GROWTH, MORTALITY AND FECUNDITY IN SUCCESSIVE GENERATIONS OF HEIX ASERSA MÜLLER CULTURED INDOORS AND CROWDING EFFECTS ON FAST-, MEDIUM- AND SLOW-GROWING SNAILS OF THE SAME CLUTCH
| Autor: | N. Kifonidis, D. Sioula, Th. Brouziotis, E. Alpoyanni, M. Baka, G. Vellis, E. Mihaloudi, M. Lazaridou-Dimitriadou |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | Journal of Molluscan Studies. 64:67-74 |
| ISSN: | 1464-3766 0260-1230 |
| DOI: | 10.1093/mollus/64.1.67 |
| Popis: | This paper examines the optimum conditions for edible snails Helix aspersa to be cultured indoors successfully in successive generations (originating from the crossing of snails coming from different clutches of a previous generation), and the effect of crowding on growth and reproduction in fast-, medium-, and slow-growing snails coming from the same clutches. The time needed for the snails to reach marketable size (25-32mm) varied from 2.5 to 5 months up to the 7th generation. The time needed for the snails to mature and reproduce from 4 to 7 months until the fifth generation. After the F5 x F5 generation, the final size of the snails decreased. The number of eggs did not differ statistically among the different generations but the reproductive success (how many snails reproduced/cage) increased from Fl = Fl generation onwards to F5 x F5. In F6 X F6 only three (out of 26) snails reproduced and in F7 x F7 none, although the snails remained under controlled conditions for 15 more months. Mortality in the different generations varied from 0-10% up to F5 X F5 but from F6 X F6 onwards increased and reached 25%. Concerning the origin of snails, it was found that larger snails (originating from Kyparissia, Peloponnesos) lay statistically more eggs (138.40 ± 29.60, N =5) than smaller ones (77.38 ± 40.42, N=4) (originating from Hania, island of Crete). Hatching success was greater, too. |
| Databáze: | OpenAIRE |
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