Molecular analysis of Indo-Pacific Syllinae annelids with the description of five new species from the Philippine Islands

Abstract

Syllinae is the largest and the most diverse subfamily in Syllidae and usually a dominant group in many marine habitats, both in terms of numbers of species and individuals. However, the lack of morphological synapomorphies for many genera and the non-monophyly of most of these suggested by molecular studies, have stressed taxonomic and systematic problems within this subfamily. Although several studies have revised some genera in the Indo-Pacific area, important gaps of knowledge remain for this biogeographic region. Thus, in this study we undertook detailed morphological examination of Syllis and Megasyllis specimens from the Philippine Islands and provide a phylogenetic analysis of Indo-Pacific Syllinae in order to evaluate the position of newly described species. We provide line drawings, light microscopy observations and electron microscopy micrographs for eight species, including five new to science. Maximum likelihood and Bayesian inference analyses of four molecular markers (28S rRNA, 18S rRNA, 16S rRNA, cytochrome c oxidase subunit I) from 85 specimens are presented, showing the non-monophyletic status of Syllis and Megasyllis. Overall, our study increases the biodiversity of syllids in this poorly known Indo-Pacific area, highlighting the importance of examining both morphological and molecular data to expand our knowledge of the subfamily Syllinae and to further resolve the taxonomic issues that remain in this group. The following new taxa are described: Megasyllis kurui sp. nov. Moreno-Martínez, San Martín & Álvarez-Campos, Syllis ireneae sp. nov. Moreno-Martínez, San Martín & Álvarez-Campos, Syllis santii sp. nov. Moreno-Martínez, San Martín & Álvarez-Campos, Syllis tini sp. nov. Moreno-Martínez, Syllis walong sp. nov. Moreno-Martínez, San Martín & Álvarez-Campos.

http://zoobank.org/urn:lsid:zoobank.org:pub:E35C528D-E02D-4735-B62C-2EF5C64BBCAF

Key words:

• biodiversity
• integrative taxonomy
• Syllinae
• Philippine Islands
• Indo-Pacific

Acknowledgements

We would like to express our gratitude to Virgilio Palpal-Latoc (National Museum of the Philippines), Raffy G. Cabate, Minda Go, Levi A. Ladioray (Municipality of El Nido), and the members of Club Ocellaris (Mabini, Luzón) and (Palawan Dive Center, El Nido) for assisting with permits and sampling in the Philippine Islands. Many thanks to Charlotte Watson and all the participants in the cruises from the Project CGL2009-12292 BOS (Spanish Ministry of Economy and Knowledge) to GSM, for collecting and sorting part of the material used for this study. We are grateful to Javier Sánchez-Almazán (Museo Nacional de Ciencias Naturales, Madrid) for the loan of the comparative material and Esperanza Salvador and Isidro Poveda (Servicio Interdepartamental de Investigación, Universidad Autónoma de Madrid) for the assistance with the SEM photos. LM-M was supported by the research assistant funds from Community of Madrid (PEJ-2020-AI/AMB-18983) granted to PA-C. This research also received funding from internal MCZ funds to GG, and from the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement with the Universidad Autónoma de Madrid in the line of action encouraging youth research doctors, in the context of the V PRICIT (Regional Programme of Research and Technological Innovation) (SI1/PJI/2019-00532) to PA-C.

Supplemental material

Supplemental material for this article can be accessed here: http://dx.doi.org/10.1080/14772000.2023.2227630.

Associate Editor: Dr Christoph Bleidorn