Giant black ghostshark

9/7/2016

The giant black ghostshark is… odd. Mainly because it’s not an actual ghost, but a rather large (1.5 meters), oviparous chimaera. They are dark brown to black in color, with immature giant black ghostsharks actually being a chocolate brown color. Melissa note: A winner for the #stupidcommonnames, me thinks. It’s also made me really want chocolate and there is none in the house.

This does cause a problem though, as the immature young ones could possibly be confused with the immature Hydrolagus trolli, as their ranges seem to overlap.

They are a smooth-skinned chimaera, and a sport a rather large spine in front of their dorsal fin (about equal in height). Their pectoral fins are triangular in shape, and their pelvic fins are broad and also triangular. Curious thing: they lack an anal fin.

The giant black ghostshark’s scientific name is currently Hydrolagus cf. affinis, and has been called H. sp. D, a sister species to H. affinis which is known throughout the Atlantic. This critter occurs in the North Atlantic to the Pacific, and was even observed in the Pacific-Antarctic Ridge. It seems to be widespread on deepsea slopes around southern Australia, Tasmania and New Zealand. Trawl fisheries catch it around the Lord Howe Rise, Macquarie Ridge and southern Campbell Plateau at around 731- 225 meters, but most commonly found below 1,000 meters. Like other chimaeras, they are benthic.

Their IUCN assessment is currently Data Deficient (DD).

Interested in learning more? So are we!

glossary

Benthic zone: The bottom of an ocean or lake.
Dorsal fin: Fin located on the back.
IUCN: International Union for Conservation of Nature.

Oviparity/oviparous: Where adult Chondrichthyans lay eggcases (also known as ‘mermaid’s purses) and the baby develops inside the egg before hatching.
Pectoral fins: Fins located behind the gills on either side.
Pelvic fins: Fins located on the underside of a fish’s body, attached to their pelvic girdle.
Pups: Baby sharks.
Trawl fisheries: Fisheries that pull a fishing net through the water behind one or more boats.