|Photo modified from
FishBase. 1998. FishBase 98 CD-ROM. ICLARM, Manila.
The Portuguese shark has a
stout body with two small dorsal fins that have inconspicuous spines at their
origins. The second dorsal fin is larger than the first although they are both
relatively small in comparison to the size of the shark. The upper teeth of
this shark are long, pointed and have a smooth edge. The teeth in the lower jaw
are short and broad. The colouration of this species varies with the age of the
individual. Adults are brown while individuals that are half grown are black,
and juveniles are dark blue. This shark reaches a maximum size of 1.2 meters (4
feet). Dermal denticles in the young and juveniles have three points and are
widely spaced, while adults have dermal denticles that are large, scale-like
and closely overlapped.
The diet of the Portuguese
shark consists of squid and bottom dwelling fishes. Marine mammal skin and
muscle have also been found in stomachs, but it is not clear if mammals are
part of their regular diet.
Development in this shark
is ovovivparous and litters are usually 13 to 16 pups. When the young are born
they are generally 27 to 30 cm (11 to 12 inches) in length.
This shark lives in very
deep waters with most captures being at depths greater than 910 meters (3000
feet). However they have also been caught at depths of 2700 meters (8920 feet).
The temperature of water in which these sharks are found is between 5 and 6
The Portuguese shark is
present in both the western and eastern North Atlantic. It also occurs in the
western Mediterranean, in Japanese waters and in the Pacific off New Zealand.
In the western North Atlantic this shark ranges from the Grand Banks to
Delaware Bay. There are reports that the Portuguese shark occurs on the Scotian
Shelf (specifically Banquereau Bank) and Georges Bank.
- Colouration: juveniles are dark blue,
half grown individuals are black and adults are brown
- No anal fin
- Inconspicuous dorsal fin
- Teeth with single cusp; upper teeth long
and pointed, lower teeth short, broad and strongly oblique
- Large, scale-like dermal