto, a abordagem destas questões requer o conhecimento abrangente da composição taxonômica da fauna bentônica marinha de TMV. Com o intuito de documentar a biodiversidade em TMV foram efetuadas amostragens da fauna de invertebrados bentônicos durante cinco anos consecutivos do entre-marés até profundidades de 30 m. Nesta oportunidade apresentamos dez novos registros de crustáceos Decapoda para TMV, juntamente com comentários ecológicos e notas zoogeográficas. Gnathophyllum americanum e Thor amboinensis são espécies circumtropicais, enquanto que Stenopus hispidus, Gnathophylloides mineri e Parribacus antarcticus são espécies circumtropicais disjuntas na medida em que sua distribuição no oceano Atlântico encontra-se limitada à leste pelas ilhas TMV ou Ascensão (S. hispidus), consequentemente, não se estendendo ao Atlântico oriental. Gnathophyllum circellum e Thor manningi são espécies do Atlântico ocidental; G. circellum era conhecida previamente apenas do Mar do Caribe. Pontonia manningi, Tuleariocaris neglecta e Enoplometopus antillensis são espécies anfi-Atlânticas. Estes novos registros para TMV corroboram a ideia de que a fauna marinha bentônica de TMV constitui-se em um mosaico de espécies atlântico-ocidentais, atlântico-orientais, centro-atlânticas (insulares), anfi-Atlânticas, endêmicas e circumtropicais. O componente atlântico ocidental tem forte influência na formação faunística de TMV.

Towards a review of the decapod crustacea from the remote oceanic archipelago of Trindade and Martin Vaz, south Atlantic Ocean: new records and notes on ecology and zoogeography

The remoteness of the Trindade and Martin Vaz young volcanic archipelago (TMV) raises questions about the source of its marine benthic fauna and levels of endemism. Addressing these questions requires a comprehensive knowledge of the taxonomic composition of the marine fauna of the islands. A five-year survey in the shallow marine waters (up to 30 m) and a literature review on the data published for TMV have been conducted to document the biodiversity of the benthic fauna. Here we report on ten new records of decapod crustaceans from TMV: Gnathophyllum americanum and Thor amboinensis are circumtropical in distribution, whereas Stenopus hispidus, Gnathophylloides mineri and Parribacus antarcticus are disjunct circumtropical species as their distribution in the Atlantic Ocean is limited eastwardly to TMV or Ascension Island (S. hispidus), therefore, do not extending into the eastern Atlantic. Gnathophyllum circellum and Thor manningi are western Atlantic species, with G. circellum previously known only from the Caribbean Sea. Pontonia manningi, Tuleariocaris neglecta and Enoplometopus antillensis are amphi-Atlantic in distribution. Two of the above species are recorded from the southwestern Atlantic for the first time: Gnathophyllum circellum and Tuleariocaris neglecta. These new records corroborate that the marine benthic invertebrate fauna of the TMV archipelago is actually a [...](AU)

O grande isolamento geográfico do jovem arquipélago vulcânico Trindade e Martin Vaz (TMV) suscita questionamentos sobre a origem e os níveis de endemismo de sua fauna. Entretanto, a abordagem destas questões requer o conhecimento abrangente da composição taxonômica da fauna bentônica marinha de TMV. Com o intuito de documentar a biodiversidade em TMV foram efetuadas amostragens da fauna de invertebrados bentônicos durante cinco anos consecutivos do entre-marés até profundidades de 30 m. Nesta oportunidade apresentamos dez novos registros de crustáceos Decapoda para TMV, juntamente com comentários ecológicos e notas zoogeográficas. Gnathophyllum americanum e Thor amboinensis são espécies circumtropicais, enquanto que Stenopus hispidus, Gnathophylloides mineri e Parribacus antarcticus são espécies circumtropicais disjuntas na medida em que sua distribuição no oceano Atlântico encontra-se limitada à leste pelas ilhas TMV ou Ascensão (S. hispidus), consequentemente, não se estendendo ao Atlântico oriental. Gnathophyllum circellum e Thor manningi são espécies do Atlântico ocidental; G. circellum era conhecida previamente apenas do Mar do Caribe. Pontonia manningi, Tuleariocaris neglecta e Enoplometopus antillensis são espécies anfi-Atlânticas. Estes novos registros para TMV corroboram a ideia de que a fauna marinha bentônica de TMV constitui-se em um mosaico de espécies atlântico-ocidentais, atlântico-orientais, centro-atlânticas (insulares), anfi-Atlânticas, endêmicas e circumtropicais. O componente atlântico ocidental tem forte influência na formação faunística de TMV.(AU)

Crustacean communities in coastal ephemeral pools in the Araucanía region (38° S, Chile) / Comunidades de crustáceos em lagoas efêmeras costeiras na região de Araucanía (38° S, Chile)

The fauna communities of ephemeral pools in southern Chile are characterized by heterogeneity of crustacean taxa; nevertheless, no detailed studies exist of their community structure. The aim of the present study was to analyze the crustacean community structure in two groups of ephemeral pools (Puaucho and Nigue pools) in the coastal zone of the Araucanía region. A correlation matrix was made by species abundance against temperature, conductivity, pH and total dissolved solids. In a second step, a null model for species co-occurrence was applied to the total data and to each group. The results for total data revealed a significant direct relation between the abundance of H. costera, C. dubia and Mesocyclops. For the Puaucho pools, the same results were found together with direct associations with total dissolved solids, conductivity and pH. Finally, different results were found for the Nigue pools, with no clear significant associations, either direct or indirect, between the abundance of different crustacean taxa and abiotic parameters. These results were supported by the co-occurrence null model analysis, which revealed the presence of regulator factors for the total data, and for each of the two groups. Ecological topics are discussed with emphasis on meta-community dynamics.(AU)

As comunidades faunísticas das lagoas efêmeras do sul do Chile são caracterizadas pela heterogeneidade dos seus táxons. Entretanto, estudos detalhados da sua estrutura de comunidade ainda não existem. O objetivo do presente estudo foi analisar a estrutura da comunidade de crustáceos em dois grupos de lagoas efêmeras (Puaucho e Nigue) na zona costeira da região de Araucanía. A matriz de correlação foi feita com a abundância das espécies em função da temperatura, condutividade, pH e sólidos totais dissolvidos. Num segundo passo, um modelo nulo para as espécies de coocorrência foi aplicado aos dados totais e para cada grupo. Os resultados para os dados totais revelaram uma relação direta e significativa entre a abundância de H. costera, C. dubia e Mesocyclops. Para as lagoas Puaucho, os mesmos resultados foram encontrados, juntamente com associações diretas com sólidos totais dissolvidos, condutividade e pH. Finalmente, diferentes resultados foram encontrados para as lagoas Nigue, sem associações significativas claras, diretas ou indiretas entre a abundância de diferentes táxons de crustáceos e parâmetros abióticos. Estes resultados foram suportados pela análise de modelo de coocorrência nula, a qual revelou a presença de fatores reguladores para o total de dados, e para cada um dos dois grupos. Temas ecológicos são discutidos com ênfase na dinâmica de meta-comunidade.(AU)

Description of two new associated infaunal decapod crustaceans (Axianassidae and Alpheidae) from the tropical eastern Pacific

Two new species of infaunal decapod crustaceans are described based on material collected in Bahía Málaga, Pacific coast of Colombia, in 2009. The mud-shrimp Axianassa darrylfelderi sp. nov. (Axianassidae) appears to be most closely related to A. australis Rodrigues & Shimizu, 1992, A. canalis Kensley & Heard, 1990, and A. jamaicensis Kensley & Heard, 1990. The new species may be distinguished from each of them by a combination of morphological features, mainly on the uropodal exopod, antennal acicle, third maxilliped and first pleonite. The shrimp Leptalpheus canterakintzi sp. nov. (Alpheidae), associated with burrows of A. darrylfelderi sp. nov., undoubtedly represents the eastern Pacific sister species of the western Atlantic L. axianassae Dworschak & Coelho, 1999, which lives exclusively in burrows of A. australis. The two species are reliably distinguishable only by the proportions of the merus and propodus of the third pereiopod. Leptalpheus azuero Anker, 2011, previously known only from the Pacific coast of Panama, is reported for the first time from Bahía Málaga, Colombia.

O presente estudo descreve duas novas espécies de crustáceos decápodos da infauna baseado em material coletado na Bahía Málaga, costa pacífica da Colombia, em 2009. A primeira delas, o corrupto Axianassa darrylfelderi sp. nov. (Axianassidae), aparenta estar mais relacionada morfologicamente a A. australis Rodrigues & Shimizu, 1992, A. canalis Kensley & Heard, 1990, e A. jamaicensis Kensley & Heard, 1990. Contudo, a nova espécie difere em uma combinação de caracteres morfológicos, principalmente no exópodo uropodial, acículo (escama) antenal, terceiro maxilípede e primeiro pleonito. A segunda espécie nova, o camarão Leptalpheus canterakintzi sp. nov. (Alpheidae), associado às galerias de A. darrylfelderi sp. nov., incontestavelmente representa a espécie-irmã no Pacífico Oriental da espécie L. axianassae Dworschak & Coelho, 1999 do Atlântico Ocidental, a qual vive exclusivamente em galerias de A. australis. As duas espécies são distinguíveis apenas pelas proporções do mero e propodo do terceiro par de pereiópodos. Além disso, Leptalpheus azuero Anker, 2011, previamente conhecido somente para o Panamá, é registrado pela primeira vez para a Colômbia.