Suárez-Morales, E., M.C. Franco-Gordo & J.A. Cohuo-Colli. (2026). First report of oncaeids (Copepoda, Cyclopoida) feeding on pelagic nudibranchs in the mexican Pacific. Crustaceana. 99(1): 1-7. Jan 2026.
Suárez-Morales, E., M.C. Franco-Gordo & J.A. Cohuo-Colli
2026
First report of oncaeids (Copepoda, Cyclopoida) feeding on pelagic nudibranchs in the mexican Pacific.
Crustaceana
99(1): 1-7. Jan 2026
Publication
Available for editors
Zooplankton samples collected from coastal-neritic systems in the Mexican Pacific yielded
numerous individuals of a pelagic nudibranch. Several of these specimens were carrying copepods
attached to their surface. Copepods belong to the cyclopoid family Oncaeidae, generally deemed as
free-living planktonic forms that can display raptorial or symbiotic behaviours. They have been
found attached to different groups of macrozooplankton, including jellyfish, siphonophores, and
chaetognaths, but had not been recorded in association with planktonic nudibranchs. Thus, the
discovery of oncaeid copepods anchored to the body surface of the Mexican coastal nudibranchs
represents the first observation of an interaction between these two groups in the marine zooplankton. Our observations and previous data suggest that oncaeid copepods may display a raptorial behaviour to approach the nudibranch and attach themselves to its body surface with their maxillipeds thus enabling them to nibble its integument
