Salmon shark - Lamna ditropis

 

Illustration © Marc Dando

WHAT TO LOOK FOR
This shark has a heavy body with a short, conical snout, and long gill slits. Its first dorsal fin has a dark free rear tip. It has strong keels on its caudal peduncle, and short, secondary keels on the base, and a crescent tail.

COLOR
Dark grey or blackish on top, with the underside being white with dusky blotches. It has a white patch under the pectoral base.

SIZE
At birth, the shark is 1.3 to 1.6 ft [40 to 50 cm] in length. Males mature at approximately 5.9 ft [1.8 m], and females mature at 7.2 ft [2.2 m]. Their maximum length is over 9.8 ft [3 m].

HABITAT
This shark prefers cool coastal and oceanic waters, from 0 to at least 738.2 ft [225 m] deep.

DISTRIBUTION
These sharks are in the north Pacific (males are common the west, and females are common the east).

BIOLOGY

  • General – A high body temperature enables this shark to actively hunt prey in very cold water.

  • Prey – Schooling fishes (salmon, herring, and sardines).

  • Reproduction – They have litters of 2-5 pups which are born in the spring in nursery grounds.

BEHAVIOR
These sharks are seasonally migratory (following their prey), and they segregate by age and sex (adults move further north than the young).

STATUS
Their bycatch status in pelagic fisheries is largely unrecorded.