Bioluminescence induction in the ophiuroid Amphiura filiformis (Echinodermata)

Abstract

Bioluminescence is a widespread phenomenon in the marine environment. Among luminous substrates, coelenterazine is the most widespread luciferin, found in eight phyla. The wide phylogenetic coverage of this light-emitting molecule has led to the hypothesis of its dietary acquisition, which has so far been demonstrated in one cnidarian and one lophogastrid shrimp species. Within Ophiuroidea, the dominant class of luminous echinoderms, Amphiura filiformis is a model species known to use coelenterazine as substrate of a luciferin/luciferase luminous system. The aim of this study was to perform long-term monitoring of A. filiformis luminescent capabilities during captivity. Our results show (i) depletion of luminescent capabilities within 5 months when the ophiuroid was fed a coelenterazine-free diet and (ii) a quick recovery of luminescent capabilities when the ophiuroid was fed coelenterazine-supplemented food. The present work demonstrates for the first time a trophic acquisition of coelenterazine in A. filiformis to maintain light emission capabilities.