Elasmobranchii (sharks and rays) > Carcharhiniformes
(Ground sharks) > Sphyrnidae
(Hammerhead, bonnethead, or scoophead sharks)
Etymology: Sphyrna: Greek, sphyra = hammer (Ref. 45335).
Environment / Climate / Range
Marine; demersal; depth range 8 - ? m (Ref. 58018). Tropical; 31°N - 34°S
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 150 cm TL male/unsexed; (Ref. 5217); common length : 100.0 cm TL male/unsexed; (Ref. 5217)
Western Atlantic: Panama to southern Brazil. Eastern Pacific: Gulf of California to Ecuador and probably northern Peru.
Little-known. Found in inshore areas over the continental shelves. Viviparous (Ref. 50449). Utilized fresh for human consumption and for fishmeal.
Compagno, L.J.V., 1984. FAO Species Catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 2 - Carcharhiniformes. FAO Fish. Synop. 125(4/2):251-655. Rome: FAO.
IUCN Red List Status (Ref. 90363)
Threat to humans
Fisheries: minor commercial
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
CollaboratorsPicturesStamps, CoinsSoundsCiguateraSpeedSwim. typeGill areaOtolithsBrainsVision
Estimates of some properties based on empirical models
Phylogenetic diversity index (Ref. 82805
= 0.5029 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00302 (0.00130 - 0.00702), b=3.17 (2.97 - 3.37), based on LWR estimates for this Subfamily-BS (Ref. 93245
Trophic Level (Ref. 69278
): 3.9 ±0.6 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
): Low, minimum population doubling time 4.5 - 14 years (Fec assumed to be <100).
Vulnerability (Ref. 59153
): High vulnerability (58 of 100) .