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Sawsharks
A sawshark or saw shark is a member of a shark order (Pristiophoriformes ) bearing a unique long, saw-like rostrum (snout or bill) edged with sharp teeth, which they use to slash and disable their prey. There are eight species within the Pristiophoriformes, including the longnose or common sawshark (''Pristiophorus cirratus''), shortnose sawshark (''Pristiophorus nudipinnis''), Japanese sawshark ('' Pristiophorus japonicas''), Bahamas sawshark (''Pristiophorus schroederi''), sixgill sawshark ('' Pliotrema warreni''), African dwarf sawshark (''Pristiophorus nancyae''), Lana's sawshark ('' Pristiophorus lanae'') and the tropical sawshark ('' Pristiophorus delicatus''). Sawsharks are found in many areas around the world, most commonly in waters from the Indian Ocean to the southern Pacific Ocean. They are normally found at depths around 40–100 m, but can be found much lower in tropical regions. The Bahamas sawshark was discovered in deeper waters (640 m to 915 m) of the north ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pristiophorus Cirratus
The longnose sawshark (''Pristiophorus cirratus'') or common sawshark, is a sawshark of the family Pristiophoridae. Description The longnose sawshark has a slender, slightly flattened body with a very long rostrum that can make up to 30% of its total body length. It has pale yellow or grayish-brown dorsal coloring, white ventral coloring, and variegated, sometimes faint dark blotches, spots, and bars on its back. The barbels of the longnose sawshark are halfway down the rostrum, but slightly closer to the rostral tip than the nostrils. Its maximum length is . The longnose sawshark can be confused with one of many species of sawfish, a family of rays, but is distinguished by the five gills located on the sides of its head, as opposed to sawfish which have gills located on the underside of the head. Distribution and habitat The longnose sawshark is found in the eastern Indian Ocean around southern Australia and Tasmania on the continental shelf at depths of 20 - 600m. While it ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pristiophorus Schroederi
The Bahamas sawshark, ''Pristiophorus schroederi'', is a sawshark of the family Pristiophoridae, found in the western Central Atlantic Ocean from the Bahamas and Cuba at depths of between 400 and 1,000 m. These sharks are at least 80 cm long. The Bahamas sawshark is found on continental and insular slopes. Its reproduction is ovoviviparous. ''Pristiophorus schroederi'' is the first member of the sawsharks (family ''Pristiophoridae'') described from the western hemisphere.Springer, Stewart, and Harvey R. Bullis, Jr. "A New Species of Sawshark, Pristiophorus Schroederi, From the Bahamas." Bulletin of Marine Science 10.2 (1960): 241-54. Ingentaconnect. Web. May 31, 2013. Like its family members, it is most likely a descendant of the Cenozoic sawshark, ''Pristiophorus lanceolatus'' from New Zealand and Australia.Keyes, W. I. "The Cenozoic Sawshark Pristiophorus Lanceolatus (Davis) (Order Selachii) of New Zealand and Australia, with a Review of the Phylogeny and Distribution of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliotrema Warreni
The sixgill sawshark, ''Pliotrema warreni'' is a sawshark of the family Pristiophoridae. Unlike other sawsharks, the barbs on this shark's rostrum continue onto the sides of the head. Its barbels are also closer to its mouth than in other species. At maximum, females can reach over long, and males can reach over long. Range and habitat The sixgill sawshark is found in the temperate and subtropical waters of the western Indian Ocean between latitudes 23° S and 37° S, at depths of between . This shark lives in the benthic and benthopelagic zones of the continental shelf. Adults are partially segregated from juveniles, as they naturally tend to aggregate at lower depths. Behavior Using their sensitive barbels and electric sense, sixgill sawsharks are able to find their prey and then incapacitate them with their rostrum. Their known diet includes small fish, crustaceans, and squids. The only observed predator of the sixgill sawshark is the tiger shark, though it is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliotrema
''Pliotrema'' is a genus of sawsharks found in the Western Indian Ocean. Members of this genus differ from sawsharks of the genus '' Pristiophorus'' in having six gill slits. The presence of six pairs of gill slits highlights this genus among sharks; outside Hexanchiformes order, ''Pliotrema'' is the only shark genus with more than five gill slits. The genus was formerly monotypic, featuring only ''P. warreni'' until the two new species were described in 2020. Taxonomy The genus name ''Pliotrema'' comes from Ancient Greek ''pléōn'', meaning "many", and ''-trḗma'', meaning "holes". The specific name ''warreni'' honours Ernest Warren (1871–1945), who sent specimens to the British Museum. The specific names of the two new species are named for female relatives of Simon Weigmann, the senior author - his daughter for ''P. kajae'' and his niece for ''P. annae''. Species There are currently three recognized species in this genus: * '' Pliotrema annae'' Weigmann, Gon, Leeney & Tem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pristiophorus
''Pristiophorus'' is a genus of sawsharks found in the Pacific, Atlantic and Indian oceans. Members of this genus differ from sixgill sawsharks of the genus ''Pliotrema'' in having five gill slits. Their rostral sawteeth lack prominent transverse ridges on the basal ledges, and the large teeth are not posteriorly serrated. Taxonomy The genus name ''Pristiophorus'' comes from Ancient Greek ''pristēs'', meaning "saw", and ''-phóros'', meaning "bearing". Species There are currently seven recognized species in this genus: * ''Pristiophorus cirratus'' ( Latham, 1794) (Longnose sawshark) * '' Pristiophorus delicatus'' Yearsley, Last & W. T. White, 2008 (Tropical sawshark) * '' Pristiophorus japonicus'' Günther, 1870 (Japanese sawshark) * '' Pristiophorus lanae'' Ebert & Wilms, 2013 (Lana's sawshark) * ''Pristiophorus nancyae'' Ebert & Cailliet, 2011 (African dwarf sawshark) * ''Pristiophorus nudipinnis'' Günther, 1870 (Shortnose sawshark) * ''Pristiophorus peroniensis'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shortnose Sawshark
The shortnose sawshark, (''Pristiophorus nudipinnis'') or southern sawshark, is a sawshark of the family Pristiophoridae. The body of this shark is slightly compressed, and its rostrum is narrow. The two dorsal fins are almost identical in size. In color, the dorsal side of this sawshark tends to be uniformly slate gray, with few or no markings. The ventral side is pale white or cream. Females reach around long, and males reach around long. These sharks can live up to 9 years. Behavior Leading a benthic lifestyle, the shortnose sawshark primarily feeds on benthic invertebrates and small bony fish. Like other sawsharks, this species' reproduction is ovoviviparous. It gives birth biannually to a litter of 7-14 pups. The size of pups at birth is about . Conservation Because of stable commercial catch rates, reduced Total Allowable Catch, protection in Victorian waters, and a high rate of biological productivity, the shortnose sawshark is listed as Least Concern by the IUCN Red L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pristiophorus Nancyae
''Pristiophorus nancyae'', the African dwarf sawshark or dwarf sawshark, is a sawshark of the family Pristiophoridae. The species was discovered in 2011 when a specimen was caught off the coast of Mozambique at a depth of .California Academy of Sciences, "140 NEW SPECIES DESCRIBED BY CALIFORNIA ACADEMY OF SCIENCES IN 2011", California Academy of Sciences - San Francisco Museum and Planetarium - Bay Area Natural History Museum, December 14, 2011.http://www.calacademy.org/newsroom/releases/2011/new_species.php Description Like other sawsharks, the African dwarf sawshark has a long "saw" like snout, or rostrum. The rostrum is edged with pointy teeth that are used for both hunting and defense. This species is noted for its general elongated and slender form and a rostrum roughly 1/3 of its total length. This shark was named by researchers at the Pacific Shark Research Center at Moss Landing Marine Laboratories, the west coast representative of the National Shark Research Consorti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pristiophorus Japonicus
The Japanese sawshark (''Pristiophorus japonicus'') is a species of sawshark in the family Pristiophoridae. This shark has a long, narrow rostrum. Its first dorsal fin originates behind the tips of the pectoral fins, and its caudal fin is angled almost straight in line with the body. The Japanese sawshark reaches a maximum length of up to . Range and habitat Found in the northwest Pacific Ocean around Japan, Korea, Taiwan, and northern China between latitudes 48°N and 22°N. It is found over the sandy or muddy bottoms of the continental shelf at depths of . This species may vertically migrate in the water column because of changes in temperature. Behavior The Japanese sawshark has a varied diet of small benthic organisms. Like seemingly all sawsharks, this species is ovoviviparous. After an unknown gestation period, the female shark gives live birth to around 12 pups. These pups average around long. At sexual maturity the male is long, and the female is around long. Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pristiophorus Nudipinnis
The shortnose sawshark, (''Pristiophorus nudipinnis'') or southern sawshark, is a sawshark of the family Pristiophoridae. The body of this shark is slightly compressed, and its rostrum is narrow. The two dorsal fins are almost identical in size. In color, the dorsal side of this sawshark tends to be uniformly slate gray, with few or no markings. The ventral side is pale white or cream. Females reach around long, and males reach around long. These sharks can live up to 9 years. Behavior Leading a benthic lifestyle, the shortnose sawshark primarily feeds on benthic invertebrates and small bony fish. Like other sawsharks, this species' reproduction is ovoviviparous. It gives birth biannually to a litter of 7-14 pups. The size of pups at birth is about . Conservation Because of stable commercial catch rates, reduced Total Allowable Catch, protection in Victorian waters, and a high rate of biological productivity, the shortnose sawshark is listed as Least Concern by the IUCN Red L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Fin
Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only by muscles. Fish fins are distinctive anatomical features with varying structures among different clades: in ray-finned fish (Actinopterygii), fins are mainly composed of bony spines or rays covered by a thin stretch of scaleless skin; in lobe-finned fish ( Sarcopterygii) such as coelacanths and lungfish, fins are short rays based around a muscular central bud supported by jointed bones; in cartilaginous fish ( Chondrichthyes) and jawless fish ( Agnatha), fins are fleshy " flippers" supported by a cartilaginous skeleton. Fins at different locations of the fish body serve different purposes, and are divided into two groups: the midsagittal ''unpaired fins'' and the more laterally located ''paired fins''. Unpaired fins are pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gill Slit
Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of cartilaginous fish such as sharks and rays, as well as deep-branching vertebrates such as lampreys. In contrast, bony fishes have a single outer bony gill covering called an operculum. Most sharks and rays have five pairs of gill slits, but a few species have 6 or 7 pairs. Shark gill slits lie in a row behind the head. The anterior edge of a gill slit is motile, moving outward to allow water to exit, but closing to prevent reverse flow. A modified slit, called a spiracle, lies just behind the eye, which assists the shark with taking in water during respiration and plays a major role in bottom–dwelling sharks. Spiracles are reduced or missing in active pelagic sharks. While the shark is moving, water passes through the mouth and over the gills in a process known as "ram ventilation". While at rest, most sharks pump water over their gil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbel (anatomy)
In fish anatomy and turtle anatomy, a barbel is a slender, whisker like sensory organ near the mouth (sometimes called whiskers or tendrils). Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the zebrafish, the black dragonfish and some species of shark such as the sawshark. Barbels house the taste buds of such fish and are used to search for food in murky water. The word ''barbel'' comes from Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ... ''barbula'' 'little beard'. Barbels are sometimes erroneously referred to as '' barbs'', which are found in bird feathers for flight. Barbels may be located in a variety of locations on the head of a fish. "Maxillary barbels" refers to barbels on either side of the mouth. Barbels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
