Species profile
Scalloped Hammerhead
Sphyrna lewini
Identify Scalloped Hammerhead (Sphyrna lewini) from a photo — free, unlimited, no sign-up — with the CatchRules iPhone app. Plus current fishing rules across 7 jurisdictions.
At a glance
Scalloped Hammerhead (Sphyrna lewini) is an IUCN Critically Endangered shark or ray regulated in 9 of 66 jurisdictions tracked by CatchRules across the U.S. and Canada.
Bag limits are uniform at 1 per angler across the 7 regulating jurisdictions.
Across 6 jurisdictions with stated minimum sizes, the average minimum is 81.5 in (≈ 6 ft 10 in).
Confirmed by 153 research-grade iNaturalist observations, with Hawaii, Florida, and Texas the top jurisdictions by observation count.
Listed under CITES and the U.S. Endangered Species Act — verify protected-species rules with the issuing agency before retaining or handling.
Notable details
- The wavy, scalloped indentations along the front edge of its head give this shark its name.
- Adults can reach up to 14 feet in length and weigh over 300 pounds.
- Scalloped Hammerheads form massive schools of hundreds to thousands of individuals, especially near seamounts.
- Their wide-set eyes provide nearly 360-degree vision with almost no blind spots.
- They are listed as Endangered on the IUCN Red List, largely due to overfishing for shark fins.
Where Scalloped Hammerhead are seen
Jurisdictions with rules for Scalloped Hammerhead
Protected status
- CITES Appendix II (Sphyrnidae — all hammerheads, CoP17+CoP19).
- Scalloped hammerhead — 2 DPS endangered.
- Scalloped hammerhead — 2 DPS threatened.
Always verify protected-species rules with the issuing agency before retaining or handling.
Background
The scalloped hammerhead (Sphyrna lewini) is a species of hammerhead shark, and part of the family Sphyrnidae. Originally known as Zygaena lewini, its genus name was later changed to its current name. The Greek word sphyrna translates into "hammer" in English, referring to the shape of this shark's head. The most distinguishing characteristic of this shark, as in all hammerheads, is the 'hammer'…
Background excerpt adapted from Wikipedia's Scalloped Hammerhead article (CC BY-SA). Visit Wikipedia for the full entry.
Other sharks & rays on CatchRules
Frequently asked questions
What is Scalloped Hammerhead?
Scalloped Hammerhead (Sphyrna lewini) is an IUCN Critically Endangered shark or ray regulated in 9 of 66 jurisdictions tracked by CatchRules across the U.S. and Canada.
What is the scientific name for Scalloped Hammerhead?
Scalloped Hammerhead is Sphyrna lewini.
Is Scalloped Hammerhead regulated for fishing?
Yes — Scalloped Hammerhead has fishing regulations in 7 U.S. states and/or Canadian provinces tracked by CatchRules. See the "Jurisdictions with rules" section above for the binding-source links.
How can I identify Scalloped Hammerhead?
Take a photo with the free CatchRules iPhone app — on-device identification recognizes Scalloped Hammerhead along with ~1,500 other species. No sign-up, unlimited use.
Photo credit: iNaturalist / Wikipedia. Identification reference only — verify regulations with the issuing wildlife agency before retaining a catch.