Scientific Name
Sphyrna zygaena  
Sphyrna zygaena錘頭雙髻鯊
by: Lab of Fish Ecol. and Evo., BRCAS
Author (Linnaeus, 1758) Depth 0 - 200M
Chinese 錘頭雙髻鯊 Poisonous Fish No 
Family_Chinese 雙髻鯊科 Economic Fish Yes 
Family F030 Sphyrnidae Edible Fish Yes  Chinese In Mainland China 錘頭雙髻鯊 
Max Length 500 cm  Aquarium Fish No  Common Name 錘頭丫髻鯊、犛頭沙、雙髻鯊、雙過仔、丫髻鮫、白肉雙髻(澎湖) 
Distribution in World global   Distribution in Taiwan East、West、North、Greeb IS. 
Habitats Ocean、Deep Sea、Coral、Benthos、
Holotype Locality Mediterranean Sea and Atlantic [original:  
Synonyms Sphyrna lewini, Sphyrna mokarran, Sphyrna zigaena, Spyrna zygaena, Squalis pictus, Squalus carolinensis, Squalus malleus, Squalus zygaena, Zygaena malleus, Zygaena subarcuata, Zygaena vulgaris   
Reference 臺灣魚類誌(沈等, 1993);中國動物誌-圓口綱及軟骨魚綱(朱等, 2001);FAO Species Catalogue, Vol.4 Sharks of the world  Schwartz, F.J. etc. 1981 Schwartz, F.J. 1983 
Specimen List ASIZP0806235. ASIZP0806236. ASIZP0916235. ASIZP0916236. NMMBP06279. NMMBP06296. NMMBP06569. NTMP0629. NTMP0687. NTUM01632. NTUM01633. NTUM08229.  
Barcode2014-10-30,Kwang-Tsao Shao,CO1,100% 2014-10-30,Kwang-Tsao Shao,CO1,100% 2015-12-01,Chia-Hao Chang,CO1,100% 2015-12-01,Chia-Hao Chang,CO1,100% 2015-12-01,Chia-Hao Chang,CO1,100%
Common Name Round-headed hammerhead; Smooth hammerhead; Round-headed hammerhead shark; Common smooth hammerhead shark; Common hammerhead; Common hammerhead shark; Hammerhead; Hammerhead shark 
Redlist Status LR/nt IUCN Redlist: Lower Risk/near threatened(LR/nt)  2000-06-30  CITES Appendix 2 CITES Appendix 2 
Characteristic A large hammerhead shark with expanded prebranchial head. Head width 26-29 % of total length. Anterior margin of head very broadly arched with prominent lateral indentations, but no medial indentation. Preoral snout about 1/5 to less than 1/3 of head width. Anterior teeth with moderately long, very stout cusps, and smooth or weakely serrated edges. Posterior teeth mostly cuspidate and not keeled and molariform. First dorsal fin origin over pectoral insertions, its free rear tip well aneterior to pelvic origins. Second dorsal fin low, less than anal fin height, its inner margin long, about twice fin height. Anal fin slightly larger than 2nd dorsal fin. Total vertebral centra 193-206. Colour dark olive or dark grey-brown above, white below, undersides of pectoral fin tips dusky.
habitats An active, common, coastal-pelagic and semi-oceanic hammerhead. Viviparous, with a yolk-sac placenta. Litter size 29-37. Maximum size 370-400 cm. Males maturing at about 210-240 cm and females maturing at about 256. Size at birth 50-61 cm. 
Distribution Western Atlantic from Scotia to Florida and Virgin Islands. Southern Brazil to southern Argentina. Eastern North Atlantic from Mediterranean and British Isles to Senegal, Cape Verde Islands, Guinea, and Ivory Coast. Western Indian Ocean including South Af 
Utility This species is caught with pelagic longlines, handlines, and even pelagic and bottom trawls. It is utilized fresh, dried salted, and possibly smoked for human consumption. Hides are processed fro leather. Liver oil is extracted for vitamins. Fins are pro