Cryptic niche switching in a chemosymbiotic gastropod. Issue 1882 (11th July 2018)

• Record Type: Journal Article
• Authors: Chen, Chong; Linse, Katrin; Uematsu, Katsuyuki; Sigwart, Julia D.
• Is Part Of: Proceedings. Volume 285:Issue 1882(2018)
• Publication Date: 2018-07-11
• Subjects: cryptometamorphosis -- hydrothermal vent -- life history -- metamorphosis -- mollusc; Biology -- Periodicals; 570.5
• DOI: 10.1098/rspb.2018.1099
• Languages: English
• ISSNs: 0962-8452

Abstract

Abstract : Life stages of some animals, including amphibians and insects, are so different that they have historically been seen as different species. 'Metamorphosis' broadly encompasses major changes in organism bodies and, importantly, concomitant shifts in trophic strategies. Many marine animals have a biphasic lifestyle, with small pelagic larvae undergoing one or more metamorphic transformations before settling into a permanent, adult morphology on the benthos. Post-settlement, the hydrothermal vent gastropod Gigantopelta chessoia experiences a further, cryptic metamorphosis at body sizes around 5–7 mm . The terminal adult stage is entirely dependent on chemoautotrophic symbionts; smaller individuals do not house symbionts and presumably depend on grazing. Using high-resolution X-ray microtomography to reconstruct the internal organs in a growth series, we show that this sudden transition in small but sexually mature individuals dramatically reconfigures the organs, but is in no way apparent from external morphology. We introduce the term 'cryptometamorphosis' to identify this novel phenomenon of a major body change and trophic shift, not related to sexual maturity, transforming only the internal anatomy. Understanding energy flow in ecosystems depends on the feeding ecology of species; the present study highlights the possibility for adult animals to make profound shifts in biology that influence energy dynamics.