Pacific white skate
Encyclopedia
The Pacific white skate (Bathyraja spinosissima) is a species of skate
, family Rajidae. It is one of the deepest-living of all skates, occurring at a depth of 800 to 2,938 m on the continental slope. It is native to the southeast Pacific Ocean
from the Galapagos Islands
to off Waldport, Oregon
; an egg case and embryo
has been collected from the Farallon Islands
off San Francisco. Reports of it from the Sea of Okhotsk
may represent a different species. Its species name, spinosissima, comes from the Latin
spinosus meaning "thorny", referring to its covering of dermal denticles.
The flattened pectoral fin disc of the Pacific white skate is slightly wider than long, with broadly rounded tips. The disc is covered with numerous small denticles above and below, giving it a shagreen
-like texture. Adult males possess alar spines (on the dorsal surface of the pectoral fins near the tips). The tail is slightly longer than the disc, bearing a single median row of 23-29 thorns and two similar-sized dorsal fin
s near the end without an interdorsal thorn. The caudal fin is long and taperine, with a filamentous fold on its upper surface. Its teeth number 34 in the upper jaw and 23 in the lower. This species is a uniform pale to salty gray above and below, with dusky outer disc margins.
The Pacific white skate feeds on benthic fish
es. Like other skates they are oviparous; the egg cases are olive green in color and longitudinally striated, with horn-like projections on the shell. The size at birth is about 25 cm; the maximum known size is 1.5 m. They are of no commercial interest but are occasionally taken as by-catch
.
Skate
Skates are cartilaginous fish belonging to the family Rajidae in the superorder Batoidea of rays. There are more than 200 described species in 27 genera. There are two subfamilies, Rajinae and Arhynchobatinae ....
, family Rajidae. It is one of the deepest-living of all skates, occurring at a depth of 800 to 2,938 m on the continental slope. It is native to the southeast Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
from the Galapagos Islands
Galápagos Islands
The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...
to off Waldport, Oregon
Waldport, Oregon
Waldport is a city in Lincoln County, Oregon, United States. The population was 2,050 at the 2000 census. The city is located on the Alsea River and Alsea Bay, south of Newport and north of Yachats.-Geography:...
; an egg case and embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
has been collected from the Farallon Islands
Farallon Islands
The Farallon Islands, or Farallones , are a group of islands and sea stacks in the Gulf of the Farallones, off the coast of San Francisco, California, USA. They lie outside the Golden Gate and south of Point Reyes, and are visible from the mainland on clear days...
off San Francisco. Reports of it from the Sea of Okhotsk
Sea of Okhotsk
The Sea of Okhotsk is a marginal sea of the western Pacific Ocean, lying between the Kamchatka Peninsula on the east, the Kuril Islands on the southeast, the island of Hokkaidō to the far south, the island of Sakhalin along the west, and a long stretch of eastern Siberian coast along the west and...
may represent a different species. Its species name, spinosissima, comes from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
spinosus meaning "thorny", referring to its covering of dermal denticles.
The flattened pectoral fin disc of the Pacific white skate is slightly wider than long, with broadly rounded tips. The disc is covered with numerous small denticles above and below, giving it a shagreen
Shagreen
Shagreen is a type of leather or rawhide consisting of rough untanned skin, formerly made from a horse's back or that of an onager . Shagreen is now commonly made of the skins of sharks and rays....
-like texture. Adult males possess alar spines (on the dorsal surface of the pectoral fins near the tips). The tail is slightly longer than the disc, bearing a single median row of 23-29 thorns and two similar-sized dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
s near the end without an interdorsal thorn. The caudal fin is long and taperine, with a filamentous fold on its upper surface. Its teeth number 34 in the upper jaw and 23 in the lower. This species is a uniform pale to salty gray above and below, with dusky outer disc margins.
The Pacific white skate feeds on benthic fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
es. Like other skates they are oviparous; the egg cases are olive green in color and longitudinally striated, with horn-like projections on the shell. The size at birth is about 25 cm; the maximum known size is 1.5 m. They are of no commercial interest but are occasionally taken as by-catch
By-catch
The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...
.