The embryonic life history of the tropical sea hare Stylocheilus striatus (Gastropoda: Opisthobranchia) under ambient and elevated ocean temperatures

PeerJ

article

Rael Horwitz¹  Matthew D. Jackson³  Suzanne C. Mills¹ 

[1] Paris Sciences et Lettres ,(PSL) Research University: École Pratique des Hautes Études ,(EPHE)-Université de Perpignan Via Domitia ,(UPVD)-Centre National de la Recherche Scientifique ,(CNRS), Unité de Service et de Recherche 3278 Centre de Recherches Insulaires et Observatoire de l’Environnement;Laboratoire d’Excellence “CORAIL”;School of Geography and Environmental Sciences, Ulster University

关键词: Opisthobranch;    Embryonic development;    Ocean warming;    Life history;    Sea hare;    Elevated temperature;    Stylocheilus striatus;   

DOI  :  10.7717/peerj.2956

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Ocean warming represents a major threat to marine biota worldwide, and forecasting ecological ramifications is a high priority as atmospheric carbon dioxide (CO2) emissions continue to rise. Fitness of marine species relies critically on early developmental and reproductive stages, but their sensitivity to environmental stressors may be a bottleneck in future warming oceans. The present study focuses on the tropical sea hare, Stylocheilus striatus (Gastropoda: Opisthobranchia), a common species found throughout the Indo-West Pacific and Atlantic Oceans. Its ecological importance is well-established, particularly as a specialist grazer of the toxic cyanobacterium, Lyngbya majuscula. Although many aspects of its biology and ecology are well-known, description of its early developmental stages is lacking. First, a detailed account of this species’ life history is described, including reproductive behavior, egg mass characteristics and embryonic development phases. Key developmental features are then compared between embryos developed in present-day (ambient) and predicted end-of-century elevated ocean temperatures (+3 °C). Results showed developmental stages of embryos reared at ambient temperature were typical of other opisthobranch species, with hatching of planktotrophic veligers occurring 4.5 days post-oviposition. However, development times significantly decreased under elevated temperature, with key embryonic features such as the velum, statocysts, operculum, eyespots and protoconch developing approximately 24 h earlier when compared to ambient temperature. Although veligers hatched one day earlier under elevated temperature, their shell size decreased by approximately 20%. Our findings highlight how an elevated thermal environment accelerates planktotrophic development of this important benthic invertebrate, possibly at the cost of reducing fitness and increasing mortality.

【 授权许可】

CC BY