Two new species of Diaptomidae (Crustacea: Copepoda: Calanoida) from the Neotropical Region (Paraná River)

Two new species of Diaptomidae were found in the Middle Paraná River. The new species are referred to as Diaptomus curvatus sp. nov. and Diaptomus frutosae sp. nov. Important character states in Diaptomus curvatus include: right fifth leg with a well-developed endopod and with the lateral spine of the second exopod segment curved and longer than the segment on which it is inserted, plus the presence of a large dorsal process on urosomite 4 of the male. For Diaptomus frutosae they include: a differentiated hook-like process on segment 20 with chitinous protuberances at base of male right antennule; the last segment of the right leg 5 of male is triangular, and the lateral spine inserted distal to mid-level of this segment. Both species are placed in Diaptomus sensu lato as a temporary placement. http://www.zoobank.org/urn:lsid:zoobank.org:pub:FECDD6C4-C0AC-4043-ADDD-F29539B451F0. © 2013 Copyright Taylor and Francis Group, LLC.

Morphological diversity of setae on the second maxilliped of fiddler crabs (Decapoda: Ocypodidae) from the southwestern Atlantic coast

Fiddler crabs are deposit feeders, and use the setae on their mouth appendages to manipulate sediment particles to extract food. The number of spoon-tipped setae on the second maxilliped is frequently related to the distribution of fiddler crabs on estuarine sediments, but no study has compared the morphological diversity of these setae among multiple fiddler crab species. Here, we describe and classify the setae of the second maxillipeds of the nine Uca spp. known from the Brazilian coast. The second maxilliped of each species was examined by scanning electron microscopy. Six types of setae (five papposerrate, and one pappose) were described on the meropodite of the second maxilliped. Among the papposerrate setae, one type had a spoon-like tip, and the morphology of this type, especially the degree of curvature, differed between species. Members of Uca leptodactylus, U. uruguayensis, and U. maracoani had highly concave spoon-tipped setae. In U. rapax and U. cumulanta, the setal tip was moderately curved, while in U. thayeri, U. burgersi, and U. mordax, this curvature was slight. At the other extreme, the meropodite of the second maxilliped of U. vocator lacked setae altogether. This is the first study that describes differences in the degree of curvature of spoon-tipped setae in fiddler crabs. This trait may be strongly related to the distribution of these fiddler crabs on different estuarine substrates. © 2012, The American Microscopical Society, Inc.

Brachyuran and anomuran crabs associated with Schizoporella unicornis (Ectoprocta, Cheilostomata) from southeastern Brazil

The main goals of this investigation were to describe the community structure of anomuran and brachyuran crabs inhabiting reefs constituted by colonies of Schizoporella unicornis, and to provide a species importance ranking for this community. Collections were carried out on S. unicornis reefs at two-month intervals from May 2003 to May 2004, in the rocky sublittoral of the southeastern Brazilian coast. Relative abundance and occurrence were used to rank these species in the hierarchy importance. A total of 2,018 individuals were obtained, in 11 families, 22 genera and 31 species. Porcellanidae and Pilumnidae were the most abundant families, comprising respectively almost 60% and 15% of individuals sampled. The species ranking indicated four main groups A, B, C and D, with group A subdivided. Subgroup A1 contained 9 species, including the species of greatest ecological importance for community regarding abundance and occurrence. The great abundance of crabs associated with S. unicornis seems to be the result of its recognized importance during the crab developmental cycle, and as shelter and food for some Decapod species. These observations reveal the importance of conserving the areas occupied by these reef colonies, which appear to be an important environment for maintaining local biodiversity.

The ovarian cycle histochemistry and its relationship with hepatopancreas weight in the blue crab Callinectes danae (Crustacea: Portunidae)

Zara, F.J., Gaeta, H.H., Costa, T.M., Toyama, M.H. and Caetano, F.H. 2011. The ovarian cycle histochemistry and its relationship with hepatopancreas weight in the blue crab Callinectes danae (Crustacea: Portunidae). -Acta Zoologica (Stockholm) 00:1-13. Several studies use macroscopic patterns of the ovarian development in crustaceans. Here, we examined the relationship between ovary histochemistry, changes in gonadosomatic and hepatosomatic indices against the macroscopic pattern of the ovarian development in Callinectes danae. Animals were collected in the south coast of São Paulo State, Brazil. Ovaries were macroscopically classified as juvenile, rudimentary, developing, intermediary, mature, and rudimentary ovigerous. Samples were fixed in 4% paraformaldehyde, processed for historesin, and stained with HE, protein, and neutral and acid polysaccharides detection. The juvenile oocytes are not enclosed by follicular cells and have fewer yolk nuclei being less intense in PAS reactivity than rudimentary oocytes. Developing oocytes show yolk granules and thick follicular cells. Yolk granules were positive for proteins and neutral polysaccharides. The intermediary stage is marked by a qualitative increase in yolk granules and the onset of chorion formation. In mature oocytes, cytoplasm is completely filled by yolk granules and the chorion is completely formed. Ovigerous ovaries have several atretic follicles and large quantities of hemocytes in the process of tissue reorganization. In C. danae, the changes in cell, goandosomatic and hepatosomatic indices coinciding with macroscopic observations and any combination of different macroscopic stages in a single pattern should be avoided. © 2011 The Royal Swedish Academy of Sciences.

Ultrastructure of the spermatophores and spermatozoa from the gecarcinid land crab, Cardisoma guanhumi Latreille, 1828, (Crustacea, Brachyura, Gecarcinidae) from the western Atlantic

The ultrastructure of the sperm of the gecarcinid land crab Cardisoma guanhumi is described by scanning and transmission electron microscopy. Ultrastructural sperm morphology lends support for the monophyletic origin of the Thoracotremata, and for the placement of C. guanhumi in that clade. Additionally, it further attests the low level of variability within the thoracotreme clade. With regard to ultrastructural morphology, small differences concerning the apical button, the hyaline periopercular rim, the inner acrosome zone, and the outer two lamellations in the outer acrosome zone have been found between the spermatozoa of C. guanhumi and Cardisoma carnifex, the only other species in this genus studied for spermatozoal morphology. Copyright © 2013 Taylor & Francis.

Onset of sexual maturity and relative growth of the freshwater crab Trichodactylus fluviatilis (Trichodactyloidea) in south-eastern Brazil

The main purpose of this study was to provide an estimate for the onset of morphological sexual maturity in the freshwater crab Trichodactylus fluviatilis, from a population located in south-eastern Brazil, based on the relative growth relationships, as well as the characterization of ''handedness''. Monthly collections were carried out at night, from January 2006 to January 2007, in a small water body. In the laboratory, the crabs were sexed; the following body structures were measured and the estimate of onset of sexual maturity was given by the logistic function, as y a/(1\+becx), for 50% of the population to reach the adult phase (CW50carapace width). Right propodus length and abdomen width were the best-fit relationships to represent the onset of sexual maturity for males and females, respectively. Based on the logistic function, the onset of sexual maturity was estimated to occur at around 18mm CW for both sexes. The relative growth recorded for this species is consistent with the model for brachyuran crabs (Hartnoll RG. 1982, Growth. In: Bliss, DE, editor. The biology of Crustacea: embryology, morphology and genetics. New York: Academic Press. p. 111-196), except for the abdomen growth, which is likely to be an adaptive condition related to protection of the newly hatched young. © 2013 Taylor & Francis.

Relative growth and reproduction in Achelous spinicarpus (Crustacea: Portunidae) on the south-eastern continental shelf of Brazil

This investigation aimed to study the relative growth, morphological sexual maturity and fecundity of the swimming crab Achelous spinicarpus in a tropical region, on the south-eastern continental shelf of Brazil (25°S). Biometry of all specimens was conducted, including measurements of the cephalothorax, cheliped, abdomen and gonopods. Relative growth was described based on the equation for allometry (y = axb), and size at sexual maturity was determined from inflections in relations involving the cheliped, gonopods (males), and abdomen (females), as dependent variables, related to the cephalothorax width (independent variable). Fecundity was estimated by the gravimetric method. The relations of the length of the chelar propodus and carpal spine to the carapace width without the lateral spines (CW) showed positive allometry in both sexes, with a significant variation in the constant 'b' for males between the developmental stages (juvenile and adult) and the size at maturity estimated at 37 mm CW. In females, the abdomen was most appropriate for the estimate of morphological maturity, which occurred at a smaller size (32 mm CW), with a change in the growth pattern between the stages, passing from isometric (juveniles) to positive allometric (adults). The gonopods also showed different growth rates between developmental stages, in synchrony with the variables of the cheliped. Mean fecundity for the species was 53,984 eggs, with a positive correlation between the number of eggs exteriorized and the size of the female; the equations allowed interconversion between these variables, due to the adjustment of the power function (r2 ≥ 86%). © 2012 Marine Biological Association of the United Kingdom.

Distribution related to temperature and salinity of the shrimps Acetes americanus and Peisos petrunkevitchi (Crustacea: Sergestoidea) in the south-eastern Brazilian littoral zone

The abundance and ecological distribution of Acetes americanus and Peisos petrunkevitchi were investigated from July 2006 to June 2007, in Ubatuba, Brazil. Eight transects were identified and sampled monthly: six of these transects were located in Ubatuba bay, with depths reaching 21 m, and the other two transects were in estuarine environments. A total of 33,888 A. americanus shrimp were captured, with the majority coming from the shallower transects (up to 10 m). Conversely, 6,173 of the P. petrunkevitchi shrimps were captured in deeper areas (from 9 to 21 m). No individuals from either species were found in the estuary. The highest abundances obtained for both species were sampled during the summer. Canonical correlation analysis resulted in a coefficient value of 0.68 (P = 0.00). The abundance of both species was strongly correlated with depth. Variations in temperature and salinity values were also informative in predicting the seasonal presence of P. petrunkevitchi in deeper areas and A. americanus in the shallower areas of the bay. It is conceivable that the shrimp adjust their ecological distribution according to their intrinsic physiological limitations. © 2012 Marine Biological Association of the United Kingdom.

Comparison of body size, relative growth and size at onset sexual maturity of Uca uruguayensis (Crustacea: Decapoda: Ocypodidae) from different latitudes in the south-western Atlantic

Some crustaceans show variations of their reproductive biology within their geographical distribution, and knowledge about such variations is important for the comprehension of their reproductive adaptations. This study compared two populations of the fiddler crab Uca uruguayensis from two locations on the south-western Atlantic coast: Ubatuba Bay, São Paulo, Brazil and Samborombón Bay, Buenos Aires, Argentina. The population features analysed were the body size variation (carapace width = CW) and the size at the onset of sexual maturity (SOM) in order to test the hypothesis that the size at SOM, should be the same in relative terms (RSOM), independently of the latitudinal position. In the Brazilian population the CW ranged from 4.18 to 11.60 mm for males and 3.90 to 9.80 mm for females, and in the Argentinean population from 3.60 to 14.10 mm for males and 2.85 to 12.00 mm for females. In the Brazilian population the SOM was 7.1 (RSOM = 0.58) and 5.9 mm CW (RSOM = 0.57) for males and females, respectively, and in the Argentinean population it was 7.0 (RSOM = 0.42) and 6.75 mm CW (RSOM = 0.53) for males and females, respectively. This fact is probably related to a great plasticity in the life history features of Uca uruguayensis under different environmental conditions. © 2012 Marine Biological Association of the United Kingdom.

Conchostráceos Palaeolimnadiopsis (Spinicaudata, Crustacea) do grupo Bauru (cretáceo superior, bacia Bauru): Taxonomia, paleoecologia e paleobiogeografia

The present study presents a taxonomic review of Palaeolimnadiopsis suarezi Mezzalira described in Bauru Group. The geographic and stratigraphic distribution of the genus Palaeolimnadiopsis is widespread, including occurrences in several countries as Brazil, Bolivia, Chile, Uruguay, USA, Congo, China, Australia, Tasmania, Russia, Germany, Scottland, France and Belgium, in rocks from the Devonian to the Cretaceous. This taxon was probably eurytopic, with a high dispersal potential and very conservative in evolution. One specimen identified as Palaeolimnadiopsis sp. is much larger than the average (~3.5 cm long), presenting relatively wide and few growth bands. The gigantism of this specie may be related to conditions that excluded potential predators and competitors from the environment, as is indicated by the presence of more saline and/or alkaline water conditions than in normal fresh water suggested a relatively high proportion of carbonates in that region and stratigraphic interval. © 2013 by the Sociedade Brasileira de Paleontologia.

Mangrove habitat partitioning by Ucides cordatus (Ucididae): Effects of the degree of tidal flooding and tree-species composition during its life cycle

Environmental factors strongly affect mangrove crabs, and some factors modulate population structure and habitat partitioning during the crabs' life cycle. However, the effect of these environmental factors on habitat selection by mangrove crabs is still unknown. We evaluated habitat selection by the mangrove crab Ucides cordatus in mangrove forests with different degrees of predominance of Rhizophora mangle, Laguncularia racemosa or Avicennia schaueriana, two tidal flooding levels (less- and more-flooded), and two biological periods (breeding and non-breeding seasons). Sampling was conducted in four mangrove forests with different influences of these biotic and abiotic parameters. We used the data for sex ratio to explain environmental partitioning by this species. Females predominated in R. mangle mangroves, independently of the biological period (breeding or non-breeding seasons), and males predominated only in the less-flooded L. racemosa mangroves. The flooding level affected the sex ratio of U. cordatus, with a predominance of males in less-flooded mangroves, independently of the biological period; and a gender balance in the more-flooded mangroves only during the breeding season. Outside the breeding season, the largest specimens were recorded in the R. mangle mangroves, but in the breeding season, the largest crabs were recorded in the L. racemosa mangroves with a higher level of flooding. These results suggest that tree-species composition and tidal flooding level can have a significant effect on the habitat partitioning of sexes and sizes of the mangrove crab U. cordatus both during and outside the breeding season. © 2012 Springer-Verlag and AWI.

Morphology of the female genital ducts of the blue land crab Cardisoma guanhumi (Crustacea: Brachyura: Gecarcinidae)

This is a histological and histochemical analysis of the terminal portion of the female reproductive system and genital ducts of the blue land crab (Cardisoma guanhumi). Animals were collected in the Jaguaribe estuary (Ceará, Brazil) and dissected. Genital duct fragments were fixed and submitted to different staining techniques. The female reproductive system consists of a pair of ovaries and a pair of genital ducts. In the mid-posterior portion of each lobe, the ovaries communicate with the genital ducts, which are subdivided into oviduct, spermatheca, vagina, and gonopore. Histologically, the spermatheca of C. guanhumi is composed of columnar secretory epithelium and is divided into a dorsal zone and a ventral zone, the latter covered internally by a cuticle layer. Both zones are enveloped by a thin layer of loose connective tissue. Histological cross sections revealed the vagina to be concave, a pattern considered phylogenetically more advanced than the simple, tubular form. Our findings suggest fertilization is internal, favoring sperm from the most recent copulation. © 2012 The Authors. Acta Zoologica © 2012 The Royal Swedish Academy of Sciences.

Desenvolvimento embrionário do camarão-da-amazônia Macrobrachium amazonicum (Heller, 1862) (Crustacea, Decapoda, Palaemonidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da alimentação e densidade de estocagem no desempenho zootécnico e perfil celular do hepatopâncreas do camarão-da-amazônia Macrobrachium amazonicum (Heller, 1862) (Crustacea, Palaemonidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização do ciclo da vitelogênese do camarão de água doce Macrobrachium olfersi (Wiegmann, 1836) (Crustacea, Decapoda, Palaemonidae)

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC