Abstract Alpheus christofferseni Anker, Hurt and Knowlton, 2007 was described based on four specimens from Atol das Rocas, northeastern Brazil, and one specimen from Bocas del Toro, the Caribbean coast of Panama. Here, we report the collection of two specimens from Pernambuco, Brazil (~ 8°41’S), thus increasing the knowledge on species distribution along the Brazilian coast by approximately five latitudinal degrees south of its type locality (Atol das Rocas, Rio Grande do Norte, ~ 3°51'S). We also report a substantial increase in the known bathymetric distribution from shallow intertidal to approximately 51 m. Notes on morphological variation are provided based on the new material, and the first sequence of the 16S ribosomal subunit gene for the Brazilian coast is provided and compared with congeners.

Abstract Marine shrimps of the genus Thor Kingsley, 1878 are distributed in the eastern and western Atlantic, eastern Pacific, and Indo-West Pacific. Thor manningi Chace, 1972 was originally described from Antigua and since then has been recorded from other Atlantic localities, including the Caribbean Sea, Bermuda, USA, Brazil, and Ascension Island. Specimens previously identified as T. manningi from Panama and Brazil were analyzed using a combination of morphological and molecular approaches. The analyses yielded a new species from the Atlantic coast of Panama, herein described as Thor paulae sp. nov. Moreover, we provide additional morphological observations on T. manningi, mainly regarding mouthparts and pereopods. The new species is morphologically similar to the Pacific Thor cocoensis Wicksten and Vargas, 2001 and Thor marguitae Bruce, 1978. However, it can be separated from them by the carpus of the second pereopod, rostral dorsal dentition, and chela of the first pereopod, respectively. The two species studied here can be easily distinguished by the supraorbital prominence in T. manningi (versus absent in the new species), and the pterygostomial margin rounded and unarmed in T. manningi (versus angular, with tooth in the new species). Thor manningi is morphologically closer to the western Atlantic Thor dobkini Chace, 1972 and Thor floridanus Kingsley, 1878, but can be separated from both by the merus of the first pereopod (T. dobkini) and dactylus of fourth and fifth pereopods (T. floridanus, but with the possibility of overlap). We provide a comparative table with morphological characters of all 17 valid species of Thor, as well as a worldwide identification key to the genus.

Abstract The objective of this study was to investigate some life history traits of the palaemonid shrimp Typton carneus collected from a reef in northeastern Brazil. Samples of the sponges Amphimedon compressa, A. viridis, Desmapsamma anchorata, Dysidea etheria, Haliclona implexiformis and Tedania ignis were analyzed and shrimps were removed from them. A total of 41 individuals were found in Te. ignis, three in H. implexiformis and one in D. etheria; the latter two sponges are new records of sponge hosts for Ty. carneus. Of the specimens associated with Te. ignis, 24 were males, 10 ovigerous females, six non-ovigerous females and one juvenile male. Fecundity varied between 19 to 56 eggs (37 ± 14) per female, and the mean egg volume was 0.033 ± 0.010 mm³. Eleven heterosexual pairs were obtained. Characteristics of the pairs suggest a monogamous mating system for the studied population, such as: the absence of sexual dimorphism in weaponry and body size and presence of paired non-brooding and brooding females carrying eggs in different development stages; and a sex ratio that does not differ from the expected 1:1. However, the lack of size-assortative pairing as well as the low proportion of pairs, compared to solitary individuals, have been observed in polygamous mating systems.

Abstract Studies on fecundity and embryo size have been frequently used to infer about the reproductive potential, embryogenesis, and the energy investment in embryo production in crustaceans. These parameters are relevant to the knowledge of life-history and diversity of reproductive strategies developed by this group. This study addressed the embryo production by the estuarine shrimp Salmoneus carvachoiAnker, 2007, a poorly known caridean shrimp. We investigated whether there was (1) a correlation between fecundity and carapace length, (2) an increase in embryo volume along the embryonic development, and (3) loss of embryos along development. In addition, we investigated whether the esternite length and height and width of the pleura of the second abdominal somite were good predictors of fecundity. A total of 53 embryo-carrying individuals were collected in December 2016 and February 2017 in a tidal mudflat from the estuary of the Paripe River, Ilha de Itamaracá, Pernambuco, Brazil. The carapace length ranged from 3.23 to 4.64 mm (3.78 ± 0.26 mm). Among those, 25 individuals had embryos in initial stage, 5 in intermediate stage and 15 in final stage. Fecundity ranged from 14 to 67 (33.65 ± 12.51 embryos) and was weakly correlated with carapace length. However, fecundity was strongly correlated with the width of the second sternite and width of the pleura of the second abdominal somite. Embryo volume increased markedly (93%) from the initial to the final stage of development. This increase might be due to water uptake to facilitate the membrane rupture at the onset of larvae hatching. There was significant loss of embryos only between the initial and intermediate stage. Future studies on the embryo production by other species of Salmoneus Holthuis, 1955 are necessary to understand and compare these aspects of reproductive biology.

Abstract The association of the caridean shrimps Anchistioides antiguensis (Schmitt, 1924) and Typton gnathophylloides Holthuis, 1951 with the sponges Dysidea janiae (Duchassaing & Michelotti, 1864) and Amphimedon viridis Duchassaing & Michelotti, 1864, respectively, is reported for the first time. The material was collected in coral reefs surrounding Santa Barbara Island, Abrolhos Archipelago, Bahia, Brazil. The shrimps occupied different locations inside the sponges. Previous records of associations between these carideans and other hosts were revised and the possible type of association between the shrimps and their hosts is discussed. The occurrence of the sponge A. viridis in the Abrolhos Archipelago is also reported for the first time.

Abstract The ghost shrimp Ctenocheloides almeidai Anker and Pachelle, 2013 was described based on a single specimen collected at Ponta Verde, Maceió, state of Alagoas, northeastern Brazil. Here, we report the species from Porto Seguro, Bahia (~16º23'S), extending its distribution in the Brazilian coast in approximately 7 degrees south from the type locality in Maceió, Alagoas (~9º40'S). Notes on morphological variation of the species are provided based on the present material.

ABSTRACT The occurrence of the alien alpheid shrimp Athanas dimorphus Ortmann, 1894 is reported for the first time for the state of Pernambuco, northeastern Brazil, based on two ovigerous females collected at Praia do Paraíso, near the Suape Harbor (08º21'29.9"S 34º57'00.9"W). The species, native from the Indo-West Pacific region, was previously reported from two other Brazilian states (Ceará and São Paulo), also occurring in localities with nearby harbors. The presence of ovigerous females suggests that the species was successfully introduced into the area. The main possible introduction vectors for A. dimorphus in Pernambuco and the dispersal potential of the species along the Brazilian coast are discussed.

ABSTRACTThe objective of this study is to report new occurrences of five species of snapping shrimps of the genus AlpheusFabricius, 1798 in Brazil and, thus, contribute to the knowledge of their zoogeography. The southern limit of distribution of A. formosus Gibbes, 1850 and A. peasei (Armstrong, 1940) is extended from Paraná to Santa Catarina and from Bahia to Rio de Janeiro, respectively. The northern distribution limit of A. pouang Christoffersen, 1979 and A. verrilli (Schmitt, 1924) is substantially extended from São Paulo to Pará and from Bahia to Pará, respectively. Finally, A. rudolphi Almeida & Anker, 2011, previously known from Ceará and Alagoas, is recorded for the first time in Pernambuco, filling a gap in its known distribution.

We provide an updated checklist of the snapping shrimps of the genus Alpheus Fabricius, 1798 (Crustacea: Alpheidae) from the Brazilian coast, as well as a key for their identification. The checklist was based on an exhaustive analysis of the literature published up to now, supported by analysis of material of 24 of the 33 species presently recorded from Brazil. Illustrations of the main diagnostic characters are provided to facilitate the identification process, as well as color photographs of 16 species collected by the authors, to facilitate the identification of fresh specimens. For each species, we provide information on the distribution and a list of previous records for the Brazilian coast. Comments on dubious records or taxonomic remarks are provided when appropriate. Finally, the zoogeography of the species is briefly discussed.

The decapod crustaceans inhabiting dead portions of the fire-coral Millepora alcicornis Linnaeus, 1758 and coral rubble were surveyed in six reef areas on the coast of the state of Bahia, Brazil, in 2011. A total of 453 specimens belonging to 39 species in the infraorders Stenopodidea (family Spongicolidae), Caridea (families Palaemonidae, Alpheidae, Hippolytidae, and Processidae), Axiidea (family Callianassidae), Gebiidea (family Upogebiidae), Anomura (family Porcellanidae), and Brachyura (families Majidae, Pilumnidae, Domeciidae, Panopeidae, and Grapsidae) were collected. Members of the families Alpheidae and Porcellanidae were prominent, with 14 and 9 species, respectively. Of the species collected, the alpheid shrimp Alpheus peasei (Armstrong, 1940) is recorded for the first time in the southwestern Atlantic. Microprosthema semilaeve (von Martens, 1872), Corallianassa hartmeyeri Schmitt, 1935, and Petrolisthes marginatu Stimpson, 1859 also had their known geographic ranges extended along the western Atlantic. Alpheus nuttingi (Schmitt, 1924), Synalpheus scaphoceris Coutière, 1910, and Pachycheles riisei (Stimpson, 1858) are new records for Bahia.

A carcinofauna dos ambientes marinhos e costeiros das regiões sudeste e sul da Bahia, Brasil, ainda é pobremente conhecida. O objetivo deste estudo foi realizar um inventário da fauna de crustáceos decápodos do município de Ilhéus, localizado no sudeste da Bahia (14º47'55"S, 39º02'01"W). As amostragens foram realizadas de Fevereiro de 2001 a Fevereiro de 2005, nas zonas supra, meso e infralitoral. Os exemplares coletados foram fixados em etanol 70% e depositados na coleção de crustáceos da Universidade Estadual de Santa Cruz, Ilhéus (MZUESC). Foi coletado um total de 51 espécies pertencentes a 14 famílias. A família mais representativa em termos de número de espécies foi Ocypodidae, representada nas amostragens por 8 espécies. A distribuição geográfica conhecida para as espécies Alpheus heterochaelis (Caridea: Alpheidae), Merguia rhizophorae (Caridea: Hippolytidae) e Sesarma curacaoense (Brachyura: Sesarmidae) foi estendida. A ocorrência do siri exótico Charybdis hellerii, originário do Indo-Pacífico, foi registrada para o estuário do rio Cachoeira. Estes resultados indicam que os estuários de Ilhéus abrigam elevada riqueza de espécies.

The carcinofauna from marine and coastal environments from the southeast and southern Bahia, Brazil, is so far poorly known. The objective of this study was to survey decapod crustaceans occurring along the estuarine environments of Ilhéus, located on the southeast coast of Bahia (14º47'55"S, 39º02'01"W). Samplings were carried out from February 2001 to February 2005, covering supratidal, intertidal and subtidal habitats. Voucher specimens were fixed in ethanol 70% and deposited in the collection of Crustacea of the Universidade Estadual de Santa Cruz, Ilhéus (MZUESC). We report a total of 51 species, belonging to 14 families. The most representative family concerning the number of species was Ocypodidae, represented in our samples by 8 species. Geographic range known for the species Alpheus heterochaelis (Caridea: Alpheidae), Merguia rhizophorae (Caridea: Hippolytidae) and Sesarma curacaoense (Brachyura: Sesarmidae) was enlarged. The Indo-Pacific portunid crab Charybdis hellerii was recorded for the Cachoeira river estuary. The results indicate a high species richness of decapod crustaceans in the estuarine environments of Ilhéus.

The absence of morphological external characteristics that allow the recognition of the sex as well as the presence of both male and female gonopores in the same animal [except in some sexual forms of Parastacus nicoleti (Philippi, 1882)] gives rise to the hypothetical existence of some form of hermaphroditism in crayfishes belonging to the genus Parastacus Huxley, 1879. Specimens of Parastacus brasiliensis (von Martens, 1869) were collected in a rivulet at Mariana Pimentel municipality, Rio Grande do Sul, Brazil. In the laboratory they were reared and dissected. The results suggest that P. brasiliensis may be a sequential hermaphroditic species, but male and female gonadal tissues were not simultaneously present in the analized samples. In testes and ovaries two pairs of genital ducts are present; that connect, respectively, to the gonopores on the coxae of the fifth and the third pairs of pereiopods. In the females only the apertures and anterior ducts seem to be functional, while in the males only the apertures and posterior ducts may be functional. The existence of different degrees of obstruction in the female genital apertures and different degrees of projection in the male genital apertures was observed. The aspect of the gonopores were used to recognize, externally, the sex of animais.