Integrative taxonomy revisits the ontogeny and trophic niches of Rimicaris vent shrimps
Methou, P.; Michel, L.N.; Segonzac, M.; Cambon Bonavita, M.-A.; Pradillon, F. (2020). Integrative taxonomy revisits the ontogeny and trophic niches of Rimicaris vent shrimps. Royal Society Open Science 7(7): 200837. https://dx.doi.org/10.1098/rsos.200837 In: Royal Society Open Science. The Royal Society: London. ISSN 2054-5703; e-ISSN 2054-5703, more |   |
| Keywords | Crustacea [WoRMS]; Rimicaris Williams & Rona, 1986 [WoRMS]; Rimicaris chacei Williams & Rona, 1986 [WoRMS]; Rimicaris exoculata Williams & Rona, 1986 [WoRMS]
Marine/Coastal | | Author keywords | hydrothermal vents; stable isotopes; taxonomy; crustaceans; life history; trophic shift |
| Authors | | Top | - Methou, P.
- Michel, L.N., more
- Segonzac, M., more
| - Cambon Bonavita, M.-A.
- Pradillon, F.
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| Abstract | Among hydrothermal vent species, Rimicaris exoculata is one of the most emblematic, hosting abundant and diverse ectosymbioses that provide most of its nutrition. Rimicaris exoculata co-occurs in dense aggregates with the much less abundant Rimicaris chacei in many Mid-Atlantic Ridge vent fields. This second shrimp also houses ectosymbiotic microorganisms but has a mixotrophic diet. Recent observations have suggested potential misidentifications between these species at their juvenile stages, which could have led to misinterpretations of their early-life ecology. Here, we confirm erroneous identification of the earliest stages and propose a new set of morphological characters unambiguously identifying juveniles of each species. On the basis of this reassessment, combined use of C, N and S stable isotope ratios reveals distinct ontogenic trophic niche shifts in both species, from photosynthesis-based nutrition before settlement, towards a chemosynthetic diet afterwards. Furthermore, isotopic compositions in the earliest juvenile stages suggest differences in larval histories. Each species thus exhibits specific early-life strategies that would, without our re-examination, have been interpreted as ontogenetic variations. Overall, our results provide a good illustration of the identification issues persisting in deep-sea ecosystems and the importance of integrative taxonomy in providing an accurate view of fundamental aspects of the biology and ecology of species inhabiting these environments. |
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