1
|
de Gier W, Helleman P, van den Oever J, Fransen CHJM. Ecomorphological convergence in the walking leg dactyli of two clades of ascidian- and mollusc-associated shrimps (Decapoda: Caridea: Palaemonidae). Ecol Evol 2023; 13:e10768. [PMID: 38125954 PMCID: PMC10731117 DOI: 10.1002/ece3.10768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/03/2023] [Accepted: 11/10/2023] [Indexed: 12/23/2023] Open
Abstract
Symbiotic species, living within or on the surface of host organisms, may evolve a wide range of adaptations as a result of various selection pressures, host specificity of the symbiont and the nature of the symbiosis. In tropical marine coral reef ecosystems, palaemonid shrimps (Crustacea: Decapoda: Caridea) live in association with at least five different invertebrate phyla. Host switches between (distantly) related host groups, and the thereby associated selection pressures were found to play a major role in the diversification of these shrimp lineages, giving rise to various host-specific adaptations. Two lineages of palaemonid shrimp, which have switched from an ectosymbiotic association towards endosymbiosis, are studied for their morphological diversification and possible convergence. Special attention is given to the between-phyla host switches involving ascidian and bivalve hosts, which are characteristic for these lineages. Using landmark-based (phylo)morphospace analyses and Scanning Electron Microscopy, the walking leg dactylus shape and the microstructures on these dactyli are studied. No specific bivalve- or ascidian-associated morphotypes were found, but morphological convergence in dactylus morphology was found in various species within the two studied clades with similar host groups. In addition, multiple lineages of bivalve-associated species appear to be morphologically diverging more than their ascidian-associated relatives, with 'intermediate' morphotypes found near host-switching events.
Collapse
Affiliation(s)
- Werner de Gier
- Naturalis Biodiversity CenterLeidenThe Netherlands
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Pepijn Helleman
- Naturalis Biodiversity CenterLeidenThe Netherlands
- Institute of Biology LeidenLeiden UniversityLeidenThe Netherlands
| | - Jurriaan van den Oever
- Naturalis Biodiversity CenterLeidenThe Netherlands
- Institute of Biology LeidenLeiden UniversityLeidenThe Netherlands
| | | |
Collapse
|
2
|
Chow LH, Ahyong ST, Tsang CTT, Lam YF, Naruse T, Ng PKL, Tsang LM. Shift in symbiotic lifestyle as the major process shaping the evolution of pea crabs (Decapoda: Brachyura: Pinnotheroidea). Mol Phylogenet Evol 2023; 188:107904. [PMID: 37579893 DOI: 10.1016/j.ympev.2023.107904] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 08/07/2023] [Accepted: 08/11/2023] [Indexed: 08/16/2023]
Abstract
The pea crabs, superfamily Pinnotheroidea, are exceptional among brachyuran crabs in their diverse symbiotic associations involving both inquilinism and protective symbiosis. While this group presents a rare opportunity for evolutionary comparative study of host switching and morphological evolution in marine macroinvertebrates, previous phylogenetic studies have been focused on systematics. Here, we reconstructed the most extensive phylogeny of Pinnotheroidea based on two mitochondrial and six nuclear markers, with the aim of elucidating the host switching pathways and the correlation between symbiotic lifestyles and selected morphological adaptations. Ancestral state reconstruction of host association revealed a monophyletic origin of symbiosis in the form of inquilinism. Subsequent shifts in microhabitat preference for burrows or worm tubes, and the move to protective symbiosis, primarily in the switch to mollusc endosymbiosis, contributed to radiation in Pinnotheridae. Further parallel colonisations of echinoderms and tunicates occurred but did not lead to extensive diversification, except in the Clypeasterophilus + Dissodactylus lineage, which experienced a unique switch to echinoderm ectosymbiosis. The evolution of the third maxillipeds, carapace shape and ambulatory pereiopods suggests a rather strong coupling with the symbiotic lifestyle (whether inquilinism or protective symbiosis). Phenotypic diversity of these characters was higher among species engaged in protective symbiosis, with convergence in form (or function) among those sharing the same host affiliation. Species having different host affiliations or symbiotic lifestyles might also exhibit convergence in the form of the three morphological traits, suggesting a common adaptive value of the specialisations. Pinnotherid crabs overall exhibited a lower trait diversity than the also symbiotic palaemonid shrimps with comparable species diversity. This may plausibly be attributed to differences in potential for morphological modification to serve additional functions among the traits analysed in the two groups, the less frequent host switching and the less diverse host affiliations, and thus a less complicated evolutionary history in pinnotherids.
Collapse
Affiliation(s)
- Lai Him Chow
- Simon F.S. Li Marine Science Laboratory, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Shane T Ahyong
- Australian Museum Research Institute, 1 William St, Sydney, NSW 2010, Australia; School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, NSW 2052, Australia
| | - Chandler T T Tsang
- Simon F.S. Li Marine Science Laboratory, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Yu Fung Lam
- Simon F.S. Li Marine Science Laboratory, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Tohru Naruse
- Tropical Biosphere Research Center, Iriomote Station, University of the Ryukyus, 870 Uehara, Taketomi, Okinawa 907-1541, Japan
| | - Peter K L Ng
- Lee Kong Chian Natural History Museum, Faculty of Science, National University of Singapore, Kent Ridge, Singapore 119260, Singapore
| | - Ling Ming Tsang
- Simon F.S. Li Marine Science Laboratory, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
| |
Collapse
|