A new species of Catapagurus A. Milne-Edwards (Crustacea: Decapoda: Anomura: Paguridae) from Brazil, with a key to the western Atlantic species

We describe herein a new species of Catapagurus, the twenty-second species of the genus. This is the third species of Catapagurus recorded from the western Atlantic and the second from Brazil; the remaining 19 species occur in the Indo-Pacific region.

Composition and Seasonal Variation of Brachyura and Anomura (Crustacea, Decapoda) Associated with Brown Mussel Farms at Praia da Cocanha, Brazil

The composition and seasonal variation of brachyuran and anomuran species associated with mussel farms were evaluated at Praia da Cocanha, Sao Paulo between May 2007 and February 2008. Nine mussel ropes were sampled at random in each quarter, and 1,208 organisms were identified, comprising five families and 28 species. The most numerous species was the porcellanid Pachycheles laevidactylus (18.5%), followed by the xanthids Acantholobulus schmitti (16.6%), Hexapanopeus paulensis (11.3%), Panopeus americanus (10.2%), and Menippe nodifrons (8.4%). The exotic crab Charybdis hellerii was recorded throughout the study period. The ecological descriptors, except Pielou evenness index, varied significantly over the time. The highest abundance and diversity of the species were recorded during November and February. This pattern was reversed for Berger-Parker dominance, with the lowest values recorded in February. The development of epifauna was correlated with the different stages of the mussel farms, since the mean size of mussels and consequently the abundance of epibiotic organisms and the structural complexity on the mussel ropes increased from May (seeding) until February (harvest). Despite this, the temporal population variations in recruitment patterns of the different epibionts should not be overlooked. The results indicated that the mussel farms provided favorable conditions for the development of these crustacean groups, which could be used in environmental monitoring programs and / or be exploited for the aquarium trade.

Composition and seasonal variation of brachyura and anomura (Crustacea, Decapoda) associated with brown mussel farms at Praia da Cocanha, Brazil

The composition and seasonal variation of brachyuran and anomuran species associated with mussel farms were evaluated at Praia da Cocanha, São Paulo between May 2007 and February 2008. Nine mussel ropes were sampled at random in each quarter, and 1,208 organisms were identified, comprising five families and 28 species. The most numerous species was the porcellanid Pachycheles laevidactylus (18.5%), followed by the xanthids Acantholobulus schmitti (16.6%), Hexapanopeus paulensis (11.3%), Panopeus americanus (10.2%), and Menippe nodifrons (8.4%). The exotic crab Charybdis hellerii was recorded throughout the study period. The ecological descriptors, except Pielou evenness index, varied significantly over the time. The highest abundance and diversity of the species were recorded during November and February. This pattern was reversed for Berger-Parker dominance, with the lowest values recorded in February. The development of epifauna was correlated with the different stages of the mussel farms, since the mean size of mussels and consequently the abundance of epibiotic organisms and the structural complexity on the mussel ropes increased from May (seeding) until February (harvest). Despite this, the temporal population variations in recruitment patterns of the different epibionts should not be overlooked. The results indicated that the mussel farms provided favorable conditions for the development of these crustacean groups, which could be used in environmental monitoring programs and / or be exploited for the aquarium trade.

Comparative analysis of shell occupation by two southern populations of the hermit crab Loxopagurus loxochelis (Decapoda, Diogenidae)

The present study aimed to comparatively verify the relation between the hermit crabs and the shells they use in two populations of Loxopagurus loxochelis. Samples were collected monthly from July 2002 to June 2003, at Caraguatatuba and Ubatuba Bay, São Paulo, Brazil. The animals sampled had their sex identified, were weighed and measured; their shells were identified, measured and weighed, and their internal volume determined. To relate the hermit crab's characteristics and the shells' variables, principal component analysis (PCA) and a regression tree were used. According to the PCA analysis, the three gastropod shells most frequently used by L. loxochelis varied in size. The regression tree successfully explained the relationship between the hermit crab's characteristics and the internal volume of the inhabited shell. It can be inferred that the relationship between the morphometry of an individual hermit crab and its shell is not straightforward and it is impossible to explain only on the basis of direct correlations between the body's and the shell's attributes. Several factors (such as the morphometry and the availability of the shell, environmental conditions and inter- and intraspecific competition) interact and seem to be taken into consideration by the hermit crabs when they choose a shell, resulting in the diversified pattern of shell occupancy shown here and elsewhere.

Temporal, diel and spatial variability of decapod larvae from St Paul`s Rocks, an equatorial oceanic island of Brazil

Temporal, spatial and diel variation in the distribution and abundance of organisms is an inherent property of ecological systems. The present study describes these variations and the composition of decapod larvae from the surface waters of St Paul`s Rocks. The expeditions to the archipelago were carried out in April, August and November 2003, March 2004 and May 2005. Surface plankton samples were collected during the morning and dusk periods, inside the inlet and in increasing distances around the archipelago (similar to 150, 700 and 1500 m). The identification resulted in 51 taxa. Seven species, six genera and larvae of the families Pandalidae and Portunidae were identified for the first time in the area. The mean larval density varied from zero to 150.2 +/- 69.6 individuals 100 m(-3) in the waters surrounding the archipelago and from 1.7 +/- 3.0 to 12,827 +/- 15,073 individuals 100 m(-3) inside the inlet. Significant differences on larval density were verified between months and period of the day, but not among the three sites around the archipelago. Cluster and non-metric multidimensional scaling analysis indicated that the decapod larvae community was divided into benthic and pelagic assemblages. Indicator species analysis (ISA) showed that six Brachyura taxa were good indicators for the inlet, while three sergestids were the main species from the waters around the archipelago. These results suggest that St Paul`s Rocks can be divided into two habitats, based on larval composition, density and diversity values: the inlet and the waters surrounding the archipelago.

Ontogenetic Variation in Ammonia Excretion during the Early Life Stages of the Amazon River Prawn, Macrobrachium amazonicum

Dry mass (DM) and total ammonia-N (TAN) excretion were determined in embryos, larvae (ZI-ZIX, Z = zoea ), and postlarvae (PL) at 1, 7, and 14 d after metamorphosis (PL1, PL7, and PL14) of Macrobrachium amazonicum. Animals in postmolt-intermolt (A-C) stages were sorted according to their developmental stages, and placed into incubation chambers (similar to 30 mL) for 2 h to quantify TAN excretion. After this period, analyses were carried out using Koroleff`s method for TAN determination. Individual TAN excretion generally increased throughout ontogenetic development and varied from 0.0090 +/- 0.0039 mu g TAN/individual/h in embryo to 1.041 +/- 0.249 mu g TAN/individual/h in PL14. There was no significant difference between embryo-ZIV and ZV-ZIX (P > 0.05), whereas PL1, PL7, and PL14 differed (P < 0.05) from each other. Higher increments in individual ammonia-N excretion were observed between ZIV-ZV, PL1-PL7, and PL7-PL14. Mass-specific excretion rates presented two groups, embryo-ZII (P > 0.05) and ZIII-PL14 (P > 0.05). The lowest value was found in embryo (0.17 +/- 0.07 mu g TAN/mg DM/h) and the maximum values in ZV and PL1 (0.65 +/- 0.25 and 0.64 +/- 0.27 mu g TAN/mg DM/h, respectively). Results indicate that metabolic rate is proportional to the body mass in M. amazonicum, during early life stages. Variations in ammonia excretion during this phase may be associated mainly with body size. Data obtained in the present study may be useful in developing and optimizing rearing techniques of M. amazonicum, such as the proportions between biofilter and rearing tank size, and stocking density in culture tanks or in transport bags.

Biometric relationships of the spotted lobster, Panulirus echinatus, from Tamandare coastal reefs, Pernambuco State, Brazil

Biometric relationships were recorded for 2431 male and female Panulirus echinatus sampled at Tamandare coastal reefs, Pernambuco, Brazil. The following body measurements were taken: carapace length and width, abdomen length and width, total length, third and fifth pereiopod length, cephalothorax-abdomen and total weight. Twelve relationships were studied to compare the biometric characteristics Of males and females. Eleven of them showed difference between the sexes. Comparing sexes with the same carapace length, males have a heavier cephalothorax and longer third and fifth pereiopods than females, whereas females are longer, wider, and have a heavier abdomen than males. For genders with the same total length, males are heavier and have a longer carapace than females, while females have a larger abdomen. For genders with the same abdomen length, males have a heavier abdomen than females. The relationships TWg/TL and A Wg/AL showed positive allometric growth for the males. All other relationships involving weight, presented negative allometric growth for both sexes.

Are the preference and selection patterns of hermit crabs for gastropod shells species- or site-specific?

Experimental analyses of hermit crabs and their preferences for shells are essential to understand the intrinsic relationship of the crabs` dependence on shells, and may be useful to explain their shell use pattern in nature. The aim of this study was to evaluate the effect of crab species and site on the pattern of shell use, selection, and preference in the south-western Atlantic hermit crabs Pagurus brevidactylus and Pagurus criniticornis, comparing sympatric and allopatric populations. Differently from the traditional approach to evaluate shell preference by simply determining the shell selection pattern (i.e., the number of shells of each type selected), preference was defined (according to [Liszka, D., Underwood, AJ., 1990. An experimental design to determine preferences for gastropod shells by a hermit-crab. J. Exp. Mar. Biol. Ecol., 137(1), 47-62]) by the comparison of the number of crabs changing for a particular shell type when three options were given (Cerithium atratum, Morula nodulosa, and Tegula viridula) with the number of crabs changing for this same type when only this type was offered. The effect of crab species was tested at Cabelo Gordo Beach, where P. brevidacrylus was found occupying shells of C. atratum, M. nodulosa, and T viridula in similar frequencies, whereas P. criniticornis occupied predominantly shells of C atratum. In laboratory experiments the selection patterns of the two hermit-crab species for these three gastropods were different, with P criniticornis selecting mainly shells of C atratum, and R brevidactylus selecting more shells of M. nodulosa. The shell preference was also dependent on crab species, with P. criniticornis showing a clear preference for shells of C atratum, whereas P. brevidactylus did not show a preference for any of the tested shells. The effect of site was tested for the two species comparing data from Cabelo Gordo to Preta (P brevidactylus) and Araca beaches (P. criniticornis). The pattern of shell use, selection, and preference was demonstrated to be dependent on site only for P. brevidactylus. The results also showed that the shell use pattern of P criniticornis can be explained by its preference at both sites, whereas for P. brevidactylus it occurred only at Cabelo Gordo, where the absence of preference was correlated with the similar use of the three gastropod species studied. Finally, the results showed that the shell selection pattern cannot be considered as a measure of shell preference, since it overestimates crab selectivity. (C) 2009 Elsevier B.V. All rights reserved.

Development of the ovaries of the lobster Panulirus echinatus (Crustacea: Palinuridae) based on macroscopic and microscopic examination and gonadosomatic relation (GSR)

The developmental stages of the ovaries of the lobster Panulirus echinatus Smith, 1869 were characterized using macroscopic and microscopic features and the gonadosomatic relation (GSR). Based on monthly samples (November, 1999 to October, 2000), a total of 711 females were captured using gillnets. The dorsal region of the carapace was removed to evaluate the ovaries, which were dissected, weighted, preserved in Bouin`s solution, and submitted to histological procedures. The microscopic analysis of the ovaries was assessed by the presence of germinative cells in different developmental phases. When this analysis was combined with macroscopical observations (changes in color and volume of the gonads in the cephalothorax) and GSR, five developmental stages could be identified: immature (I), intermediate (II); pre-maturation (III); mature (IV) and post-spawning stage (V). Statistical analyses confirmed that GSR can be used as an indicator of developmental stage.

CLEANER SHRIMP (CARIDEA: PALAEMONIDAE) ASSOCIATED WITH SCYPHOZOAN JELLYFISH

Shrimp are found in association with many hosts (sponges, anthozoans, mollusks, echinoids, ascidians and fish). Shrimp are rarely observed in association with jellyfish. The interaction between the cleaner shrimp Periclimenes paivai and jellyfish is poorly known, with only one published report for Brazilian waters. We add new information about this association, based on field and laboratory observations. Shrimp were collected from three locations on the coast Of Sao Paulo State (Cananeia, Santos and Sao Sebastiao) and from two species of scyphozoan rnedusae: Chrysaora lactea and Lychnorhiza lucerna. We classify the association as facultative commensalism, since the shrimp gain protection and probably feed on mucus produced by the jelly fish. The maximum carapace length of the shrimp collected was 9.2 min. Medusa bel I diameter ranged between about 10 and 19 cm for C. lactea and between 4.5 and 25 cm for L. lucerna. We also provide a list of records of Periclimenes in association with different scyphornedUsae, and additional information on the size and coloration of P. paivai.

Podochela meloi Sankarankutty, Ferreira & Cunha, 2001, a junior synonym of the spider crab Inachoides forceps A. Milne-Edwards, 1879 (Crustacea: Brachyura: Inachoididae)

Podochela meloi Sankarankutty, Ferreira & Cunha, 2001, originally described in the Inachidae MacLeay, 1838, was recently transferred to the Inachoididae genus Inachoides H. Milne Edwards & Lucas, 1842, based upon overall similarities. Placement of P. meloi in both Inachoididae and Inachoides is found to be supported by a number of synapomorphies as shown herein. Podochela meloi is shown to be a junior synonym of Inachoides forceps A. Milne-Edwards, 1879.

Reproductive migration and population dynamics of the blue crab Callinectes danae in an estuary in southeastern Brazil

Portunid crabs are an important resource in estuaries, and require appropriate management to guarantee their long-term availability. We investigated the population dynamics and reproduction of Callinectes danae in the Estuarine-Bay Complex of Sao Vicente, Sao Paulo, Brazil, to provide basic biological information for public policies for the management of this fishery. Monthly samples were obtained from March 2007 to February 2008 on eight transects, four in the estuary and four in the bay. A total of 2261 specimens (403 males, 1288 females, of which 570 were ovigerous) were collected. Males were significantly larger than females, and the size-frequency distribution was unimodal for males, females and ovigerous females. The sex ratio was nearly always skewed toward females (M:F - 1:4.6). C. danae showed seasonal-continuous reproduction, with high reproductive activity in the warmer season. C. danae breeds in the estuarine-bay complex, with males and juvenile females concentrated in the estuary. After copulation, fertilized females migrate to the estuary entrance and the bay, where ovigerous females are commonly found spawning in high-salinity areas. Therefore, to manage this important economic resource, both the estuary and the bay should be considered for protection, but special attention should be given to the estuary entrance during the summer months, when ovigerous females concentrate.

Relative abundance and population biology of the non-indigenous crab Charybdis hellerii (Crustacea: Brachyura: Portunidae) in a southwestern Atlantic estuary-bay complex

Invasive species are potential threats to biodiversity, especially if they become established and outnumber native species. In this study, a population of the non-indigenous crab Charybdis hellerii was analyzed in an estuary-bay complex on the southeastern Brazilian coast, with respect to its abundance relative to sympatric native brachyuran species, as well as the size structure, sexual maturity, sex ratio, frequency of mutilation, reproductive period, and development of the reproductive system. Crabs were sampled monthly both in the intertidal zone of rocky shores and on sublittoral soft-bottom. Nine species were recorded on the rocky shores, where C. hellerii was the second most abundant species; only three individuals of C. hellerii were collected in the sublittoral samples. This population of C. hellerii showed a unimodal size structure composed mainly of mature individuals; males were larger than females, and the sex ratio was skewed toward males (3.1:1). About 46.9% of the individuals (75 of 160 crabs) had mutilated or regenerating appendages, more frequent in males (56.8%) than in females (28.2%), which may reflect both inter- and intraspecific agonistic interactions. A continuous reproductive pattern is suggested for this population, although ovigerous females occurred unevenly during the year, with 58.82% of them being collected in winter. There was evidence of multiple spawning, since the ovigerous females with an initial egg mass showed mature ovaries as well as seminal receptacles filled with sperm. C. hellerii is well established in the estuary-bay complex, but is concentrated in intertidal and shallow subtidal rocky shores, where it may compete with and replace other species such as the portunid Cronius ruber. This study also highlights the importance of systematic monitoring studies to evaluate the effects of the introduction of non-indigenous species on ecologically similar natives.

Reproductive apparatus of the male giant hermit crab Petrochirus diogenes (Anomura, Diogenidae): morphology and phylogenetic implications

We describe the male reproductive apparatus of the giant hermit crab Petrochirus diogenes, with morphological and biometric analyses of the spermatophore, the gonopore and the ultrastructure of the spermatozoa. Specimens were collected from the southern coast of Sao Paulo, Brazil. Morphological analyses were done using stereoscopic, light, transmission and scanning electron microscopy. The reproductive system of this hermit crab is composed of elongate and lobular testes followed by vasa deferentia that connect to the exterior via gonopores. The gonopores are ovoid and surrounded by setae, and each gonopore is composed of a membranous operculum that forms a depression constituting the gonopore opening. The gonopore constitutes a unique structure among the Diogenidae due to its number of setae. The spermatophores are tripartite, composed of a sperm-containing ampulla, a peduncle and a proximal foot. The spermatozoon has 3 main regions (acrosomal vesicle, nucleus and cytoplasm). The structure of the spermatophore indicates that this species can be considered an exception within Diogenidae with regard to spermatophore morphology and can therefore be used for phylogenetic inferences.

Spatial-temporal variation of Paralonchurus brasiliensis (Actinopterygii: Sciaenidae) density in relation to some environmental factors on the inner shelf of south-eastern Brazilian coast

The temporal and spatial variation of Paralonchurus brasiliensis density (fish per m(2)) in relation to environmental factors was studied on the coasts of Ubatuba and Caraguatatuba, south-eastern Brazil. The fish were collected by shrimp fishery trawl on a monthly basis from January to December, 2002. Seven depths were previously established and for each one the temperature, salinity, organic matter content and grain size of the sediment (phi) was measured. The seasonal analysis of temperature and salinity indicated the presence of the water masses South Atlantic Central Water (SACW) and Coastal Waters (CW) acting in the study area. A total of 29,808 fish were collected during the study period. The highest densities were registered during the summer and autumn indicating an association with CW. The fish population moved to shallow depths during the intrusion of the cold water mass, SACW. The highest densities were registered in depths where the sediment composition ranged from fine sand to silt-clay. Thus, the temperature and type of the sediment are the main environmental factors which affect the spatial-temporal variation of P. brasiliensis density in south-eastern Brazil.