{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,10]],"date-time":"2026-01-10T09:40:27Z","timestamp":1768038027641,"version":"3.49.0"},"reference-count":48,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2026,1,8]],"date-time":"2026-01-08T00:00:00Z","timestamp":1767830400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Fishes"],"abstract":"<jats:p>In external fertilisation, spawning synchrony is often mediated by pheromones. However, their chemical nature is rarely well-established; this is particularly true for bivalves. This study used an electrophysiological technique\u2014the electro-osphradiogram (EOsG)\u2014to investigate the spawning-inducing pheromone (SIP) in the Pacific oyster (Magallana gigas), a species of economic and environmental relevance. Recording the electrophysiological response of the osphradium to conspecific sperm milt and its fractions, we show that the SIP is multicomponent, likely proteinaceous\u2014with at least one component linked to the spermatozoa and the other components in free solution\u2014and all resistant to freezing. At least three active components are involved: one of about 35 kDa, one between 3 and 10 kDa and one of less than 3 kDa. All three, alone, evoke responses from the osphradium, but all three must probably be present to evoke the full biological response\u2014gamete release\u2014in the receiver. All three are likely polar; none were retained by a range of solid-phase extraction cartridges. We suggest that the EOsG will be useful to isolate and identify the individual components of the oyster SIP. Successful identification of the SIP will represent an important step towards more sustainable and efficient bivalve hatchery practices.<\/jats:p>","DOI":"10.3390\/fishes11010034","type":"journal-article","created":{"date-parts":[[2026,1,8]],"date-time":"2026-01-08T09:01:29Z","timestamp":1767862889000},"page":"34","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Unravelling the Chemical Nature of the Spawning-Inducing Pheromone (SIP) in the Pacific Oyster (Magallana gigas)"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1150-2757","authenticated-orcid":false,"given":"Ana","family":"Rato","sequence":"first","affiliation":[{"name":"Department of Sea and Marine Resources, Portuguese Institute for Sea and Atmosphere (IPMA, I.P.), Av. 5 de Outubro s\/n, 8700-305 Olh\u00e3o, Portugal"},{"name":"Centre of Marine Sciences (CCMAR), University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6324-5908","authenticated-orcid":false,"given":"Sandra","family":"Joaquim","sequence":"additional","affiliation":[{"name":"Department of Sea and Marine Resources, Portuguese Institute for Sea and Atmosphere (IPMA, I.P.), Av. 5 de Outubro s\/n, 8700-305 Olh\u00e3o, Portugal"},{"name":"Interdisciplinary Centre of Marine Environmental Research (CIIMAR), University of Porto, Terminal de Cruzeiros do Porto de Leix\u00f5es, Av. General Norton de Matos s\/n, 4450-208 Matosinhos, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2191-7497","authenticated-orcid":false,"given":"Domit\u00edlia","family":"Matias","sequence":"additional","affiliation":[{"name":"Department of Sea and Marine Resources, Portuguese Institute for Sea and Atmosphere (IPMA, I.P.), Av. 5 de Outubro s\/n, 8700-305 Olh\u00e3o, Portugal"},{"name":"Interdisciplinary Centre of Marine Environmental Research (CIIMAR), University of Porto, Terminal de Cruzeiros do Porto de Leix\u00f5es, Av. General Norton de Matos s\/n, 4450-208 Matosinhos, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3007-4647","authenticated-orcid":false,"given":"Peter C.","family":"Hubbard","sequence":"additional","affiliation":[{"name":"Centre of Marine Sciences (CCMAR), University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1007\/s12562-021-01563-0","article-title":"Chemical Cues for Intraspecific Chemical Communication and Interspecific Interactions in Aquatic Environments: Applications for Fisheries and Aquaculture","volume":"88","author":"Kamio","year":"2022","journal-title":"Fish. 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