Taxonomy, biogeography and phylogeny of Cretaceous frog crabs (Crustacea, Decapoda, Brachyura) from the Neotropics

Le but du présent travail est d’apporter la preuve paléontologique mettant en évidence que le clade Raninoida était bien établi dans le Néotropique durant la période Crétacée, où il était représenté par les plus anciennes familles ou par quelques–uns des plus anciens membres des plus anciennes familles. Je décris des taxa raninoïdiens ou similaires, incluant Archaeochimaeridae n. fam. et Archaeochimaera macrophthalma n. gen. n. sp., du Cénomanien supérieur (~95 Ma.) de Colombie (Chapitre 3), Planocarcinus n. gen., Planocarcinus olssoni (Rathbun, 1937) n. comb. et Notopocorystes kerri n. sp., de l’Aptien supérieur (~115 Ma.) de Colombie (Luque et al., accepté) (Chapitre 2). Ces taxa nouveaux, plus la présence de Cenomanocarcinus vanstraeleni Stenzel, 1945, dans l’Albien supérieur de Colombie (Vega et al., 2010), et d’Araripecarcinus ferreirai Martins–Neto, 1987, dans l’Albien du Brésil (Luque et al., en cours) (Chapitre 4), représentent certains des plus anciens signalements de quatre des sept familles raninoïdiennes, au moins, connues à ce jour. La nouvelle famile Archaeochimaeridae se présente comme le groupe frère du clade Raninidae + clade Symethidae. Cependant, la combinaison unique de caractères primitifs, dérivés et homoplasiques est inégalable chez les Raninoida, et, en fait, chez les autres sections de crabes podotrèmes. Alors que les taxa raninoïdiens du Crétacé sont bien connus aux latitudes élevées, les signalements en Amérique du Sud tropicale sont rares et épars, avec pour résultat de considérables distorsions pour traiter des importantes questions biogéographiques et phylogénétiques. Sur la base de données taxonomiques, paléobiogéographiques et cladistiques, une ré–appréciation des toute premières distributions spatio–temporelle des “crabes grenouilles” est proposée, avec pour objet de contribuer à une plus large compréhension de la diversité, phylogénie et évolution des premiers brachyoures au cours des âges.

Studies On Pobtunid Crabs [Crustacea Decapoda Brachyura)

True crabs are the most fascinating group of organisms among the decapod crustaceans. Great importance is attached at present to the increased exploitation of these animals and therefore there is great scope for further development of their fishery. They have a broad and hard carapace, massive chelate legs, bent abdomen and exhibit high degree of adaptation to the environment. They show pelagic, benthic, intertidal, burrowing and terrestrial modes of life. Their commensal association with other invertebrates, their breeding behaviour and life history are of great interest to biologists. More than six hundred species of crabs are known to occur in Indian waters and among them about eight species form a regular fishery along the entire stretch of peninsular India (Rao §§_al., 1973) round the year. Crab fishery in India is fast developing and there is vast scope for them as there are many more potential species. Among the various crustacean diets, crabs are celebrated for deliciousness and for nutritional richness. In recent days, crab food items have become more popular and gained global reception. These resources can also be augmented further by culturing them in ponds in the future. Information on biology and ecology of constituent species go a long way not only in effective exploitation and regulation of the respective fishery resources but also helps in evolving a suitable gear for their capture. Information collected on the national level in various aspects as reproduction, growth rate, larval development, parasites, diseases, nutritive values etc. will be of help in evolving a national policy for the effective utilisation and conservation of this resource. They also provide the baseline information for undertaking any purposeful and meaningful culture activities. Information on the various aspects mentioned above is very much restricted in true crabs and hence the present study

MYZOBDELLA PLATENSIS (HIRUNDINIDA: PISCICOLIDAE) IS TRUE PARASITE of BLUE CRABS (CRUSTACEA: PORTUNIDAE)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ecological aspects of hermit crabs (Crustacea, Anomura, Paguroidea) off the northern coast of São Paulo State, Brazil

The occurrence of species of hermit crabs and their ecological distribution in soft bottoms off Ubatuba, São Paulo, Brazil were analyzed. To better understand the distribution of the species in relation to environmental factors, the similarity and species-diversity indexes were calculated. Paguroideans were sampled monthly from January through December 2000. The trawls were made with two otter-trawl nets at 13 different sites, at depths of 2-40 m. Water temperature, salinity, sediment texture, and organic matter content were measured. Gastropod shells occupied by hermit crabs were also assessed. A total of 1,238 specimens was collected, belonging to the families Diogenidae and Paguridae, comprising seven genera and thirteen species. The most abundant hermit crab species were Dardanus insignis (761 specimens) and Loxopagurus loxochelis (351 specimens). Phimochirus holthuisi is newly reported from the São Paulo coast. The highest diversity index was found for the shallower sites near rocky shores. The results of the grouping analysis for sites and species indicated three distinct groups for sites, and four groups for species. This suggests that the occurrence of these anomurans is associated with the environmental and biotic factors analyzed.

Biodiversity of brachyuran crabs (Crustacea : Decapoda) from non-consolidated sublittoral bottom on the northern coast of São Paulo State, Brazil

The brachyuran community of the coast of São Paulo State is represented by about 188 species of crabs inhabiting different kinds of coastal marine environments. The biodiversity of brachyurans found on non-consolidated sublittoral bottom was investigated. The Ubatuba region (Ubatumirim, Ubatuba and Mar Virado bays, Couves and Mar Virado Islands, offshore region) was sampled for 3 years (1998-2000), at depths of 2-40 m. All sampling was performed using a fishing boat equipped with two double-rig nets. We collected 79 brachyuran species representing 9 superfamilies (4 Dromioidea, 1 Homoloidea, 2 Calappoidea, 5 Leucosioidea, 20 Majoidea, 7 Parthenopoidea, 17 Portunoidea, 18 Xanthoidea, and 5 Pinnotheroidea) and 41 genera. Ubatuba bay showed the greatest species richness with 50 species, followed by Ubatumirim with 45 and Mar Virado with 29. The number of species collected represents about 57% of the known species of crabs already reported for the shore of São Paulo State. It is worth noticing that this percentage is restricted only to non-consolidated sublittoral bottom. This fact indicates a great biodiversity of the habitat in this studied region, probably one to the diversity of habitat types present in the bays.

Checklist of the brachyuran crabs (Crustacea: Decapoda) in the rocky subtidal of Vitoria Archipelago, southeast coast of Brazil.

Biodiversity can be useful as an ecosystem indicator for conservation and monitoring, through continuous assessment of its main properties including stability, primary productivity, exploitation tolerance and even global environmental changes. The main purpose of this study was to provide a checklist of the crabs associated with subtidal rocky bottoms at the Vitoria Archipelago, southeastern Brazilian coast. Monthly collections were carried out from February 2004 through January 2006 on three islands at the Vitoria Archipelago (23[degree]44'S-45[degree]01'W). The crabs were hand-caught by SCUBA divers during the daytime, in rock subtidal. A total of 3084 individuals were caught, belonging to 42 species, 28 genera, and 12 families, highlighting Mithraculus forceps (1528) and Stenorhynchus seticornis (407) representing more than 60% of the sample. on the other hand, Dromia erythropus, Moreiradromia antilensis, Ebalia stimpsoni, Garthiope spinipes and Tumidotheres maculatus had only one individual sampled.

New records of Fredius denticulatus (H. Milne-Edwards, 1853) and F. reflexifrons (Ortmann, 1897), and the eastern limits of the distribution of pseudothelphusid crabs (Crustacea: Decapoda) in Brazil

É registrada pela primeira vez a ocorrência de Fredius reflexifrons (Ortmann, 1897), um caranguejo da família Pseudothelphusidae de ampla distribuição na Amazônia e nas Guianas, no estado do Ceará, Nordeste do Brazil. São feitos registros adicionais de dessa espécie e de Fredius denticulatus (H. Milne-Edwards, 1853) para a região amazônica. É feita uma discussão sobre os limites orientais da distribuição da família Pseudothelphusidae no Brasil.

Illustrated key for the identification of the known zoeal stages of brachyuran crabs (Crustacea: Decapoda) from tropical and subtropical Brazil, southwestern Atlantic

Approximately 370 brachyuran species have so far been recorded from the Brazilian coast, 123 of which have had their larval stages fully or partially described. The pictorial guide allows the identification of the first zoea of 110 species. The remaining 13 species with known larval stages are treated to the genus level because of difficulties in the morphological differentiation of closely related species.

A review of the genus Speocarcinus Stimpson, 1859 (Crustacea: Brachyura: Xanthidae), with a key to its species and the description of one new species

Speocarcinus dentatus n. sp. is described from the southwestern Atlantic. The new species can be easily separated from its congeners by a suite of carapace and appendage characters. Speocarcinus Stimpson, 1859, now includes eight extant species, all from the Atlantic or Pacific coasts of the Americas. Additional characters to further differentiate between S. carolinensis Stimpson, 1859, and S. lobatus Guinot, 1969, and between S. granulimanus Rathbun, 1894, and S. spinicarpus Guinot, 1969 are documented. The lectotype of S. granulimanus is first described and a key to the species of Speocarcinus is provided.

Variabilidade populacional em manguezais: análises moleculares e morfológicas em caranguejos Brachyura (Crustacea: Decapoda)

A análise da estruturação populacional de espécies codistribuídas permite a comparação de padrões de estruturação, fornecendo informações acerca dos fatores que influenciam a diferenciação em espécies pertencentes ao mesmo ecossistema. Este projeto teve como objetivo principal analisar a variabilidade intraespecífica em caranguejos habitantes de manguezais, codistribuídos ao longo do Oceano Atlântico Ocidental, por meio de ferramentas moleculares e morfológicas, visando testar a hipótese de elevada estruturação populacional em manguezais. Para este fim, cinco espécies foram utilizadas como modelo (Aratus pisonii, Goniopsis cruentata, Sesarma rectum, Uca thayeri e Ucides cordatus) e avaliadas por meio de marcadores mitocondriais COI e 16S e nuclear H3 e análises morfológicas comparativas e de morfometria. Os dados moleculares revelaram dois padrões, indicando elevada estruturação populacional para as espécies A. pisonii e U. thayeri e ausência de estruturação para G. cruentata, S. rectum e U. cordatus. Os dados morfológicos, no entanto, não acompanham esses padrões, já que não foram encontradas diferenças morfológicas ou morfométricas associadas aos grupos evidenciados pelas análises moleculares. A ausência de fluxo gênico entre regiões para algumas espécies deve-se, muito provavelmente, à existência de fatores que não se limitam ao isolamento por distância, mas também devido a diferenças na duração do estágio larval e a diferenças bruscas em alguns fatores abióticos, como a salinidade, por exemplo, que, associados às diferentes características do desenvolvimento larval de cada espécie, culminam na existência de estruturas populacionais diferentes. Além disso, os padrões de diferenciação genética observados concordam com os cenários biogeográficos propostos para o Atlântico Ocidental, no qual mudanças e flutuações geológicas, climáticas e oceanográficas, resultantes do fechamento do Istmo do Panamá e de ciclos glaciais na América do Norte, promoveram divergência genética.

Brachyuran community in Ubatuba Bay, northern coast of São Paulo State, Brazil

A bruchyuran crab assemblage from eight transacts at a non-consolidated sublittoral site in Ubatuba Bay was studied on a monthly basis from September 1995 to August 1996. Data about number of individuals of 50 species found and other information such as distribution of the dominant crabs are reported. The family Majidae was represented by 13 species, followed by Xanthidae (13), Portunidae (10), Leucosiidae (5), Calaphidae (2), Dromiidae (2), Parthenopidae (2), Goneplacidae (1), Pinnotharidne (1), and Ocvpodidae (1). The brachyuran taxocoenosis was dominated by Callinectes ornatus (60.4%), Callinectes danae (18.8%), and Hepatus pudibundus (7.7%). representing together 86.9% of the total number of collected brachyurans. The Shannon-Weaver diversity index ranged from 1.10 to 2.06 between transects, and from 1.33 to 2.22 between months, depending more on equitability than on richness.

On two species of euxanthine crabs from the South China Sea, including a description of a new species of Crosnierius (Crustacea : Decapoda : Brachyura : Xanthidae)

A new species of the previously monotypic xanthid genus Crosnierius Serene & Vadon, 1981 is described from the South China Sea. The species differs from Crosnierius carinatus Serene & Vadon, 1981 in the structure of the anterolateral teeth, ambulatory leg proportions and form of the male first pleopod. Paramedaeus planifrons (Sakai, 1965) is also reported from the South China Sea, the first record of the species outside its type locality of Japan.

On two species of spider crabs of the genus Doclea (Crustacea : Decapoda : Brachyura : Majidae : Pisinae) from China, one of which is new

A new species of spider crab, Doclea unidentata, is described from the South China Sea. Allied to D. brachyrhynchos Bleeker, 1856, and D. macracanthus Bleeker, 1856, it can easily be distinguished by its very short, unidentate rostrum. The identity of Doclea canalifera Stimpson, 1857, is resolved with the selection of a neotype, and it is here regarded as a senior subjective synonym of D. japonica Ortmann, 1893. The taxonomy of this species as well as the allied D. ovis (Fabricius, 1787) is also discussed.