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, preferred ?; 31°N - 34°S
Western Atlantic: Panama to southern Brazil. Eastern Pacific: Gulf of California to Ecuador and probably northern Peru.
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)
Little-known. Found in inshore areas over the continental shelves. Viviparous (Ref. 50449). Utilized fresh for human consumption and for fishmeal.
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. 109396)
CITES (Ref. 94142)
Threat to humans
Fisheries: minor commercial
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 (0.00127 - 0.00686), b=3.17 (2.97 - 3.37), based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 4.0 ±0.4 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 (59 of 100) .