# An Ocean of Opsins

## TL;DR

This study uses marine data to explore opsin diversity and evolution, finding that arthropods and vertebrates dominate the sequences and identifying new insights into known opsin subfamilies.

## Contribution

The study provides taxonomic insights into known opsin subfamilies and presents novel sequences from under-researched marine taxa.

## Key findings

- Most opsin sequences belong to arthropods and vertebrates.
- All known opsin subfamilies were detected, including r-opsin, c-opsin, xenopsin, and Group-4 opsins.
- Novel opsin sequences were identified in chaetognaths, rotifers, acoelomates, and tunicates.

## Abstract

In this study, we explored the diversity and evolution of opsins using meta-omic data from the Tara Oceans and Tara Polar Circle expeditions, one of the largest marine datasets available. By using sequence similarity methods and phylogenetic analyses, we identified opsins across the different metazoan groups. Our results indicate that most of the opsin sequences belong to arthropods and vertebrates. We also detected sequences from all known opsin subfamilies, including r-opsin, c-opsin, xenopsin, and Group-4 opsins. Despite the broad taxonomic scope, no new opsin families were discovered; however, we provide valuable taxonomic insights into known opsin subfamilies and reinforce existing phylogenetic hypotheses. Additionally, we present novel opsin sequences from less-studied taxa, such as chaetognaths, rotifers, acoelomates, and tunicates, and which may serve as a valuable resource for future research into opsin function and diversity.