Elasmobranchii (sharks and rays) > Carcharhiniformes
(Ground sharks) > Sphyrnidae
(Hammerhead, bonnethead, or scoophead sharks)
Etymology: Sphyrna: Greek, sphyra = hammer (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
Marine; demersal; depth range - 100 m (Ref. 121788), usually - m (Ref. ). Tropical; 0°C - ; 32°N - 19°S, 115°W - 69°W
Eastern Pacific: southern Mexico to northern Peru, probably including the Gulf of California.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 92.0 cm TL male/unsexed; (Ref. 244)
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. 124695)
Threat to humans
Fisheries: subsistence fisheries
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Preferred temperature (Ref. 115969
): 15.9 - 25.2, mean 20.8 °C (based on 20 cells).
Phylogenetic diversity index (Ref. 82805
= 0.5029 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00347 (0.00155 - 0.00778), b=3.12 (2.93 - 3.31), in cm total length, 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. 120179
): Very Low, minimum population doubling time more than 14 years (Fec=2).
Vulnerability (Ref. 59153
): Moderate vulnerability (37 of 100) .
Nutrients (Ref. 124155
): Calcium = 75.2 [10.8, 290.8] mg/100g ; Iron = 0.663 [0.146, 1.917] mg/100g ; Protein = 19.2 [17.2, 21.2] % ; Omega3 = 0.148 [0.061, 0.347] g/100g ; Selenium = 63.9 [16.2, 192.5] μg/100g ; VitaminA = 10.3 [4.3, 24.8] μg/100g ; Zinc = 0.748 [0.362, 1.725] mg/100g (wet weight);