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. Tropical; 13°N - 18°S, 115°W - 69°W
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 92.0 cm TL male/unsexed; (Ref. 244)
Eastern Pacific: southern Mexico to northern Peru, probably including the Gulf of California.
Found on the continental shelf, presumably inshore. Viviparous, presumably with 2 young per litter. Probably the smallest species of hammerhead.
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Viviparous, placental (Ref. 50449).
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. (Ref. 244)
IUCN Red List Status (Ref. 96402)
CITES (Ref. 94142)
Threat to humans
Fisheries: subsistence fisheries
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5029 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00295 (0.00125 - 0.00696), b=3.17 (2.97 - 3.37), based on LWR estimates for this (Sub)Family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.9 ±0.4 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
): Very Low, minimum population doubling time more than 14 years (Fec=2).
Vulnerability (Ref. 59153
): Moderate vulnerability (37 of 100) .