Update November 2020: The Orange Peel Nudibranch has been reclassified to now be Tochuina gigantea. See source below.
Here’s a Valentine’s related blog item. It’s all about Big Orange Love – the reproduction of the Orange Peel Nudibranch
These sea slugs are very aptly named since their skin is reminiscent of both the texture and vibrant colour of an orange. But, the name does nothing to indicate the size to which these giants can grow. They are one of the world’s largest sea slugs with literature reporting them to lengths of up to 30 cm and weight to 1.4 kg.
As if this sea slug species’ colour, size and beautifully intricate white gills are not enough to create awe, you should see their eggs! I will never forget the first time I saw the huge tubular mass that looked like udon noodles. I think my brain almost exploded and I was propelled all the more feverishly on my “The Marine Detective” path, wanting to be able to identify the egg masses of all sea slugs in our waters (each species’ eggs look different).
This is the time of year when the Orange Peel Nudibranchs mate and lay eggs.
It’s all to be seen on my “Big Orange Love” slideshow below (note that this slide show is from before the species was reclassified to be Tochuina gigantea).
Korshunova T, Martynov A (2020) Consolidated data on the phylogeny and evolution of the family Tritoniidae (Gastropoda: Nudibranchia) contribute to genera reassessment and clarify the taxonomic status of the neuroscience models Tritonia and Tochuina. PLoS ONE 15(11): e0242103. https://doi.org/10.1371/journal.pone.0242103