Evolution of life cycle dimorphism: An example of sacoglossan sea slugs

JOURNAL OF THEORETICAL BIOLOGY

卷:525

Article

Yamaguchi, Sachi¹  Yusa, Yoichi²  Iwasa, Yoh³ 

[1] Tokyo Womans Christian Univ, Div Math Sci, Suginami Ku, 2-6-1 Zempukuji, Tokyo 1678585, Japan

[2] Nara Womens Univ, Div Nat Sci, Nara 6308506, Japan

[3] Kwansei Gakuin Univ, Sch Sci & Technol, Dept Biosci, 2-1 Gakuen, Sanda, Hyogo 6691337, Japan

关键词: Kleptoplasty;    Direct development;    Plankton;    Benthos;    Poecilogony;    Bet-hedging;   

DOI  :  10.1016/j.jtbi.2021.110760

来源: Elsevier

【 摘 要 】

Many sea slugs of Sacoglossa (Mollusca: Heterobranchia) are sometimes called solar-powered sea slugs because they keep chloroplasts obtained from their food algae and receive photosynthetic products (termed kleptoplasty). Some species show life cycle dimorphism, in which a single species has some individuals with a complex life cycle (the mother produces planktotrophic larvae, which later settle in the adult habitat) and others with a simple life cycle (mothers produce benthic offspring by direct development or short-term nonfeeding larvae in which feeding planktonic stages are skipped). Life cycle dimorphism is not common among marine species. In this paper, we ask whether some aspects of the ecology of solar-powered sea slugs have promoted the evolution of life cycle dimorphism in them. We study the population dynamics of the two life-cycle types that differ in summer (one with planktonic life and the other with benthic life), but both have benthic life in other seasons. We obtain the conditions in which two types with different life cycles coexist stably or a single type generating offspring with different life cycles evolves. We conclude that the stable coexistence of two life cycles can evolve if benthic individuals in summer experience strongly density-dependent processes or if the between-year fluctuation of biomass growth in summer is very large. We discuss whether these results match the life cycles of solar-powered sea slugs with life cycle dimorphism. (C) 2021 The Authors. Published by Elsevier Ltd.

【 授权许可】

Free