Euprymna scolopes

NOTOC Euprymna scolopes, also known as the Hawaiian bobtail squid, is a species of bobtail squid in the family Sepiolidae native to the central Pacific Ocean, where it occurs in shallow coastal waters off the Hawaiian Islands and Midway Island. The type specimen was collected off the Hawaiian Islands and is deposited at the National Museum of Natural History in Washington, D.C. Euprymna scolopes grows to in mantle length. Hatchlings weigh and mature in 80 days. Adults weigh up to . In the wild, E. scolopes feeds on species of shrimp, including Halocaridina rubra, Palaemon debilis, and Palaemon pacificus. In the laboratory, E. scolopes has been reared on a varied diet of animals, including mysids (Anisomysis sp.), brine shrimp (Artemia salina), mosquitofish (Gambusia affinis), prawns (Leander debilis), and octopuses (Octopus cyanea). The Hawaiian monk seal (Monachus schauinslandi) preys on E. scolopes in northwestern Hawaiian waters. On June 3, 2021, SpaceX CRS-22 launched E. scolopes, along with tardigrades, to the International Space Station. The squid were launched as hatchlings and will be studied to see if they can incorporate their symbiotic bacteria into their light organ while in space. Euprymna scolopes lives in a symbiotic relationship with the bioluminescent bacteria Aliivibrio fischeri, which inhabits a special light organ in the squid's mantle. The bacteria are fed a sugar and amino acid solution by the squid and in return hide the squid's silhouette when viewed from below by matching the amount of light hitting the top of the mantle (counter-illumination). E. scolopes serves as a model organism for animal-bacterial symbiosis and its relationship with A. fischeri has been carefully studied. The bioluminescent bacterium, A. fischeri, is horizontally transmitted throughout the E. scolopes population. Hatchlings lack these necessary bacteria and must carefully select for them in a marine world saturated with other microorganisms. To effectively capture these cells, E.