Opalescent Nudibranch

Hermissenda opalescens

Summary 5

Hermissenda opalescens is a species of brightly coloured sea slug or nudibranch, a marine gastropod mollusc in the family Facelinidae.

Description 6

The species grows to be about 50 mm, or about 2 inches.

This slug has been treated as a model organism and used in studies into classical conditioning, memory consolidation and associative learning, the structure of neural circuits and neural physiology. It has also been used to investigate ultrastructure and anatomy, larval and reproductive ecology, behavioral ecology and pharmacology and toxicology including studies into Beta thymosins. Unfortunately these studies did not differentiate between the three species of Hermissenda.

Distribution 6

This nudibranch was described from San Diego, California, USA. It has been reported from Northern California, to Punta Eugenia, Mexico. Its distribution overlaps with Hermissenda crassicornis in Northern California and this latter species is found north to Alaska. The two species have usually been treated as a single species during the last 90 years.

The species has also been observed in Bahia de los Angeles, Gulf of California.

Life habits 6

This nudibranch feeds on hydroids and other marine organisms such as ascidians and sea anemones. It sometimes attacks other nudibranchs, and will eat smaller specimens of its own species. It is host to the ectoparasitesHalicyclops thysanotusWilson C.B., 1935 and Hemicyclops thysanotusWilson C.B., 1935.

Sources and Credits

  1. (c) Robin Agarwal (ANudibranchMom on iNaturalist), some rights reserved (CC BY-NC), https://www.flickr.com/photos/30314434@N06/19862959022/
  2. (c) anudibranchmom, some rights reserved (CC BY-NC), uploaded by Robin Agarwal, http://www.inaturalist.org/photos/3921612
  3. (c) Robin Agarwal (ANudibranchMom on iNaturalist), some rights reserved (CC BY-NC), https://www.flickr.com/photos/30314434@N06/20831815756/
  4. (c) anudibranchmom, some rights reserved (CC BY-NC), uploaded by Robin Agarwal, http://www.inaturalist.org/photos/3921594
  5. Adapted by Robin Agarwal from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Hermissenda opalescens
  6. (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Hermissenda_opalescens

More Info

iNat Map

Color blue, orange