Speciation of coral-associated barnacles: Generalists versus specialists in the Indo-West Pacific
Lin, H.-C.; Halasan, L.C.; Nozawa, Y.; Chan, B.K.K. (2025). Speciation of coral-associated barnacles: Generalists versus specialists in the Indo-West Pacific. Coral Reefs Online first. https://dx.doi.org/10.1007/s00338-025-02687-w
In: Coral Reefs. Springer: Berlin; Heidelberg; New York. ISSN 0722-4028; e-ISSN 1432-0975, more
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| Authors | | Top |
- Lin, H.-C.
- Halasan, L.C.
- Nozawa, Y.
- Chan, B.K.K.
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| Abstract |
Coral-associated invertebrates possess a continuum of host specificity in their host usage, with generalists inhabiting a wide selection of host corals and specialists inhabiting a narrower range of hosts. The population genetics of three coral-associated barnacle species with different degrees of host specificity were examined using cytochrome c oxidase I gene sequences. The relative generalist Cantellius euspinulosum showed deep and host-related intraspecific divergence in two sympatric groups in the Indo-West Pacific (K2P = 4.43%). There are host coral species exclusive to each group, suggesting the possibility of intraspecific host-driven divergence. The relative specialists C. septimus and Darwiniella angularis only showed genetic divergence associated with geographical distribution, not with the host coral species. Historical demography analyses indicated that all species underwent expansion around the mid to late Pleistocene. Higher contemporary population size was observed in the C. euspinulosum groups, albeit not significantly different from that of C. septimus, implying that neither generalists’ nor specialists’ propensities guarantee higher fitness advantages regarding expansion. Generalists appeared to have greater gene flow at geographical scales, but their population structures were driven by host specializations. In contrast, the relatively specialist species have fewer stepping stones for dispersal and often have genetic differentiation correlated with geographic scales. |
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