Observações taxonômicas sobre os Decápodos fósseis do Cretáceo da Chapada do Araripe, Brasil, e inferências ecológicas

Beurlenia araripensis Martins-Neto and Mezzalira, 1991 (Decapoda: Caridea) and Paleomattea deliciosa Maisey and Carvalho, 1995 (Decapoda: Penaeoidea) are reviser baseated upon new and better preserved samples. The new specimens were found in the Santana Formation, Araripe Basin, Northeast Brazil, respectively in the Crato and Romualdo members. B. araripensis is represented by a well preserved specimen, where is possible to see a cephalothorax with antennal and branchiostegal spines, rostrum with 14 dorsal spines, and telson with posterior spines. This material permits a better characterization of the species’ morphology and its placement in Palaemonidae. The Dendrobranchiata material of P. deliciosa, found in the bituminous shale of Romualdo Member, is for the fi rst time recorded in clusters of fragmentary parts that suggest mass mortality and morphologies that point to a planktonic lifestyle, as occurs with extant forms of sergestids. Key words: Crustacea, Palaemonidae, Sergestoidea, Lower Cretaceous, Santana Formation, Brazil.Restos fósseis de camarões da Formação Santana, Chapada do Araripe, Cretáceo Inferior, referentes à Beurlenia araripensis Martins-Neto e Mezzalira, 1991 (Decapoda: Caridea) e Paleomattea deliciosa Maisey e Carvalho, 1995 (Decapoda: Penaeoidea) são revisados e novos materiais referidos. O primeiro deles se refere a um exemplar bem preservado de B. araripensis, proveniente dos calcáreos laminados do Membro Crato e que, pela presença de um cefalotórax com espinhos antenais e branquiostegais, rostro com 14 espinhos dorsais, e télson com espinhos posteriores, permite sua melhor caracterização e a proposta de sua inclusão na família Palaemonidae. O material adicional refere-se a um grande número de espécimes de sergestídeos (Penaeoidea) registrados nas camadas de xisto betuminoso no Membro Romualdo e referentes à Paleomattea deliciosa (Dendrobranchiata). Os agrupamentos, além de sugerirem mortalidade em massa, exibem morfologias que caracterizam um hábito de vida planctônico, similar aos sergestídeos modernos. Palavras-chave: Crustacea, Palaemonidae, Sergestoidea, Cretáceo Inferior, Formação Santana, Brasil

Estudo da morfologia funcional reprodutiva e desenvolvimento larval em laboratório de Stenopus hispidus(Olivier, 1811) (Crustacea, Decapoda, Stenopodidea)

A hipótese de que a deposição espermática e a fecundação no camarão Stenopus hispidus ocorrem externamente ao corpo foram testadas, baseando-se no comportamento reprodutivo em laboratório e na anatomia reprodutiva. Para isso, 12 casais adultos foram mantidos em aquários interligados, em salinidade 35%o, temperatura 26°C, fotoperíodo 12 horas e alimentados com ração industrializada para peixes. 0 comportamento reprodutivo foi filmado e fêmeas recém-copuladas tiveram os esternos analisados. Posteriormente, os casais foram anestesiados e dissecados para a descrição da forma e localização das gônadas e pleópodos. O aparelho reprodutivo (AR) de ambos os sexos, esternos, genitálias e primeiro pleópodo também foram preparados e fotografados em microscopia eletrônica de varredura. A cópula ocorre quando a fêmea está em pós-muda, e espermatozóides puderam ser observados em seus esternos somente fazendo-se um esfregaço em lâmina. Apenas o primeiro pleópodo e masculino parece estar envolvido na cópula, já que é diferenciado dos demais. 0 AR masculino é reduzido e restrito à carapaça, com testículos lobulados e vasos deferentes não enovelados, abrindo-se na base do 5° pereiópodo. 0 AR feminino é bem desenvolvido, com o ovário ocupando grande parte da carapaça e alcançando até o terceiro somito abdominal; os ovidutos são curtos e sem estrutura aparente para estocagem de espermatozóides. As fendas genitais femininas se abrem na base do terceiro par de pereiópodos e são circundadas por cerdas plumosas, comuns também nos esternitos torácicos. Assim, o macho deposita uma massa espermática simples na região ventral da fêmea, e a fecundação ocorre no momenta da exteriorização dos oócitos madurosReproductive morphology and sperm transfer in Stenopus hispidus (Olivier, 11) (Crustacea, Decapoda, Stenopodidae). The hypothesis that the deposition of sperm and fertilization in the shrimp Stenopus hispidus occurs externally of the body were tested, based on reproductive behavior in the laboratory and reproductive anatomy. For this, 12 adult pairs were kept isolated on interconnected aquaria with salinity 35%o, temperature 26°C, photoperiod 12 hours and daily fed with ornamental fish food. The reproductive behavior was taken with video camera and females had the sternum analyzed after mate. After that, the shrimps were anesthetized and dissected to describe the shape and location of the gonads and pleopods morphology. The reproductive systems (RS), sternum, first pleopods and genitalia were prepared and photographed by scanning electron microscopy. The mating occurs when the female was in pos-molt, and spermatozoa were seen in their sternum only by microscope slide smear preparation. Only the first male pleopod seems to be involved in the mating, since it is different from the others. The male RS is reduced and restricted to the carapace, with lobulated testis and vas deferens not convolute, opening in the 5th pereiopod basis. The female RS is well developed, with the ovary occupying much of the carapace and reaching the third abdominal segment; the oviduct is short and without apparent structure for sperm storage. The female genitalia open at third pereiopod basis and are surrounded by dense plumose setae, common also in the sternites. Thus, the male deposits a simple spermatophoric mass in the ventral region of the female and the fertilization occurs at the moment of the mature oocytes exteriorizationCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

The first record of external abnormalities in the subterranean Aegla marginata Bond-Buckup & Buckup, 1994 (Crustacea: Decapoda: Aeglidae), from a karst area of Southeastern Brazil

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Population biology of the burrowing crab Neohelice granulata, (Crustacea: Decapoda: Varunidae) from a tropical mangrove in Brazil

The population biology of the burrowing crab Neohelice granulata (Dana, 1851) from a mangrove in Jabaquara Beach, Paraty, state of Rio de Janeiro, Brazil (23º13'04"S and 44º42'47"W), was studied with respect to the following traits: size-frequency distribution, recruitment, reproductive period, fecundity, and sex ratio. Specimens were sampled monthly from April, 2003 to March, 2004, at the river margins during low tide periods. Size, sex, presence of eggs, and stage of the female gonad were recorded. Ovigerous females had their eggs removed and counted. The reproductive period was continuous and the highest frequency of ovigerous females was recorded in the fall and winter. Mature gonads were found throughout the year and recruitment was continuous but more intense during the summer. The fecundity of N. granulata (30028.3 ± 10861.2 eggs) was high in comparison to studies in other localities. In general, the proportion of males was similar to that of females (1:0.92); however, males were predominant in the fall (1:0.77) and winter (1:0.75). All the information available so far on the reproduction of N. granulata involves populations from subtropical salt marshes; therefore, comparative studies including other habitats, such as mangrove forests, are needed to further understand the environmental influences on the population and reproductive biology of semiterrestrial crabs

Relative growth and morphological sexual maturity of Chasmagnathus granulatus (Crustacea, Varunidae) from a mangrove area in southeastern Brazilian coast

The relative growth and morphological sexual maturity of Chasmagnathus granulatus Dana, 1851 are presented for the first time to a mangrove population. The crabs were obtained during low tide periods, in the mangrove of Jabaquara Beach, Paraty, Rio de Janeiro, Brazil. All crabs in intermolt stage were sexed and had their body parts measured as follows: body height (BH), carapace length (CL) and width (CW), major cheliped propodus height (PH) and length (PL) for each sex, gonopod length (GL) and abdomen width (AW) for males and females, respectively. The relative growth was described using the allometric equation y=ax b and the size at onset sexual maturity was achieved using the software Mature I. The size of specimens ranged from 4.1 mm to 39.5 mm CW. The growth pattern was different between sexes in the cheliped relationships; the relationships BH vs. CW evidenced positive allometry for juveniles; PL vs. CW and PH vs. CW positive allometry for most crabs except juvenile females; AW vs. CW and GL vs. CW evidenced positive allometry for juveniles and isometry for adults. The relationships that best indicated the change from the juvenile to the adult phase were PH vs. CW for males and AW vs. CW for females. The size in which 50% of males from this population are mature is at 19.7 mm of CW (F=144.14; p<0.05) and for females it is at 19.2 mm of CW (F=166.54; p<0.05). The sizes obtained in this mangrove population are larger than those from previous studies, that could be attributed to a species plasticity concerning the habitat structure

Distribution of Neohelice granulata (Dana 1851) in its northernmost latitudinal occurrence in a tropical mangrove forest, Brazil (Crustacea, Decapoda, Brachyura, Grapsoidea, Varunidae).

Neohelice granulata ecological distribution was evaluated in its northernmost latitudinal occurrence in a Brazilian tropical mangrove (23[degree]13'4" S, 44[degree]42'47" W). Samples were collected in three sites along the main river in the mangrove. Crabs were manually captured by two people, 15 min each, at low tide periods. The sex of the animals was assessed and carapace width measured. The size-frequency distribution was determined in each site. Environmental factors (salinity, temperature, organic matter and sediment texture) were analyzed, compared among sites and related to crab abundance and size in each site. Crab abundance decreased with the distance from the sea. Juvenile crabs were more frequent next to the sea, whereas larger and ovigerous ones were mainly found in the most distant site. Crab size was proportional to the organic matter percentage in the sediment. N. granulata spatial distribution varies along the river course, which is probably related to the most productive areas that have more nutrients available; this may also occur in order to prevent intraspecific competition