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
Carcharhinus acronotus "Carcharhinus acronotus". "Carcharhinus acronotus" Carcharhinus acronotus
what is the scientific name of blacknose shark?
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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
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
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
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
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 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
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 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
"salmonicida".
Blacktip reef shark | Biology and ecology
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
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
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
Males attain a length of and females . There are unsubstantiated records of individuals long. The maximum known weight is .
Daggernose shark | Description
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
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 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 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
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
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 longnose pygmy shark was described by American zoologist Henry Weed Fowler in a 1934 volume of "Proceedings of the Academy of Natural Sciences of Philadelphia", based on a long female collected off Point Ocean Beach in Durban, South Africa. Fowler had originally thought the shark to belong to the genus "Heteroscymnus" (a junior synonym of "Somniosus"), and thus he created for it the new genus "Heteroscymnoides" from the Greek "oidos" ("resemblance"). He gave it the specific epithet "marleyi" in honor of Harold Walter Bell-Marley, and his contributions to the study of South African fishes. The relationship between "Heteroscymnoides" and the rest of its family is uncertain.
Longnose pygmy shark | Taxonomy
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
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 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
It is of minor commercial importance.
Sharpnose sevengill shark | Introduction
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 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
Juveniles have dark blotches on the flank and dark tips on the dorsal fin and upper caudal lobe.
Sharpnose sevengill shark | Description
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
Like other members of their family, they exhibit a viviparous mode of reproduction in which the developing embryos are sustained by a placental connection. The females give birth to three to six young in late spring or early summer, either annually or biennially, after a gestation period of eight to 11 months. This species is not known to attack humans, though it has been documented performing a threat display towards divers. It is of moderate commercial and recreational importance. The International Union for Conservation of Nature has assessed this species as near threatened. In 2009, the U.S. National Oceanic and Atmospheric Administration announced the populations of the blacknose shark off the United States are being overfished, and proposed new conservation measures.
Blacknose shark | Introduction
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
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 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
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
The specific name, "nasicus", is from the Latin "nasus" ("nose"), in reference to the upturned snout. The subspecific name, "gloydi", is in honor of American herpetologist Howard K. Gloyd (1902–1978). The subspecific (or specific) name, "kennerlyi", is in honor of American naturalist Caleb Burwell Rowan Kennerly (1829–1861).
Western hognose snake | Etymology
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
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
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
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 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
However, Lesson's name remained forgotten for so long that "Carcharhinus longimanus" remains widely accepted.
Oceanic whitetip shark | Taxonomy
Sharks present were the great white shark ("Carcharodon carcharias") and the extinct broad-toothed mako ("Cosmopolitodus hastalis").
Orcinus paleorca | Paleobiology
An extinct relative, "I. acuarius", dates back to the Middle Eocene (45 Ma).
Daggernose shark | Taxonomy and phylogeny
Like many sharks, this sevengill is counter-shaded. Its dorsal surface is silver-gray to brown in order to blend with the dark water and substrate when viewed from above. In counter to this, its ventral surface is very pale, blending with the sunlit water when viewed from below. The body and fins are covered in a scattering of small black & white spots. In juveniles, their fins often have white margins. It is also known as sevengill shark or simply sevengill and was formerly known as cow shark and mud shark; it is called sevengill due to its seven gill slits.
Broadnose sevengill shark | Introduction
A small, fast-swimming predator, the blacknose shark feeds primarily on small, bony fishes, including pinfish, croakers, porgies, anchovies, spiny boxfish, and porcupinefish, as well as on octopus and other cephalopods. When competing for bait, their speed allows them to snatch food from larger sharks such as the Caribbean reef shark ("C. perezi"). This species may form large schools that are sometimes associated with anchovies and mullet. Blacknose sharks demonstrate a high degree of philopatry: both juveniles and adults have been documented returning to the same local area year after year. Blacknose sharks are preyed upon by larger sharks, and captives have been observed to perform an apparent threat display towards encroaching divers or newly introduced members of their species.
Blacknose shark | Biology and ecology
The blacknose dace is either of two ray-finned fish species:
Blacknose dace | 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
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
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
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.
Shortnose sawshark | Introduction
The bluntnose sixgill shark has a large body and long tail. The snout is blunt and wide, and its eyes are small. There are 6 rows of saw-like teeth on its lower jaw and smaller teeth on its upper jaw. Skin color ranges from tan, through brown, to black. It has a light-colored lateral line down the sides and on the fins' edges, and darker colored spots on the sides. They also get stains/spots on their neural arches, and the number of stains increase as they get older. Its pupils are black and its eye color is a fluorescent blue-green.
Bluntnose sixgill shark | Description
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
The basking shark is the only extant member of the family Cetorhinidae, part of the mackerel shark order Lamniformes. Johan Ernst Gunnerus first described the species as "Cetorhinus maximus", from a specimen found in Norway, naming it. The genus name "Cetorhinus" comes from the Greek "ketos", meaning "marine monster" or "whale", and "rhinos", meaning "nose". The species name "maximus" is from Latin and means "greatest". Following its initial description, more attempts at naming included: "Squalus isodus", in 1819 by Italian Zoologist Saverio Macri (1754–1848); "Squalus elephas", by Charles Alexandre Lesueur in 1822; "Squalus rashleighanus", by Jonathan Couch in 1838; "Squalus cetaceus", by Laurens Theodorus Gronovius in 1854; "Cetorhinus blainvillei" by the Portuguese biologist Felix Antonio De Brio Capello (1828–1879) in 1869; "Selachus pennantii", by Charles John Cornish in 1885; "Cetorhinus maximus infanuncula", by the Dutch Zoologists Antonius Boudewijn Deinse (1885–1965) and Marcus Jan Adriani (1929–1995) in 1953; and "Cetorhinus maximus normani", by Siccardi in 1961.
Basking shark | Taxonomy
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 species was redescribed twice more by Day in 1876 and Chu and Chen in 1958. Being Swainson is the first author to correctly describe the fish, even though he initially ascribed it to the wrong genus, the ICZN recognises "Alepes melanoptera" as the correct name, and the rest as invalid junior synonyms. Such synonymy is common in the genus "Alepes" due to the abundance of similar genera. The specific name 'melanoptera' literally means 'black wing' in Greek; a reference to its distinctive colouration.
Blackfin scad | Taxonomy and naming
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 shark was identified and named by shark researcher Vicky Vásquez. The specific name "benchleyi" derives from Peter Benchley, author of the 1974 novel "Jaws" that was used as a basis for Steven Spielberg's film of the same name.
Ninja lanternshark | Origin of scientific name
The oceanic whitetip shark, or lesser white shark, was described in 1831 by naturalist René-Primevère Lesson, who named the shark "Carcharhinus maou". It was next described by Cuban Felipe Poey in 1861 as "Squalus longimanus". The name "Pterolamiops longimanus" has also been used. The species epithet ' refers to the size of its pectoral fins (' translates from Latin as "long hands"). The oceanic whitetip shark has many common names in English: Brown Milbert's sand bar shark, brown shark, nigano shark, oceanic white-tipped whaler, and whitetip shark. The rules of the International Commission on Zoological Nomenclature are that in general the first-published description has priority; therefore, the valid scientific name for the oceanic whitetip shark should be "Carcharhinus maou".
Oceanic whitetip shark | Taxonomy
"Web of Science [v.5.15] - All Databases Full Record." Web of Science [v.5.15] - All Databases Full Record. N.p., n.d. Web. 23 Oct. 2014.
Whitespotted bamboo shark | See also
The caudal fin is black with white corners.
Live sharksucker | Description
The specific epithet "falciformis" is Latin for "sickle-shaped", which refers to the outline of the dorsal and pectoral fins. The silky shark's common name comes from the fine texture of its skin compared to other sharks, a product of its tiny, densely packed dermal denticles. It may also be referred to as blackspot shark (usually used for "C. sealei"), grey reef shark (usually used for "C. amblyrhynchos"), grey whaler shark, olive shark, reef shark, ridgeback shark, sickle shark, sickle silk shark, sickle-shaped shark, silk shark, and silky whaler.
Silky shark | Taxonomy
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
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
The generic name combines the Latin term ""nano"" ("dwarvish") with ""Cetorhinus"" (the generic name of the basking shark), and references the resemblance the teeth of "Nanocetorhinus" bear to those of "Cetorhinus", but on a smaller scale. The species epithet refers to the tuberculate surface ornament of the teeth.
Nanocetorhinus | Etymology
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 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
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
Jack Garrick, in his 1982 morphological study, did not place it close to any other member of the genus. Leonard Compagno in 1988 tentatively grouped it with the smalltail shark ("C. porosus"), blackspot shark ("C. sealei"), spottail shark ("C. sorrah"), creek whaler ("C. fitzroyensis"), whitecheek shark ("C. dussumieri"), hardnose shark ("C. macloti"), and Pondicherry shark ("C. hemiodon"). The Borneo shark resembles the sharpnose sharks ("Rhizoprionodon") in certain traits, for example the enlarged pores by its mouth. Nevertheless, other aspects of its morphology firmly place it within "Carcharhinus".
Borneo shark | Taxonomy and phylogeny
The genus name "Heptranchias" is from the Greek "heptra" meaning "seven arms", and "agchein" meaning "throttle", referring to this shark's seven pairs of gill slits. Other common names for this species include one-finned shark, perlon shark, sevengill cow shark, sevengilled Mediterranean shark, sevengilled shark, sharpnose seven-gill shark, snouted sevengill shark and slender sevengill shark. Some authors believe this species is distinct enough to merit its own family, Heptranchiidae.
Sharpnose sevengill shark | Taxonomy
Melanognathus (Greek for "black jaw") is a genus of prehistoric lungfish which lived during the Devonian period.
Melanognathus | Introduction
The hardnose shark forms large groups, often associating with spottail sharks and Australian blacktip sharks ("C. tilstoni"). Males and females generally roam separately from each other. Bony fishes form the main part of this shark's diet, with cephalopods and crustaceans making up the remainder. Parasites of this species include the nematode "Acanthocheilus rotundatus" and the tapeworm "Otobothrium carcharidis". The hardnose shark is viviparous; like in other requiem sharks, once the embryos exhaust their yolk supply, the empty yolk sac develops into a placental connection through which the mother provides nutrition. Females give birth once every other year to one or two pups, following a gestation period of twelve months.
Hardnose shark | Biology and ecology
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
The caudal fin has a well-developed lower lobe and a longer upper lobe with a ventral notch near the tip. The skin is covered by overlapping, oval-shaped dermal denticles; each denticle has three horizontal ridges leading to marginal teeth. This species is bronze above and white below, with a barely noticeable pale band on the flanks. The pectoral, pelvic, and anal fins sometimes have lighter margins, while the first dorsal fin and upper caudal fin lobe may have darker margins. The hardnose shark reaches in length.
Hardnose shark | Description
This is the first confirmed case of hybridization among cartilaginous fishes.
Australian blacktip shark | Biology and ecology
Eastern blacknose dace ("Rhinichthys atratulus") is a species of ray-finned fish in the genus "Rhinichthys". Its name originates from the Old French word "dars" which is the nominative form of the word "dart" in reference to their swimming pattern. The western blacknose dace ("Rhinichthys obtusus") formerly was considered conspecific. While morphologically the two species are not significantly different, they are allopatric. The eastern blacknose dace is found across the southeast portion of Canada and down along the United States' east coast. It is dark brown to olive on its dorsal surface and silvery white below, the two shades separated by the darkly pigmented lateral line.
Eastern blacknose dace | Introduction
limbatus") or lemon sharks ("Negaprion brevirostris").
Pigeye shark | Biology and ecology
They have a pair of pectoral fins and a pair of abdominal ventral fins, as well as an anal fin with 7 rays. All fins are clear to yellow except males during spawning season acquire an orange to red tint in all fins and along the lateral line.
Eastern blacknose dace | Physical description
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
The blackspot shark is a relatively slender species with a streamlined appearance, growing to a length around . The snout is fairly long, pointed or slightly rounded at the tip. The eyes are large, oval, and set horizontally, and are protected by a nictitating membrane on the lower side. The flaps of skin beside the nostrils are triangular, and the furrows on the upper lip are short. Usually, 12 tooth rows occur on either side of both top and bottom jaws, but the number can vary from 11 to 13. The upper teeth have strongly serrated oblique cusps and smooth-edged cusplets, and the lower teeth have oblique cusps, either serrated or smooth.
Blackspot shark | Description
As in other requiem sharks, the blacknose shark is viviparous; after the developing embryos exhaust their supply of yolk, the empty yolk sac develops into a placental connection through which the mother provides nourishment. Off the United States, males are thought to reproduce every year, while females reproduce every other year. However, off northeastern Brazil, the female reproductive cycle is short enough to occur annually. Vitellogenesis (the formation of yolk within the ovary) occurs in the late summer, and is immediately followed by mating and fertilization in the fall, with the young being born the following spring to summer. The seasonality of these events means the reproductive cycle is offset by six months between populations in the Northern and Southern Hemispheres.
Blacknose shark | Life history
They have elongated bodies from in length. They have a number of green or red light-producing photophores aligned along the undersides of their heads or bodies. Their chief common name, bristlemouth, comes from their odd, equally sized, and bristle-like teeth. They are typically black in color which provides camouflage from predators in deep, dark waters.
Gonostomatidae | Introduction
The body is robustly built, with large, broad, paddle-like pectoral fins that originate under the fifth gill slit. The first dorsal fin originates over the posterior half of the pectoral fin bases. The second dorsal fin is about half as tall as the first and located over or slightly ahead of the anal fin. The anal fin is smaller than the second dorsal fin and has a deep notch in the rear margin. The caudal fin has a well-developed lower lobe and is preceded by a crescent-shaped notch on the upper side of the caudal peduncle. The coloration is a plain gray above, sometimes with a brownish or yellowish cast, and lighter below.
Daggernose shark | Description
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
dussumieri") and the blackspot shark ("C. sealei"). Shane Lavery, in a 1992 study based on allozymes, reported that this species was close to the nervous shark ("C. cautus") and the blacktip reef shark ("C. melanopterus"). Ximena Vélez-Zuazoa and Ingi Agnarsson, in a 2011 study based on nuclear and mitochondrial genes, found it to be the basal member of a clade also containing the graceful shark ("C. amblyrhynchoides"), the blacktip shark ("C. limbatus"), and the Australian blacktip shark ("C. tilstoni").
Creek whaler | Taxonomy and phylogeny
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 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
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
Superficially, the smoothtooth blacktip shark resembles the blacktip reef shark ("C. melanopterus"). It is rather robust in build, with a short and blunt snout. The large nostrils are preceded by well-developed, triangular flaps of skin. The small, circular eyes are equipped with nictitating membranes. The mouth forms a wide arch and has very short furrows at the corners. Sixteen upper and 14–15 lower tooth rows are on either side, along with two or three small teeth at the symphysis (center) of either jaw. The teeth are distinctive in shape, having narrow, upright cusps without serrations; finetooth sharks and juvenile spinner sharks are the only other members of "Carcharhinus" with similar teeth.
Smoothtooth blacktip shark | Description
Physically, the Australian blacktip shark can only reliably be distinguished from the common blacktip shark by the number of vertebrae (174–182 total, 84–91 before the tail in "C. tilstoni", 182–203 total, 94–102 before the tail in "C. limbatus"). It has a moderately robust, spindle-shaped body and a long, pointed snout. The anterior rims of the nostrils are slightly enlarged into low triangular flaps. The large, circular eyes are equipped with nictitating membranes. The furrows at the corners of the mouth are barely evident. There are 32–35 upper and 29–31 lower tooth rows; each upper tooth has a slender, upright cusp and fine serrations that become coarser near the base, while the lower teeth are narrower and more finely serrated.
Australian blacktip shark | Description
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
Newborns measure long, and sexual maturity is attained at long. The maximum lifespan is at least 15–20 years.
Hardnose shark | Biology and ecology
The lower teeth number 26–29 rows and are narrow and smooth-edged. There are five pairs of fairly short gill slits. The pectoral fins are fairly short and pointed, with a falcate (sickle-like) shape. The first dorsal fin is medium-sized and triangular, and originates roughly over the pectoral fin free rear tips. The second dorsal fin is small and low, and originates over the middle of the anal fin base. Both dorsal fins have very long free rear tips, and there is a subtle midline ridge between them. A prominent notch is present on the caudal peduncle at the dorsal origin of the caudal fin.
Hardnose shark | Description
The long and wide pectoral fins have pointed tips and nearly straight margins. The first dorsal fin originates roughly over the rear of the pectoral fin bases; it is fairly tall and falcate (sickle-shaped), with a blunt apex and a long free rear tip. The second dorsal fin is relatively large with a short free rear tip, and is positioned slightly ahead of the anal fin. A high midline ridge is present between the dorsal fins. The caudal peduncle has a crescent-shaped notch at the origin of the upper caudal fin margin. The caudal fin has a large lower lobe and a strong ventral notch near the tip of the upper lobe.
Bignose shark | Description
The hindermost of the five gill slits is above the origin of the pectoral fins, and no spiracles occur. The first dorsal fin is long, narrow, and curved (falcate) and has a short rear tip. It is either pointed or narrowly rounded at the apex and its origin is directly over the free posterior end of the pectoral fins. The second dorsal fin is relatively large. It also has a short rear tip and its origin is slightly behind the origin of the anal fin. The pectoral fins are falcate, long and narrow, and taper to a blunt point. No fleshy keel exists along the sides of the caudal peduncle.
Blackspot shark | Description
The hardnose shark is a slim-bodied species with a long, narrow, and pointed snout. Unlike in other "Carcharhinus" species, its rostral (snout) cartilages are highly calcified, hence the name "hardnose". The circular eyes are rather large and equipped with protective nictitating membranes. There is a narrow lobe of skin on the anterior rim of each nostril. The arched mouth bears inconspicuous furrows at the corners; some sources report that the hyomandibular pores (a series of pores above the corners of the mouth) are enlarged, while others report that they are not. The upper teeth number 29–32 rows and have a narrow, smooth-edged central cusp with very coarse serrations at the base on either side.
Hardnose shark | Description
The teeth of adult males are more abruptly curved than those of females. The pectoral fins are large and narrowly falcate (sickle-shaped), tapering to points. The sizable first dorsal fin is high with a curving "S"-shaped rear margin, and originates over the free rear tips of the pectoral fins. The second dorsal fin is relatively large with a short rear margin, and is placed opposite the anal fin. There is no ridge between the dorsal fins. This shark is a pale grayish-brown above and white below, with an obvious white band on the sides extending forward from above the anal fin.
Blacktip reef shark | Description
The blacknose shiner is a soft-rayed species up to 9.8 cm with toothless jaws, but gill arches that contain one or two rows of distinctive teeth. It has cycloid scales, but a scaleless head. There are 19 caudal rays, and the dorsal and anal fins are very short. The anal fin is closer to the middle of the body than to the caudal fin. Usually, it is a murky yellow on the dorsal side with a pale underside. There are two long, lateral stripes on the fish along the center of the body, and on the dorsal side of the fish.
Blacknose shiner | Description
Based on morphology, Leonard Compagno in 1988 tentatively grouped the smoothtooth blacktip shark with the spinner shark ("C. brevipinna"), the blacktip shark ("C. limbatus"), the graceful shark ("C. amblyrhynchoides"), and the finetooth shark ("C. isodon"). Using molecular phylogenetic techniques on mitochondrial DNA sequences, Alec Moore and colleagues reported in 2011 that this species is closely related to the graceful shark, the blacktip shark, and the Australian blacktip shark ("C. tilstoni").
Smoothtooth blacktip shark | Taxonomy and phylogeny
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
Known parasites of the sharpnose sevengill shark include nematodes in the genera "Anisakis" and "Contracaecum", and the cestode "Crossobothrium dohrnii". Reproduction is ovoviviparous, with no apparent reproductive season. The females give birth to litters of 9–20 pups; the newborns measure about long. Males mature at long and females at . The onset of sexual maturation in males may be marked by the formation of mucus on the tips of the claspers.
Sharpnose sevengill shark | Biology and ecology