Thunnus obesus   (Lowe,  1839) (Fish)
Organism information awaits expert curation
Taxonomy
Kingdom:Animalia
Phylum:Chordata
Class: Actinopterygii
Order:Perciformes
Family:Scombridae

Image copyrights: Archambault, C.

Description
Size: 250 cm.

Max. weight reported: 210 kg.

Color: Dark to grayish blue on back becoming silvery white below. Spinous dorsal grayish. Pectoral blackish above, lower rays yellowish. Ventral gray with yellowish tinge. Anal pale, tips yellowish. Anal and dorsal finlets yellowish gray.

Head 3.4-3.7 in standard length, 3.9 -4.2 in total length. Depth of body 3.4-3.8 in standard length, 3.9-4.3 in total length. Eye diameter 5.0-6.0 in head, 1.6-1.8 in snout and 2.0-2.4 in interorbital space. Maxillary almost reaching to below middle of eye. Preoperculum more or less angular at lower posterior margin. A single series of conical teeth in jaws and in elongate patches on vomer and palatines. First dorsal spine equal to or slightly longer than snout and eye diameter together. Soft dorsal about equal to postorbital length of head. Anal fin height almost equal to that of dorsal fin. Pectoral fin equal to or slightly longer than head, surpassing vertical through dorsal origin. Ventral fin slightly shorter than snout and eye. Caudal keel well developed. Distance between tip of pectoral and caudal keel greater than length of head. Body completely scaled.
Number of spines in the first dorsal fin: XIV-XV; number of spines and rays in the second dorsal fin: 13-14+9; number of spines and rays in the anal fin: 14+8; number of rays in the pectoral fin: 34-35; number of spines and rays in the ventral fin: I, 5; gill raker count: 7+18-19.

Dioecious, external fertilization, nonguarders, open water or substratum egg scatterers. Spawning frequency variable throughout range. Are multiple spawners that may spawn every 1 or 2 days over several months. They spawn over periods of the full moon. Spawn throughout the year in tropical waters.

Max. age reported: 11 years.

Remarks: Values in above description denote proportions.


Synonym (s)
Germo obesus (Lowe, 1839)
(Senior synonym)
Germo sibi (Temminck & Schlegel, 1844)
(Junior synonym)
Neothunnus obesus (Lowe, 1839)
(Senior synonym)
Orcynus sibi (Temminck & Schlegel, 1844)
(Junior synonym)
Parathunnus obesus (Lowe, 1839)
(Senior synonym)
Parathunnus obesus mebachi (Kishinouye, 1915)
(Junior synonym)
Parathunnus sibi (Temminck & Schlegel, 1844)
(Junior synonym)
Thunnus atlanticus (non Lesson, 1830)
(Misapplied name)
Thunnus mebachi Kishinouye, 1915
(Junior synonym)
Thunnus obesus mebachi Kishinouye, 1915
(Junior synonym)
Thunnus obesus sibi (Temminck & Schlegel, 1844)
(Junior synonym)
Thunnus sibi (Temminck & Schlegel, 1844)
(Junior synonym)
Thynnus obesus Lowe, 1839
(Senior synonym)
Thynnus sibi Temminck & Schlegel, 1844
(Junior synonym)
Parathunnus obesus mebachi Jones and Silas, 1960
Thunnus (Parathunnus) mebachi Jones, 1969
Thunnus (Parathunnus) obesus mebachi Jones and Silas, 1964
Thunnus (Parathunnus) obesus sibi Jones and Silas, 1963
Parathunnus mebachi (Kishinouye, 1915)
(Junior synonym)
Thunnus abesus (Lowe, 1839)
(Misspelling)
Thunus obesus (Lowe, 1839)
(Misspelling)

Common Name (s)
• Bigeyed Tuna (English)
• Bigeye Tuna Fish (English)
• Big Eye Tunny (English)
• Big Eye (English)
• Valiya Choora (Malayalam)
• Bigeye Tuna
Economic Importance and Threats
Importance:  Commercial
(Fisheries, gamefish)

Ecology
Habitat:  Pelagic
Trophic Level:  Tertiary Consumer
Prey:  Zoobenthos, zooplankton, cephalopods, finfish, bony fish
Predator:  Isistius brasiliensis, Orcinus orca, billfishes, Makaira nigricans, toothed whales
IUCN Status:  Vulnerable

Biogeography


• Andaman and Nicobar Islands (Lat: 12.53) (Long: 92.82) INDIA
• Lakshadweep, Kavaratti INDIA
• Lakshadweep Sea INDIA
• Andaman and Nicobar Islands INDIA
• INDIA

Literature Source(s)
  • UNEP World Conservation Monitoring Centre Available at - http://www.unep-wcmc.org/
  • Rajan, PT (2003) A field guide to marine food fishes of Andaman and Nicobar Islands ZSI, 234/4, AJC Bose Road, 2nd MSO Building, (13th Floor), Nizam Palace, Kolkata-700 020 260 pp Available at - NCL, Pune
  • Heemstra, E; Heemstra, P; Smale, M; Hoopers, T and Pelicier, D (2004) Preliminary checklist of coastal fishes from the Mauritian island of Rodrigues Journal of natural history Taylor and Francis 38(23-24) 3315 - 3350 Available at - taylorandfrancis.metapress.com/ index/
  • Letourneur, Y; Chabanet, P; Durville, P; Taquet, M; Teissier, E; Parmentier, M; Quero, JC and Pothin, K (2004) An updated checklist of the marine fish fauna of Reunion Island, south-western Indian Ocean Cybium 28(3) 199-216
  • Froese, R and Pauly, D (2000) Fishbase 2000: Concepts, design and data sources ICLARM 344 pp Available at - http://www.fishbase.org
  • Jones, S and Kumaran, M (1980) Fishes of the Laccadive Archipelago The Nature Conservation and Aquatic Sciences Service, Trivandrum, Kerala 760 pp 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
  • (2003) IUCN Red list of threatened species Available at - http://www.iucnredlist.org/
  • Fischer, W and Bianchi, G (Eds.) (1984) FAO species identification sheets for fishery purposes. Western Indian Ocean (Fishing Area 51) FAO, Rome 4 Available at - http://www.fao.org/docrep/009/ad468e/ad468e00.HTM#Contents
  • Fischer, W and Whitehead, PJP (1974) FAO species identification sheets for fishery purposes. Eastern Indian Ocean - Fishing Area 57 and Western Central Pacific - Fishing Area 71 FAO, Rome 4 Available at - http://www.fao.org/docrep/009/e9163e/e9163e00.htm
  • Talwar, PK (1990) Fishes of Andaman and Nicobar Islands: A synoptic survey Journal of the Andaman Science Association Andaman Science Association, Port Blair 6(2) 71-102 Available at - NIO,Goa
  • Pillai, PKM and Augustine, SK (2000) A code list of common marine living resources of the Indian seas CMFRI Special Publication No.12 CMFRI 1-115 Available at - eprints.cmfri.org.in/3975/1/Special_Publication_No_12_Revised.pdf

Page last updated on:2011-12-07

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