Cartilaginous Fish at Axial

Skates and sharks have cartilage skeletons, and are classified separately from the Bony Fish.  At Axial Seamount, two skate species and no sharks have been observed to date.

Deep Sea Skate (Bathyraja abyssicola)

This Deep Sea Skate was photographed by the ROV ROPOS at 1756 m (5761 feet) beneath the ocean’s surface on the flank of Axial Seamount. Photo credit: NSF-OOI/UW/CSSF; Dive R1466; V11

Bathyraja abyssicola, the Deep Sea Skate, also known as the Abyssal Skate, is a relatively rare species of skate found at sites all around the North Pacific Ocean, yet is has been sighted several times at Axial Seamount.  This skate grows to be around 1.1 m in length at maturity, and can be found at depths between 0 and 3000 m. It is known to have a diet of mollusks, supplemented with bony fish. It is an egg-layer, with horned, oblong eggs 100 mm long and 65 mm wide.
References:
http://www.fishbase.org/summary/22552
http://www.iucnredlist.org/details/2636/0
http://eol.org/pages/208497/details

 

Roughtail Skate (Bathyraja trachura)

A Roughtail Skate (Bathyraja trachura) was found resting near a vent on Axial Seamount. Photo credit: NSF-OOI/UW/CSSF; Dive R1617; V13

Bathyraja trachura, also known as the Roughtail Skate, is a species of skate found all across the North Pacific Ocean. The Roughtail Skate is a higher-order predator, eating mainly crustaceans and bony fish, although specimens have been found to eat a number of worms and other, smaller animals.
The Roughtail Skate is a bottom-dweller, and can be found all over Axial Seamount. This skate is typically 70 to 80 cm in length, although specimens can be found that are only 90 cm long. Juveniles are born at around 9 to 16 cm long, in distinctively oblong, horned eggs.
References:
http://www.fishbase.org/summary/Bathyraja-trachura.html
http://www.iucnredlist.org/details/161375/0
http://eol.org/pages/212615/detailsTrophic Interactions of Bathyraja trachura and Sympatric Fishes, Boyle