Bigfin Squid Fish Identification Guide

Key identification features

• Elongated, tapering, eel-like body with soft, almost gelatinous flesh
• Enlarged, fan-like fins set low on the body, giving the "bigfin" appearance
• Blunt, rounded snout with a small, low-slung mouth
• Very small eyes suited to deep, dim water
• Reduced or absent pelvic fins in adults
• Tail tapers to a fine point without a distinct fan-shaped caudal fin
• Pale pinkish-brown, tan, or grayish coloration with a smooth, scaleless surface

Common look-alikes

• Cusk-eels: have long dorsal and anal fins that merge continuously into the tail, unlike the separate large fins of the squid fish
• Oarfish: far more elongated and ribbon-like, with a bright red dorsal fin running the entire length of the body rather than large paired fins
• True eels: have a firmer, muscular body and a distinct pointed caudal fin, lacking the soft, gelatinous texture and enlarged fins

Where you'll see one

Bigfin squid fish inhabit deep continental slopes and the seafloor of the mid- to lower bathyal zone worldwide, typically hovering or resting just above soft sediment far from light.