rudimentary nictitating membranes (protective third eyelids) and indistinct ridges underneath. The mouth is sizable and forms a long arch; there are well-developed furrows around the corners. The teeth are small and number around 47 rows in the upper jaw and 50 rows in the lower jaw; each has a narrow central cusp and typically two pairs of smaller cusplets on the sides. The five pairs of gill slits are short, with the fourth pair about level with the pectoral fin origins. The first dorsal fin has a blunt apex and is positioned over the latter half of the pelvic fin bases. The second dorsal fin resembles the first but is slightly smaller, and is positioned over the latter third of the anal fin base. The pectoral fins are rather large and broad, with rounded corners. The pelvic fins are small with angular margins; the claspers of adult males are short and do not reach the anal fin. The anal fin base measures roughly 12% of the total length, shorter than the distance between the dorsal fins but longer than the distance between the pelvic and anal fins. The caudal peduncle is almost cylindrical, and leads to a low caudal fin with a subtle lower lobe and a ventral notch near the tip of the upper lobe. The skin is covered by small, overlapping dermal denticles; each has a leaf-shaped crown with a horizontal ridge and three marginal teeth. There is a crest of enlarged denticles along the upper edge of the caudal fin. This species is grayish above and patterned with darker, fuzzy-edged saddles and blotches along the body and tail. The underside, dorsal and caudal fin trailing margins, and interior of the mouth are white. Biology and ecology Schooling in nature, the gecko catshark feeds opportunistically on a wide variety of bony fishes (including lanternfish), cephalopods (including sepiolid and enoploteuthid squid), and crustaceans (including isopods, amphipods, krill, and decapods). The relative importance of the three prey categories varies between geographical areas and seasons, likely reflecting what is most available in the environment. This species is oviparous; adult females have a single functional ovary, on the right, and two functional oviducts. A single egg matures within each oviduct at a time. Mature eggs are contained within smooth, translucent yellow, vase-shaped capsules measuring roughly long and across, with the top squared off and the bottom converging on a short projection. One