Bigfin reef squids are characterised by a large oval fin that extends throughout the margins of its mantle, giving them a superficial similarity to cuttlefish.

Bigfin reef squids have the fastest recorded growth rates of any large marine invertebrate, reaching 600 g (1.3 lb) in only four months.

They are found in the temperate and tropical waters of the Pacific and Indian Oceans, and have recently been introduced into the Mediterranean as a Lessepsian migrant.

Because of their rapid growth rate, short life span, and tolerance to handling and captivity, bigfin reef squids are regarded as one of the most promising species for mariculture.

[6][7] Other common names include green-eyed squid in English; koonthal in Malayalam; oosi kanava in Tamil;[8] calmar tonnelet in French; calamar manopla in Spanish;[9] Großflossen-Riffkalmar in German;[10] mu he`e in Hawaiian; 莱氏拟乌贼 in Chinese;[11] torak in Malaysian;[12] アオリイカ (aori-ika) in Japanese;[13] kinn mon in Burmese;[14] and 무늬오징어 (munuiojing-eo), 흰꼴뚜기 (huinkkolttugi), or 미즈이카 (mizuika) in Korean.

[18] It was first described by the French naturalist André Étienne d'Audebert de Férussac and named after René Primevère Lesson.

The type specimen was collected by Lesson off the coast of New Guinea during the circumnavigational voyage of the French corvette La Coquille (1822–1825) under the command of Louis Isidore Duperrey.

In 1939 the Belgian malacologist William Adam examined the specimens of Sepioteuthis recovered from the tropical western Pacific.

[20] A study in 1993 by Segawa et al. revealed that the population of S. lessoniana in Okinawa may actually be composed of three distinct species.

[24][25] Because of these fins, bigfin reef squids are sometimes mistaken for cuttlefish,[citation needed] a fact reflected by their scientific names.

[27] A pair of prominent ridges (olfactory crests) are present on the ventral surface of the head at the rear edge of the eyes.

[24][26][27] Like some other cephalopods, bigfin reef squids are capable of metachrosis – rapidly changing body colouration and patterns through voluntary control of chromatophores.

[28] They also possess iridophores (particularly in the head), a form of structural colouration that produces iridescent metallic greens and red when illuminated.

[30] Bigfin reef squids are remarkable for having the ability to produce complex body patterns from the moment they hatch.

[2] Their original range extends east to the Hawaiian Islands, west to the Red Sea, north to Japan, and south to Australia and New Zealand (42°N to 42°S and 32°E to 154°W).

They may have already existed in significant populations in the area prior to their discovery in 2002, as they have acquired a common name among the fishermen of the Aegean Sea – σουπιοκαλάμαρο (soupiocalamaro, literally "cuttlefish-like squid").

[28] Bigfin reef squids are, in turn, preyed upon by tuna, marlin, swordfish, and other predator fish and groundfish.

Studies have proposed that this might be an involuntary stimulus behaviour, as the squids immediately stop all other movements once a light source is switched on.

Unlike fishes, cephalopods do not possess air-filled swim bladders, which might amplify sound waves travelling in water.

It showed that bigfin reef squids and octopuses utilise their statocysts for detecting vibrations, an organ primarily used for maintaining spatial orientation.

The ability to hear is particularly relevant for avoiding mammalian predators of the suborder Odontoceti (particularly dolphins), who use echolocation to find prey.

[38][39] Bigfin reef squids exhibit two most common social body patterning and posturing behaviours related to mating.

In contrast to the previous behaviours, in this position the male actually inserts his hectocotylus into the mantle cavity of the female, attaching the spermatophores right at the opening of the oviduct rather than at the mouth.

[44] These are laid in single straight strands on rocks, corals, aquatic plants, submerged branches and other surfaces.

Upon hatching, the paralarvae are 6 mm (0.24 in) in mantle length (excluding tentacles), with fully functioning fins and ink sacs.

[50] Fishing operations for bigfin reef squids (particularly in jigging) are usually done at night and utilise bright lights, taking advantage of their attraction to illumination.

[23] Because of their rapid growth rate, short life span, and tolerance to handling and captivity, bigfin reef squids are regarded as one of the most promising species for mariculture.

It is remarkable for its ability to readily adapt to being confined in tanks,[31][53] and is one of the few squid species of which the entire life span has been observed under laboratory conditions.

[56] Bigfin reef squids adapt to warmer temperatures by laying more eggs, making them a good indicator species for climate change.

[47][57] In conjunction with their rapid growth rates and short lifespans, bigfin reef squid populations may rise dramatically in response to global warming.