Systematics, genetics, and biogeography of intertidal mites (Acari, Oribatida) from the Andaman Sea and Strait of Malacca

Abstract

This study demonstrates for the first time the presence of marine‐associated mites in the Andaman Sea and Strait of Malacca and reveals a relatively high diversity of these taxa with six species from two different families: Selenoribatidae and Fortuyniidae. Indopacifica , a new genus of Selenoribatidae, is described from Thailand and Malaysia, with two new species, Indopacifica pantai n. sp. and Indopacifica parva n. sp. The genus is characterized by the unique combination of following characters: lacking lamellar ridges, incomplete dorsosejugal suture, fourteen pairs of notogastral setae, and presence of epimeral foveae. A phylogenetic reconstruction based on 18S ribosomal RNA sequences clearly confirms the distinctness of the new genus Indopacifica and places it close to the genus Rhizophobates . The lack of molecular genetic data of possible relatives impedes a clear assessment, and hence, we emphasize the need for further combined approaches using morphological and molecular genetic sequence data. All species show wide distribution areas within this geographic region suggesting that these taxa are good dispersers despite their minute size and wingless body. Molecular genetic data demonstrate recent gene flow between far distant populations of I. pantai n. sp. from the coasts of Thailand and two islands of Malaysia and hence confirm this assumption. The seasonally changing surface currents within this geographic area may favor hydrochorous dispersal and hence genetic exchange. Nevertheless, morphometric data show a slight trend to morphological divergence among the studied populations, whereas this variation is suggested to be a result of genetic drift but also of habitat differences in one population of Alismobates pseudoreticulatus .

New and cryptic species of intertidal mites (Acari, Oribatida) from the Western Caribbean – an integrative approach

“…Molecular genetic data are not comprehensive enough to address this issue as there are no comparable data for the Mediterranean T. riparius and the Indo-Pacific T. tenuisetosus. In GenBank, there is a sequence presented under the name Thalassozetes shimojanai but this should be corrected to Rhizophobates shimojanai Karasawa & Aoki, 2005(Pfingstl et al 2018. The separation of R. shimojanai from true Thalassozetes species is further supported by their isolation in the phylogenetic tree based on 18S rRNA sequences (Figure 14).…”

The intertidal genus Indopacifica (Acari, Oribatida, Selenoribatidae): new species, juvenile morphology and distribution

“…For a graphic illustration of these variables we refer to Pfingstl et al (2019) (variable efw from the original set was excluded in advance because it does not exist in I. mauritiana). For further comparison we included the measurements of 51 specimens of Indopacifica pantai from Malaysia and Thailand published by Pfingstl et al 2019. Non-metric multidimensional scaling (NMDS) based on Euclidean distances was performed in order to visualize morphometric differences between the three species. Separation between the species was tested by PERMANO-VA.…”

“…Pfingstl & Schuster 2014). Indopacifica was recently proposed with two species, Indopacifica pantai Pfingstl, Shimano & Lienhard, 2019 and Indopacifica parva Pfingstl, Shimano & Lienhard, 2019 from the Andaman Sea and the Strait of Malacca, respectively. The former was reported from coasts of Singapore, Malaysia and Thailand and the latter only from Singapore and Malaysia (Pfingstl et al 2019).…”

“…Indopacifica was recently proposed with two species, Indopacifica pantai Pfingstl, Shimano & Lienhard, 2019 and Indopacifica parva Pfingstl, Shimano & Lienhard, 2019 from the Andaman Sea and the Strait of Malacca, respectively. The former was reported from coasts of Singapore, Malaysia and Thailand and the latter only from Singapore and Malaysia (Pfingstl et al 2019). Based on their wide distributions and on recent gene flow, as indicated by molecular genetic data, both species are good dispersers despite their wingless body and minute size (Pfingstl et al 2019).…”

“…The former was reported from coasts of Singapore, Malaysia and Thailand and the latter only from Singapore and Malaysia (Pfingstl et al 2019). Based on their wide distributions and on recent gene flow, as indicated by molecular genetic data, both species are good dispersers despite their wingless body and minute size (Pfingstl et al 2019). Knowledge about their ecology is largely incomplete but they seem to inhabit and feed on diverse kinds of algae growing on littoral rocks.…”