Epibionts on the krill (Euphausia pacifica) from the E coast of Japan

Abstract

Fernandez-Leborans, G. 2011. Epibionts on the krill (Euphausia pacifica) from the E coast of Japan. —Acta Zoologica (Stockholm) 00: 1–10. Specimens of Euphausia pacifica collected from shallow waters of the E coast of Japan showed ciliate epibionts belonging to two suctorian species: Ephelota plana and Gymnodinioides sp. The epibionts were present in a total of 27 anatomical units of E. pacifica, in numbers fluctuating between 8 and 80 individuals per basibiont. Gymnodinioides showed the highest mean number of epibionts. The presence–absence of epibionts indicated some specificity of the species by different locations on the basibiont body, which is corroborated by the analysis of the colonization throughout the longitudinal axis of the basibiont. Ephelota plana was recorded by the first time on E. pacifica, while Gymnodinioides sp. extended its geographical area with respect to previous studies. Morphological, taxonomical features of the species and the statistical analysis of their spatial distribution on E. pacifica are included.