Classification / Names
Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa
Elasmobranchii (sharks and rays) >
Carcharhiniformes (Ground sharks) >
Sphyrnidae (Hammerhead, bonnethead, or scoophead sharks)
Etymology: Sphyrna: Probable misspelling of sphyra (Gr.), hammer, referring to their hammer-shaped heads (See ETYFish).
Environment: milieu / climate zone / depth range / distribution range
Ecology
Marine; brackish; reef-associated. Tropical
Western Pacific: Belize to Brazil; including Panama, Colombia, Trinidad and Tobago. S. tiburo from North Carolina, U.S to Belize have potential contact zone with S. alleni between Mexico and Belize (Yucatan Peninsula).
Size / Weight / Age
Maturity: Lm ? range ? - ? cm
Max length : 6.5 cm TL male/unsexed; (Ref. 132488); 10.3 cm TL (female)
Short description
Identification keys | Morphology | Morphometrics
This small hammerhead shark (<150 cm at maturity) is distinguished by the following characters: a flat, shovel shaped head without indentations on its anterior edge; cephalofoil anterior margin is pointed (like a triangle) in both sexes and the posterior margins are lobule shaped; anterior margin of males exhibits a pronounced bulge; with enlarged, molariform posterior teeth, the first
dorsal rear tip in front of pelvic origins, and shallowly concave posterior anal margin.; differs from S. tiburo with anterior margin of the head more rounded and the lobules on the posterior margin are not present; precaudal vertebral counts 80-83 (ca.10 more vertebrae than S. tiburo) (Ref. 132488).
Cross section: oval.
Occurs in coastal waters, estuaries, coral reefs, seagrass beds, and sand bottoms (Ref. 132488).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Gonzalez, C., B. Postaire, W. Driggers, S. Caballero and D, Chapman, 2024. Sphyrna alleni sp. nov., a new hammerhead shark (Carcharhiniformes, Sphyrnidae) from the Caribbean and the Southwest Atlantic. Zootaxa 5512(4):491-511. (Ref. 132488)
IUCN Red List Status (Ref. 130435: Version 2024-2)
Threat to humans
Harmless
Human uses
Tools
Special reports
Download XML
Internet sources
Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5006 [Uniqueness, from 0.5 = low to 2.0 = high].
Trophic level (Ref.
69278): 3.4 ±0.4 se; based on size and trophs of closest relatives
Resilience (Ref.
120179): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref.
59153): Low vulnerability (10 of 100).
🛈
