Coastal Cephalopod Fauna of Southern Brazil

In the coastal waters between Cabo Frio, Rio de Janeiro State (Lat. 23°S) and Chui, Rio Grande do Sui State (Lat. 34°S), more than 30 species of cephalopods occur in the different marine environments. Temperate benthic octopuses of low fecundity, bearing large eggs, are restricted to the cold bottom waters of the outer shelf and the slope, in contrast to species of tropical origin, which occupy the more diverse shallow water habitats, principally along the Rio de Janeiro coast. Cosmopolitan warm-water octupuses with high fecundity, like Scaeurgus unicirrhus and Octopus vulgaris, are found along the entire area because the transport of pelagic juveniles is favored by the warm, southward flowing superficial Brazil Current. All three families of epipelagic octopuses are represented. The neritic squid fauna includes only five myopsid squids, four of them of tropical origin. At the upper slope Illex argentinus is dominant and several mesopelagic and bathipelagic oegopsids, widely distributed in tropical and temperate Atlantic Ocean waters, also occur. The absence of endemic species indicates the transitional character of the fauna between the Caribbean and the Patagonian regions.