Gulper Shark

Centrophorus granulosus

These deep-water sharks have a slow reproduction rate, so are at risk for exploitation. They are long and slender dogfish, rarely larger than 5 feet, with two dorsal fins, and green eyes. They migrate and appear to school in small groups, but there is a lot about their life and behavior that is unknown. Because of the depth of their habitat, they are considered little to no threat to humans.

Order – Squaliformes
Family – Centrophoridae
Genus – Centrophorus
Species – granulosus

Common Names

Common names for the gulper shark include: žralok hltac obecný (Czech Rep), zaghrun (Japan), uroko-aizame (Japan), squalechagrin commun (France), sorghaj (Sweden), sagru (Malta), sagrì (Italy), sagri (Malta), sagri, (Italy), ruwe zwelghaai (Netherlands), ru pighaj (Denmark), requin chagrin (France), rauher dornhai (Germany), ramudo (Madeira Is.), quelve (Spain), quelvacho (Spain), quelme (Canary Is.), quelme (Cape Verde), quelma (Azores Is.), queime (Cape Verde), pixxinotte (Malta), peshk derr (Albania), pas kostelj dubinac (Croatia), negra (Spain), lixa-de-lei (Cape Verde), lixa granulosa (Mozambique), köpek baligi (Turkey), kotsan khad snapir (Israel), kokokentroforos (Greece), kokkoagathitis (Greece), kewaczo (Poland), kentroni (Greece), kalb (Morocco), gulper shark (UK), gulper shark (Azores Is.), gulper shark (Malta), gulper shark (Australia), galludo manchado (Cuba), chien gris (France), centroforo comune (Italy), centroforo (Italy), cação (Angola), barroso (Cape Verde), barroso (Angola), aiguillat gros yeux (France), and agathitis (Greece).

Importance to Humans

The gulper shark is fished with a variety of methods including bottom trawls, hook and line, or with pelagic trawls in the eastern Atlantic. Although sometimes caught as bycatch, some deepwater longline fisheries do target this species. The gulper shark can be smoked and/or dried/salted for human consumption and is also processed for fishmeal and liver oil. The gulper shark is potentially very valuable for its large liver with high oil content.

Danger to Humans

This shark poses no threat to humans due to its deep water habitat.

Conservation

> Check the status of the gulper shark at the IUCN website.

The IUCN is a global union consisting of states, governmental agencies, and non-governmental organizations that evaluate the conservation status of species.

Geographical Distribution

The gulper shark occurs globally in tropical to temperate marine waters. The gulper shark has been noted in the eastern and western north Atlantic; common in Portugal, Senegal, the Ivory Coast and Nigeria to France and along the coast of North America around North Carolina and the Gulf of Mexico. The gulper shark has also been observed in the western Indian Ocean in locations such as South Africa, the Morambique Channel and Madagascar. Gulper sharks have also been seen in the western Pacific near the Taiwan Island. It is, however, apparently rare outside of these observed regions.

Habitat

The gulper shark is a bathydemersal, living and feeding at depths exceeding 656 ft (200m), marine, deep-water dogfish most commonly found between 328 ft and 3937 ft (100 -1,200 meters). The gulper shark is commonly observed along the outer continental shelves and upper slopes, usually on or near the bottom substrate.

Biology

Distinctive Features
The gulper shark is a slim, relatively long dogfish with two dorsal fins bearing long grooved spines. The origin of the first dorsal fin is over the axil of the pectoral fin. The rear tips of the pectoral fins have narrowly expanded, angular, rear lobes that extend posterior to the origin of the first dorsal spine. The second dorsal fin is shorter than the first, and its base is about three-fourths the length of the first dorsal fin. The distance from the first and second dorsal fins is equal to the distance from the tip of the snout to the axil of the pectoral fin. The gulper shark lacks an anal fin. The snout is somewhat long but the anterior nasal flap is short in this species. The upper lobe of the caudal fin is moderately long and developed and the ventral lobe is well formed and sturdy. All gulper sharks in the family Centrophoridae differ from other Squaliformes through several distinctive physical characteristics such as green eyes, grooved dorsal fin spines, and long narrow rear lobes of the pectoral fins. Subtle differences between the dermal denticles throughout the family Centrophoridae can be used for specific species identification.

Coloration
The color of the gulper shark is olive-grey to grey-brown or sandy grey to brown dorsally and lighter ventrally with no obvious markings in adults; juveniles may be lighter and may have dusky tips on the dorsal and caudal fins.

Dentition
Teeth of both jaws are “blade-like” and form interconnecting cutting edges. The teeth of the upper jaw are moderately broad with cusps varying from upright to oblique. The teeth of the lower jaw are broader than that of those on the upper jaw and they have a oblique asymmetrical cusp. The number of tooth rows vary from 33-40 tooth rows on the upper jaw to 30 rows on the low jaw.

Denticles
The dermal denticles of the gulper shark are non-overlapping, widely-spaced, and blocklike with crowns sessile on bases and without pedicels. The crowns of the dermal denticles are broad and transversely rhomboidal in adults.

Size, Age, and Growth
The maximum total length recorded for the gulper shark is 5 ft (150 cm). Gulper shark pups average from 1 ft – 1.4 ft (30-42 cm) total length at birth. Precise details of the size, age, and growth, such as size at maturity for the gulper shark, are currently unknown.

Food Habits
The diet of the gulper shark has not been fully described, but the gulper shark is thought to feed on species of hake perhaps in the family Macruronidae and lanternfish perhaps in the family Myctophidae.

Reproduction
The gulper shark is ovoviviparous with a gestation period of about 2 years. At birth, each pup measures approximately 1 ft – 1.4 ft (30-42 cm) total length. Further details of the reproductive biology of the gulper shark have yet to be determined.

Predators
Predators of the gulper shark are unknown but may include larger fishes and marine mammals.

Taxonomy

The gulper shark, Centophorus granulosus, belongs to the family Centrophoridae. The gulper shark was originally described as Squalus granulosus by Bloch and Schneider in 1801. The current valid scientific name for the gulper shark is Centophorus granulosus. The genus word, Centrophorus is derived from the Greek words kentron meaning “thorn” and pherein meaning “to bear” in reference to the spines that all dogfish bear on both the first and second dorsal fins.

Prepared by: Ashley Jennings