The blacktip sawtail catshark (Galeus sauteri) is a species of catshark, and part of the family Scyliorhinidae, found off the coasts of Taiwan and the Philippines. It is demersal in nature and occurs deeper than . Growing up to long, this slim-bodied species is characterized by its plain brownish dorsal coloration with dark tips on the dorsal and caudal fins, and a prominent crest of enlarged dermal denticles on the upper edge of the caudal fin. It is oviparous, with females producing encapsulated eggs two at a time year-round. The blacktip sawtail catshark is caught incidentally in bottom trawls and used for fishmeal in Taiwan. Taxonomy and phylogeny In 1906, the Carnegie Museum purchased an extensive collection of fishes assembled from the markets of Takao (Kaohsiung), Taiwan by Hans Sauter. American ichthyologists David Starr Jordan and Robert Earl Richardson described several new species from the collection in a 1909 issue of Memoirs of the Carnegie Museum, including a catshark of the genus Pristiurus that they named in Sauter's honor. Jordan and Richardson referenced six syntypes long in their description, of which four survive to the present day. Later authors have recognized Pristiurus as a junior synonym of the genus Galeus. A 2005 phylogenetic study, based on mitochondrial and nuclear DNA, found that this species, G. eastmani, and G. gracilis form a clade apart from G. melastomus and G. murinus. Distribution and habitat The blacktip sawtail catshark is found in the waters around Taiwan, where it is very common, and the Philippines. It was once thought to occur off southern Japan as well, but recent observations by Kazuhiro Nakaya have determined that this is not the case. This species is found on or near the bottom over the continental shelf. In the Taiwan Strait, it has been recorded over mud at depths of , while off Guishan Island it is known from . Description A small species, the blacktip sawtail catshark attains a maximum length of . Its body is slim and firm, with the head comprising roughly one-fifth of the total length. The rather long snout is pointed, with large nostrils divided by triangular flaps of skin on their anterior margins. The large, horizontally oval eyes bear rudimentary nictitating membranes (protective third eyelids) and lack prominent ridges underneath. Behind each eye is a small spiracle. The mouth is large and forms a long, wide arch; the corners of the mouth