Berry's bobtail squid

Euprymna berryi

Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Sepiolida
Family: Sepiolidae
Genus: Euprymna
Species: Euprymna berryi

Berry's bobtail squid is a small, rounded cephalopod with a mantle of only about 3 to 5 cm, short arms and two little ear-like fins. Its translucent body is covered in dark chromatophores and shimmering iridescent patches that flash electric blue, green and purple under a torch, making it one of the most photogenic critters on a night dive.

It lives on sandy and silty bottoms in the western Pacific, including across the Philippines, where it is a regular find on night dives over muck sites. By day it buries itself in the sand, using its arms to pull a coat of grains over its body, and it emerges after dark to hunt small shrimps and other crustaceans.

Like other Euprymna bobtails, it carries a light organ that houses bioluminescent bacteria, which it uses to cancel out its own shadow against moonlight. When threatened it can squirt ink or quickly dig back into the sand. It lives only a few months, and is easily confused with other bobtails, so close-up photos of its colour pattern help with identification.