The blacknose shark ("Carcharhinus acronotus") is a species of requiem shark, belonging to the family Carcharhinidae, common in the tropical and subtropical waters of the western Atlantic Ocean. This species generally inhabits coastal seagrass, sand, or rubble habitats, with adults preferring deeper water than juveniles. A small shark typically measuring long, the blacknose has a typical streamlined "requiem shark" shape with a long, rounded snout, large eyes, and a small first dorsal fin. Its common name comes from a characteristic black blotch on the tip of its snout, though this may be indistinct in older individuals. Blacknose sharks feed primarily on small bony fishes and cephalopods, and in turn fall prey to larger sharks.
Introduction
Blacknose shark
Blacknose shark | Introduction
Tropical and subtropical waters of the western Atlantic Ocean In the tropical and subtropical waters of western Atlantic Ocean. In the tropical and subtropical waters of the western Atlantic Ocean. Tropical and subtropical waters of the western Atlantic Ocean
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Carcharhinus acronotus
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The blacknose shark ("Carcharhinus acronotus") is a species of requiem shark, belonging to the family Carcharhinidae, common in the tropical and subtropical waters of the western Atlantic Ocean. This species generally inhabits coastal seagrass, sand, or rubble habitats, with adults preferring deeper water than juveniles. A small shark typically measuring long, the blacknose has a typical streamlined "requiem shark" shape with a long, rounded snout, large eyes, and a small first dorsal fin. Its common name comes from a characteristic black blotch on the tip of its snout, though this may be indistinct in older individuals. Blacknose sharks feed primarily on small bony fishes and cephalopods, and in turn fall prey to larger sharks.
Blacknose shark | Introduction
falciformis") and the blacktip reef shark ("C. melanopterus"). Molecular analyses have been similarly equivocal regarding the blacknose shark's phylogenetic relationships: Gavin Naylor's 1992 allozyme analysis found this species to be the most basal member of "Carcharhinus", while Mine Dosay-Abkulut's 2008 ribosomal DNA analysis indicated affinity between it and the blacktip shark ("C. limbatus") or the smalltail shark ("C. porosus"). The whitenose shark ("Nasolamia velox"), found along the tropical western coast of the Americas, may be descended from blacknose sharks that experienced the teratogenic effects of incipient cyclopia.
Blacknose shark | Taxonomy and phylogeny
The display consists of the shark hunching its back, lowering its pectoral fins, gaping its jaws, and swimming with an exaggerated side-to-side motion. Known parasites of this species include the copepods "Nesippus orientalis", "Perissopus dentatus", "Pandarus sinuatus", "Kroyeria sphyrnae", "Nemesis atlantica", and "Eudactylina spinifera", as well as tapeworms in the genera "Paraorygmatobothrium" and "Platybothrium".
Blacknose shark | Biology and ecology
The Cuban naturalist Felipe Poey published the first description of the blacknose shark in 1860 as "Squalus acronotus", in his "Memorias sobre la historia natural de la Isla de Cuba". Later authors moved this species to the genus "Carcharhinus". The type specimen was a 98-cm (3.2-ft)-long male caught off Cuba. Based on morphological data, Jack Garrick suggested in 1982 that the blacknose shark has a sister relationship to a group containing the whitecheek shark ("C. dussumieri") and the blackspot shark ("C. sealei"), while Leonard Compagno proposed in 1988 that this shark belongs in a group with five other species, including the silky shark ("C.
Blacknose shark | Taxonomy and phylogeny
A distinctive dark blotch at the tip of the snout is most obvious in young sharks. The tips of the second dorsal fin, upper caudal fin lobe, and sometimes the lower caudal fin lobe, are dark. Blacknose sharks are typically long and in weight. The maximum length and weight on record is and , respectively.
Blacknose shark | Description
Subsequent authors moved the blacktip reef shark to the genus "Carcharhinus"; in 1965 the International Commission on Zoological Nomenclature designated it as the type species for the genus. In some earlier literature, the scientific name of this shark was mistakenly given as "C. spallanzani", now recognized as a synonym of the spottail shark ("C. sorrah"). Other common names for this species include blackfin reef shark, black-finned shark, blacktip shark, reef blacktip shark, and guliman.
Blacktip reef shark | Taxonomy
The first dorsal fin is small and somewhat sickle-shaped, with a pointed apex and a short, free, rear tip; its origin lies over the free rear tips of the pectoral fins. The second dorsal fin is relatively large, though still less than half the height of the first. No ridge is seen between the dorsal fins. The pectoral fins are short and tapered. The body is covered with overlapping dermal denticles that bear five to seven longitudinal ridges (three in very young individuals) leading to three to five marginal teeth. The coloration is yellowish to greenish-gray or brown above and white to yellow below.
Blacknose shark | Description
The bignose shark ("Carcharhinus altimus") is a species of requiem shark, in the family Carcharhinidae. Distributed worldwide in tropical and subtropical waters, this migratory shark frequents deep waters around the edges of the continental shelf. It is typically found at depths of , though at night it may move towards the surface or into shallower water. The bignose shark is plain-colored and grows to at least in length. It has a long, broad snout with prominent nasal skin flaps, and tall, triangular upper teeth. Its pectoral fins are long and almost straight, and there is a ridge on its back between the two dorsal fins.
Bignose shark | Introduction
Dutch ichthyologist Pieter Bleeker first described the grey reef shark in 1856 as "Carcharias (Prionodon) amblyrhynchos", in the scientific journal "Natuurkundig Tijdschrift voor Nederlandsch-Indië". Later authors moved this species to the genus "Carcharhinus". The type specimen was a -long female from the Java Sea. Other common names used for this shark around the world include black-vee whaler, bronze whaler, Fowler's whaler shark, graceful shark, graceful whaler shark, grey shark, grey whaler shark, longnose blacktail shark, school shark, and shortnose blacktail shark. Some of these names are also applied to other species. In older literature, the scientific name of this species was often given as "C.
Grey reef shark | Taxonomy and phylogeny
The hardnose shark was described by German biologists Johannes Müller and Jakob Henle in their 1839 "Systematische Beschreibung der Plagiostomen". They named it "Carcharias (Hypoprion) macloti" in honour of Heinrich Christian Macklot, who collected the type specimen from New Guinea. In 1862, American ichthyologist Theodore Gill elevated "Hypoprion" to the rank of full genus, with "C. macloti" as the type species. In 1985, Jack Garrick synonymised "Hypoprion" with "Carcharhinus". This species may also be called Maclot's shark.
Hardnose shark | Taxonomy
Because of its very patchy range, the copper shark has been scientifically described several times from different locales. The earliest valid description is presently considered to be British zoologist Albert Günther's account of "Carcharias brachyurus" in the 1870 eighth volume of "Catalogue of the fishes in the British Museum". The earliest name was once thought to be Auguste Duméril's 1865 "Carcharias remotus", until it was found that the type specimen associated with that name is actually a blacknose shark ("C. acronotus"). Thus, this shark was often referred to as "C. remotus" in older literature. An even earlier name, Richard Owen's 1853 "Galeolamna greyi", is of questionable taxonomic status as it was based solely on a set of now-destroyed jaws that may or may not have belonged to a copper shark.
Copper shark | Taxonomy
The blacknose shark has a slender, streamlined body with a long, rounded snout and large eyes. A well-developed flap of skin occurs in front of each nostril, defining the inflow and outflow openings. Twelve to 13 and 11 to 12 tooth rows occur on either side of the upper and lower jaws, respectively, with one or two teeth at the symphysis (middle). The teeth are triangular and oblique, with serrated edges; the upper teeth are stouter than the lower teeth. The five pairs of gill slits are short, measuring less a third the length of the first dorsal fin base.
Blacknose shark | Description
"salmonicida".
Blacktip reef shark | Biology and ecology
The small dermal denticles have sharp wedge-shaped crowns bearing median ridges, and are placed on stalks (pedicels). This species is dark brown, with prominent blackish, then light bands at the fin margins. The underside is covered by minute light-producing photophores.
Longnose pygmy shark | Description
The Caribbean sharpnose shark ("Rhizoprionodon porosus") is a requiem shark, and part of the family Carcharhinidae. It is found in the tropical waters of the western Atlantic Ocean and the Caribbean, between latitudes 28° N and 40° S, from the surface to a depth of 500 m. It can reach a length of about 1.1 m.
Caribbean sharpnose shark | Introduction
However, Lesson's name remained forgotten for so long that "Carcharhinus longimanus" remains widely accepted.
Oceanic whitetip shark | Taxonomy
The hardnose shark ("Carcharhinus macloti") is a species of requiem shark, in the family Carcharhinidae, so named because of the heavily calcified cartilages in its snout. A small bronze-coloured shark reaching a length of , it has a slender body and a long, pointed snout. Its two modestly sized dorsal fins have distinctively elongated rear tips. The hardnose shark is widely distributed in the western Indo-Pacific, from Kenya to southern China and northern Australia. It inhabits warm, shallow waters close to shore. Common and gregarious, the hardnose shark is a predator of bony fishes, cephalopods, and crustaceans. This species is viviparous, with the growing embryos sustained to term via a placental connection to their mother.
Hardnose shark | Introduction
Males attain a length of and females . There are unsubstantiated records of individuals long. The maximum known weight is .
Daggernose shark | Description
Sharks present were the great white shark ("Carcharodon carcharias") and the extinct broad-toothed mako ("Cosmopolitodus hastalis").
Orcinus paleorca | Paleobiology
The blacktip shark was first described by French zoologist Achille Valenciennes as "Carcharias (Prionodon) limbatus" in Johannes Müller and Friedrich Henle's 1839 "Systematische Beschreibung der Plagiostomen". The type specimens were two individuals caught off Martinique, both of which have since been lost. Later authors moved this species to the genus "Carcharhinus". The specific epithet "limbatus" is Latin for "bordered", referring to the black edges of this shark's fins. Other common names used for the blacktip shark include blackfin shark, blacktip whaler, common or small blacktip shark, grey shark, and spotfin ground shark.
Blacktip shark | Taxonomy
Shark expert Stewart Springer described the bignose shark as "Eulamia altima" in a 1950 issue of the scientific journal "American Museum Novitates". Later authors have regarded the genus "Eulamia" as a synonym of "Carcharhinus". The specific epithet "altimus" is derived from the Latin "altus" ("deep"), and refers to the shark's deepwater habits. The type specimen is an immature female long, caught off Cosgrove Reef in the Florida Keys on April 2, 1947. An alternate common name for this species is Knopp's shark, originally used by Florida fishery workers since before the species was described. Phylogenetic studies published by Jack Garrick in 1982 and Leonard Compagno in 1988, based on morphology, placed the bignose shark in the ""obscurus" group" of "Carcharhinus", centered on the dusky shark ("C.
Bignose shark | Taxonomy and phylogeny
The spinner shark was originally described as "Carcharias (Aprion) brevipinna" by Johannes Peter Müller and Friedrich Gustav Jakob Henle in their 1839 "Systematische Beschreibung der Plagiostomen", based on the mounted skin of a 79-cm-long specimen collected off Java. This species was subsequently moved to the genera "Aprion", "Squalus", and "Aprionodon" before being placed within the genus "Carcharhinus". The tooth shape and coloration of this species varies significantly with age and between geographical regions, which caused much taxonomic confusion. Other common names include black-tipped shark, great blacktip shark, inkytail shark, large blacktip shark, long-nose grey shark, longnose grey whaler, and smoothfang shark.
Spinner shark | Taxonomy and phylogeny
The blacknose shark inhabits the continental and insular shelves off the eastern coast of the Americas, as far north as North Carolina and as far south as southern Brazil, including the Bahamas, the Gulf of Mexico, and the Caribbean Sea. They frequent coastal waters over beds of seagrass, sandy flats, and shell or coral rubble. This species is spatially segregated by size and sex. Generally, only young sharks are encountered in shallow water, as the adults prefer depths greater than and is most common at . Blacknose sharks in the South Atlantic Bight (off the Atlantic coast of the southern United States) migrate northward in the summer and southward (or possibly offshore) in the winter; a similar migration occurs for sharks in the Gulf of Mexico.
Blacknose shark | Distribution and habitat
The great white shark was one of the many amphibia originally described by Carl Linnaeus in his landmark 1758 10th edition of "Systema Naturae", with its first scientific name, "Squalus carcharias". Later, Sir Andrew Smith gave it "Carcharodon" as its generic name in 1833, and also in 1873. The generic name was identified with Linnaeus' specific name and the current scientific name, "Carcharodon carcharias", was finalized. "Carcharodon" comes from the Ancient Greek words (, 'sharp' or 'jagged'), and (), (, 'tooth').
Great white shark | Taxonomy
The blacktip shark ("Carcharhinus limbatus") is a species of requiem shark, and part of the family Carcharhinidae. It is common to coastal tropical and subtropical waters around the world, including brackish habitats. Genetic analyses have revealed substantial variation within this species, with populations from the western Atlantic Ocean isolated and distinct from those in the rest of its range. The blacktip shark has a stout, fusiform body with a pointed snout, long gill slits, and no ridge between the dorsal fins. Most individuals have black tips or edges on the pectoral, dorsal, pelvic, and caudal fins. It usually attains a length of .
Blacktip shark | Introduction
A single small dorsal fin is located behind the pelvic fins, with a straight front margin, narrowly rounded tip, and concave rear margin. The pectoral fins are small with a weakly convex outer margin. The anal fin is small with nearly straight margins. The caudal peduncle is long, and the distance between the dorsal fin origin and the caudal fin is more than twice the dorsal fin base. The closely overlapping dermal denticles are very thin and transparent; each is longer than it is broad, bearing a distinct median ridge and two lateral ridges ending in marginal teeth. The coloration is brownish gray to olive above and lighter below; some individuals have dark blotches on the body or light posterior fin margins.
Sharpnose sevengill shark | Description
These sharks are found worldwide in cold temperate to tropical seas from the surface down to .
Echinorhinus | Distribution
It is mainly found on the outer continental shelf and upper continental slope, and may aggregate around seamounts.
Sharpnose sevengill shark | Distribution and habitat
The genus name "Notorynchus" a portmanteau is derived from the Ancient Greek νῶτον (nôton, meaning "back") prefixed to the Ancient Greek ῥῠ́γχος (rhúnkhos, meaning “snout”). It has been interpreted that this refers to the spots on the broadnose sevengill's dorsal. The specific epithet "cepedianus" is derived from a variation of the name "Lacepede", which refers to Bernard Germain de Lacépède, a French naturalist during the late 18th and early 19th century. Altogether, the scientific name as a whole literally means "Lacepede's back snout". The common name "broadnose sevengill shark" refers to the seven gill slits the species possesses and the shape of its snout.
Broadnose sevengill shark | Name
dussumieri") and the blackspot shark ("C. sealei"). This grouping was equivocally supported by Gavin Naylor's 1992 allozyme-based phylogenetic analysis. Alternately, a 2011 phylogenetic study by Ximena Vélez-Zuazoa and Ingi Agnarsson, based on nuclear and mitochondrial genes, found close relationships between the smalltail shark, the daggernose shark ("Isogomphodon oxyrhynchus"), the blacknose shark ("C. acronotus"), and the finetooth shark ("C. isodon"). The Pacific smalltail shark ("C. cerdale") was once mistakenly synonymized with "C. porosus", until 2011 when José Castro resurrected it as a distinct taxon. An undescribed species closely similar to "C. porosus" is known from Southeast Asia.
Smalltail shark | Taxonomy and phylogeny
The blackspot shark can be confused with the whitecheek shark ("Carcharhinus dussumieri"), but that species has a triangular first dorsal fin that is only slightly falcate, and a small second dorsal fin that merely has a dark margin.
Blackspot shark | Description
The Atlantic sharpnose shark ("Rhizoprionodon terraenovae") is a requiem shark in the family Carcharhinidae, found in the subtropical waters of the northwestern Atlantic Ocean, between latitudes 43°N and 18°N.
Atlantic sharpnose shark | Introduction
French naturalists Jean René Constant Quoy and Joseph Paul Gaimard originally described the blacktip reef shark during the 1817–1820 exploratory voyage of the corvette "Uranie". In 1824, their account was published as part of "Voyage autour du monde...sur les corvettes de S.M. l'Uranie et la Physicienne", Louis de Freycinet's 13-volume report on the voyage. The type specimen was a -long juvenile male caught off the island of Waigeo, west of New Guinea. Quoy and Gaimard chose the name "Carcharias melanopterus", from the Greek "melas" meaning "black" and "pteron" meaning "fin" or "wing", in reference to this shark's prominent fin markings.
Blacktip reef shark | Taxonomy
Coates's shark ("Carcharhinus coatesi") is a species of requiem shark found off northern Australia (from Shark Bay in Western Australia to Fraser Island in Queensland) and possibly also off the coast of New Guinea.
Coates's shark | Introduction
No ridge occurs between the dorsal fins. The back is bronze-gray in color, and the belly is white. The fins are plain, but may be darker than the body. The maximum known length is , though unsubstantiated reports indicate individuals reaching .
Spadenose shark | Description
The species is widespread in deeper waters (samples off South Africa have been obtained from ~650 m) and occurs on a variety of shark species. Records are known both from cold from waters off Greenland, Britain, New Zealand, Chile and South Africa, as well as warmer waters off Spain, the Canary Islands, Australia, and in the Gulf of Mexico.
Anelasma | Distribution
The Australian sharpnose shark ("Rhizoprionodon taylori") is a requiem shark, belonging to the family Carcharhinidae. It is found in the tropical waters of the western Pacific Ocean off Papua New Guinea and northern Australia, between latitudes 8°N and 28°S, from the surface to a depth of 110 m. It can grow up to a length around 70 cm.
Australian sharpnose shark | Introduction
An extinct relative, "I. acuarius", dates back to the Middle Eocene (45 Ma).
Daggernose shark | Taxonomy and phylogeny
The whitenose shark ("Nasolamia velox") is a species of shark of the family Carcharhinidae. The only member of the genus Nasolamia, it is found in the tropical waters of the eastern Pacific Ocean between latitudes 31° N and 18° S, between depths of 15 to 200 m. It can grow up to a length of 1.5 m. The whitenose shark is viviparous, with 5 young in a litter, and a birth size around 53 cm.
Whitenose shark | Introduction
Juveniles have dark blotches on the flank and dark tips on the dorsal fin and upper caudal lobe.
Sharpnose sevengill shark | Description
In South Africa, the species seems to be resident, but some increase in numbers occurs during the summer.
Blackspot shark | Distribution
It is of minor commercial importance.
Sharpnose sevengill shark | Introduction
Carcharoides is an extinct genus of mackerel shark which lived during the Oligocene and Miocene epochs. It is a widespread genus, known from specimens in North and South America, Europe, Africa, and Australia. It is most common in the European portion of its range, being comparatively uncommon in other places. It is only known from isolated teeth, which are relatively delicate.
Carcharoides | Introduction
melanopterus"). Leonard Compagno in 1988 tentatively grouped these two species with the blacknose shark ("C. acronotus"), the copper shark ("C. brachyurus"), the silky shark ("C. falciformis"), and the night shark ("C. signatus"). The close relationship between the nervous and blacktip reef sharks was upheld in a 1992 phylogenetic study by Shane Lavery, based on allozymes, and again in a 2011 study by Ximena Vélez-Zuazoa and Ingi Agnarsson, based on nuclear and mitochondrial genes.
Nervous shark | Taxonomy and phylogeny
The closest relatives of the blacktip shark were originally thought to be the graceful shark ("C. amblyrhynchoides") and the spinner shark ("C. brevipinna"), due to similarities in morphology and behavior. However, this interpretation has not been borne out by studies of mitochondrial and ribosomal DNA, which instead suggest affinity with the blacknose shark ("C. acronotus"). More work is required to fully resolve the relationship between the blacktip shark and other "Carcharhinus" species. Analysis of mitochondrial DNA has also revealed two distinct lineages within this species, one occupying the western Atlantic and the other occupying the eastern Atlantic, Indian, and Pacific Oceans.
Blacktip shark | Phylogeny and evolution
In the South Atlantic Bight, both sexes mature at a fork length (from snout tip to caudal fin fork) around , corresponding to ages of 4.3 years for males and 4.5 years for females. In the Gulf of Mexico, both sexes mature at a fork length around , corresponding to ages of 5.4 years for males and 6.6 years for females. The maximum lifespan has been calculated as 19 years in South Atlantic Bight and 16.5 years in the Gulf of Mexico.
Blacknose shark | Life history
The blackmouth catshark ("Galeus melastomus") is a species of catshark, and part of the family Scyliorhinidae, common in the northeastern Atlantic Ocean from Iceland to Senegal, including the Mediterranean Sea. It is typically found over the continental slope at depths of , on or near muddy bottoms. The youngest sharks generally inhabit shallower water than the older juveniles and adults. This slim-bodied species is characterized by the black interior of its mouth, a marbled pattern of pale-edged brownish saddles or blotches along its back and tail, and a prominent saw-toothed crest of enlarged dermal denticles along the upper edge of its caudal fin.
Blackmouth catshark | Introduction
The dorsal and anal fin membranes are not adnate with the body. These fish reach sexual maturity at just over 16 millimetres (.63 in) SL, and have not been observed to exceed 20 mm (.79 in) SL. This species is found in flooded plants, primarily grasses and sedges, in black water (stained by tannin).
Acanthobunocephalus nicoi | Introduction
obscurus") and the Galapagos shark ("C. galapagensis"). The group consists of large, triangular-toothed sharks with a ridge between the dorsal fins. Gavin Naylor's 1992 study, based on allozyme sequences, upheld and further resolved this "ridge-backed" group. The bignose shark was found to be the sister species of the sandbar shark ("C. plumbeus"), with the two forming one of the group's two branches.
Bignose shark | Taxonomy and phylogeny
The blackspot shark ("Carcharhinus sealei") is a small species of requiem shark in the family Carcharhinidae found in the tropical Indo-West Pacific Ocean between latitudes 24°N and 30°S, from the surface to a depth around . Its length is a little under one meter (yard) and it is not considered to be dangerous to humans. It feeds mainly on fish, crustaceans, and squid. This shark is also caught in small-scale fisheries for human consumption.
Blackspot shark | Introduction
The caudal fin is black with white corners.
Live sharksucker | Description
The first scientific description of the daggernose shark, as "Carcharias oxyrhynchus", was published by German biologists Johannes Peter Müller and Friedrich Gustav Jakob Henle in their 1839 "Systematische Beschreibung der Plagiostomen". They chose the specific epithet "oxyrhynchus", from the Greek ' ("sharp" or "pointed") and ' ("nose"). In 1862, American ichthyologist Theodore Gill coined the genius "Isogomphodon" for this species, from the Greek ' ("equal"), ' ("nail" or "peg"), and "" ("tooth"). However, "Isogomphodon" was subsequently relegated to being a synonym of "Carcharhinus", until it was resurrected by shark authority Stewart Springer in 1950. Regardless of its taxonomic validity, "Isogomphodon", along with the genera "Nasolamia" and "Prionace", is closely related to "Carcharhinus".
Daggernose shark | Taxonomy and phylogeny
The Australian blacktip shark was described by Australian ichthyologist Gilbert Percy Whitley in a 1950 issue of the scientific journal "Western Australian Naturalist". He named it "Galeolamna pleurotaenia tilstoni" in honor of Richard Tilston, assistant surgeon at Port Essington, Northern Territory. The type specimen is a long female caught from Van Cloon Reef in Joseph Bonaparte Gulf. Later authors have regarded "Galeolamna" as a synonym of the genus "Carcharhinus". This shark may also be referred to as blacktip whaler, Tilston's whaler shark, and Whitley's blacktip shark. After Whitley's initial description, "C. tilstoni" was generally regarded as synonymous with "C. limbatus", the common blacktip shark.
Australian blacktip shark | Taxonomy and phylogeny
The blacktip reef shark ("Carcharhinus melanopterus") is a species of requiem shark, in the family Carcharhinidae, which can be easily identified by the prominent black tips on its fins (especially on the first dorsal fin and its caudal fin). Among the most abundant sharks inhabiting the tropical coral reefs of the Indian and Pacific Oceans, this species prefers shallow, inshore waters. Its exposed first dorsal fin is a common sight in the region. The blacktip reef shark is usually found over reef ledges and sandy flats, though it has also been known to enter brackish and freshwater environments. It typically attains a length of .
Blacktip reef shark | Introduction
However, the various fishing pressures within its range are cause for concern given its slow reproductive rate, and it may have already declined in the northwestern Atlantic and elsewhere.
Bignose shark | Introduction
The whitecheek shark or widemouth blackspot shark ("Carcharhinus dussumieri") is a requiem shark of the family Carcharhinidae, found in the Indo-West Pacific Ocean between latitudes 34°N and 25°S. It can reach a length of 1 m. It feeds mainly on fish, cephalopods, and crustaceans. It is a viviparous species, with the female giving birth to up to four live young.
Whitecheek shark | Introduction
The first scientific description of the spadenose shark was published in 1838 by the German biologists Johannes Peter Müller and Friedrich Gustav Jakob Henle, in their "Systematische Beschreibung der Plagiostomen". The holotype is presumed to be a -long stuffed specimen in the Zoologisches Museum of Berlin. The generic name "Scoliodon" is derived from the Greek "skolex" ("worm") and "odon" ("tooth"), while the specific epithet "laticaudus" comes from the Latin "latus" ("broad" or "wide") and "cauda" ("tail"). Other common names used for this species include Indian dog shark, sharp-nosed shark, trowel-nose shark, and yellow dog shark. Phylogenetic analyses based on morphological and molecular data indicate the spadenose shark is one of the most basal members of its family, along with the related genus "Rhizoprionodon" and "Galeocerdo", the tiger shark.
Spadenose shark | Taxonomy and phylogeny
The sharpnose sevengill shark is uncommon, but widely distributed in the tropical and temperate regions of all oceans except for the northeastern Pacific Ocean. It is found from North Carolina to Cuba, including the northern Gulf of Mexico, and from Venezuela to Argentina in the western Atlantic. In the eastern Atlantic, it occurs from Morocco to Namibia, including the Mediterranean Sea. It is reported from the Indian Ocean off southwestern India, Aldabra Island, southern Mozambique, and South Africa. In the Pacific Ocean, it is known from Japan to China, Indonesia, Australia, New Zealand, and northern Chile. This is a demersal to semipelagic species usually captured at a depth of , but is occasionally found close to the surface (though these reports may represent misidentifications) or down to .
Sharpnose sevengill shark | Distribution and habitat
Crassodontidanus is an extinct genus of sharks and the sole member of the family Crassonotidae, in the order Hexanchiformes. It contains two extinct species.
Crassodontidanus | Introduction
The evolutionary relationships of the hardnose shark have not been fully resolved. In a 1988 study based on morphology, Leonard Compagno tentatively grouped the hardnose shark with the Borneo shark ("C. borneensis"), whitecheek shark ("C. dussumieri"), Pondicherry shark ("C. hemiodon"), creek whaler ("C. fitzroyensis"), smalltail shark ("C. porosus"), blackspot shark ("C. sealei"), and spottail shark ("C. sorrah"). Results from molecular phylogenetic analyses have been inconsistent, with some supporting parts of Compagno's hypothesis: a 1992 study could not resolve the hardnose shark's position in detail, a 2011 study reported that it was close to the clade formed by the whitecheek and blackspot sharks, and a 2012 study concluded that it was the sister species of the Borneo shark.
Hardnose shark | Phylogeny and evolution
Ischanacanthiformes is an order of Acanthodii or spiny sharks found in Canada, Ukraine and United Kingdom. Members of this order were nektonic carnivores, eating animals that swim rather than plankton. They had slender builds, light armor, deeply inserted spines, shark-like teeth, and two dorsal fins. Some species were around 2 meters (6.56 feet) long. It was described by Berg in 1940.
Ischnacanthiformes | Introduction
The black sharkminnow ("Labeo chrysophekadion"), also known as the black shark or black labeo, is a species of freshwater fish in the carp family. It is found in the Mekong and Chao Phraya river basins, Malay Peninsula, Sumatra, Java and Borneo. It can reach a length of and a weight of . It is sometimes seen in the aquarium trade, but is generally unsuitable for home aquaria due to its large adult size and territorial, aggressive behavior.
Black sharkminnow | Introduction
"Calothamnus quadrifidus" subsp. "obtusus" is found between Shark Bay, Kalbarri and Mullewa in the Carnarvon, Geraldton Sandplains and Yalgoo biogeographic regions. It usually grows in sand in kwongan.
Calothamnus quadrifidus subsp. obtusus | Distribution and habitat
The first efforts to determine the evolutionary relationships of the copper shark were based on morphology and returned inconclusive results: in 1982 Jack Garrick placed it by itself as a grouping within "Carcharhinus", while in 1988 Leonard Compagno placed it in an informal "transitional group" that also contained the blacknose shark ("C. acronotus"), the blacktip reef shark ("C. melanopterus"), the nervous shark ("C. cautus"), the silky shark ("C. falciformis"), and the night shark ("C. signatus"). Gavin Naylor's 1992 allozyme study concluded that the closest relative of the copper shark is the spinner shark ("C. brevipinna"), but could not resolve their wider relationships with the rest of the genus.
Copper shark | Phylogeny and evolution
The bluntnose sixgill shark ("Hexanchus griseus"), often simply called the cow shark, is the largest hexanchoid shark, growing to in length. It is found in tropical and temperate waters worldwide and its diet is widely varied by region.
Bluntnose sixgill shark | Introduction
The blacktip tope ("Hypogaleus hyugaensis"), also known as pencil shark or blacktip topeshark, is a houndshark of the family Triakidae, and the only member of the genus Hypogaleus. It is found in the deep waters of the continental shelf in the Indo-West Pacific, from East Africa to Japan, at depths between 40 and 230 m. It can grow up to a length of 1.27 m.
Blacktip tope | Introduction
longimanus"). Dusky shark teeth have also been recovered from the vicinity of two baleen whales in North Carolina, one preserved in Goose Creek Limestone dating to the Late Pliocene ("c." 3.5 Ma), and the other in mud dating to the Pleistocene-Holocene ("c." 12,000 years ago). In 1982, Jack Garrick published a phylogenetic analysis of "Carcharhinus" based on morphology, in which he placed the dusky shark and the Galapagos shark ("C. galapagensis") at the center of the "obscurus group". The group consisted of large, triangular-toothed sharks with a ridge between the dorsal fins, and also included the bignose shark ("C. altimus"), the Caribbean reef shark ("C.
Dusky shark | Phylogeny and evolution
The silky shark ("Carcharhinus falciformis"), also known by numerous names such as blackspot shark, grey whaler shark, olive shark, ridgeback shark, sickle shark, sickle-shaped shark and sickle silk shark, is a species of requiem shark, in the family Carcharhinidae, named for the smooth texture of its skin. It is one of the most abundant sharks in the pelagic zone, and can be found around the world in tropical waters. Highly mobile and migratory, this shark is most often found over the edge of the continental shelf down to . The silky shark has a slender, streamlined body and typically grows to a length of .
Silky shark | Introduction
"G. gangeticus" was originally known only from three 19th-century museum specimens, one each in the Muséum national d'histoire naturelle, Paris, Museum für Naturkunde, Berlin, and Zoological Survey of India, Calcutta. No records exist between 1867 and 1996, and the 1996 records have not been confirmed as "G. gangeticus". A specimen collected 84 km upstream of the mouth of the Hooghly River at Mahishadal in 2001 was identified as "G. gangeticus", but on photographs of the jaw only. If "Carcharias murrayi" (Günter, 1887) can be considered a junior synonym of this species, one was found near Karachi, Pakistan. However, the holotype was apparently lost or misplaced in the British Museum of Natural History.
Ganges shark | Specimens
"Calothamnus formosus" is found in and between the Shark Bay and Yuna districts in the Carnarvon, Geraldton Sandplains and Yalgoo biogeographic regions. It grows in sand on sandplains.
Calothamnus formosus | Distribution and habitat
Patchy records from around the world indicate the bignose shark probably has a circumglobal distribution in tropical and subtropical waters. In the Atlantic Ocean, it occurs from Delaware Bay to Brazil, in the Mediterranean Sea, and off West Africa. In the Indian Ocean, it is known in South Africa and Madagascar, the Red Sea, India, and the Maldives. In the Pacific Ocean, it has been recorded from China to Australia, around Hawaii, and from the Gulf of California to Ecuador. It is reportedly common off Florida, the Bahamas, and the West Indies, and rare off Brazil and in the Mediterranean.
Bignose shark | Distribution and habitat
Teeth apparently belonging to the hardnose shark have been recovered from the Pungo River and Yorktown Formations in the United States, and from the Pirabas Formation in Brazil. The earliest of these fossils date to the Lower Miocene (23–16 Ma).
Hardnose shark | Phylogeny and evolution
Like most other members of its genus, the phylogenetic position of the blacktip reef shark remains indeterminate. Based on morphology, Jack Garrick proposed in 1982 that the closest relative of the blacktip reef shark was the nervous shark ("C. cautus"). Leonard Compagno's 1988 morphological analysis suggested affinity not only between this species and the nervous shark, but also four other species, and could not resolve their relationships further. A 1998 allozyme analysis by Gavin Naylor again yielded ambiguous results, finding that the blacktip reef shark forms a polytomy (irresolvable group) with 10 other "Carcharhinus" species.
Blacktip reef shark | Phylogeny
The blackmouth lanternshark ("Etmopterus evansi") is a shark of the family Etmopteridae found off Western Australia and the Arafura Sea, at depths between 430 and 550 m. Its length is up to 26 cm. Reproduction is ovoviviparous.
Blackmouth lanternshark | Introduction
A black strip runs from the snout through the eye and the chin and throat have large black blotches on a white background. There are 8 vertical black bars, 2 on the nape and 6 on the body. The caudal fin has a black bar at itrs base and the membrane is marked with black spots. The dorsal fin has twin lines of black spots along it while the base of the anal fin has a single line of black spots. The maximum publsihed total length is .
Serranus tigrinus | Description
Although Jordan and Gilbert referred to a set of jaws that came from a dusky shark, the type specimen they designated was later discovered to be a copper shark ("C. brachyurus"). Therefore, "C. lamiella" is not considered a synonym of "C. obscurus" but rather of "C. brachyurus". Other common names for this species include bay shark, black whaler, brown common gray shark, brown dusky shark, brown shark, common whaler, dusky ground shark, dusky whaler, river whaler, shovelnose, and slender whaler shark.
Dusky shark | Taxonomy
Carcharodon is a genus of sharks within the family Lamnidae. The only extant member of the genus is the great white shark ("Carcharodon carcharias"). Extinct members of the genus include "Carcharodon caifassii" and "Carcharodon hubbelli". "Carcharocles megalodon" is still argued by some paleontologists (e.g. Michael D. Gottfried and Ewan Fordyce) to be a close relative of "Carcharodon carcharias". The megalodon's scientific name was originally 'Carcharodon' "megalodon" (belonging to the same genus as the great white shark), but more recently, the giant shark has been assigned by most scientists to the genus "Carcharocles". The name of the genus comes from the Greek for “sharp/jagged tooth”.
Carcharodon | Introduction
Hexanchus collinsonae (named after M. E. Collinson) is a species of prehistoric shark that was found in the Eocene London Clay beds. It is a member of the family Hexanchidae.
Hexanchus collinsonae | Introduction
menisorrah". The blacktail reef shark ("C. wheeleri"), native to the western Indian Ocean, is now regarded as the same species as the grey reef shark by most authors. It was originally distinguished from the grey reef shark by a white tip on the first dorsal fin, a shorter snout, and one fewer upper tooth row on each side. Based on morphological characters, vertebral counts, and tooth shapes, Garrick (1982) concluded the grey reef shark is most closely related to the silvertip shark ("C. albimarginatus"). This interpretation was supported by a 1992 allozyme phylogenetic analysis by Lavery.
Grey reef shark | Taxonomy and phylogeny
The grey sharpnose shark, "Rhizoprionodon oligolinx", is a requiem shark of the family Carcharhinidae. It is found in the tropical waters of the Indo-West Pacific Oceans, between latitudes 30° N and 18° S, from the surface to a depth of 36 m. It can reach a length of about 70 cm. It is fished in the Gazetteer Indo-West Pacific and the waters from the Persian Gulf east to Thailand, Indonesia, China, and Japan. It has also been found in the Gulf of Carpentaria and Palau. In appearance and size, this species is very close to Rhizoprionodon taylori. The diet of the grey sharpnose shark consists of crustaceans, fishes, and cephalopods.
Grey sharpnose shark | Introduction
In 1996, Siverson synonymized "Cretolamna woodwardi" with "Pseudoisurus tomosus" after finding that their referred type specimens pertained to the same species. Later in 1999, Siverson reassessed the taxonomy of "Pseudoisurus tomosus" and concluded that its syntypes are lost, making it a "nomen dubium". He also found that the former "Cretalamna woodwardi" actually represents two distinct genera of sharks, which was also the likely case for "Pseudoisurus tomosus"- The first was "C. ricki" (which he already described using WAM.96.4.45), and the other was assigned the taxon "Dwardius woodwardi".
Cardabiodon | Discovery and naming
abdominalis"), and several species of sharks in other parts of the world.
Philasterides dicentrarchi | Introduction
The dermal denticles are closely spaced but non-overlapping, such as that the skin shows between them; each is oval with three horizontal ridges leading to marginal teeth. The coloration is gray to bronze above, with a faint pale stripe on the flank, and white below; sometimes there is a green sheen along the gills. The tips of the fins (except for the pelvic fins) are darker; this is most obvious in young sharks. Males and females grow to at least and long respectively; this species possibly reaches in length. The maximum weight on record is .
Bignose shark | Description
Italian naturalist Camillo Ranzani published the first scientific description of the smalltail shark in an 1839 volume of "Novi Commentarii Academiae Scientiarum Instituti Bononiensis". He named the new shark "Carcharias porosus" from the Greek "porus" ("pore"), referring to the prominent pores behind its eyes. The type specimen, a -long male from Brazil, has since been lost. This species was moved to the genus "Carcharhinus" by later authors. Its Trinidadian name is puppy shark. The evolutionary relationships of the smalltail shark are uncertain. Based on morphology, Jack Garrick in 1982 and Leonard Compagno in 1988 tentatively placed it in a group defined by the whitecheek shark ("C.
Smalltail shark | Taxonomy and phylogeny
Carcharodon hubbelli is an extinct species of shark in the genus "Carcharodon", known from fossils found in the Pisco Formation in southwestern Peru. The shark is a transitional species, showing intermediate features between present-day great white sharks and smaller, prehistoric mako sharks. This shark was named in honour of Gordon Hubbell (the scientist who recovered the specimen from a farmer who found it in 1988) in recognition of his contribution to shark palaeontology.
Carcharodon hubbelli | Introduction
This helps us to identify the teeth, and even the species.
Shark tooth | Research and identification
This marine species occurs off the Kermadec Islands and New Caledonia.
Calliotropis blacki | Distribution
Nanocetorhinus is an extinct genus of sharks in the subclass Neoselachii. The type and only described species is N. tuberculatus, which existed in what is now Slovakia during the Miocene epoch, and was described by Charlie J. Underwood and Jan Schlogl in 2011. It was described from 28 fossilized teeth.
Nanocetorhinus | Introduction
This marine species occurs off New Zealand.
Calliostoma blacki | Distribution
The Swiss naturalist Louis Agassiz, first identified this shark as a species of genus "Carcharodon" in 1835. In 1964, shark expert, L. S. Glikman recognized the transition of "Otodus obliquus" to "C. auriculatus" and moved "C. angustidens" to genus "Otodus". (See "external links" below) However, in 1987, shark expert H. Cappetta recognized the "C. auriculatus" - "C. megalodon" lineage and placed all related megatooth sharks along with this species in the genus "Carcharocles". The complete "Otodus obliquus" to "C. megalodon" transition then became clear and has since gained the acceptance of many other experts with the passage of time. Within the "Carcharocles" lineage, "C.
Otodus angustidens | Taxonomy
galapagensis"), dusky shark ("C. obscurus"), oceanic whitetip shark ("C. longimanus"), and the blue shark ("Prionace glauca"). However, more work is required to fully resolve the interrelationships within "Carcharhinus".
Caribbean reef shark | Taxonomy and phylogeny
This species is distributed in the Red Sea.
Nassarius deshayesianus | Distribution
The "C. escheri" holotype tooth was first placed by Agassiz (1843) in the taxon "Carcharodon escheri". However, on an earlier page and figure in the same publication he named a pathological tooth of the same species "Carcharodon subserratus." In 1927, Leriche revised the taxon as a variation "Oxyrhina hastalis var. escheri". In 1961, Kruckow deemed the shark as a subspecies rather than a variation of the then "Isurus hastalis" and renamed it as "Isurus hastalis escheri".
Carcharomodus escheri | Taxonomic History
Sometimes, the name is shortened to "sevengill shark" or simply "sevengill". However, a variety of other common names are known in many languages. Other known common names in English include the bluntnose sevengill shark, broad-snout, cowshark, ground shark, seven-gill cowshark, seven-gilled shark, spotted cow shark, spotted seven-gill shark, and Tasmanian tiger shark. Common names from other languages include cação-bruxa (Portuguese), cañabota gata, gatita, tiburón de 7 gallas, tiburón pinto, and tollo fume (Spanish), ebisuzame and minami-ebisuzame (Japanese), gevlekte zevenkieuwshaai (Dutch), kammzähner and Siebenkiemiger Pazifischer Kammzähner (German), koeihaai (Afrikaans), k'wet'thenéchte (Salish), minami-ebisuzame (Japanese), platneus-sewekiefhaai (Afrikaans), platnez and requin malais (French), siedmioszpar plamisty (Polish), and tuatini (Maori).
Broadnose sevengill shark | Name
Chlamydoselachus garmani is an extinct species of large frilled shark from the Miocene. Fossils have been found in Germany.
Chlamydoselachus garmani | Introduction
However, fossil evidence suggests "I. hastalis", like the great white shark, also belonged to the genus "Carcharodon".
Isurus | Description
Chiloscyllium is a genus of sharks in the family Hemiscylliidae. This genus is distinguished by a relatively long snout with subterminal nostrils. The eyes and supraorbital ridges are hardly elevated. The mouth is closer to the eyes than to the tip of the snout, with lower labial folds usually connected across the chin by a flap of skin. The pectoral and pelvic fins are thin and not very muscular. No black hood on the head or large black spot on the side is present (though juveniles often are strongly marked with dark spots/bars).
Chiloscyllium | Introduction
The Galapagos shark was originally described as "Carcharias galapagensis" by Robert Evans Snodgrass and Edmund Heller in 1905; subsequent authors moved this species to the genus "Carcharhinus". The holotype was a long fetus from the Galapagos Islands, hence the specific epithet "galapagensis". Garrick (1982) placed the Galapagos shark and the dusky shark at the center of the "obscurus group", one of two major groupings within "Carcharhinus". The group consisted of the bignose shark ("C. altimus"), Caribbean reef shark ("C. perezi"), sandbar shark ("C. plumbeus"), dusky shark ("C. obscurus"), and oceanic whitetip shark ("C. longimanus"), all large, triangular-toothed sharks and is defined by the presence of a ridge between the two dorsal fins.
Galapagos shark | Taxonomy and phylogeny
The longnose pygmy shark ("Heteroscymnoides marleyi") is a rare species of squaliform shark in the family Dalatiidae and the only member its genus. It is known only from a handful of specimens collected from the cold oceanic waters of the Southern Hemisphere, between the surface and a depth of . Reaching in length, this diminutive shark is characterized by a slender, dark brown body with a very long, bulbous snout. In addition, it has two spineless dorsal fins of nearly equal size, with the origin of the first lying over the pectoral fin bases. The longnose pygmy shark does not appear substantially threatened by fisheries, and has been assessed as Least Concern by the International Union for Conservation of Nature (IUCN).
Longnose pygmy shark | Introduction
The Seri word for "shark", which is "hacat", was chosen by ichthyologist Juan Carlos Pérez Jiménez to name a newly discovered species of smooth-hound shark in the Gulf of California ("Mustelus hacat").
Seri language | Trivia