Squaliformes Squaliformes CentrophoridaeCentrophoridae

(the gulper sharks)(the gulper sharks)

Jeff GuertinJeff Guertin

9/18/079/18/07

Two GeneraTwo Genera

►Centrophorus Centrophorus (11 recognized species)(11 recognized species) Most well known is Most well known is Centrophorus Centrophorus

granulosusgranulosus, which was found in 1801, which was found in 1801

►DeaniaDeania (4 species) (4 species)

General CharacteristicsGeneral Characteristics

►Small to medium-sized sharks (up to Small to medium-sized sharks (up to 200cm, but most under 150cm)200cm, but most under 150cm)

►Mostly benthopelagicMostly benthopelagic►Centrophorus Centrophorus first appeared in Upper first appeared in Upper

Cretaceous (Lithuania & rest of Cretaceous (Lithuania & rest of Europe)Europe)

►DeaniaDeania are known from the Miocene of are known from the Miocene of Europe and the West IndiesEurope and the West Indies

General CharacteristicsGeneral Characteristics

►Three major ecomorphotypesThree major ecomorphotypes DeaniaDeania – small size, long flat snout – small size, long flat snout

General CharacteristicsGeneral Characteristics

►Three major ecomorphotypesThree major ecomorphotypes CentrophorusCentrophorus – a few large, short-snouted – a few large, short-snouted

species; a few intermediatesspecies; a few intermediates

General CharacteristicsGeneral Characteristics

►Three major ecomorphotypesThree major ecomorphotypes CC. . moluccensismoluccensis – narrow head and conical snout – narrow head and conical snout

Distinctive FeaturesDistinctive Features

► Both dorsal fins with grooved spinesBoth dorsal fins with grooved spines► Teeth on lower jaw larger than those on upper jaw Teeth on lower jaw larger than those on upper jaw ► Precaudal pits and lateral keels absent on caudal Precaudal pits and lateral keels absent on caudal

pedunclepeduncle► Second dorsal fin is shorter than the firstSecond dorsal fin is shorter than the first► Lacks an anal finLacks an anal fin

Distinctive FeaturesDistinctive Features

► Usually dark brown, gray, or blackUsually dark brown, gray, or black► The dermal denticles of the gulper shark are The dermal denticles of the gulper shark are

non-overlapping, widely-spaced, and block-likenon-overlapping, widely-spaced, and block-like► Have green eyesHave green eyes

HabitatHabitat

►Mostly temperate and tropical waters (Indian Mostly temperate and tropical waters (Indian ocean, Atlantic ocean, western Pacific ocean ocean, Atlantic ocean, western Pacific ocean

► Absent from eastern North Pacific; only one Absent from eastern North Pacific; only one species in the eastern South Pacific species in the eastern South Pacific

Food HabitsFood Habits

►Feeds mainly on bony fishes such as Feeds mainly on bony fishes such as hake, epigonids, lanternfish, herring, hake, epigonids, lanternfish, herring, smelts, cods, rattails, squid and smelts, cods, rattails, squid and crustaceanscrustaceans

►Larger sharks feed on small dogfish Larger sharks feed on small dogfish sharkssharks

Size, Age, GrowthSize, Age, Growth

►Have a wide range of ages; maximum Have a wide range of ages; maximum belong to belong to Centrophorus squamosusCentrophorus squamosus (55yrs for males and 70yrs for (55yrs for males and 70yrs for females)females)

►Very low rates of population increase Very low rates of population increase (leaves at risk for overfishing, etc)(leaves at risk for overfishing, etc)

►Late onset of maturity (12-16 years in Late onset of maturity (12-16 years in females)females)

ReproductionReproduction

►Ovoviviparous, embryos feed solely on Ovoviviparous, embryos feed solely on yolkyolk

►Have relatively few young, typically 1-Have relatively few young, typically 1-6 per litter; most species of 6 per litter; most species of CentrophorusCentrophorus usually only 1-2 per usually only 1-2 per litter; litter; Deania Deania can have up to 12 young can have up to 12 young per litterper litter

►Size at birth typically 30-40cmSize at birth typically 30-40cm

PredatorsPredators

Largely unknown but may include Largely unknown but may include larger fishes and/or marine mammalslarger fishes and/or marine mammals

Humans are becomingly increasingly Humans are becomingly increasingly problematicproblematic

ConservationConservation

► Most are data deficientMost are data deficient► Some are marketed both smoked and dried salted Some are marketed both smoked and dried salted

for human consumption; also processed into for human consumption; also processed into fishmeal and as a source of liver oilfishmeal and as a source of liver oil

► Caught with bottom trawls, long lines, fixed bottom Caught with bottom trawls, long lines, fixed bottom nets, hook and line and pelagic trawlsnets, hook and line and pelagic trawls

► Some are near threatenedSome are near threatened Centrophorus niaukangCentrophorus niaukang (Taiwan gulper shark) - highly (Taiwan gulper shark) - highly

vulnerable to population depletion through fisheries vulnerable to population depletion through fisheries bycatch; widely but patchily distributed globallybycatch; widely but patchily distributed globally

► Others are vulnerableOthers are vulnerable Centrophorus squamosusCentrophorus squamosus (Leafscale gulper shark) – (Leafscale gulper shark) –

harvested for its flesh and liverharvested for its flesh and liver

BibliographyBibliography

►1) Compagno, L.J.V., 1984. FAO species 1) Compagno, L.J.V., 1984. FAO species catalogue. Vol. 4. Sharks of the world. catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue An annotated and illustrated catalogue of shark species known to date. Part 1 - of shark species known to date. Part 1 - Hexanchiformes to Lamniformes. FAO Hexanchiformes to Lamniformes. FAO Fish. Synop. 125(4/1):1-249. Fish. Synop. 125(4/1):1-249.

►2) Carrier J, Musick J, Heithaus M. 2) Carrier J, Musick J, Heithaus M. 2004. Biology of Sharks and their 2004. Biology of Sharks and their Relatives. CRC Press, Boca Raton, FL, Relatives. CRC Press, Boca Raton, FL, pp. 56-63, 180, 228.pp. 56-63, 180, 228.