An experimental assessment on the effects of photoperiod treatments on the somatic and gonadal growth of the juvenile European purple sea urchin Paracentrotus lividus |
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| Authors: | Eimear McCarron Gavin Burnell Joe Kerry Gerry Mouzakitis |
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| Institution: | 1. Aquaculture and Fisheries Development Centre, University College Cork, Irish Distillers, Cork, Ireland;2. Department of Zoology, Ecology and Plant Science, University College Cork, Cork, Ireland;3. Department of Food Science and Technology, University College Cork, Cork, Ireland |
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| Abstract: | Determining the optimum light conditions for sea urchins reared in land‐based systems is vital for the future use and assessment of possible commercial systems of sea urchin farming. The effects of two different light regimes, complete darkness and a long day photoperiod of 16 h light:8 h darkness, on the somatic and gonadal growth of the European sea urchin Paracentrotus lividus (19.5–23.0 mm) was investigated using the commercial UrchinPlatter? System over a 6‐month period (5 March to 5 September). Hatchery‐produced P. lividus were transported to the Aquaculture Fisheries Development Centre (AFDC, University College, Cork UCC). Before arrival at the AFDC, sea urchins were reared on a diet of Laminaria digitata. Females were the predominant species of the animal group, displaying a reproductive Stage III (growing stage) where gametogenesis was commencing. Results show that darkness supports higher somatic growth than the photoperiod treatment. Feeding rates were higher for sea urchins reared under darkness with gonadal growth increasing for both experimental treatments. Individuals reared under darkness had a higher per cent change in gonad index from the initial sample taken at the beginning of the experiment. |
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| Keywords: | Paracentrotus lividus light regime cage systems growth parameters |
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