Brazil Crayfish

   

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The family Parastacidae, in South America, is represented by three genera: (1) Parastacus, (2) Samastacus and (3) Virilastacus. Six crayfish species occur in temperate regions of Brazil, more precisely in the southernmost States, Rio Grande do Sul and Santa Catarina, all of them belonging to the genus Parastacus. These species burrow in two types of habitat: swampy grounds and muddy banks of small lotic systems. They have a seasonal reproduction, that starts in the early spring and stops in the late summer. Intersexuality and hermaphroditism are common phenomena in Parastacus. All Brazilian species have male and female genital apertures. The bigger species are P. pilimanus and P. brasiliensis, but they rarely reach a size over 10cm.
Parastacus brasiliensis is a species with nocturnal habits, which constructs burrows in stream margins. Morphological examination of the species reproductive system indicated the occurrence of protandrous hermaphroditism (sex change from male to female sex).
Geographic distribution: Rio Grande do Sul.

 

   

   

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More about the contributor ALEXANDRE OLIVEIRA DE ALMEIDA