An Experimental Study of Growth and Reproduction in the Hawaiian Tree Snails Achatinella mustelina and Partulina redfieldii (Achatinellinae)
dc.contributor.author | Kobayashi, Sharon R. | |
dc.contributor.author | Hadfield, Michael G. | |
dc.date.accessioned | 2008-10-15T06:53:43Z | |
dc.date.available | 2008-10-15T06:53:43Z | |
dc.date.issued | 1996-10 | |
dc.description.abstract | Hawaiian tree snails of the subfamily Achatinellinae are unique to the Hawaiian Islands and highly endangered in the wild. Achatinellines are arboreal pulmonate gastropods characterized by slow growth and late age at first reproduction. Objectives of the laboratory studies described here were to add to the understanding of growth and reproduction of achatinelline snails. Juvenile Partulina redfieldii (Newcomb) and Achatinella mustelina Migheis were kept in laboratory environmental chambers with conditions set to emulate those in the native habitat of P. redfieldii. The snails were provided with fresh leaves and branches of Metrosideros polymorpha Gaud., a natural substratum for the snails. Laboratory comparisons of P. redfieldii and A. mustelina maintained with a natural diet augmented or not with cultures of native fungi grown on potato dextrose agar revealed that snails of both species grew significantly faster on the augmented diet and that P. redfieldii attained sexual maturity at an earlier age. Comparison of growth of P. redfieldii in the laboratory with similarly sized snails in the field revealed significantly faster growth in the laboratory animals. There was no significant difference between growth rates of A. mustelina provided with an augmented food supply in the laboratory and similarly sized animals in the field. It is likely that food availability limits growth rate in the field for P. redfieldii, but there is no evidence that growth in the field for A. mustelina is food-limited. However, the natural diet or temperature-humidity requirements of A. mustelina may not have been adequately met in the laboratory, obscuring laboratory-field comparisons. Partulina redfieldii, collected from the field as adults and maintained in isolation in the laboratory, produced offspring for at least 4 yr without the opportunity to outcross. Fecundity of isolated individuals was comparable with that reported for animals in the field, and there was no indication of fecundity decreasing over time in isolation. In addition, four of five P. redfieldii isolated as juveniles attained apparent sexual maturity at ages of 3.2 to ca. 5 yr. A single offspring was produced by one of these snails, suggesting self-fertilization as one mechanism allowing the species to reproduce for prolonged periods of time in the absence of mates. | |
dc.identifier.citation | Kobayashi SR, Hadfield MG. 1996. An experimental study of growth and reproduction in the Hawaiian tree snails Achatinella mustelina and Partulina redfieldii (Achatinellinae). Pac Sci 50(3): 339-354. | |
dc.identifier.issn | 0030-8870 | |
dc.identifier.uri | http://hdl.handle.net/10125/2907 | |
dc.language.iso | en-US | |
dc.publisher | University of Hawaii Press | |
dc.title | An Experimental Study of Growth and Reproduction in the Hawaiian Tree Snails Achatinella mustelina and Partulina redfieldii (Achatinellinae) | |
dc.type | Article | |
dc.type.dcmi | Text |