Elasmobranchii (sharks and rays) > Carcharhiniformes
(Ground sharks) > Sphyrnidae
(Hammerhead, bonnethead, or scoophead sharks)
Etymology: Sphyrna: Greek, sphyra = hammer (Ref. 45335).
Environment / Climate / Range
Marine; benthopelagic, usually ? - 12 m (Ref. 244). Subtropical; 46°N - 57°S, 73°W - 37°E (Ref. 244)
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 134 cm TL male/unsexed; (Ref. 244); 148.0 cm TL (female)
Southwest Atlantic: Venezuela to Argentina (Ref. 58839). Also Mediterranean Sea and Eastern Pacific (Ref. 7251).
A little-known inshore shark of the continental shelf, found down to at least 12 m depth. Feeds on small bony fishes, including sea catfish and grunts, but also newborn scalloped hammerheads, swimming crabs, squids, and shrimp. Viviparous with a yolk-sac placenta; number of young probably 6 to 9 per litter (Ref. 244).
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: subsistence fisheries
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 (0.00129 - 0.00705), b=3.16 (2.96 - 3.36), based on LWR estimates for this Subfamily-BS (Ref. 93245
Trophic Level (Ref. 69278
): 3.6 ±0.5 se; Based on diet studies.
Resilience (Ref. 69278
): Very Low, minimum population doubling time more than 14 years (Fec=6).
Vulnerability (Ref. 59153
): High vulnerability (56 of 100) .