---
title: Scalloped Hammerhead (Sphyrna lewini)
scientific_name: Sphyrna lewini
common_name: Scalloped Hammerhead
taxon: Hammerhead sharks
conservation_status: DD - Data Deficient
published: 2024-01-03T21:43:12.529Z
updated: 2026-08-11T20:07:04.687Z
tags: Scalloped Hammerhead, Sphyrna lewini, Hammerhead sharks, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/sharks/hammerhead-sharks/scalloped-hammerhead
---

# Scalloped Hammerhead (*Sphyrna lewini*)

## Quick facts

- **Group:** Hammerhead sharks (*Sphyrnidae*)
- **Size:** up to 4.3 m
- **Weight:** 29 - 36 Kg
- **Depth:** 1-500 m
- **Diet:** Carnivore
- **Activity:** Nocturnal
- **Rarity:** Uncommon
- **Habitat:** Offshore reefs, seamounts and drop-offs, schooling in open water by day
- **Reproduction:** Live-bearer
- **Hazard:** Dangerous
- **CITES:** Appendix II
- **Conservation status:** DD - Data Deficient

## How to recognise it

- head with a notch in the middle of the front edge and a dip either side
- eyes and nostrils at the extreme tips of the head
- tall hooked first dorsal fin, bronze to olive back
- often in slow-circling schools over offshore reefs by day

A hammerhead of 2 to 3 m (6.5 to 10 ft) in the animals divers usually meet, and up to 4.3 m (14 ft) at the extreme, with a scalloped front edge to the head: a central notch with a dip either side, which separates it from the smooth curve of the Great Hammerhead. Bronze to olive above, white below, with a tall hooked first dorsal fin. The eyes sit at the very ends of the head, and so do the nostrils.

The head is a sensor array spread wide. Sharks navigate and hunt partly by electricity, using pores in the skin that read the tiny fields given off by muscle and nerve, and stretching those pores across a meter-wide plane sweeps a much broader strip of seabed with every swing of the head. A hammerhead crossing sand moves its head side to side like a man with a metal detector, and it can find a stingray buried out of sight.

The eyes buy something too. Set at the extremes of the head, their fields overlap in front and behind, giving this animal binocular vision forward and a blind spot smaller than almost any other shark's. It can see, in three dimensions, what is directly above and behind it.

By day they school. Dozens to hundreds gather over seamounts and offshore reefs, almost all of them female, circling slowly in the current and doing no feeding at all; the hunting happens alone after dark. What the schools are for is still argued over, with the best evidence pointing to a social hierarchy rather than safety in numbers. Daedalus and the other offshore reefs hold these gatherings in summer, and they are the reason liveaboards run that route at all.

The species is Critically Endangered. Schooling at predictable places and times is a fatal habit when the fins are worth what they are worth, and populations have fallen by more than 80 percent across much of the range.

## Also known as

- **English:** scalloped hammerhead, Bronze hammerhead shark, Scalloped Hammerhead Shark
- **Arabic:** القرش أبو مطرقة الصدفي, قرش رأس المطرقة الصدفي, قرش كلوي الرأس
- **Hebrew:** פטישן כד-חרטום
- **French:** Requin marteau à festons, Requin-marteau halicorne
- **Italian:** Squalo martello smerlato
- **German:** Bogenstirn-Hammerhai, Wellenkopf-Hammerhai, gekerbter Hammerhai
- **Spanish:** cornuda común, Tiburón Martillo Común, tiburón martillo
- **Greek:** Σφυροκέφαλος
- **Turkish:** çekiç balığı
- **Portuguese:** Cambeva, Tubarão-martelo-recortado, Tubarão-mona
- **Dutch:** Geschulpte hamerhaai, Lewins hamerhaai
- **Polish:** Glowomlot tropikalny, głowomłot tropikalny
- **Czech:** kladivoun bronzový
- **Japanese:** アカシュモクザメ, Akashumokuzame
- **Chinese:** 犛頭沙, 紅肉丫髻鮫, 紅肉雙髻
- **Ukrainian:** Акула-молот бронзова, Бронзова риба-молот
- **Russian:** Бронзовая акула-молот
- **DA:** Indopacifisk hammerhaj
- **EPO:** Martelŝarko
- **FI:** Kampavasarahai
- **GUJ:** Kannar
- **HU:** Csipkés pörölycápa
- **ID:** Hiu martil
- **JAV:** Hiu caping
- **LT:** bronzinis kūjaryklis
- **MSA:** Yu mata jauh, Yu sanggul lintang, Kad suar
- **SL:** valovitoglava kladvenica
- **TH:** ปลาฉลามหัวค้อนสีเงิน

## Scientific synonyms

- *Cestracion leeuwenii* Day, 1865
- *Cestracion oceanica* Garman, 1913
- *Sphyrna diplana* Springer, 1941
- *Sphyrna leweni* (Griffith & Smith, 1834)
- *Zygaena erythraea* Klunzinger, 1871
- *Zygaena indica* van Hasselt, 1823
- *Zygaena lewini* Griffith & Smith, 1834

## Range

Djibouti, Eritrea, Federal Republic of Somalia, Gulf of Mexico, Kenya, Madagascar, Mozambique, North Atlantic Ocean, Red Sea, Republic of Mauritius, Seychelles, South Africa, Tanzania, Western Indian Ocean

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*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/sharks/hammerhead-sharks/scalloped-hammerhead)*
*Updated: August 11, 2026*