Will shrinking body size and increasing species diversity of crustaceans follow the warming of the Arctic littoral?

• Published in: Ecology and Evolution
• Main Authors: Jan M. Węsławski, Joanna Legeżyńska, Maria Włodarska‐Kowalczuk
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: Arctic; biodiversity; competition; global warming; size; species distribution; Ecology; QH540-549.5; Arctic biodiversity; Global warming; North Atlantic
• Online Access: https://doi.org/10.1002/ece3.6780; https://doaj.org/article/8e0ce63e557242db89798c69a179c2fa

Abstract Over thirty species of littoral marine Gammaridea occur along the coasts of the North Atlantic. From one to several species can coexist in a single region. There is an evident, inverse relationship between egg incubation time and temperature (from 14 to >120 days) and consequent trends in the size of the animals on reaching maturity (from 5 mm in warmer waters to 30 mm in the coldest ones) and in lifespan (from <6 months to >5 years). Littoral gammarids are a good example of the shrinking size effect of increasing temperatures and size‐related species diversity. In large species, the annual cohorts of the population (3–5 annual size groups) functionally replace the adults of smaller species. The ongoing warming of the European Arctic seas may extend the distribution limits of boreal species so that more Gammarus species may appear on northern coasts hitherto occupied by just one or at most two species.