---
title: Bigfin Reef Squid (Sepioteuthis lessoniana)
scientific_name: Sepioteuthis lessoniana
common_name: Bigfin Reef Squid
taxon: Cephalopods
conservation_status: DD - Data Deficient
published: 2024-11-02T22:33:47.032Z
updated: 2026-08-11T19:10:24.574Z
tags: Bigfin Reef Squid, Sepioteuthis lessoniana, Cephalopods, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/invertebrate/molluscs/cephalopods/bigfin-reef-squid
---

# Bigfin Reef Squid (*Sepioteuthis lessoniana*)

## Quick facts

- **Group:** Cephalopods (*Cephalopoda*)
- **Size:** 40 cm
- **Weight:** 0.6 - 1.8 Kg
- **Depth:** 1-100 m
- **Diet:** Carnivore
- **Activity:** Cathemeral
- **Rarity:** Common
- **Habitat:** Mid-water beside reef and over sand, often near the surface
- **Reproduction:** Egg layer, Gonochoric, Semelparous
- **Conservation status:** DD - Data Deficient

## How to recognise it

- broad oval fins running the entire length of the mantle
- translucent body that flushes with color in fractions of a second
- hangs in mid-water in small groups, often at the safety stop
- length to 40 cm

The squid divers actually meet: 40 cm (16 in) of translucent body with broad oval fins running the full length of the mantle, hanging in mid-water in small groups near the reef, usually at the safety stop. The fins make it look like a cuttlefish, but it swims like a squid and it watches you the whole time.

It grows faster than almost any animal in the sea. A hatchling can reach 600 g (1.3 lb) in four months, and the entire life is over in under a year: hatch, grow at a rate that consumes a third of its body weight in food per day, breed once, die. That pace is why squid populations recover quickly from fishing while shark populations do not, and it is one of the clearest examples of two completely different bets on the same ocean.

Color is conversation. Chromatophores under direct nervous control let the animal run patterns down its body in fractions of a second, and courting males hold one display toward a female and another toward a rival at the same time. Groups keep a spacing that looks like schooling but is closer to a negotiation.

Eggs are laid in white finger-like capsules attached to rock, coral or a wreck, in clusters that several females contribute to. The hatchlings are miniature adults and hunt within a day.

## Also known as

- **English:** bigfin reef squid
- **German:** Großflossen-Riffkalmar, Großflossen-Sepiakalmar

## Scientific synonyms

- *Sepioteuthis arctipinnis* A. A. Gould, 1852
- *Sepioteuthis brevis* R. Owen, 1881
- *Sepioteuthis dorensis* A. Férussac, 1835
- *Sepioteuthis guinensis* Quoy & Gaimard, 1832
- *Sepioteuthis hemprichii* Ehrenberg, 1831
- *Sepioteuthis indica* E. S. Goodrich, 1896
- *Sepioteuthis krempfi* G. C. Robson, 1928
- *Sepioteuthis lunulata* Quoy & Gaimard, 1832
- *Sepioteuthis malayana* Wülker, 1913
- *Sepioteuthis mauritiana* Quoy & Gaimard, 1832
- *Sepioteuthis neoguinaica* Pfeffer, 1884
- *Sepioteuthis sieboldi* Joubin, 1898
- *Sepioteuthis sinensis* A. d'Orbigny, 1848

## Range

Eritrea, Federal Republic of Somalia, New Zealand, Red Sea, South Africa, South Pacific Ocean

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*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/invertebrate/molluscs/cephalopods/bigfin-reef-squid)*
*Updated: August 11, 2026*