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.

Reproductive cycle and recruitment period of Ocypode quadrata (Decapoda, Ocypodidae) at a sandy beach in southeastern Brazil

The reproductive cycle and recruitment period of a ghost crab population from Ubatuba, São Paulo, Brazil were investigated by means of examining the developmental stages of gonads of breeding crabs and the ingress of young recruits to the studied population. Monthly collections over a one-year period were carried out during nocturnal low-tide periods at Vermelha beach. The morphology of the abdomen and pleopods was used for sex determination. All captured crabs were measured for carapace width and dissected for the determination of the development stage of the gonads. A total of 582 specimens was captured: 271 males, 241 females, and 70 juveniles. Size ranged from 8.5 to 37.5 mm for males, from 9.5 to 39.2 mm for females, and from 5.8 to 12 mm for early juveniles. Median size of males and females did not differ statistically. The frequency of ovigerous females was markedly low. The onset of sexual maturity in females is achieved at around 23 mm of carapace width. Mature females with advanced gonad stages were not recorded from May to September. Recruitment of young was highest during summer, but the presence of early and late juvenile specimens throughout the year indicates that continuous recruitment is taking place in the studied population.

Larval stages of Stenocionops furcatus (Olivier, 1791) (Decapoda : Brachyura : Majoidea) and a reappraisal of larval morphological characters for Mithracidae

Stenocionops furcatus is a spider crab found in the western Atlantic, from Georgia, USA to Rio Grande do Sul, Brazil, on sand, coral, rocks or mud bottoms from the intertidal zone to 180 m. We describe all laboratory-reared larval stages of S. furcatus obtained from the northern coast of São Paulo State, Brazil, and compare our data with existing larval descriptions for the genus and other mithracids. The larval development of S. furcatus consists of two zoeal stages and one megalopa. The durations of the first and second zoeal stage were similar to4 and 5 days respectively, the megalopa appearing 10-18 days after hatching. Our results show that the zoeae of S. furcatus differ from those of other Mithracidae by possessing four setae on the proximal lobe of the coxal endite of the maxilla, instead of five, and by the presence of mid-dorsal setae on the third abdominal somite in the second zoeal stage, which are lacking in other mithracids. Larval descriptions for Stenocionops in two previous publications were attributed to the subspecies S. furcatus coelatus from the Caribbean. Larvae from Brazilian waters closely resemble one of these accounts, suggesting that this taxon extends beyond the West Indies and that the other description represents larvae of S. furcatus furcatus. Additional morphological details, not available previously, are provided.

Larval development of Epialtus bituberculatus H. Milne Edwards, 1834 (Crustacea : Decapoda : Brachyura : Majidae) with comments on majid larvae from the southwestern Atlantic

The larval development of the spider crab Epialtus bituberculatus H. Milne Edwards which Lives on rocky shores with algae such as Sargassum and Hypneia, is described. Larvae were obtained from ovigerous females collected in Ubatuba, State of São Paulo, Brazil. Rearing was carried out at 24 +/- 1 degreesC, with an average salinity of 35 parts per thousand. Larval development consists of two zoeal stages and one megalopa. Zoeal development was completed in 9.5 days. Analysis indicated that zoeae of E. bituberculatus are very similar to those of E. brasiliensis Dana and Acanthonyx scutiformis (Dana). Differences noted between these species pertain to the setation of the carapace, maxillule and second maxilliped. The main morphological features useful for identification are presented together with a summary of features that characterize larvae of majid subfamilies in Brazil. A key for the identification of southwestern Atlantic majid zoeae to the family level is provided.

Larval stages of Paradasygyius depressus (Bell, 1835) (Crustacea : Decapoda : Brachyura : Majidae) and a phylogenetic analysis for 21 genera of Majidae

All larval stages and the first crab instar of Paradasygyius depressus (Bell) were obtained in laboratory culture. Larval development consists of two zoeal stages, followed by the megalopa. Each larval stage is described in detail. Beginning with the first zoea, the duration of each stage was 4--7 (4.5 +/- 0.7), 4-5 (4.5 +/- 0.5), and 7 days, the megalopa and first crab instar appearing 11 +/- 1 and 15 days after hatching, respectively. A phylogenetic analysis of 21 genera of Majidae is provided based on 34 zoeal and three megalopal characters. The phylogenetic analysis resulted in four equally parsimonious trees 173 steps long (CI = 0.66, RI = 0.71, and RC = 0.47) supporting the monophyly of Oregoniinae, Majinae, and Inachinae (with the exclusion of Macrocheira de Haan incertae sedis). Based on general agreement of sister-group hypotheses, we provide sets of larval characters that define Oregoniinae, Majinae, and Inachinae. Our phylogenetic hypothesis suggests that Oregoniinae is the most basal clade within the Majidae, and Majinae and the clade (Epialtus H. Milne Edwards + Inachinae [excluding Macrocheira incertae sedis]) are sister taxa. Within Inachinae, all trees suggest that Inachus Weber and Macropodia Leach are sister taxa nested as the most derived clade, followed by Achaeus Leach, Pyromaia Stimpson, Paradasygyius Garth, Anasimus A. Milne-Edwards, and the most basal Stenorhynchus Lamarck. The sister-group relationships of the clade (Pisa Leach (Taliepus A. Milne-Edwards + Libinia Leach)), Mithrax Latreille and Microphrys H. Milne Edwards remained unresolved.

Larval development of Apiomithrax violaceus (A. Milne Edwards, 1868) (Decapoda : Brachyura : Majoidea : Pisidae) reared in laboratory conditions, and a review of larval characters of Pisidae

Apiomithrax violaceus (A. Milne Edwards, 1868 ) is a pisid majoid crab occurring in tropical and subtropical coastal waters of the eastern and western South Atlantic. Larval development consists of two zoeal stages and a megalopa. Beginning with the first zoea, the duration of each larval stage at 24degreesC was 3-8 (5+/-1), 3-5 (4+/-0.5) and 9-15 (11+/-2) days, the megalopa and first crab instar appearing 9-11 (10+/-1) and 20-27 (23+/-2) days after hatching, respectively. Larval characters agree with those proposed for the Majoidea, in having nine or more setae on the scaphognathite in the first zoea and well-developed pleopods in the second zoea. However, larvae of A . violaceus do not fit larval pisid features. Zoeal stages differ from most other Pisidae in having lateral spines, a long rostral spine extending beyond the antenna, two spines per telson fork and a dorsolateral process on the third abdominal somite. The megalopa differs in having a spine dorsally on the carapace and on the basial segment of the second pereiopod. Two characters that are potentially unique to Apiomithrax include a zoeal antenna with an exopod that is much longer than the protopod, and a rostral spine that is longer than the dorsal spine. These characters should facilitate the identification of this taxon and could also be useful for phylogenetic studies. A review of larvae of 28 species among 14 genera indicated that there is no apparent single larval character that differentiates the Pisidae, with more limited phylogenetic analyses suggesting that this is a paraphyletic group. Apiomithrax , Eurynolambrus , Pisoides , Rochinia and Scyra have the most divergent morphological characters within the family. The analysis and inclusion of additional taxa is likely to shed more light on the sister-group relationships of the Pisidae. However, based on the extent of morphological interspecific variability of known larvae it is likely that the group, as presently defined by adult morphology, is not monophyletic.

Relative growth of Petrochirus diogenes (Linnaeus, 1758) (Crustacea, Anomura, Diogenidae) in the Ubatuba region, São Paulo, Brazil

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

Relative growth of Uca burgersi (Crustacea, Ocypodidae) from two mangroves in the southeastern Brazilian coast

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

The megalopa and early juvenile development of Hepatus pudibundus (Crustacea: Brachyura: Aethroidea) reared from neuston samples

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

SEDIMENT PARTICLE SELECTION DURING FEEDING BY FOUR SPECIES of UCA (BRACHYURA, OCYPODIDAE)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Juvenile development of Callinectes ornatus Ordway, 1863 (Crustacea : Decapoda : Portunidae), from megalopae obtained in the neuston

The juvenile development of Callinectes ornatus was studied from megalopae collected in the neuston off Ubatuba, São Paulo State, Brazil. The animals were raised in the laboratory under constant temperature (25 +/- 1 degrees C), filtered sea water (35 parts per thousand) from the sampling location, and the natural photoperiod. Eleven stages of the juvenile phase were obtained. The main features of the first juvenile stage diagnostic of the species are: the number of segments in the antenna; number of setae on the exopod, endopod, basal endite and coxal endite of the maxilla, on the exopod, endopod, basal endite, coxal endite and epipod of the 1(st) maxilliped, and on the exopod, endopod and epipod of the 2(nd) maxilliped. Sexual dimorphism becomes apparent from the fourth juvenile stage onwards.

Marine anomurans (Decapoda) from the non-consolidated sublittoral bottom at the southeastern coast of Brazil

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

FIRST ZOEAL STAGE and MEGALOPA of UCA (UCA) MARACOANI (DECAPODA: BRACHYURA), WITH COMMENTS on THE LARVAL MORPHOLOGY of SOUTH-AMERICAN SPECIES of OCYPODIDAE

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

Relative growth and morphological sexual maturity of Uca Cumulanta (Crustacea : Decapoda : Ocypodidae) from a tropical Brazilian mangrove population

The relative growth of the fiddler crab Uca cumulanta was studied, primarily to determine the size at the onset of sexual maturity for a mangrove population in the estuary of the Patitiba River, Paraty, Rio de Janeiro state, Brazil. The evaluation of the morphological sexual maturity of U. cumulanta was performed using the allometric technique. The relationships that most precisely indicated the size at onset of sexual maturity were carapace length (CL) vs propodus length for males and CL vs abdomen width for females. Males and females are mature at 5.25 and 4.75 mm CL, respectively. The remarkable ontogenetic changes observed in the allometric growth of the male major cheliped and the female abdomen, indicate that growth of these structures is closely connected to the timing of sexual maturity. The relative size at onset maturity obtained for this species was 0.68 and this index was compared to that seen in other species in the genus.

The invasion of five alien species in the Delta do Parnaiba Environmental Protection Area, Northeastern Brazil

Marine biological invasions have been regarded as one of the major causes of native biodiversity loss, with shipping and aquaculture being the leading contributors for the introductions of alien species in aquatic ecosystems. In the present study, five aquatic alien species (one mollusk, three crustaceans and one fish species) were detected during dives, shore searches and from the fisheries on the coast of the Delta do Parnaiba Environmental Protection Area, in the States of Piaui and Maranhao, Northeastern Brazil. The species were the bicolor purse-oyster Isognomon bicolor, the whiteleg shrimp Litopenaeus vannamei, the giant river prawn Macrobrachium rosenbergii, the Indo-Pacific swimming crab Charybdis hellerii and, the muzzled blenny Omobranchus punctatus. Ballast water (I. bicolor, C. hellerii, and O. punctatus) and aquaculture activities (L. vannamei and M. rosenbergii) in adjacent areas are the most likely vectors of introduction. All exotic species found have potential impact risks to the environment because they are able to compete against native species for resources (food and habitat). Isognomon bicolor share the same habitat and food items with the native bivalve species of mussels and barnacles. Litopenaeus vannamei share the same habitat and food items with the native penaeids such as the pinkspot shrimp Farfantepenaeus brasiliensis, the Southern brown shrimp Farfantepenaeus subtilis, and the Southern white shrimp Litopenaeus schmitti, and in the past few years L. vannamei was responsible for a viral epidemics in the cultivation tanks that could be transmitted to native penaeid shrimps. Charybdis hellerii is also able to cause impacts on the local fisheries as the species can decrease the populations of native portunid crabs which are commercialized in the studied region. Macrobrachium rosenbergii may be sharing natural resources with the Amazon River prawn Macrobrachium amazonicum. Omobranchus punctatus shares habit with the native redlip blenny Ophioblennius atlanticus and other fishes, such as the frillfin goby Bathigobius soporator. Some immediate remedial measures to prevent further introductions from ballast water and shrimp farm ponds should be: (i) to prevent the release of ballast water by ship/vessels in the region; (ii) to reroute all effluent waters from shrimp rearing facilities through an underground or above-ground dry well; (iii) to install adequate sand and gravel filter which will allow passage of water but not livestock; (iv) outdoor shrimp pounds located on floodable land should be diked, and; (v) to promote environmental awareness of those directly involved with ballast water (crews of ship/vessels) and shrimp farms in the region. Rev. Biol. Trop. 58 (3): 909-923. Epub 2010 September 01.