Did you know that many oviparous sharks can only lay 2 egg cases at a time (one from each oviduct)? A female blackmouth catshark is able to produce up to 13 eggs at a time (annually up to 100). The cases are bullet-shaped and without any tendrils.
Blackmouth catsharks are abundant in the northeastern Atlantic Ocean and the Mediterranean Sea. The bottom dwelling shark is little: up to 31 in -79 cm- for Atlantic sharks and 25 in -64 cm- for Mediterranean sharks (due to the lack of nutrients in the Mediterranean waters are the sharks there notoriously smaller than their Atlantic Ocean counterparts).
As seen in the picture, the shark has got a unique pattern of dark spots (most probably used for camouflage) on its back, and the inside of its mouth is black (thus its name). Its skin is very thick and covered by well-calcified dermal denticles. While hunting it uses its high number of ampullae of Lorenzini and its large eyes (the rod cells are most sensitive to the wavelengths emitted by bioluminescence, which is exhibited by most of the organisms it hunts).
Rarely used commercially, blackmouth catsharks are a common bycatch of bottom trawl and longline fisheries. Even discarded the sharks die. There are areas where most of the blackmouth catsharks captured are immature, suggesting there has been a negative impact of fishing pressure. But a ban on trawling deeper than 3,300 ft -1,000 m- in the Mediterranean seems to provide protection for the deep sea species.
Since 2005 the blackmouth catshark (Galeus melastomus) is a species of the shark family pentanchidae instead of catsharks, as still wrongly claimed in English sites.