Terry Jackson writes an informative article about the wonderful Black Mouth Shark:
The Latin name for these delicate members of the shark family is Galeus melastomus, and until a few years ago, they were almost un-heard of in Ireland. They are reasonably common in the deep waters of Western Scotland, but began to show up in good numbers around the Ulster coastline when small-boat anglers became proficient in deep-water anchoring. The Black-mouthed Dogfish is easily recognised by the anaconda-style elongated markings along the flanks and, as its name suggests, the inside of the mouth is completely black!

A stunning member of the shark species.
A stunning member of the shark species.

As their name suggests, the inside of the mouth is black
As their name suggests, the inside of the mouth is black

By submitting many detailed catches to the Irish Specimen Fish Committee over a period of three years, the organisation eventually recognised Black-Mouthed Dogfish as a new species in Irish waters and a viable angling target. As a naturally small species similar to the Lesser-spotted dogfish, there are no fighting qualities to be had, only an interesting curiosity in seeing this stunning little shark first hand, in all its glory. Their eyes are large and specifically designed for hunting in deep, cold waters and as with most shark species; they are equipped with a multitude of sensors to detect prey. In fact, their head is basically a living radar dish!
Wonderful python-like markings.
Wonderful python-like markings.

For such a small shark, they have a huge appetite and will take large baits destined for other species. The bite indication on the rod-tip would suggest a much larger fish has shown an interest, but once hooked, it’s a matter of reeling it to the surface with little feel of any fish at all on the line! Saying that, it is always a delight to see a Black-Mouth Dogfish break the surface.
Amazing green eyes, similar to that of a spurdog.
Amazing green eyes, similar to that of a spurdog.

As a point of interest, one female Black-Mouth actually dropped six egg-cases on the boat deck whilst un-hooking. I carefully put them in water and delivered them to Exploris, my local public salt-water aquarium. The gestation period was nine months, when all egg-cases successfully hatched. I believe this is the first time this has occurred in captivity. The young sharks were perfect replicas of the adult fish.
Typical baits to tempt a Black-Mouth.
Typical baits to tempt a Black-Mouth.

 
An egg-case from a Black-Mouthed Dogfish.
An egg-case from a Black-Mouthed Dogfish.

 
Colm Crothers with his first Black-Mouth Dogfish.
Colm Crothers with his first Black-Mouth Dogfish.

Terry Jackson.
Web: Terry Jackson blog