Borneo shark (Carcharhinus borneensis)

Biology

This small species is characterized by the following: snout long and pointed; slender body and tail; alongside each mouth corner is a row of enlarged hyomandibular pores (5-12); upper anterior teeth finely serrated with a single narrow, oblique cusp; distal edge deeply notched and with several cusplets; lower anterior teeth with narrower, similarly oblique cusps; no lateral cusplets; total tooth row counts 23-26/23-25, or 46-50; second dorsal-fin origin well posterior of anal-fin origin, about opposite or just anterior to anal-fin midbase while second dorsal-fin origin to anal-fin origin 2.2-4.1% TL, 0.4-0.9 times second dorsal-fin base; interdorsal space 20.7-22.7% TL; pelvic fins small, anterior margins 4.4-5.8% TL and 35-42% of pectoral anterior margin; first dorsal fin triangular, with nearly straight posterior margin, free rear tip about opposite pelvic-fin origins, length 14.5-17.6% TL, 1.8-2.4 times height, inner margin 1.9-2.8 in base; second dorsal fin much smaller than first

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