首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Population structure and growth of Donax trunculus (Bivalvia: Donacidae) in the western Mediterranean
Authors:M Ramón  P Abelló  C A Richardson
Institution:(1) Institut de Ciències del Mar (C.S.I.C.), Plaça del Mar s/n, 08039 Barcelona, Spain;(2) School of Ocean Sciences, University of Wales-Bangor, Menai Bridge, LL59 5EY Gwyneld, UK
Abstract:A comparison of shell growth in Donax trunculus (collected between 1988 and 1990 of Cullera, Spain) has been carried out using an analysis of cohort progression in monthly length frequency distributions, hyaline surface shell growth rings and internal microgrowth bands. In the Mediterranean there are two periods of recruitment of D. trunculus, one in the summer (July to September) and the other in winter (December to February). Clams recruited to the population in winter display a clear cessation in shell growth during the following summer which may possibly be correlated with spawning, whereas individuals of the summer recruited cohort show no growth cessation the following summer and continue to deposit shell during this period. The normally opaque shell of D.trunculus reveals the presence of translucent hyaline growth rings when the shells are backlit by a strong light source, and these have been shown to be laid down in the shell during summer months. Formation of a hyaline ring is accompanied by a narrowing of the microgrowth patterns present in shell sections. Both the hyaline rings and the length frequency distributions have been used to determine the age and growth rate of D. trunculus.
Keywords:
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号