Hawaiian Bobtail Squid

Euprymna scolopes

The Hawaiian Bobtail Squid is an itty bitty little thing that has a mantle length of only around one inch! As the name suggests, they can be found off of Hawaiian waters, though they also live in other shallow coastal areas of the central Pacific as well.

The most important thing that you need to know about the Hawaiian Bobtail Squid is has a symbiotic relationship with a bacteria known as Vibrio fischeri.

The bacteria inhabit an organ in the Squid's mantle. The Squid feeds the Bacteria a solution of amino acids and sugar, and in return for the meal the Bacteria gives the Squid a defensive advantage. You see, the organ that the Bacteria lives in deals with light, and the Bacteria itself is bioluminescent. The Bacteria are able to determine the amount of light hitting the top of the Squid's mantle, and then emulate that on the underside. This makes it very difficult to see the Bobtail Squid when looking upwards.

The Squids are not born with the Bacteria ready to go, they must acquire the little helpers by using an attractive mucus. At the end of the Squid's day, most of the Bacteria is expelled in order to conserve body energy.

Hawaiian Bobtail Squid feed on tiny crustaceans, and they themselves are preyed upon primarily by Monk Seals. Even if they are able to avoid the hungry Pinnipeds, the Bobtail Squids have very short lifespans, typically living only 3-10 months.

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IUCN Status : Not Listed

Location : Pacific Ocean
Size : mantle length 1.2in (3cm)

Classification : Phylum : Mollusca -- Class : Cephalopoda -- Order : Sepiolida
Family : Sepiolidae -- Genus : Euprymna -- Species : E. scolopes