Squaliformes Centrophoridae (the gulper sharks) Jeff Guertin 9/18/07.

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1 Squaliformes Centrophoridae (the gulper sharks) Jeff Guertin 9/18/07

2 Two Genera ► Centrophorus (11 recognized species)  Most well known is Centrophorus granulosus, which was found in 1801 ► Deania (4 species)

3 General Characteristics ► Small to medium-sized sharks (up to 200cm, but most under 150cm) ► Mostly benthopelagic ► Centrophorus first appeared in Upper Cretaceous (Lithuania & rest of Europe) ► Deania are known from the Miocene of Europe and the West Indies

4 General Characteristics ► Three major ecomorphotypes  Deania – small size, long flat snout

5 General Characteristics ► Three major ecomorphotypes  Centrophorus – a few large, short-snouted species; a few intermediates

6 General Characteristics ► Three major ecomorphotypes  C. moluccensis – narrow head and conical snout

7 Distinctive Features ► Both dorsal fins with grooved spines ► Teeth on lower jaw larger than those on upper jaw ► Precaudal pits and lateral keels absent on caudal peduncle ► Second dorsal fin is shorter than the first ► Lacks an anal fin

8 Distinctive Features ► Usually dark brown, gray, or black ► The dermal denticles of the gulper shark are non- overlapping, widely-spaced, and block-like ► Have green eyes

9 Habitat ► Mostly temperate and tropical waters (Indian ocean, Atlantic ocean, western Pacific ocean ► Absent from eastern North Pacific; only one species in the eastern South Pacific

10 Food Habits ► Feeds mainly on bony fishes such as hake, epigonids, lanternfish, herring, smelts, cods, rattails, squid and crustaceans ► Larger sharks feed on small dogfish sharks

11 Size, Age, Growth ► Have a wide range of ages; maximum belong to Centrophorus squamosus (55yrs for males and 70yrs for females) ► Very low rates of population increase (leaves at risk for overfishing, etc) ► Late onset of maturity (12-16 years in females)

12 Reproduction ► Ovoviviparous, embryos feed solely on yolk ► Have relatively few young, typically 1-6 per litter; most species of Centrophorus usually only 1-2 per litter; Deania can have up to 12 young per litter ► Size at birth typically 30-40cm

13 Predators  Largely unknown but may include larger fishes and/or marine mammals  Humans are becomingly increasingly problematic

14 Conservation ► Most are data deficient ► Some are marketed both smoked and dried salted for human consumption; also processed into fishmeal and as a source of liver oil ► Caught with bottom trawls, long lines, fixed bottom nets, hook and line and pelagic trawls ► Some are near threatened  Centrophorus niaukang (Taiwan gulper shark) - highly vulnerable to population depletion through fisheries bycatch; widely but patchily distributed globally ► Others are vulnerable  Centrophorus squamosus (Leafscale gulper shark) – harvested for its flesh and liver

15 Bibliography ► 1) 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 1 - Hexanchiformes to Lamniformes. FAO Fish. Synop. 125(4/1):1-249. ► 2) Carrier J, Musick J, Heithaus M. 2004. Biology of Sharks and their Relatives. CRC Press, Boca Raton, FL, pp. 56-63, 180, 228.