Species delimitation of common reef corals in the genus Pocillopora using nucleotide sequence phylogenies, population genetics and symbiosis ecology

Abstract

Stony corals in the genus Pocillopora are among the most common and widely distributed of Indo-Pacific corals and, as such, are often the subject of physiological and ecological research. In the far Tropical Eastern Pacific (TEP), they are major constituents of shallow coral communities, exhibiting considerable variability in colony shape and branch morphology and marked differences in response to thermal stress. Numerous intermediates occur between morphospecies that may relate to extensive hybridization. The diversity of the Pocillopora genus in the TEP was analysed genetically using nuclear ribosomal (ITS2) and mitochondrial (ORF) sequences, and population genetic markers (seven microsatellite loci). The resident dinoflagellate endosymbiont (Symbiodinium sp.) in each sample was also characterized using sequences of the internal transcribed spacer 2 (ITS2) rDNA and the noncoding region of the chloroplast psbA minicircle. From these analyses, three symbiotically distinct, reproductively isolated, nonhybridizing, evolutionarily divergent animal lineages were identified. Designated types 1, 2 and 3, these groupings were incongruent with traditional morphospecies classification. Type 1 was abundant and widespread throughout the TEP; type 2 was restricted to the Clipperton Atoll; and type 3 was found only in Panama and the Galapagos Islands. Each type harboured a different Symbiodinium'species lineage' in Clade C, and only type 1 associated with the 'stress-tolerant'Symbiodinium glynni (D1). The accurate delineation of species and implementation of a proper taxonomy may profoundly improve our assessment of Pocillopora's reproductive biology, biogeographic distributions, and resilience to climate warming, information that must be considered when planning for the conservation of reef corals.

From population connectivity to the art of striping Russian dolls: the lessons from Pocillopora corals

“…Nevertheless, host–symbiont association could be, on the contrary, more specific at the genus level. Indeed, Pinzón and LaJeunesse (2011) found some exclusive associations between subclades of Symbiodinium Clade C and ORF type of Pocillopora [e.g., C1b‐c and D were exclusively found in association with Pocillopora type 1 (PSH09 herein)]. The host–symbiont association should be further studied considering the clusters within the three SSHs to investigate the existence of specific associations at the different levels of genetic structuring in this host.…”

“…Likewise, Combosch and Vollmer (2015) revealed hybridization between Pocillopora type 1 and type 3 using RADseq. Moreover, each time hybridization has been demonstrated in Pocillopora corals (Combosch, Guzman, Schuhmacher, & Vollmer, 2008; Combosch & Vollmer, 2015; Pinzón & LaJeunesse, 2011), it seemed dominated by type 1 maternal lineages since all hybrid colonies exhibited mitochondrial type 1 haplotypes (Combosch & Vollmer, 2015). Frequent events of hybridization could comfort Veron's suggestion about metaspecies (or syngameon) existence in corals (Veron, 1995).…”

The New Systematics of Scleractinia: Integrating Molecular and Morphological Evidence

“…Larger geographic contrasts such as between Red Sea and Pacific Ocean populations of Dipsastraea and Stylophora have also revealed molecular separation between regions Arrigoni et al 2012;Keshavmurthy et al 2013). However, to reach a stage where taxonomic revisions can be attempted, broad geographic sampling across the Indo-Pacific and detailed studies of closely-related species are necessary, such as in the case of species in Astreopora (Suzuki and Nomura 2013), Pocillopora (Pinzón and LaJeunesse 2010;Pinzón et al 2012Pinzón et al , 2013Torda et al 2013a, b;Marti-Puig et al 2014;Schmidt-Roach et al 2013, 2014 and Psammocora (Benzoni et al 2010;Stefani et al 2008a). In particular, boundaries among Psammocora species were clarified through a series of rigorous molecular and morphological analyses (Stefani et al 2008a, b;Benzoni et al 2007Benzoni et al , 2010, which saw 24 nominal species reorganised as seven valid species-P. albopicta, P.…”

Cryptic Diversity in the Neotropical Gecko Genus Phyllopezus Peters, 1878 (Reptilia: Squamata: Phyllodactylidae): A New Species from Paraguay

“…Molecular data are now often used for species identification [12][13][14] and species delimitation [15][16][17][18] helping taxonomists to improve the global knowledge of alpha taxonomy. This led to the recognition of many cryptic phylogenetic lineages of reptiles in the Neotropics [9,19].…”