Blacknose shark

Last updated

Blacknose shark
Blacknose shark nmfs.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Subdivision: Selachimorpha
Order: Carcharhiniformes
Family: Carcharhinidae
Genus: Carcharhinus
Species:
C. acronotus
Binomial name
Carcharhinus acronotus
(Poey, 1860)
Carcharhinus acronotus distmap.png
Range of the blacknose shark
Synonyms

Prionodon curcuriCastelnau, 1855
Squalus acronotusPoey, 1860

Contents

* ambiguous synonym

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. [2] This species generally inhabits coastal seagrass, sand, or rubble habitats, with adults preferring deeper water than juveniles. A small shark typically measuring 1.3 m (4.3 ft) 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. 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. 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.

Taxonomy and phylogeny

Drawing of a blacknose shark and one of its upper teeth - the arrows and vertical line refer to diagnostic features of the species. Carcharhinus acronotus drawing.jpg
Drawing of a blacknose shark and one of its upper teeth - the arrows and vertical line refer to diagnostic features of the species.

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. [3]

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. 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). [4] [5] 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. [3]

Distribution and habitat

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 Uruguay, 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. [6] 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 9 m (30 ft) and is most common at 18–64 m (59–210 ft). [1] [7] 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. [8]

Description

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. [7] [9]

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. [9] 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. [7] The coloration is yellowish to greenish-gray or brown above and white to yellow below. 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 1.3–1.4 m (4.3–4.6 ft) long and 10 kg (22 lb) in weight. [3] [9] The maximum length and weight on record is 2.0 m (6.6 ft) and 18.9 kg (42 lb), respectively. [10]

Biology and ecology

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. [7] When competing for bait, their speed allows them to snatch food from larger sharks such as the Caribbean reef shark (C. perezi). [11] [12] This species may form large schools that are sometimes associated with anchovies and mullet. [7] Blacknose sharks demonstrate a high degree of philopatry: both juveniles and adults have been documented returning to the same local area year after year. [13]

Blacknose sharks are preyed upon by larger sharks, [7] and captives have been observed to perform an apparent threat display towards encroaching divers or newly introduced members of their species. 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. [3] [14] Known parasites of this species include the copepods Nesippus orientalis, Perissopus dentatus, Pandarus sinuatus, Kroyeria sphyrnae, Nemesis atlantica, and Eudactylina spinifera, [15] as well as tapeworms in the genera Paraorygmatobothrium and Platybothrium. [16] [17]

Life history

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. [18] However, off northeastern Brazil, the female reproductive cycle is short enough to occur annually. [1] [19] 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. [7] The seasonality of these events means the reproductive cycle is offset by six months between populations in the Northern and Southern Hemispheres. The gestation period has been variously estimated at eight months off northeastern Brazil and 9–11 months off the southeastern United States. [19]

Females typically give birth to litters of one to six pups in shallow nursery areas, such as coastal bays or mangrove swamps; [1] [20] one known nursery area is Bulls Bay off South Carolina. [7] No relationship is seen between female size and the number of young. [8] The newborns measure 38–50 cm (15–20 in) long. [3] Female blacknose sharks grow more slowly, attain a larger ultimate size, and have a longer lifespan than males. In addition, Gulf of Mexico sharks are slower-growing and longer-lived than those from the South Atlantic Bight. [21] In the South Atlantic Bight, both sexes mature at a fork length (from snout tip to caudal fin fork) around 90 cm (3.0 ft), 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 85 cm (2.79 ft), corresponding to ages of 5.4 years for males and 6.6 years for females. [8] The maximum lifespan has been calculated as 19 years in South Atlantic Bight and 16.5 years in the Gulf of Mexico. [1]

The blacknose shark is not known to pose a danger to humans. Carcharhinus acronotus noaa.jpg
The blacknose shark is not known to pose a danger to humans.

Human interactions

The blacknose shark has never been implicated in an attack on humans. However, caution should be exercised if it begins to perform a threat display. [20] This species is regarded as a game fish and offers a respectable fight on light tackle (a more delicate fishing line). [7] It is also of regional commercial importance, being taken intentionally and as bycatch via gillnets and surface longlines across its range, most significantly off southwestern Florida, Venezuela, and Brazil; the meat is sold dried and salted. Large numbers of blacknose sharks are also caught incidentally by shrimp trawlers, which may pose a greater threat to its population, as many of the sharks taken are immature. [1] [3]

Off the United States, the fishing of the blacknose shark is regulated by the U.S. National Marine Fisheries Service 1993 Fisheries Management Plan (FMP) for Atlantic and Gulf of Mexico sharks. For the purposes of commercial quotas and bag limits, the blacknose shark is classified within the "small coastal shark" (SCS) complex. [8] From 1999 to 2005, an average of 27,484 blacknose sharks (62 metric tons) was caught each year off the United States. Recent stock assessments conducted by the U.S. National Oceanic and Atmospheric Administration (NOAA) have determined the populations of this species have become overfished in both the Atlantic and the Gulf of Mexico. In 2009, the NOAA proposed instituting a separate quota for blacknose sharks of 6,065 sharks per year, and a ban on using gillnets to catch sharks in the Atlantic. [22] By contrast, blacknose shark stocks off northern Brazil appear to be stable, while no fishery data are available from the Caribbean. The International Union for Conservation of Nature has assessed this species as endangered globally. [1]

Related Research Articles

<span class="mw-page-title-main">Silky shark</span> Species of fish

The silky shark, also known by numerous names such as blackspot shark, gray 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 50 m (164 ft). The silky shark has a slender, streamlined body and typically grows to a length of 2.5 m. It can be distinguished from other large requiem sharks by its relatively small first dorsal fin with a curving rear margin, its tiny second dorsal fin with a long free rear tip, and its long, sickle-shaped pectoral fins. It is a deep, metallic bronze-gray above and white below.

<span class="mw-page-title-main">Sandbar shark</span> Species of shark

The sandbar shark, also known as the brown shark or thickskin shark, is a species of requiem shark, and part of the family Carcharhinidae, native to the Atlantic Ocean and the Indo-Pacific. It is distinguishable by its very high first dorsal fin and interdorsal ridge. It is not to be confused with the similarly named sand tiger shark, or Carcharias taurus.

<span class="mw-page-title-main">Copper shark</span> Species of shark

The copper shark, bronze whaler, or narrowtooth shark is a species of requiem shark found mostly in temperate latitudes. It is distributed in a number of separate populations in the northeastern and southwestern Atlantic, off southern Africa, in the northwestern and eastern Pacific, and around Australia and New Zealand, with scattered reports from equatorial regions. The species can be found from brackish rivers and estuaries to shallow bays and harbors, to offshore waters 100 m (330 ft) deep or more. Females are found apart from males for most of the year, and conduct seasonal migrations. A large species reaching 3.3 m (11 ft) long, the copper shark is difficult to distinguish from other large requiem sharks. It is characterized by its narrow, hook-shaped upper teeth, lack of a prominent ridge between the dorsal fins, and plain bronze coloration.

<span class="mw-page-title-main">Dusky shark</span> Species of shark

The dusky shark is a species of requiem shark, in the family Carcharhinidae, occurring in tropical and warm-temperate continental seas worldwide. A generalist apex predator, the dusky shark can be found from the coast to the outer continental shelf and adjacent pelagic waters, and has been recorded from a depth of 400 m (1,300 ft). Populations migrate seasonally towards the poles in the summer and towards the equator in the winter, traveling hundreds to thousands of kilometers. One of the largest members of its genus, the dusky shark reaches more than 4 m (13 ft) in length and 350 kg (770 lb) in weight. It has a slender, streamlined body and can be identified by its short round snout, long sickle-shaped pectoral fins, ridge between the first and second dorsal fins, and faintly marked fins.

<span class="mw-page-title-main">Silvertip shark</span> Species of shark

The silvertip shark is a large species of requiem shark, in the family Carcharhinidae, with a fragmented distribution throughout the tropical Indian and Pacific Oceans. It is often encountered around offshore islands and coral reefs, and has been known to dive to a depth of 800 m (2,600 ft). The silvertip shark resembles a larger and bulkier grey reef shark, but can be easily identified by the prominent white margins on its fins. It attains a maximum length of 3 m (10 ft).

<span class="mw-page-title-main">Blacktip shark</span> Species of shark

The blacktip shark 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 1.5 m (4.9 ft).

<span class="mw-page-title-main">Caribbean reef shark</span> Species of shark

The Caribbean reef shark is a species of requiem shark, belonging to the family Carcharhinidae. It is found in the tropical waters of the western Atlantic Ocean from Florida to Brazil, and is the most commonly encountered reef shark in the Caribbean Sea. With a robust, streamlined body typical of the requiem sharks, this species is difficult to tell apart from other large members of its family such as the dusky shark and the silky shark. Distinguishing characteristics include dusky-colored fins without prominent markings, a short free rear tip on the second dorsal fin, and tooth shape and number.

<span class="mw-page-title-main">Bignose shark</span> Species of shark

The bignose shark 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 90–430 m (300–1,410 ft), though at night it may move towards the surface or into shallower water. The bignose shark is plain-colored and grows to at least 2.7–2.8 m (8.9–9.2 ft) 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.

<span class="mw-page-title-main">Graceful shark</span> Species of shark

The graceful shark or Queensland shark is a species of requiem shark, in the family Carcharhinidae, found in the tropical Indo-Pacific, from the Gulf of Aden to northern Australia. It is a midwater species that has been recorded to a depth of 50 m (160 ft). A stoutly built shark growing up to 1.7 m (5.6 ft) long, the graceful shark has a short, wedge-shaped snout, large, sickle-shaped pectoral fins and first dorsal fin, and black tips on most fins.

<span class="mw-page-title-main">Hardnose shark</span> Species of shark

The hardnose shark 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 1.1 m (3.6 ft), 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.

<span class="mw-page-title-main">Spinner shark</span> Species of shark

The spinner shark is a type of requiem shark, in the family Carcharhinidae, named for the spinning leaps it makes as a part of its feeding strategy. This species occurs in tropical and warm temperate waters worldwide, except for in the eastern Pacific Ocean. It is found from coastal to offshore habitats to a depth of 100 m (330 ft), though it prefers shallow water. The spinner shark resembles a larger version of the blacktip shark, with a slender body, long snout, and black-marked fins. This species can be distinguished from the blacktip shark by the first dorsal fin, which has a different shape and is placed further back, and by the black tip on the anal fin. It attains a maximum length of 3 m (9.8 ft).

<span class="mw-page-title-main">Nervous shark</span> Species of shark

The nervous shark is a species of requiem shark, and part of the family Carcharhinidae, so named because of its timid behavior in regard to humans. It is common in shallow, coastal waters off northern Australia, Papua New Guinea, and the Solomon Islands. A small brownish or grayish shark typically measuring 1.0–1.3 m (3.3–4.3 ft) long, this species has a short, blunt snout, oval eyes, and a relatively large second dorsal fin. The leading margins of most fins are finely edged with black, and the lower caudal fin lobe is black-tipped.

<span class="mw-page-title-main">Whitecheek shark</span> Species of shark

The whitecheek shark or widemouth blackspot shark 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.

<span class="mw-page-title-main">Pondicherry shark</span> Species of shark

The Pondicherry shark is an extremely rare species of requiem shark, in the family Carcharhinidae. A small and stocky gray shark, it grows not much longer than 1 m (3.3 ft) and has a fairly long, pointed snout. This species can be identified by the shape of its upper teeth, which are strongly serrated near the base and smooth-edged near the tip, and by its first dorsal fin, which is large with a long free rear tip. Furthermore, this shark has prominent black tips on its pectoral fins, second dorsal fin, and caudal fin lower lobe.

<span class="mw-page-title-main">Finetooth shark</span> Species of shark

The finetooth shark is a species of requiem shark, in the family Carcharhinidae, found in the western Atlantic Ocean, from North Carolina to Brazil. It forms large schools in shallow, coastal waters, and migrates seasonally following warm water. A relatively small, slender-bodied shark, the finetooth shark can be identified by its needle-like teeth, dark blue-gray dorsal coloration, and long gill slits. It attains a maximum length of 1.9 m (6.2 ft). The diet of this species consists primarily of small bony fishes, in particular menhaden. Like other members of its family, it is viviparous with females giving birth to two to six pups in estuarine nursery areas every other year.

<span class="mw-page-title-main">Smoothtooth blacktip shark</span> Species of shark

The smoothtooth blacktip shark is a species of requiem shark in the family Carcharhinidae. It is known only from the type specimen caught from the Gulf of Aden, off eastern Yemen, and a handful of additional specimens caught from the Persian Gulf, off Kuwait. Reaching 1.3 m (4.3 ft) in length, this species has a stocky greenish-colored body, a short snout, and black-tipped fins. It can be distinguished from similar species by its teeth, which are narrow, erect, and smooth-edged.

<span class="mw-page-title-main">Smalltail shark</span> Species of shark

The smalltail shark is a species of requiem shark, and part of the family Carcharhinidae. It is found in the western Atlantic Ocean, from the northern Gulf of Mexico to southern Brazil. It inhabits shallow waters close to shore, particularly over muddy bottoms around estuaries. It tends to swim low in the water column and forms large aggregations segregated by sex. A slim species generally not exceeding 1.1 m (3.6 ft) in length, the smalltail shark has a rather long, pointed snout, a broad, triangular first dorsal fin, and a second dorsal fin that originates over the midpoint of the anal fin base. It is plain gray in color, without prominent markings on its fins.

<span class="mw-page-title-main">Night shark</span> Species of shark

The night shark is a species of requiem shark, in the family Carcharhinidae, found in the temperate and tropical waters of the Atlantic Ocean. An inhabitant of the outer continental shelf and upper continental slope, this shark most commonly occurs at depths of 50–600 m (160–1,970 ft) and conducts a diel vertical migration, spending the day in deeper water and moving into shallower waters at night. Off northeastern Brazil, large numbers congregate around seamounts of varying depths. A slender, streamlined species, the night shark typically reaches a length of 2 m (6.6 ft). It can be identified by its long, pointed snout and large, green eyes, and is dark grayish blue or brown above and white below.

<span class="mw-page-title-main">Milk shark</span> Species of shark

The milk shark is a species of requiem shark, and part of the family Carcharhinidae, whose common name comes from an Indian belief that consumption of its meat promotes lactation. The largest and most widely distributed member of its genus, the milk shark typically measures 1.1 m (3.6 ft) long, and can be found in coastal tropical waters throughout the eastern Atlantic and the Indo-Pacific regions. Occurring from the surface to a depth of 200 m (660 ft), this species is common near beaches and in estuaries, and has been recorded swimming up rivers in Cambodia. Juveniles are known to inhabit tidal pools and seagrass meadows. The milk shark has a slender body with a long, pointed snout and large eyes, and is a nondescript gray above and white below. This shark can be distinguished from similar species in its range by the long furrows at the corners of its mouth, and seven to 15 enlarged pores just above them.

<span class="mw-page-title-main">Atlantic sharpnose shark</span> Species of shark

The Atlantic sharpnose shark is a species of requiem shark in the family Carcharhinidae. It is found in the subtropical waters of the north-western Atlantic Ocean, between latitudes 43°N and 18°N.

References

  1. 1 2 3 4 5 6 7 Carlson, J.; Charvet, P.; Avalos, C.; Blanco-Parra, MP, Briones Bell-lloch, A.; Cardenosa, D.; Espinoza, E.; Morales-Saldaña, J.M.; Naranjo-Elizondo, B.; Pérez Jiménez, J.C.; Schneider, E.V.C.; Simpson, N.J.; Talwar, B.S.; Crysler, Z.; Derrick, D.; Kyne, P.M.; Pacoureau, N. (2021). "Carcharhinus acronotus". IUCN Red List of Threatened Species . 2021: e.T161378A887542. doi: 10.2305/IUCN.UK.2021-1.RLTS.T161378A887542.en . Retrieved 19 November 2021.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  2. ↑ "Species Carcharhinus acronotus Poey 1860". FishWisePro. 1860. Retrieved 19 April 2020.
  3. 1 2 3 4 5 6 Compagno, L.J.V. (1984). Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date. Rome: Food and Agricultural Organization. pp. 454–455. ISBN   92-5-101384-5.
  4. ↑ Naylor, G.J.P. (1992). "The phylogenetic relationships among requiem and hammerhead sharks: inferring phylogeny when thousands of equally most parsimonious trees result". Cladistics. 8 (4): 295–318. doi:10.1111/j.1096-0031.1992.tb00073.x. hdl: 2027.42/73088 . PMID   34929961. S2CID   39697113.
  5. ↑ Dosay-Akbulut, M. (2008). "The phylogenetic relationship within the genus Carcharhinus". Comptes Rendus Biologies. 331 (7): 500–509. doi:10.1016/j.crvi.2008.04.001. PMID   18558373.
  6. ↑ Stafford-Deitsch, J. (2000). Sharks of Florida, the Bahamas, the Caribbean and the Gulf of Mexico. Trident Press. p. 68. ISBN   1-900724-45-6.
  7. 1 2 3 4 5 6 7 8 9 Bester, C. Biological Profiles: Blacknose Shark Archived 2014-10-06 at the Wayback Machine . Florida Museum of Natural History Ichthyology Department. Retrieved on June 2, 2009.
  8. 1 2 3 4 Driggers, W.B. (III), Ingram G.W., (Jr.), Grace, M.A., Carlson, J.K., Ulrich, J.F., Sulikowski, J.A. and Quattro, J.M. (2007). Life history and population genetics of blacknose sharks, Carcharhinus acronotus, in the South Atlantic Bight and the northern Gulf of Mexico. Small Coastal Shark Data Workshop Document, SEDAR-13-DW-17.
  9. 1 2 3 McEachran, J.D. & Fechhelm, J.D. (1998). Fishes of the Gulf of Mexico: Myxiniformes to Gasterosteiformes. University of Texas Press. p. 74. ISBN   0-292-75206-7.
  10. ↑ Froese, Rainer; Pauly, Daniel (eds.) (2009). "Carcharhinus acronotus" in FishBase . June 2009 version.
  11. ↑ Musick, J.A. & McMillan, B. (2003). The Shark Chronicles: A Scientist Tracks the Consummate Predator. Macmillan. pp. 57–59. ISBN   0-8050-7359-0.
  12. ↑ May, N. & Willis, C. (2002). Shark: Stories of Life and Death from the World's Most Dangerous Waters . Thunder's Mouth Press. p.  192. ISBN   1-56025-397-5.
  13. ↑ Hueter, R.E.; Heupel, M.R.; Heist, E.J.; Keeney, D.B. (2005). "Evidence of Philopatry in Sharks and Implications for the Management of Shark Fisheries". Journal of Northwest Atlantic Fishery Science. 35: 239–247. doi: 10.2960/J.v35.m493 .
  14. ↑ Martin, R.A. (March 2007). "A review of shark agonistic displays: comparison of display features and implications for shark-human interactions". Marine and Freshwater Behaviour and Physiology. 40 (1): 3–34. Bibcode:2007MFBP...40....3M. doi: 10.1080/10236240601154872 .
  15. ↑ Cressey, R.F. (1970). "Copepods Parasitic on Sharks From the West Coast of Florida". Smithsonian Contributions to Zoology. 38 (38): 1–30. doi:10.5479/si.00810282.38.
  16. ↑ Ruhnke, T.R. & Thompson, V.A. (2006). "Two New Species of Paraorygmatobothrium (Tetraphyllidea: Phyllobothriidae) from the Lemon Sharks Negaprion brevirostris and Negaprion acutidens (Carcharhiniformes: Carcharhinidae)". Comparative Parasitology. 73 (1): 35–41. doi:10.1654/4198.1. S2CID   86754695.
  17. ↑ Healy, C.J. (2003). "A revision of Platybothrium Linton, 1890 (Tetraphyllidea: Onchobothriidae), with a phylogenetic analysis and comments on host-parasite associations". Systematic Parasitology. 56 (2): 85–139. doi:10.1023/A:1026135528505. PMID   14574090. S2CID   944343.
  18. ↑ Driggers, W. B.; Oakley, D. A.; Ulrich, G.; Carlson, J. K.; Cullum, B. J.; Dean, J. M. (2004). "Reproductive biology of Carcharhinus acronotus in the coastal waters of South Carolina". Journal of Fish Biology. 64 (6): 1540–1551. Bibcode:2004JFBio..64.1540D. doi:10.1111/j.0022-1112.2004.00408.x.
  19. 1 2 Hazin, F.H.V.; Oliveira, P.G. & Broadhurst, M.K. (2002). "Reproduction of the blacknose shark (Carcharhinus acronotus) in coastal waters off northeastern Brazil" (PDF). Fishery Bulletin. 100: 143–148.
  20. 1 2 Ferrari, A. & Ferrari, A. (2002). Sharks . Firefly Books. p.  157. ISBN   1-55209-629-7.
  21. ↑ Driggers, William; Carlson, John; Cullum, Brian; Dean, John; Oakley, Doug (2004). "Age and growth of the blacknose shark, Carcharhinus acronotus, in the western North Atlantic Ocean with comments on regional variation in growth rates". Environmental Biology of Fishes. 71 (2): 171–178. Bibcode:2004EnvBF..71..171D. doi:10.1007/s10641-004-0105-z. S2CID   38114729.
  22. ↑ "NOAA Proposes Measures To Rebuild Blacknose And Other Shark Populations". (July 24, 2009). NOAA – National Oceanic and Atmospheric Administration. Retrieved on July 26, 2009.

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.