On the dentition of the sand shark, Odontaspis taurus, from the vicinity of Cananéia, Brazil

Abstract

Variation in the tooth distribution pattern and number of teeth is described from 528 jaws of the mangona or sand shark, Odontaspis taurus, from the vicinity of Cananéia, Brazil. On the basis of dental characteristics, this series gives no support to the recognition of more than one species of the shallow-water inhabiting sharks known variously over the world as sand sharks, mangonas, sardas, squalos toros, or grey nurse sharks. Counts of the teeth of 12 females and the two embryos contained in each of them show a considerable variation within each family group.

Skeletal and dental anatomy of lamniform shark,Cretalamna appendiculata, from Upper Cretaceous Niobrara Chalk of Kansas

“…However, studying elasmobranch dentitions is not an easy task because of various intraspecific variation parameters one must take into consideration. Intraspecific tooth variations in elasmobranchs can occur in number of tooth rows, in number of accessory cusps (e.g., Gudger, 1937;Sadowsky, 1970;Taniuchi, 1970), at different ontogenetic stages (e.g., Reif, 1976;Shimada, 2002b); between sexes that may also differ between different mating seasons (e.g., McCourt and Kerstitch, 1980;Gruber and Compagno, 1981;Kajiura and Tricas, 1996), among different geographic regions (Lucifora et al, 2003), or in abnormal forms (e.g., Gudger, 1937;Raschi et al, 1982;Kaneko and Goto, 2001). The lack of any consideration of such variations would lead to the 'taxonomic instability' of toothbased species common to fossil forms (Shimada and Cicimurri, 2006).…”

Conhecimento da diversidade dos Chondrichthyes marinhos no Brasil: a contribuição de José Lima de Figueiredo

“…A maioria das espécies habita áreas oceânicas (e.g., Isurus oxyrinchus, I. paucus, Lamna nasus, Pseudocarcharias kamoharai) e são capturadas por meio de barcos espinheleiros que operam nestas áreas. O cação-mangona, Carcharias taurus é o mais costeiro de todos, associado quase exclusivamente à plataforma continental (Sadowsky, 1970;Figueiredo, 1977). Já os cações-raposa, Alopias vulpinus, quando jovens, podem ser encontrados próximos da costa, ao contrário de seu congênere, A. superciliosus, restrito ao ambiente oceânico epi e mesopelágico (Gadig et al, 2001).…”

Reproductive ecology and abundance of the sand tiger shark, Carcharias taurus, from the southwestern Atlantic

“…Most previous research on C. taurus in the region has focused on taxonomy (e.g. Lahille, 1928;Sadowsky, 1970) or is limited to miscellaneous observations from comparatively few specimens (Cervigó n and Bastida, 1974;Menni et al, 1986). Until now, the general biology of C. taurus in the region has remained unknown (Menni, 1986b) despite the species being harvested throughout its regional range (Charvet, 1995;Chiaramonte, 1998;Nion, 1999;Lucifora, 2001).…”