Winghead shark

This is a good article. Click here for more information.
Source: Wikipedia, the free encyclopedia.

Winghead shark
CITES Appendix II (CITES)[2]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Subdivision: Selachimorpha
Order: Carcharhiniformes
Family: Sphyrnidae
Genus: Eusphyra
T. N. Gill
, 1862
Species:
E. blochii
Binomial name
Eusphyra blochii
(G. Cuvier, 1816)
Range of the winghead shark[3]
Synonyms
  • Zygaena blochii G. Cuvier, 1816
  • Zygaena laticeps Cantor, 1837
  • Zygaena latycephala van Hasselt, 1823

The winghead shark (Eusphyra blochii) is a

mechanoreception
, respectively.

Inhabiting the shallow coastal waters of the

endangered in 2016, as it is thought to have declined in some parts of its range due to overfishing
.

Taxonomy

In 1785, German

binomial name, his colleague Achille Valenciennes interpreted it as such in 1822 when he described another specimen of the same species in detail, calling it Zygaena Blochii nobis and attributing the name to Cuvier.[4][5]

In 1862, Theodore Gill placed the winghead shark in its own genus Eusphyra, derived from the Greek eu ("good" or "true") and sphyra ("hammer").[6][7] However, subsequent authors did not accept Eusphyra and preferred to keep this species with the other hammerheads in the genus Sphyrna. Eusphyra was resurrected by Henry Bigelow and William Schroeder in 1948, and came into wider usage after additional taxonomic research was published by Leonard Compagno in 1979 and 1988. Nevertheless, some sources still refer to this species as Sphyrna blochii.[5][8] Other common names for the winghead shark include arrowhead, arrow-headed hammerhead shark, and slender hammerhead.[7]

Phylogeny

Eusphyra blochii

Sphyrna mokarran

Sphyrna zygaena

Sphyrna lewini

Sphyrna tudes

Sphyrna media

Sphyrna tiburo

Sphyrna corona

Phylogenetic tree of hammerhead sharks based on mitochondrial and nuclear DNA[9]

The traditional view of hammerhead shark

monophyletic (including all descendants of a single ancestor). The winghead shark lineage is estimated to have diverged from the rest of the hammerheads some 15–20 million years ago during the Miocene.[8][9][10]

Description

Winghead shark, X-ray image

True to its name, the winghead shark's cephalofoil consists of a pair of long, narrow, and gently swept-back blades. The width of the cephalofoil is equal to 40–50% of the shark's total length. The front of the cephalofoil has a slight indentation in the middle and a gentle bump on each side in front of the nostrils. Each nostril is roughly twice as long as the width of the mouth and extends along almost the entire leading margin of each blade. The circular eyes, located at the forward outer corners of the cephalofoil, are equipped with protective

pectoral fin origins.[3][5][11][12]

The body is slim and streamlined, with a very tall, narrow, and falcate (sickle-shaped) first

dermal denticles, each with three horizontal ridges leading to marginal teeth.[13] This species is brownish gray to gray above and off-white below, and lacks fin markings.[3] It grows up to 1.9 m (6.2 ft) long.[11]

Distribution and habitat

The winghead shark is found in the

estuaries.[7]

Biology and ecology

Illustration of a winghead shark from Fauna of British India (1889), showing the remarkably wide cephalofoil: The function of this structure is yet unclear.

Several nonexclusive

electroreceptive ampullae of Lorenzini and mechanoreceptive lateral line.[5] The lateral blades seem too large to function in maneuvering, which has been suggested for other hammerheads.[16]

The winghead shark usually hunts close to the

tapeworms Callitetrarhynchus blochii,[18] Heteronybelinia heteromorphi,[19] Otobothrium carcharidis, O. mugilis,[20] Phoreiobothrium puriensis,[21] and Phyllobothrium blochii,[22] the nematodes Hysterothylacium ganeshi,[23] Pseudanisakis sp.,[24] Raphidascaroides blochii,[25] and Terranova sp.,[24] the copepod Caligus furcisetifer,[26] and the protozoan Eimeria zygaenae.[27]

Life history

The winghead shark is

gestation period lasts 8–9 months off western India, and 10–11 months off northern Australia.[3][17][29] Pregnant females have been reported to quarrel with each other.[5]

Initially, the embryo is nourished by yolk and develops in a similar fashion to other sharks. At a length of 4.0–4.5 cm (1.6–1.8 in), the cephalofoil and the fins begin to form. When the embryo is 12–16 cm (4.7–6.3 in) long, the yolk supply begins to run low and folds appear on the yolk sac and uterine wall, which later interlock to form the placenta. At this stage, the embryo has most of the features of an adult, albeit rudimentary and colorless. The blades of the cephalofoil are folded back along the body, and long external gill filaments protrude from the gill slits. At a length of 20–29 cm (7.9–11.4 in), the placenta has formed; the first teeth, dermal denticles, and skin pigmentation appear on the embryo, and the external gills are much reduced in size. By the time the embryo is 30 cm (12 in) long, it resembles a miniature version of the adult.[28][29]

Birthing takes place in May and June off Mumbai and

maximum lifespan is at least 21 years.[30]

Human interactions

Harmless to humans, the winghead shark is caught throughout its range using

least concern by the IUCN.[1]

References

  1. ^
    doi:10.2305/IUCN.UK.2016-1.RLTS.T41810A68623209.en
    . Retrieved 19 November 2021.
  2. ^ "Appendices | CITES". cites.org. Retrieved 14 January 2022.
  3. ^
    ISBN 978-0674034112
    .
  4. ^ Cuvier, G. (1816). Le Règne Animal distribué d'après son organisation pour servir de base à l'histoire naturelle des animaux et d'introduction à l'anatomie comparée. Deterville. p. 127.
  5. ^
    ISBN 978-9251013847
    .
  6. doi:10.1111/j.1749-6632.1862.tb00166.x
    .
  7. ^ a b c Froese, R.; Pauly, D., eds. (2011). "Eusphyra blochii, Winghead shark". FishBase. Retrieved May 18, 2013.
  8. ^ a b Martin, R.A. (1998). "Recent Changes in Hammerhead Taxonomy". ReefQuest Centre for Shark Research. Retrieved May 18, 2013.
  9. ^
    PMID 20138218
    .
  10. ^ Cavalcanti, M.J. (2007). "A phylogenetic supertree of the hammerhead sharks (Carcharhiniformes: Sphyrnidae)". Zoological Studies. 46 (1): 6–11.
  11. ^
    ISBN 978-1-921605-59-8
    .
  12. ^
    ISBN 978-0824818081
    .
  13. doi:10.1111/j.1463-6395.2011.00547.x
    .
  14. PMID 19946079
    .
  15. S2CID 6841608
    .
  16. JSTOR 1446895
    .
  17. ^
    doi:10.1071/MF9890129
    .
  18. ^ Pramanik, P.B.; Manna, B. (2006). "Callitetrarhynchus blochii new species (Cestoidea: Lacistorhynchidae) from Sphyrna blochii Cuvier, 1817 from Bay of Bengal at Digha coast, India". Journal of Natural History. 2 (2): 10–15.
  19. ^ Palm, H.W. (1999). "Nybelinia Poche, 1926, Heteronybelinia gen. nov. and Myxonebelinia gen. nov. (Cestoda: Trypanorhyncha) in the collections of The Natural History Museum, London". Bulletin of the Natural History Museum. Zoology Series. 65 (2). London: 133–153.
  20. S2CID 18892377
    .
  21. ^ Srivastav, A.K.; Capoor, V.N. (1982). "On a new cestode, Phoreiobothrium puriensis n. sp". Indian Journal of Helminthology. 34 (1–2): 82–85.
  22. ^ Srivastav, A.K.; Srivastava, B.K. (1988). "On a new cestode, Phyllobothrium blochii sp. n. (Phyllobothriidae, Cestoda) from the elasmobranch fish, Zygaena blochii (Cuvier) (Carchariidae, Euselachii) from Puri, Orissa (India)". Helminthologia. 25: 89–94.
  23. ^ Lakshmi, I.R.; Sreeramulu, K. (2007). "Hysterothylacium ganeshi n. sp (Nematoda-Anisakidae) from the intestine of Shark, Sphyrna blochii (Cuvier)". Geobios. 34 (1). Jodhpur: 29.
  24. ^
    ISBN 978-9251048542
    .
  25. doi:10.1071/IT9940583
    .
  26. ^ Margolis, L.; Kabata, Z.; Parker, R.R. (1975). "Catalogue and synopsis of Caligus, a genus of Copepoda (Crustacea) parasitic on fishes". Bulletin of the Fisheries Research Board of Canada. 192: 1–117.
  27. ^ Chakravarty, M.; Mandal, A.K. (1961). "A new coccidium, Eimeria zygaenae n. sp. from hammer headed shark, Zygaena blochii". Proceedings of the 48th Indian Science Congress (Roorkee) (Part III): abstract 93.
  28. ^ a b c Appukuttan, K.K. (1978). "Studies on the developmental stages of hammerhead shark Sphyrna (Eusphyrna) blochii from the Gulf of Mannar" (PDF). Indian Journal of Fisheries. 25 (1–2): 41–52.
  29. ^ a b c d Devadoss, P. (1988). "Observations on the breeding and development of some sharks". Journal of the Marine Biological Association of India. 30 (1–2): 121–131.
  30. doi:10.1002/aqc.2274
    .

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=Winghead_shark&oldid=1185839860"