Contrasting clonal structure among Pocillopora (Scleractinia) communities at two environmentally distinct sites in the Gulf of California

Abstract

The contributions of sexual versus asexual reproduction are thought to play an important role in the abundance and ecological success of corals, especially in marginal habitats. Pocillopora corals are distributed throughout the Indo-Pacific and dominate shallow hardbottom communities in the eastern Pacific where broad seasonal fluctuations in temperature and water turbidity create suboptimal conditions for reef community development. Previous work had revealed three genetic clades in the eastern Pacific that show little correspondence with colony morphology; the broad distribution of type 1 extends into the subtropical southern Gulf of California. Here we examine genetic and clonal structure of two type 1 communities separated by 10 km with microsatellite data. Samples were collected randomly in six 10 m radius circular plots (20 colonies per plot, 3 plots per site). Sites differed in their relative clonality because clonemates (ramets) from a single clone (genet) dominated a large portion (90.9 m long) of the protected leeward side of Gaviota Island (Number of genets/ Number of samples = 0.35; observed Genotypic diversity/ expected Genotypic diversity = 0.087), while an exposed community at the entrance to La Paz Bay, Punta Galeras, exhibited high genotypic diversity (N g /N = 0.85; G o / G e = 0.714). Gene flow was unrestricted between sites indicating these communities comprised a single population. The relative proportion of asexual colonies found between community aggregations of Pocillopora in the Gulf of California differed significantly and suggests factors at local, not regional, scales affect these patterns. The possibility that heterogeneity in clonal structure is common throughout the eastern Pacific and across the west Indo-Pacific requires further study. Finally, since morphological variation in Pocillopora has been underappreciated and is in need of taxonomic revision, the use of a consistent field-sampling protocol and high-resolution makers will advance ecological research and aid in the conservation of these corals.

Morphological variation and different branch modularity across contrasting flow conditions in dominant Pocillopora reef-building corals

“…In contrast, the coral community at Punta Galeras (24°21.276′N, 110°17.100′W) is exposed to strong wave action. The structure of main reef here is more homogeneous and is rarely interrupted by sand channels (Paz-García and ReyesBonilla 2006; Pinzón et al 2012).…”

Do reef corals age?

“…CAT, computer-assisted tomography. Soong et al (1999) may comprise many ramets that become widely dispersed, for example during storms, leading to a high degree of clonality within the population (Baums, Miller & Hellberg, 2006;Pinzon et al, 2012;Japaud et al, 2015). Genetic mosaicism has been recorded across the colony due to somatic mutations (van Oppen et al, 2011;Barfield, Aglyamova & Matz, 2016) and chimeric colonies may form by fusion of adjacent, non-clonal colonies, particularly by fusion of juveniles before the immune system is fully developed (Schweinsberg, Tollrian & Lampert, 2016).…”

One species for one island? Unexpected diversity and weak connectivity in a widely distributed tropical hydrozoan

“…Thus, colonies are spatially restricted, spanning a few centimetres or decimetres. This clonal range is quite narrow compared with some other clonal marine species, such as scleractinian corals (several kilometres (Baums et al, 2006;Pinzón et al, 2012;Japaud et al, 2015)). Nevertheless, when restricting the data to one individual per Populations grouped according to structure clusters.…”