Sexual and asexual reproduction in Didemnum rodriguesi (Ascidiacea, Didemnidae)

Iheringia. Série Zoologia

Nicole F. Ritzmann²  Rosana M. Da Rocha¹  James J. Roper¹ 

[1] ,Universidade Federal do Paraná Programa de Pós Graduação em Zoologia Curitiba Paraná ,Brazil

关键词: Reproductive investment;    sexual reproduction;    fragmentation;    tunicates;    Investimento reprodutivo;    reprodução sexuada;    fragmentação;    tunicados;   

DOI  :  10.1590/S0073-47212009000100015

来源: SciELO

【 摘 要 】

Sexual and asexual reproduction and associated population dynamics were investigated in the colonial ascidian Didemnum rodriguesi Rocha & Monniot, 1993 (Didemnidae) in southern Brazil. Investment in sexual (production of new individuals) and asexual (colony growth) reproduction was compared between seasons. Permanently marked quadrats were repeatedly photographed to measure changes in colonies. Eggs and larvae were counted monthly in collected colonies. This species alternates seasonally between sexual (summer) and asexual (winter) reproduction. In summer, colonies were smaller, brooded eggs and larvae and recruitment rates were greater, while in winter, colony size was larger and eggs and larvae were absent. There is a relationship between fecundity and colony area. Fragmentation and fusion of colonies were similar in summer and winter, as well as mortality. In conclusion, D. rodriguesi has a lifecycle usual for high latitude ascidians with a limited time length for sexual reproduction and alternate investment in sexual and asexual reproduction along the year.

【 授权许可】

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