Line
Class
kgs |
Line
Class
lbs |
Weight
in
kgs |
Weight
in
lbs. ozs |
Place
of
capture |
Country
of
capture |
Date
of
capture |
Name
of
angler |
SHARK, SHARPNOSE SEVEN-GILL / HEPTRANCHIAS PERLO |
| 60 |
130 |
5.20 |
11.7 |
Two Mile Reef |
Gibraltar |
260395 |
E. Borrell |
| AT |
AT |
5.20 |
11.7 |
Two Mile Reef |
Gibraltar |
260395 |
E. Borrell |
|
The Sharpnose Seven-gill Shark (Heptranchias Perlo), as a deepwater species, lives in waters on outer continental and insular shelves at depths from 89-3,280 feet (27-1000 m). It is usually found on or near the bottom, although on occasion it is observed close to the surface. Its wide distribution range suggests that the seven-gill shark is probably a strong swimmer.
The moderately small sharpnose sevengill shark has a slender, fusiform body with a narrow, pointed head, large green eyes and a long narrow mouth.
It has seven pairs of gill slits in contrast to the five gills that most sharks possess. These gill opening extend down onto the throat. There is only one small dorsal fin which originates over the inner margins of the pelvic fins. The front edge of the dorsal fin is either straight or slightly convex while the apex is rounded and rear edge concave. The anal fin is also small in size with nearly straight edges, originating under the posterior end of the base of the dorsal. The pectoral fin is small with a weakly convex outer margin and narrowly rounded apex. The caudal axis is just slightly raised with a convex upper margin and a subterminal notch on the lower margin.
Coloration of the sharpnose sevengill shark is brownish grey to olive on the dorsal surface, paling to a lighter ventral surface. Adults may have indistinct pale posterior margins on all fins as well as faint dark blotches on the body. Live specimens have large fluorescent green eyes. Juveniles may have dark blotches in the flank area as well as dark tips on the dorsal and caudal fins.
The smallest hexanchoid shark, the sharpnose sevengill shark grows to a maximum length of 4.5 feet (1.37 m) total length for males and 4.6 feet (1.40 m) total length for females. However, this species is more commonly observed at lengths of 2-4 feet (.6-1.2 m). Males reach maturity at 2.4-2.8 feet (.75-.85 m) total length and females reach maturity at slightly larger sizes of 3.0-3.3 feet (.9-1.0 m) total length. Biologists have observed formation of mucus on the tips of the claspers on mature and subadult males. It is believed this indicates the onset of maturity and perhaps sexual activity.
Although this shark is rather small in size, it is a voracious predator. As a generalist, it feeds on marine invertebrates including shrimp, crabs, lobsters, squid and cuttlefish as well as small bony fish, such as hake, and small sharks and rays. Feeding and activity increases during the night time hours.
The sharpnose sevengill shark is an ovoviviparous species. There appears to be
no set reproductive season. Following gestation, from 9-20 pups are born in each
litter. Each newborn pup measures approximately .8 feet (.25 m) in length.
Information supplied by www.flmnh.ufl.edu
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