Comparative phylogeography of three host sea anemones in the Indo‐Pacific

Abstract

Aim The mutualistic relationship between anemones and anemonefishes is one of the most iconic examples of symbiosis. However, while anemonefishes have been extensively studied in terms of genetic connectivity, such information is lacking entirely for host sea anemones. Here, we provide the first information on the broad‐scale population structure and phylogeographical patterns of three species of host sea anemone, Heteractis magnifica, Stichodactyla mertensii and Entacmaea quadricolor. We evaluate if there is concordance in genetic structure across several distinct biogeographical areas within the Indo‐Pacific region and to what extent the observed patterns may concur with those found for anemonefishes. Location Indo‐Pacific, including the Red Sea. Taxon Heteractis magnifica, S. mertensii and E. quadricolor Methods Microsatellite markers and a combination of statistical methods including Bayesian clustering, isolation by distance (IBD), analysis of molecular variance (AMOVA) and principal components analysis (PCA) were used to determine population structure. The congruence among distance matrices (CADM) method was used to assess similarity in spatial genetic patterns among species. Results Significant population structure was identified in the three host anemone species. Each species is likely composed of at least two genetic clusters corresponding to two biogeographical regions, the Red Sea and the rest of the Indo‐Pacific. Two of the three anemone species seem to be experiencing admixture where the two main clusters overlap (the Maldives). IBD analyses in the Red Sea revealed differences in gene flow among species, suggesting more limited dispersal potential for E. quadricolor than for S. mertensii and H. magnifica. Clonality is documented in S. mertensii for the first time. Main conclusions This research documents the genetic population structure for three ecologically important host sea anemones across the Indo‐Pacific and provides valuable insights regarding their biogeography and evolution. Specifically, we found high levels of genetic divergence between populations across different biogeographical regions, suggesting different evolutionary lineages within species. At the same time, common geographical overlap of population structures suggests similar evolutionary histories among all three species. Interestingly, the observed patterns are congruent to some extent with structure reported for several anemonefish species, reflecting their close ecological association.

Long-term exposure to artificial light at night in the wild decreases survival and growth of a coral reef fish

“…We investigated the impact of long-term exposure of ALAN on the survival and growth of resident juvenile orange-fin anemonefish, Amphiprion chrysopterus (Cuvier, 1830) in the lagoon of Moorea, French Polynesia. Anemonefish live in an obligate mutualism with sea anemones, mainly with the magnificent sea anemone, Heteractis magnifica, making them an ideal model species for long-term in situ studies [29][30][31]. Anemonefish actively feed on plankton in the water column [32] and on anemone waste products [33].…”

Phylogeography of the northernmost distributed Anisocentropus caddisflies and their comparative genetic structures based on habitat preferences

“…The distribution range of a species is influenced by the particular characteristics of each habitat's environment and/or the connectivity among habitats (Arbogast & Kenagy, 2001;Emms et al, 2020;Múrria & Hughes, 2008;Okamoto & Tojo, 2021). Therefore, it is possible that taxa having similar distribution areas may have experienced a similar evolutionary history.…”

“…Thus, it is speculated that the differences in habitat preferences have influenced phylogeographic evolutionary history and the genetic structures of these two caddisfly groups (Abellán et al, 2009;Emms et al, 2020;Ribera et al, 2003).…”

“…The genetic structure of an organism is determined by the interaction of a complex mix of factors such as preferred habitat characteristics, historical background, barriers to migration, and geological history (Arbogast & Kenagy, 2001;Emms et al, 2020;Saito & Tojo, 2016b). The two species, A. kawamurai and A. pallidus, are suitable groups for elucidating the relationship between the difference in habitat preference and the corresponding genetic structure.…”

“…Knowledge of the factors that determine the distribution ranges of organisms is necessary in order to understand evolutionary and ecological significance and contribution to biodiversity (Ellis et al, 2006;Kellermann et al, 2009;Saito & Tojo, 2016a;Tojo et al, 2017). A very effective study of such factors is to compare the distribution characteristics and genetic structures of closely related species with differing habitat preferences (Arbogast & Kenagy, 2001;Emms et al, 2020;Hjalmarsson et al, 2015;Leaché et al, 2020;Suzuki et al, 2014).…”