Fin's Fish Guide
The Bigeye squaretail (Tetragonurus atlanticus) is a saltwater fish of the family Tetragonuridae that grows up to 50 cm.
Description
The bigeye squaretail is an oceanic fish of the squaretail family (Tetragonuridae). The species has an elongate, dark body with stout, keeled scales and two bony keels on either side of the tail base, to which the name refers. It lives oceanically, usually in the upper 90 m but adults probably deeper; juveniles often live as inquilines in free-swimming tunicates (salps). It feeds on gelatinous plankton such as jellyfishes and salps. The flesh can have a strong purgative, possibly toxic effect; do not eat this fish.
Frequently asked questions
How do you recognise the Bigeye squaretail?
The Bigeye squaretail has an elongate, eel-like body, is mainly brown and shows a plain pattern. Two bony caudal keels; juveniles live in salps; flesh with a laxative, poisonous effect.
Where does the Bigeye squaretail live?
The Bigeye squaretail lives in the sea (marine waters) and is mostly found around open water. Atlantic, Indian and Pacific Ocean; oceanic and pelagic.
How big does the Bigeye squaretail get?
The Bigeye squaretail grows to a maximum of about 50 cm.
Is the Bigeye squaretail dangerous to humans?
The Bigeye squaretail is venomous — handle spines with care and seek medical help after a sting if needed. Do not eat this fish: the flesh can have a strong purgative, possibly toxic effect and cause illness. Seek medical advice if symptoms occur after eating it.
Is the Bigeye squaretail edible?
The Bigeye squaretail is not usually eaten.
More photos
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All data
Identification
Appearance
Habitat & distribution
Behaviour & biology
For anglers
Safety
Status & sources
Same genus Tetragonurus
More from the family Tetragonuridae
Want the complete picture on the Bigeye squaretail?
Point your camera at the fish and Fin names the species in seconds. Free, and the Bigeye squaretail is one of 12,519 species in the app.