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General Session 4: Marine environment, ecosystem & sustainability |
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Spawning is right in the appropriate light: Lunar periodicity of reproductive behaviour amongst marine invertebrates
GS4-08-S
Dominic Brettell* , The University of Hong Kong
Presenter Email: brettell.dom@gmail.com
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| This systemic review of scientific literature from 1951 to 2016 examines the associations between lunar periodicity and reproductive behaviour of marine invertebrate belonging to the phyla Arthropoda, Echinodermata, Cnidaria, Mollusca and Annelida.
Where lunar spawning phases were described for marine invertebrates, they were recorded. Spawning among marine Mollusca, Arthropoda and Echinodermata occurred mostly around the full moon and the new moon periods. Mollusca and Echinodermata also spawned frequently during the last quarter of the lunar calendar. Most Cnidaria spawned from the full moon through to the waning crescent while most Annelida spawned at the waning gibbous. Most invertebrates (Cnidaria, in particular) spawned at waning crescent/neap tides. Synchronized reproduction was present in 43/155 Cnidarian species, while aggregative behaviour was most common in Mollusca (16/28 species), followed by Arthropoda (18/58 species), Annelida (2/8 species) and Echinodermata (8/47 species). Suggested spawning cues included temperature, photoperiod, circadian rhythmicity, salinity and predation.
A consideration of potential and existing threats to marine invertebrates showed that overfishing and overexploitation were amongst the greatest threats, especially in species that relied on concentrated aggregations for reproduction. Other threats identified included habitat alteration, increasing sea temperature and pollution. Management should be focused on maintaining the conditions necessary for the reproductive success and viability of periodically spawning marine invertebrate species. All 8 Annelid species, 111/155 Cnidarian species, 37/47 Echinoderm species, 32/57 Arthropod species and 11/25 Mollusc species described exhibited lunar periodicity.
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