Discovery and description of a remarkable bathypelagic nudibranch, Bathydevius caudactylus, gen. et. sp. nov.

We describe an exceptional nudibranch, new to science, from bathypelagic depths in the eastern North Pacific Ocean. More than 100 individuals of Bathydevius caudactylus gen. et. sp. nov. have been observed in the water column at depths between 1013 and 3272 m. Twenty spawning individuals were observed on the seafloor at depths between 2269 and 4009 m. Anatomy, diet, behavior, bioluminescence, and habitat distinguish this surprising nudibranch from all previously described species, and genetic evidence supports its placement in a new family., Gene sequences obtained from PCR amplification and Sanger sequencing of 18S, COI, and 16S genes for pelagic molluscs, combined with data downloaded from GenBank to make a multiple-sequence alignment., , # Gene alignments for pelagic molluscs

Bruce H. Robison(1), Steven H.D. Haddock (1,2),

Discovery and description of a remarkable bathypelagic nudibranch, Bathydevius caudactylus, gen. et. sp. nov., Deep Sea Research Part I: Oceanographic Research Papers, Volume 214,(2024),104414.

(1) Monterey Bay Aquarium Research Institute

(2) University of California, Santa Cruz

https://doi.org/10.5061/dryad.3bk3j9kvp

## Description of the data and file structure

Alignment files for 18S, COI, 16S of mainly nudibranchs and gastropod molluscs. Compiled and cleaned and aligned from Genbank downloads along with original sequences of the new species *Bathydevius caudactylus*, along with *Phylliroe* sp. as an outgroup. 

## Description of software

Example R script for collapsing low-support nodes and displaying the new tree and saving as PDF