World Library  
Flag as Inappropriate
Email this Article

Taillight shark

Article Id: WHEBN0007150310
Reproduction Date:

Title: Taillight shark  
Author: World Heritage Encyclopedia
Language: English
Subject: Squaliformes, Mandarin dogfish, Sailfin roughshark, Longnose pygmy shark, Smalleye pygmy shark
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Taillight shark

Taillight shark
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Squaliformes
Family: Dalatiidae
Genus: Euprotomicroides
Hulley & M. J. Penrith, 1966
Species: E. zantedeschia
Binomial name
Euprotomicroides zantedeschia
Hulley & M. J. Penrith, 1966
Occurrences of the taillight shark

The taillight shark (Euprotomicroides zantedeschia) is a little-known species of dogfish shark in the family Dalatiidae, and the only member of its genus. It is known from only two specimens collected from deep oceanic waters in the southern Atlantic Ocean. A small shark with a laterally compressed body and a bulbous snout, this species has unusual adaptations that indicate a specialized lifestyle: its pectoral fins are paddle-like and may be used for propulsion, unlike other sharks, and it has a pouch-like gland on its abdomen that emits clouds of luminescent blue fluid. This shark is likely aplacental viviparous and a formidable predator for its size. The International Union for Conservation of Nature (IUCN) presently lacks sufficient data to assess its conservation status.

Contents

  • Taxonomy and phylogeny 1
  • Distribution and habitat 2
  • Description 3
  • Biology and ecology 4
  • Human interactions 5
  • References 6

Taxonomy and phylogeny

The first specimen of the taillight shark was collected by the Cape Town trawler Arum in 1963, and was initially identified as a longnose pygmy shark (Heteroscymnoides marleyi) before being recognized as a hitherto unknown species. The genus name Euprotomicroides comes from this shark's resemblance to the pygmy shark (Euprotomicrus bispinatus). The specific epithet zantedeschia is derived from Zantedeschia aethiopica, a species of arum lily for which the trawler Arum was named.[2]

Phylogenetic analysis based on dentition indicates that the taillight shark is the most basal member of its family, and is sister to the clade containing all other dalatiid species. Although there are no definitive fossil remains, the taillight shark may have evolved in the early Paleocene epoch (65.5–55.8 Ma), as part of a larger adaptive radiation of dogfish sharks into midwater habitats. The teeth of the extinct shark Palaeomicroides ursulae, found in early Campanian (83.5–70.6 Ma) deposits in Germany, closely resemble those of the taillight shark.[3]

Distribution and habitat

The two specimens of the taillight shark were caught off South Africa in a trawl operating at a depth of 458–641 m (1,503–2,103 ft), and off Uruguay in a trawl operating at a depth of 195–205 m (640–673 ft). These records suggest that this shark is an inhabitant of the open ocean. However, it is unclear whether the known specimens were captured near the sea bottom where the trawls operated, or from midwater as the nets were being retrieved.[1]

Description

The taillight shark is laterally compressed, with a long, rounded snout and large, oval eyes. The mouth is large, containing 29 tooth rows in the upper jaw and 34 tooth rows in the lower jaw. The upper teeth are small and needle-like, while the lower teeth are large and triangular, with their bases interlocking to form a continuous cutting surface. The lips are thick and fringed, though not modified to be suctorial. The five pairs of gill slits are large, and increase in size from the first to the last.[2][4]

The two [5] The first specimen was an immature female (originally reported incorrectly as a mature male) 17.6 cm (6.9 in) long, and the second was a mature male 41.6 cm (16.4 in) long.[1]

Biology and ecology

The muscular, lobe-like pectoral fins of the taillight shark suggest that they may be used for propulsion, in a manner more akin to that of [5] Reproduction is presumably aplacental viviparous as in the other members of its family.[4]

Human interactions

The taillight shark is not caught significantly by any fishery, possibly due to its small size and habitat preferences. The International Union for Conservation of Nature (IUCN) does not yet have enough data to assess its conservation status beyond Data Deficient.[1]

References

  1. ^ a b c d Burgess, G.H. (2006). Euprotomicroides zantedeschia. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on June 20, 2009.
  2. ^ a b c  
  3. ^ Adnet, S. and Cappetta, H. (September 2001). "A palaeontological and phylogenetical analysis of squaliform sharks (Chondrichthyes: Squaliformes) based on dental characters". Lethaia 34 (3): 234–248.  
  4. ^ a b c d 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. 89–90.  
  5. ^ a b Munk, O. and Jørgensen, J.M. (1988). "Putatively luminous tissue in the abdominal pouch of a male dalatiine shark, Euprotomicroides zantedeschia Hulley & Penrith, 1966". Acta Zoologica 69 (4): 247–251.  
  6. ^ Froese, Rainer and Pauly, Daniel, eds. (2009). "Euprotomicroides zantedeschia in FishBase. June 2009 version.
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.