INVESTIGADORES
BELLEGGIA Mauro
congresos y reuniones científicas
Título:
Endemic Genera in the Family Rajidae
Autor/es:
FIGUEROA DANIEL E.; BELLEGGIA MAURO; RIVERA PAULA
Lugar:
Montreal
Reunión:
Congreso; Joint Meeting of Ichthyologists and Herpetologists; 2008
Institución organizadora:
American Elasmobranch Society
Resumen:
The family Rajidae is one of the most useful among other marine animals, for the analysis of theorigin and distribution of sea faunas. Skates (Rajidae) are unique among chondrichthyans fortheir high species diversity. They have an extreme nonmigratory life mode and are exclusivelybottom dwelling fishes at any age, beginning from eggs with fibrillar filaments for attachmentto the bottom. The cosmopolitan distribution of the group is accounted for by its large agerather than by a deep-sea life mode. They all live at relatively low depths. Most species live inthe shelf and upper slope up to 1000 m of depth, which does not allow them to move acrossdeeper marine regions. They are most diverse at higher latitudes, but are replaced in shallower,warm temperate to tropical waters by stingrays (Myliobatoidei). The high degree of endemismexhibited by the skates is somewhat enigmatic given their relatively conserved bodymorphology and apparent restrictive habitat. The family Rajidae comprises 27 genera, 11 ofthese could be considered endemic. Most of them (eight) occurring in the southern hemisphere,whereas only three occurring in the northern hemisphere. The southern hemisphere shows thetwo extremes with respect to distribution of endemic genera. On one side, South Africa has agreat richness in genera of skates (12) but none of them is endemic, and the Antarctica with twogenera, considered the most cosmopolitan of the world. On the other side Australasia and SouthAmerica, show very curious diversity and distribution at a regional level. In the early Oligocenethe Drake Passage started to open and the cold Antarctic circumpolar current began, could thisphenomenon be the key of the numerosity and distribution of the endemism on the southhemispher.