Brown catshark Apristurus brunneus, from the US National Oceanic and Atmospheric Administration.

Belongs within: Carcharhiniformes.

Apristurus is a genus of catsharks with a broad, flattened head and long snout (Compagno 1984).

Characters (from Compagno 1984): Body not tadpole-shaped, stocky and more or less compressed, increasing in height up to the pectoral and trunk region and tapering posteriorly; body very soft and flabby, with thin skin and weakly calcified dermal denticles; stomach not inflatable; tail short, length from vent to lower caudal origin about 2/5 to 3/5 of snout-vent length. Head greatly depressed, pointed and wedge-shaped in lateral view, rather elongated, but usually slightly less than 1/4 of total length in adults; snout elongated, about equal to mouth width or greater, greatly flattened, narrow and pointed in lateral view; snout expanded laterally, narrowly spade-shaped to broadly spatulate and usually more or less bell-shaped in dorsoventral view; ampullal pores enlarged and prominent on snout; nostrils more or less enlarged, with incurrent and excurrent apertures broadly open to exterior; anterior nasal flaps reduced to angular lobes, without barbels, widely separate from each other and falling far anterior to mouth; internarial space 0.8 to 1.7 times the nostril width; no nasoral grooves; eyes dorsolateral on head, broad subocular ridges present below eyes; mouth angular or broadly arched, with lower symphysis well behind upper so that upper teeth are exposed in ventral view; labial furrows present along both upper and lower jaws, these long and reaching nearly or quite to level of upper symphysis of mouth; branchial region not greatly enlarged, distance from spiracles to fifth gill slits less than half head length; gill slits lateral on head. Two dorsal fins present, equal-sized or with the second dorsal larger than the first; origin of first dorsal varying from over the pelvic midbases to over the pelvic free rear tips; origin of second dorsal about over or slightly behind the anal midbase, anal fin enlarged and more or less elongated, larger than pelvic and dorsal fins, base length at least twice second dorsal base; origin of anal just behind pelvic bases, and insertion separated from lower caudal origin by a narrow notch; pectoral fins variable in size, their width less to greater than mouth width; inner margins of pelvic fins not fused over claspers in adult males; claspers short, thick, and distally pointed, not extending more than 2/3 of their lengths behind the pelvic fin tips and sometimes not extending past their tips. Caudal fin more or less elongated, over a fifth and often over a fourth of total length. A crest of enlarged denticles absent or variably developed on the dorsal caudal margin; supraorbital crests absent from cranium. No colour pattern, uniformly jet black, brownish-black, brown, pinkish or whitish.

<==Apristurus Garman 1913 [=Apristurius (l. c.); incl. Compagnoia Springer 1979, Parapristurus Fowler 1934] C84
    |--*A. indicus (Brauer 1906) [=Scylliorhinus indicus] C84
    |--A. atlanticus (Koefoed 1932) [=Scylliorhinus atlanticus] C84
    |--A. brunneus (Gilbert 1892) [=Catulus brunneus] C84
    |--A. canutus Springer & Heemstra in Springer 1979 C84
    |--A. herklotsi (Fowler 1934) [=Pentanchus herklotsi] C84
    |--A. investigatoris (Misra 1962) [=Pentanchus (Parapristurus) investigatoris] C84
    |--A. japonicus Nakaya 1975 C84
    |--A. kampae Taylor 1972 C84
    |--A. laurussoni (Saemundsson 1922) [=Scyllium laurussoni] C84
    |--A. longicephalus Nakaya 1975 C84
    |--A. macrorhynchus (Tanaka 1909) [=Scyliorhinus macrorhynchus] C84
    |--A. maderensis Cadenet & Maul 1966 C84
    |--A. manis (Springer 1979) [=Parmaturus (*Compagnoia) manis] C84
    |--A. microps (Gilchrist 1922) [=Scylliorhinus microps] C84
    |--A. nasutus de Buen 1959 C84
    |--A. parvipinnis Springer & Heemstra in Springer 1979 C84
    |--A. platyrhynchus (Tanaka 1909) [=Scyliorhinus platyrhynchus] C84
    |--A. profundorum (Goode & Bean 1896) [=Scylliorhinus profundorum] C84
    |--A. riveri Bigelow & Schroeder 1944 C84
    |--A. saldanha (Barnard 1925) [=Scylliorhinus saldanha] C84
    |--A. sibogae (Wber 1913) [=Scyliorhinus sibogae] C84
    |--A. sinensis Chu & Hu 1981 C84
    |--A. spongiceps (Gilbert 1895) [=Catulus spongiceps, Parapristurus spongiceps, Pentanchus spongiceps] C84
    |--A. stenseni (Springer 1979) [=Parmaturus (Compagnoia) stenseni] C84
    `--A. verweyi (Fowler 1934) [=Pentanchus verweyi] C84

*Type species of generic name indicated


[C84] Compagno, L. J. V. 1984. FAO Species Catalogue vol. 4. Sharks of the World: An annotated and illustrated catalogue of shark species known to date. Part 2—Carcharhiniformes. United Nations Development Programme, Food and Agriculture Organization of the United Nations: Rome.

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