New data on the systematics and interrelationships of sawfishes (Elasmobranchii, Batoidea, Pristiformes)

The order Pristiformes (sawfishes) (Compagno, 1973), contains seven species in two genera (Compagno, 1999). These cartilaginous, benthic fishes present a worldwide distribution in tropical and subtropical coastal waters of Atlantic and Indo-Pacific areas, including estuaries and rivers mouths, and many studies have been conducted on their morphology and ecology (Garman, 1913; Bigelow & Schroeder, 1953; Last & Stevens, 1994; Compagno & Cook, 1995; Zorzi, 1995; Compagno & Last, 1999). Pristiformes, with the single family Pristidae, are divided into two genera, Pristis Linck 1790 and Anoxypristis White & Moy-Thomas, 1941. Pristis comprises six putative species: Pristis pectinata Latham, 1794, Pristis pristis (L., 1758), Pristis zijsron Bleeker, 1851, Pristis microdon Latham, 1794, Pristis perotteti Mu ̈ ller & Henle, 1841 and Pristis clavata Garman, 1906. The genus Anoxypristis is represented by a single Indo-Pacific species, Anoxypristis cuspidata (Compagno, 1999). Interrelationships among the species have never been clearly defined and the status of some species is still uncertain because of the lack of comparative material (Stehmann, 1990; Ishihara et al., 1991; Taniuchi & Shimizu, 1991). As part of the ongoing Odontobase1 project (which is an attempt to identify chondrichtyans based on their isolated dermal elements; Deynat, 1996, 2000, 2003a, b), the dermal denticles of sawfishes were studied in detail. The aim of this paper is to show that the dermal denticles of sawfishes are useful in elucidating their systematics and in providing new information regarding the supposed synonymies of some nominal species of Pristis.