The white ghost catshark (Apristurus aphyodes) is a shark of the catshark family Scyliorhinidae found in deep water in the northeast Atlantic between latitudes 57°N and 58°N. A deep-water catshark known from the eastern North Atlantic from depths of 1,014 to 1,800 m, it is known from only a limited number of specimens. It reaches a maximum of 54 cm or 1.7 ft total length which is a medium size for the Apristurus genus.
Description and morphology
The white ghost catshark has a slender and cylindrical body with a relatively long and flattened snout. It is distinguished from the other 10 North Atlantic Apristurus species by the following. It has a uniform whitish coloration and large oval eyes with a weak subocular fold. Its snout is bell shaped and contains numerous visible pores making up ampullae of Lorenzini on the dorsal and ventral side of the snout. Its preorbital snout length (where the snout intersects its eyes) equals half of its head length. Aphyodes has elliptical ampullae patterns on the ventral midline of the snout and a slender elliptical patch on the dorsal side. Aphyodes has a strongly arched mouth with well developed labial furrows (grooves around the lips) with its upper labial furrows shorter than its lower labial furrows. Aphyodes's spiracle is small and located slightly below the horizontal axis of its eyes. It has five small gill openings the smallest of which is located above its pectoral fin. Aphyodes has widely spaced pectoral and pelvic fins with their interspace about equal to the length of its head. Its pectoral fins are small, narrow and sub quadrangular(almost quadrilateral). In contrast their pelvic fins are more normal in proportion to their body size. The catshark's dorsal fins are unequal in size and unlike most sharks its first dorsal fin is smaller than its second dorsal fin. Its first dorsal fin starts above the anterior half of the pelvic base and ends in the interspace between its pelvic and anal fins. The second dorsal fin's origin is above the middle of the anal base and ends slightly before the anal fins. Aphyodes's anal and caudal fins are only separated by a distinct subterminal notch on the caudal fin. The caudal fin itself is slender and short and its lower anterior corner is slightly expanded. Its claspers are short but robust and portions are covered in dermal denticles. The reproductive organ lacks clasper hooks or claws. Dermal denticles on aphyodes's dorsal and lateral sides are concave and tricuspid (3 pointed) with the middle point being longer than the other 2.
Habitat
North Eastern Atlantic deep water off the coast of the UK is dominated by deep ocean basins. The average ocean depth is . Sediments are composed of clay particles and calcareous from phytoplankton. Near the continental shelf the sediment is primarily made of sand and mud scales. Deep water temperatures are 5.5–7.5 °C. Habitat characteristics are shaped by North Atlantic Deep Water and its resulting thermohaline circulation. Primary productivity in this part of the ocean is low and the area is considered oligotrophic or less than 100 g carbon per m2 per year, though it experiences short phytoplankton blooms of diatoms in the spring and fall due to the thermocline being weak in those times and strong upwelling and picoplankton blooms in the summer as the thermocline strengthens. Deep water corals consisting of Lophelia pertusa are the main reef building species present. They contain the area's highest biodiversity including species such as bryozoans, hydroids, sponges, redfish, saithe, cod, squat lobsters, squid, mollusks, starfish and sea urchins. Biodiversity in the area is also concentrate around hydrothermal vents. Three vent systems have been found in North Eastern Atlantic deep water named Lucy Strike, Menez Gwen and Rainbow.
Hunting patterns
Apristurus aphyodes preys upon crustaceans, cephalopods and small teleost (ray-finned) fish at depths of 1014 to 1080 m.