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Origin and evolution of the symbiosis between sea anemones (Cnidaria, Anthozoa, Actiniaria) and hermit crabs, with additional notes on anemone-gastropod associations.

Authors :
Gusmão LC
Van Deusen V
Daly M
Rodríguez E
Source :
Molecular phylogenetics and evolution [Mol Phylogenet Evol] 2020 Jul; Vol. 148, pp. 106805. Date of Electronic Publication: 2020 Mar 23.
Publication Year :
2020

Abstract

The anemone-crab mutualism is ubiquitous in temperate and tropical marine environments. In this symbiosis, one or more anemones live on a shell inhabited by a hermit crab and reciprocal phoretic, trophic, and defensive benefits are exchanged between the partners. Sea anemone-hermit crab symbionts belong to three families: Hormathiidae (Calliactis and Paracalliactis), Sagartiidae (Carcinactis and Verrillactis), and Actiniidae (Stylobates). Hermit crabs establish most partnerships by detaching anemones and placing them on their shell; sea anemones can also mount shells unaided, triggered by a mollusc-derived substance in the periostracum of the shell. At least partial cooperation by the anemones is necessary for successful establishment of the symbiosis. Here, we expand the evolutionary framework for hormathiid symbionts by generating a phylogeny with at least one member of each actiniarian symbiotic genus with hermit crabs using five molecular markers (16S, 12S, 18S, 28S, CO3). We not only corroborated the results from a previous study by finding two origins of hermit crab symbiosis within Hormathiidae, but also found additional origins for hermit crab symbiosis within Actiniaria. We provide for the first time evidence of a close relationship between symbionts Carcinactis dolosa and V. paguri. The ability to secrete chitin by the ectoderm of the column is inferred to be broadly convergent within Actiniaria whereas the secretion of a chitinous carcinoecium by the pedal disc is a distinct but convergent morphological adaptation of several lineages within Actiniaria. Our finding of multiple origins for both the hermit crab and gastropod symbioses suggests that the shell-mounting behavior might only have been the precursor of the hermit crab association among Calliactis spp.<br />Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.<br /> (Copyright © 2020 Elsevier Inc. All rights reserved.)

Details

Language :
English
ISSN :
1095-9513
Volume :
148
Database :
MEDLINE
Journal :
Molecular phylogenetics and evolution
Publication Type :
Academic Journal
Accession number :
32217169
Full Text :
https://doi.org/10.1016/j.ympev.2020.106805