Spongehead catshark | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Chondrichthyes |
Superorder: | Selachimorpha |
Order: | Carcharhiniformes |
Family: | Scyliorhinidae |
Genus: | Apristurus |
Species: | A. spongiceps |
Binomial name | |
Apristurus spongiceps (C. H. Gilbert, 1905) | |
Range of the spongehead catshark | |
Synonyms | |
Catulus spongicepsGilbert, 1905 |
The spongehead catshark (Apristurus spongiceps) is a rare species of deep-sea catshark, family Scyliorhinidae. [2] This species was only known from two specimens taken in the Pacific Ocean: an adult from near Bird Island, Hawaii, and a juvenile from the Banda Sea off Sulawesi. They are found on or near the bottoms of insular continental slopes, at depths of 570 to 1,480 meters. [3] In 2002, the spongehead catshark was seen alive in its natural habitat for the first time, from the submersible Pisces IV at a depth of about a kilometer, on the Northampton Seamount off the northwestern Hawaiian Islands. [4]
The spongehead catshark has a thick body and head, with a moderately long, broadly rounded snout. The five pairs of gill slits are very small, and the septa between them are covered with unique pleats and folds that extend above and below, over the throat. The eyes are small and the nostrils are broad, with slit-like incurrent and excurrent openings. The mouth is long, large, and broadly arched, bearing prominently expanded dental bands. The two dorsal fins are about equal in size; the pectoral fins are rather small, while the pelvic fins are high and broadly rounded. The anal fin is short, high, and rounded. The caudal fin is moderately broad. The dermal denticles are closely set and give the skin a fuzzy or felt-like texture. It is dark brown, without fin markings. [3]
The adult holotype measured 51.4 cm long and the juvenile measured 10.5 cm long. [1] The juvenile was more slender than the adult, but shared the same distinctive pleated gills. As the holotype was a gravid female, the spongehead catshark is likely oviparous. [3] The spongehead catshark belongs to the A. spongiceps species group, characterized by a short, wide snout, seven to 12 valves in the spiral intestine, the upper labial furrows subequal to or shorter than the lower furrows, and a continuous supraorbital sensory canal. [1]
The prickly shark is one of the two species of sharks in the family Echinorhinidae, found in the Pacific Ocean over continental and insular shelves and slopes, and in submarine canyons. Bottom-dwelling in nature, it generally inhabits cool waters 100–650 m (330–2,130 ft) deep, but it also frequently enters shallower water in areas such as Monterey Bay off California. This stocky, dark-colored shark grows up to 4.0 m (13.1 ft) long, with two small dorsal fins positioned far back on its body and no anal fin. It is characterized by a dense covering of thorn-like dermal denticles, hence its common name.
The lollipop catshark is a little-known species of deep sea catshark, belonging to the family Scyliorhinidae, and the only described member of its genus. A diminutive, bottom-dwelling shark of the outer continental shelf and upper continental slope, this species can be readily identified by its tadpole-like shape with a greatly expanded, rounded head and narrow body. The large head houses expanded gills, which are thought to be an adaptation for hypoxic conditions. This shark preys on crustaceans and fishes. Reproduction is aplacental viviparous, with females retaining egg cases internally two at a time until they hatch. There is no fishery interest in this species.
The blotchy swellshark, or Japanese swellshark, is a common species of catshark, belonging to the family Scyliorhinidae. The Blotchy swellshark is found at depths of 90–200 m (300–660 ft) in the northwestern Pacific Ocean, from Japan to Taiwan. It is benthic in nature and favors rocky reefs. Reaching 1.4 m (4.6 ft) in length, this thick-bodied shark has a broad head, large mouth, and two unequally-sized dorsal fins positioned far back past the pelvic fins. It can be identified by its dorsal coloration, consisting of seven brown "saddles" and extensive darker mottling on a light tan background. This species has often been confounded with the draughtsboard shark and the Sarawak pygmy swellshark in scientific literature.
The Izak catshark or simply Izak is a species of catshark, belonging to the family Scyliorhinidae, common off the coasts of South Africa and southern Namibia. It typically inhabits the outer continental shelf at depths of 100–300 m (330–980 ft), with the males found deeper than the females and juveniles. The Izak catshark has a short, wide, flattened head and a robust body tapering to a long, slender tail. It can be identified by its ornate color pattern of dark brown spots or reticulations and blotches on a light yellowish background, as well as by the enlarged dermal denticles over its pectoral fins and along its dorsal midline from the snout to the second dorsal fin. This species reaches 69 cm (27 in) in length, with the males larger than females.
The tiger catshark is a species of catshark, belonging to the family Scyliorhinidae. It is found over sandy areas and near reef peripheries off South Africa and perhaps Mozambique, from close to shore to usually no deeper than 100 m (330 ft). Reaching a length of 50 cm (20 in), this small, slim shark has a broad, flattened head with an upturned snout tip. It can additionally be identified by its dorsal colour pattern of ten dark brown saddles on a yellowish brown background.
The southern African frilled shark is a species of shark in the family Chlamydoselachidae, described in 2009. It is found in the deep waters off southern Angola to southern Namibia. This species is difficult to distinguish from the better-known frilled shark, but is smaller at maturity and differs in several proportional measurements including head length and mouth width. It seems to be a specialized predator of smaller sharks, using its flexible jaws and numerous needle-like, recurved teeth to capture and swallow them whole. Reproduction is presumably aplacental viviparous, as with the other member of its family.
The roughtail catshark or marbled catshark is a common species of catshark, part of the family Scyliorhinidae. It is found at a depth of 36–702 m (118–2,303 ft) in the northwestern Atlantic Ocean, the Gulf of Mexico, and the Caribbean Sea, from North Carolina to Costa Rica. Individuals of different sexes and ages are segregated to some degree. A small species not exceeding 33 cm (13 in) in length, the roughtail catshark has a slender body with a marbled color pattern of dark saddles and spots, and a prominent crest of enlarged dermal denticles along the dorsal edge of its caudal fin. This species feeds mainly on shrimp and is oviparous. It is caught incidentally in shrimp trawls, though trawl fisheries within its range mostly do not operate at the depths it inhabits. As a result, the International Union for Conservation of Nature has listed it under Least Concern.
The longfin sawtail catshark is a rare, little-known species of catshark, part of the family Scyliorhinidae. Once thought to be a subspecies of the roughtail catshark along with the Antilles catshark, it inhabits deep water off the Caribbean coasts of Panama and Colombia. This slim-bodied species has a marbled dorsal color pattern and a prominent crest of enlarged dermal denticles along the dorsal edge of its caudal fin. It can be distinguished from similar species by its relatively longer anal fin and small adult length of under 35 cm (14 in). The longfin sawtail catshark is oviparous.
The longnose sawtail catshark is a little-known species of catshark, part of the family Scyliorhinidae, found off the northwestern Pacific islands of Amami Ōshima, Ogasawara, and Izu at depths of 350–550 m (1,150–1,800 ft). Reaching a length of 80 cm (31 in), it is characterized by a long flattened snout, a long space between the pelvic and anal fins, and a crest of enlarged dermal denticles along the dorsal caudal fin edge. Adults are plain dark gray above, while juveniles have a few faint dark saddles on the back and tail.
The mouse catshark is a species of catshark and part of the family Scyliorhinidae. It is common in the northeastern Atlantic Ocean from Iceland to Western Sahara. There is much taxonomic confusion regarding this species in Icelandic waters, where it may be confounded with another species of Galeus or Apristurus. Probably not exceeding 49 cm (19 in) long, the mouse catshark has a uniformly brown body and is characterized by large, rounded pelvic fins and crests of enlarged dermal denticles along both the dorsal and ventral caudal fin margins. In addition, in adult males the inner margins of the pelvic fins are merged into an "apron".
The African sawtail catshark is a species of catshark, part of the family Scyliorhinidae. Demersal in nature, it is found at depths of 160–720 m (520–2,360 ft) off the western African coast from Morocco to South Africa. This slender species has a rather long, pointed snout, a series of dark saddles along the back and tail, and a prominent crest of enlarged dermal denticles along the upper edge of the caudal fin. Its maximum known length is 46 cm (18 in).
The dwarf sawtail catshark is a little-known species of catshark, belonging to the family Scyliorhinidae, found exclusively in the deep waters off Luzon in the Philippines. Unlike other members of its genus, this slender, diminutive shark has a short, rounded snout and very short furrows at the corners of its jaws. It has indistinct darker saddles beneath each dorsal fin and two dark bands on the caudal fin, as well as a prominent crest of enlarged dermal denticles along the upper caudal fin margin.
Springer's sawtail catshark is a little-known species of catshark, belonging to the family Scyliorhinidae, found in waters 457–699 m (1,499–2,293 ft) deep off the islands of the Antilles, from Cuba to the Leewards. A small, slim-bodied species reaching a length of 48 cm (19 in), the Springer's sawtail catshark can be identified by its color pattern of horizontal dark stripes in front of the first dorsal fin, and dark dorsal saddles behind. It is additionally characterized by the presence of saw-toothed crests, made of enlarged dermal denticles along both the dorsal and the ventral edges of the caudal fin. The Springer's sawtail catshark is oviparous.
The white ghost catshark 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.
The Japanese catshark is a catshark of the family Scyliorhinidae, found in the northwest Pacific off Chiba Prefecture, Honshū, Japan, between 36 and 34°N. This shark has a relatively slender body, with the trunk tapering towards the head. Its snout is moderately long, bell-shaped, and broad; the preoral snout is about 7 to 8% of total its length. It has large gill slits, rather small eyes in adults, nostrils fairly broad, and a long broad, arched mouth. It is commonly taken by trawl off the type locality, and possibly used for oil, human consumption, and fishmeal or fish cakes locally.
The Iceland or Icelandic catshark is a species of catshark, belonging to the family Scyliorhinidae. This catshark is found in the western Atlantic, from Massachusetts, Delaware, and the northern Gulf of Mexico, as well as the eastern Atlantic from Iceland, southwestern Ireland, the Canary Islands, Madeira, South Africa, and between 67 and 11°N. They are found in depths of 550 to 1450 meters near or at the bottom over upper continental slopes.
The longhead catshark or smoothbelly catshark is a species of catshark, family Scyliorhinidae, with a patchy distribution in the Indo-Pacific from Mozambique to southern Japan to northern Australia. It is found in water between 500 and 1,140 m deep. This species grows to 59 cm (23 in) long and is characterized by its extremely long and narrow snout, short abdomen, and long anal and caudal fins. In addition, a large area of the anterior ventral portion of its body lacks dermal denticles. The longhead catshark is oviparous and the only known cartilaginous fish that is normally hermaphroditic, with the majority of individuals having both the functional reproductive organs of one sex and the undeveloped reproductive organs of the opposite sex.
The whitefin swellshark is a little-known species of catshark, belonging to the family Scyliorhinidae, endemic to southeastern Australia. It is found 126–554 m (413–1,818 ft) down, on the outer continental shelf and upper continental slope. Reaching 1.1 m (3.6 ft) in length, this shark has a very thick body and a short, broad, flattened head with a large mouth. It is characterized by a dorsal color pattern of dark saddles and blotches over a brown to gray background, and light fin margins. When threatened the whitefin swellshark can inflate itself with water or air to increase its size. Reproduction is oviparous. As of 2019 The International Union for Conservation of Nature(IUCN) has assessed this species as Critically Endangered due to the significant decline of the population.
The saddled swellshark is a rare species of catshark, and part of the family Scyliorhinidae, endemic to Eastern Australia. This bottom-dwelling species is found on the outer continental shelf and upper continental slope at a depth of 115–605 m (377–1,985 ft). It is a robustly built shark with a short, broad, flattened head and a capacious mouth. Adults are patterned with saddles on a brownish or grayish background, which varies between tropical and temperate sharks; juveniles are light-colored with many spots. This shark reaches 74 cm (29 in) in length. Like other swellsharks, it can inflate itself as a defensive measure. Reproduction is oviparous.
The painted swellshark is a little-known species of catshark, belonging to the family Scyliorhinidae, found in eastern Indonesia. This species reaches a maximum known length of 72 cm (28 in), and has a thick body with a short, broad and flattened head. It is dark gray with a variegated pattern of irregular darker and lighter blotches above, and lighter below with gray blotches and speckling on the snout. Like other swellsharks, it can inflate itself as a defensive measure.