Approximately 50 years ago, Nile tilapia were accidentally introduced to Brazil, and the decline of pearl cichlid populations, which has been intensified by habitat degradation, in some locations associated with presence tilapia. There is, however, little strong empirical evidence for negative interaction non-native fish populations native populations; such would indicate a potential behavioural mechanism that could cause population decline. In this study, we show fights staged between pairs...

Callinectes danae Smith, 1869, known as ''siri-azul'', is an important fishery resource along the Brazilian coast. The reproductive cycle of this species was studied based on their moult and development gonads. animals were collected with otter-trawl in Ubatuba region (23°26'S 45°02'W) every other month from July 1991 to May 1993. A total 1826 specimens captured: 788 males 1038 females. Ovigerous females developed gonads both sexes found all months sampled. In females, activity recorded size...

Intertidal organisms rely on physiological and behavioral adjustments to maintain homeostasis under warm exposure. We examined the effects of temperature increase related climate warming physiology behavior two fiddler crab species: Leptuca uruguayensis, which inhabits mostly vegetated areas, leptodactyla, that unvegetated areas. hypothesized L. uruguayensis would be more sensitive than leptodactyla. Crabs were exposed different temperatures: 27 °C (control), 31 33 (+4 +6 °C, respectively)...

"POPULATION BIOLOGY OF UCA THAYERI RATHBUN, 1900 (BRACHYURA, OCYPODIDAE) IN A SUBTROPICAL SOUTH AMERICAN MANGROVE AREA: RESULTS FROM TRANSECT AND CATCH-PER-UNIT-EFFORT TECHNIQUES" published on 01 Jan 2002 by Brill.

The relative growth of U. thayeri was studied for a subtropical mangrove population in the estuary Comprido and Escuro rivers, Ubatuba, São Paulo State, Brazil. evaluation morphological sexual maturity performed using allometric technique. Remarkable ontogenetic changes were observed male major cheliped female abdomen, indicating that these structures are closely connected to timing maturity. For males, relative-growth analysis propodus length rendered an estimate 13.8 mm carapace width size...

The relative growth of U. thayeri was studied for a subtropical mangrove population in the estuary Comprido and Escuro rivers, Ubatuba, São Paulo State, Brazil. evaluation morphological sexual maturity performed using allometric technique. Remarkable ontogenetic changes were observed male major cheliped female abdomen, indicating that these structures are closely connected to timing maturity. For males, relative-growth analysis propodus length rendered an estimate 13.8 mm carapace width size...

Abstract Zara, F.J., Gaeta, H.H., Costa, T.M., Toyama, M.H. and Caetano, F.H. 2011. The ovarian cycle histochemistry 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 development crustaceans. Here, we examined between ovary histochemistry, changes gonadosomatic hepatosomatic indices against pattern . Animals were collected south coast São Paulo State,...

Sediment characteristics, especially grain size, are usually considered the most important variables affecting Uca distribution, mainly due to its close relationship with mouth appendage morphology. The aim of this study was verify, from an assemblage perspective, if sediment is variable species and morphology (setae type curvature) would be related habitat occupancy. Niche metrics null model approaches were used assess test hypothesis. relevance spoon-tipped setae curvature distribution...

Fiddler crabs (Brachyura, Ocypodidae), like many other marine organisms, disperse via planktonic larvae. A lengthy pelagic larval duration is generally assumed to result in genetic connectivity even among distant populations. However, major river outflows, such as of the Amazon or Orinoco, strong currents may act phylogeographic barriers ongoing gene flow. For example, Mona Passage, located between Puerto Rico and Hispaniola, has been postulated impair exchange several species. In this...

Abstract The continuous excavation of burrows by fiddler crabs generates bioturbation in the sediment, which can be estimated from burrow morphology. aim present study was to describe morphology Uca uruguayensis and U. leptodactylus its relationship with demography resident individuals estimate level sediment generated each species. For all 2 species, sex determined carapace width (CW; mm) measured. Burrows were characterized according diameter (BD; mm), maximum depth (MBD; volume (BV; cm 3...

Abstract Fiddler crabs are key bioturbators on tidal flats. During their intense bioturbation process, they manipulate large amounts of sediment, altering the physical state existing materials. We investigated whether different types sediment produced by fiddler modulate meiofaunal assemblages and microphytobenthic content. hypothesized that sedimentary structures burrowing (the burrow itself excavation pellets) feeding (feeding generate microenvironments compared with areas without apparent...

While increasing awareness about ocean-related topics is a matter of urgent necessity, ocean and coastal-literate schoolchildren are uncommon in Brazil, even coastal cities. In the present study, we report activities an environmental education project spanning three-year period São Vicente, city surrounded by marine habitats southeastern state Paulo. This was part university initiative aiming to promote shared knowledge between biology student-monitors encircling community. With aid informal...

Ovigerous females of Uca thayeri and U. uruguayensis were used to achieve compare their reproductive pattern. The mean size was 6.6 ± 0.8mm for 17.3± 4.4mm thayeri. fecundity obtained 1883 490 eggs (N = 27) 31068 11186 31). differences observed in pattern suggest an adaptive strategy by each species: presented seasonal reproduction with a pronounced intensity from January March higher fecundity, while continuous all year round, but lower fecundity.

Mean prevalence and intensity of infestations by epibionts were evaluated in Arenaeus cribrarius (Lamarck, 1818), based on monthly samplings (May/1991 to April/1993), Ubatuba, Brazil. Bryozoans quantified terms colony numbers barnacles the number specimens. Prevalence infestation was determined 1,914 individuals A. assessed with respect sex, maturity stage season. No significant interaction detected between biological host factors. Males showed a higher rate Chelonibia patula (Ranzani, 1818)...