Rostroraja alba   (Lacepede)  1803 (Fish)
Organism information awaits expert curation
Taxonomy
Kingdom:Animalia
Phylum:Chordata
Class: Elasmobranchii
Order:Rajiformes
Family:Rajidae

Image copyrights: RIVO/Henk Heessen

Description
Size: 230 cm TL (male); 119-202 cm TL (female)

Color: Dorsal surface is grayish on the central part and the tail, and dark black at the outer edges. Ventral surface is grey in color.

Snout abruptly narrowed and produced into a long sharply pointed snout. Disc 1.4 times wider than long, with a markedly undulate anterior margin. Central part of the snout is bony and with prickles. Eyes are protruded, placed anterio-laterally and the skin covering the eye has a greenish grey color. Three rows of thorns (antorbital thorns) are present on the anterior side of each eye. Seven thorns are present on the inner sides of each eye in the centre; two rows of thorns above the spiracle. The suprascapular region and the interorbital region prickly, but devoid of thorns. Spiracles large, oval shaped openings placed just below the eye on the dorsal side. 10 nuchal thorns present in the centre below the spiracles, followed by a nuchal area, which precedes 24 median abdominal thorns. One thorn each present on either side of the 22nd median abdominal thorn. Teeth, each with a single large cusp. Tail broad, shorter than disc length, and tapering posteriorly into a blunt edge. Thirty-two thorns on the median axis of the tail, before the first dorsal fin; the alternate thorns smaller in size. On either side of the median row of thorns is another row of thorns or “bucklers”. Scattered thorns pointing outwards arise from the lateral sides. The dorsal fins are on the posterior end of the tail, the first dorsal fin is smaller, the base of which equals in distance the interdorsal space. 5 thorns in the interdorsal space. Caudal fin rudimentary. Ventral base of tail smooth. Ventral surface of the body has prickles on the snout, front margin of the disc, internasal region and tail.

Dioecious, internal (oviduct) fertilization, oviparous, nonguarders, open water/substratum egg scatterers. Paired eggs are laid. Embryos feed solely on yolk. Eggs are laid in huge cases and take up to 18 months to hatch. Eggs are oblong capsules with stiff pointed horns at the corners deposited in sandy or muddy flats. Distinct pairing with embrace. Young may tend to follow large objects, such as their mother.


Synonym (s)
Raja alba Lacepede 1803
Raja alba Norman 1935
Raja alba Fowler 1941
Raja alba van Bruggen 1965
Rostroraja alba McEachran & Dunn 1998
Rostroraja alba Heemstra & Heemstra 2004
Raia bicolor Risso 1827
Raia rostellata Risso 1810
Raja bicolor Shaw 1804
Raja bramante Sassi 1846
Raja marginata Lacepede 1803
Raja rostellata Risso 1810
Raia bicolor Risso 1827
(Ambiguous synonym)
Raia rostellata Risso 1810
(Junior synonym)
Raja alba Lacepede 1803
(Senior synonym)
Raja bicolor Shaw 1804
(Junior synonym)
Raja bramante Sassi 1846
(Junior synonym)
Raja marginata Lacepede 1803
(Junior synonym)
Raja rostellata Risso 1810
(Junior synonym)
Rostroraja alba (Lacepede) 1803
(Senior synonym)

Common Name (s)
• Spear Nose Skate (English)
Economic Importance and Threats
Importance:  Dangers
(Traumatogenic)

Ecology
Habitat:  Demersal, Sandy, Coastal
Trophic Level:  Secondary Consumer
Prey:  Benthic crustaceans, molluscs, planktonic crustaceans, squids, cuttlefish, bonyfish
IUCN Status:  Endangered

Biogeography


• Kerala, Kochi Fisheries Harbour INDIA (Record: 27/09/2003)

Literature Source(s)
  • Nair, RJ (2006) First record of spearnose skate, Rostroraja alba (Lacepede, 1803) (Rajiformes: Rajidae) from Indian waters Journal of the Marine Biological Association of India The Marine Biological Association of India, Cochin 48(1) 115-117 Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at - http://www.marinespecies.org
  • Froese, R and Pauly, D (2000) Fishbase 2000: Concepts, design and data sources ICLARM 344 pp Available at - http://www.fishbase.org
  • (2003) IUCN Red list of threatened species Available at - http://www.iucnredlist.org/

Page last updated on:2009-06-04

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