TY - JOUR AU - Iori, Dario AU - Forti, Luca AU - Massamba-N’Siala, Gloria AU - Prevedelli, Daniela AU - Simonini, Roberto PY - 2014/12/30 Y2 - 2024/03/28 TI - Toxicity of the purple mucus of the polychaete Halla parthenopeia (Oenonidae) revealed by a battery of ecotoxicological bioassays JF - Scientia Marina JA - Sci. mar. VL - 78 IS - 4 SE - Articles DO - 10.3989/scimar.04080.21B UR - https://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/1557 SP - 589-595 AB - Mucus secretions play a number of functions related to polychaete physiology and ecology. Under stress conditions, the polychaete <em>Halla parthenopeia</em> (Oenonidae) produces a purple mucus after mechanical stimulation, whose function is still unknown. Here, we assessed the toxicity of this purple mucus by means of both acute toxicity bioassays on the polychaete <em>Dinophilus gyrociliatus</em> and commercial ecotoxicological kits (Microtox®, Rotoxkit® and Artoxkit®). Palatability was also tested with the fish <em>Oryzias melastigma</em>. After emitting purple mucus, <em>H. parthenopeia</em> quickly moves away and starts releasing transparent mucus. Acute toxicity bioassays showed that the mucus was harmless (transparent), or lethal even when diluted about 1000 times (purple). Purple mucus was toxic at different concentrations, the LC50 ranging from 0.7-0.3 g l<sup>–1</sup> for <em>D. gyrociliatus</em> to 76 g l<sup>–1</sup> for <em>Artemia franciscana</em> (Artoxkit®). Freeze-dried brine shrimp coated with transparent or purple muci were both consumed by <em>O. melastigma</em>. We hypothesized that the purple mucus is involved in the chemical defence of <em>H. parthenopeia</em> against competitors and parasites, and that its colour and toxicity are due to hallachrome, a 1,2-anthraquinone found in the skin of <em>H. parthenopeia</em>. ER -