SHARK GALLERY

Sharpnose seven-gill shark (Heptranchias perlo)



Sharpnose seven-gill shark - Heptranchias perlo
© Ian K Fergusson(Bonnaterre, 1788). 


Fr Requin perlon
Sp Cañabota bocadulce; Bocadolç fosc (Catalunya)
It Squalo manzo; sadda mascolina (Messina); pesciu boe (Liguria)
Ma Murruna ta' seba gar`gi; Murruna; Morruna

Diagnosis

A moderately small and slender shark with seven gill-slits and one dorsal fin; fusiform body with distinctively pointed snout and large, green eyes; narrow, long mouth with prominent comblike teeth in the lower-jaw.  This is the only regional species with seven gill slits.  Mid-grey to olive or dun above; lighter ventrally.  Juveniles have dark tips to the dorsal and caudal fins, whilst adults have paler margins on all fins, although these may not always be very distinct.

Size

To about 137cm TL; common at 60 to 120 cm.Size at birth about 26cm. 

Status and Distribution

N.E. Atlantic: Frequent from Portugal southwards with abundance increasing south of Gibraltar; rare, very rare or nominal north of Bay of Biscay, where range extends (probably as outliers) to Southwestern England and S.W. Ireland; occasional in Biscay and Gulf of Gascony; Portuguese and Spanish coast, entire West African coast from Morrocco southwards, although records more patchily reported from Cape Verde to Equator. Insular records include Azores, Madeira and Canaries.
Mediterranean Sea: Frequent or occasional; Gibraltar eastwards throughout the Western basin, including Corsica and Sardinia;  considered common on banks in the Western Sicilian Channel (Esquerquis & L'Aventure).  Sporadic in the Southern Adriatic and North Aegean but occasional at the Dodecanese (Rhodes);  scarce  in extreme south-eastern regions. 

Biology

A deepwater species found on or near the bottom at between 27 to 700m, usually offshore but occasionally coastal where the seafloor shelves steeply; also often on the deeper boundaries of offshore banks.  Powerful and voracious predators despite a rather modest size, sevengills feed upon deepwater bony fishes such as hake, also rays and small sharks, squid, cuttlefish and crustaceans.  Ovoviviparous, bears 9 to 20 young.  Females mature at about 90 cm and males at ca. 85 cm.

The Shark Trust, 36 Kingfisher Court, Hambridge Road, Newbury, Berkshire, RG14 5SJ, UK.
Tel(+44) 01635 551150, Fax(+44) 01635 550230


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