Factors extending gastropod embryonic development and their selective cost.

摘要: Pre-hatching developmental times for prosobranch gastropods are greatly influenced by temperature and taxonomic affinity. If the data used here (including all available from Muricacea) a representative sample, then reasonably accurate estimates of time can be obtained most prosobranchs knowing only taxon. Times also significantly affected egg or hatching size. Correlations between form probably accounted Prehatching periods little, if at all, longer metamorphosed hatchlings than swimming hatchlings; in any event, differences small relative to typical free periods. Therefore, planktonic period is substantial addition total pre-juvenile period. Many embryos die before hatching. More would survive development were faster; is, therefore, prolonged measurable selective cost. Factors promoting extended should evaluated with these costs mind. For example, providing much yolk as nurse-eggs may allow species have large size same relatively brief time.