Hippolyte varians Leach, 1814 in sea lettuce, Ulva lactuca

This small shrimp can be found on the shore in small ponds at low tide. The species was recorded from Western Norway already in the early 19 hundreds by research curators in Bergens Museum (Appellöf, 1906; Grieg, 1927). Interestingly, as also observed by Appellöf (1906:page 124) individuals of this the species appear in many contrasting colour variants due to the ability of the the body to mimic the colours in the environment. The Norwegian name of Hippolyte varians is «sjøgressreke», which refers to its association with sea grass meadows (Zostera marina), in which a green body colour would seem to be an appropriate camouflage appearance. The specimen on this picture was caught in the littoral at the island Turøy amongst sea lettuce, Ulva lactuca. We see that there is a good colour match between the shrimp and the lettuce.

However, reddish, pink, brownish, black or even white colours have been are observed in other environments and it seems that at night time the shrimp may take a rest from the camouflage by attaining a transparent whitish blue appearance as shown by Moen’s picture here.

Knowledge about the distribution and biology of Hippolyte varians is summarised by C. d’Udekem d’Acoz. 

References

Appellöf, A. 1906. Die Dekapoden Crustaceen. Meeresfauna von Bergen 2(3): 113-238.

Grieg, J.A. 1927. Decapoda Crustacea from the west coast of Norway and the North Atlantic. Bergens Museums Aarbok 7:1-53.

Udekem d’Acoz, C. (1996). The genus Hippolyte Leach, 1814 (Crustacea: Decapoda: Caridea: Hippolytidae) in the east Atlantic Ocean and the Mediterranean Sea, with a checklist of all species in the genus. Zoologische Verhandelingen (Leiden) 303: 1-133.

-Endre