Phylogeographic patterns in cryptic <i>Bostrychia tenella </i>species
(Rhodomelaceae, Rhodophyta) across the Thai-Malay Peninsula

Bulan, Jakaphan; Maneekat, Sinchai; Zuccarello, Giuseppe C.; Muangmai, Narongrit; Bulan, Jakaphan; Maneekat, Sinchai; Zuccarello, Giuseppe C.; Muangmai, Narongrit

doi:2022.37.2.123

Algae > Volume 37(2); 2022 > Article

Research Article

Algae 2022;37(2): 123-133. doi: https://doi.org/10.4490/algae.2022.37.6.4

Phylogeographic patterns in cryptic Bostrychia tenella species (Rhodomelaceae, Rhodophyta) across the Thai-Malay Peninsula

Jakaphan Bulan¹, Sinchai Maneekat¹, Giuseppe C. Zuccarello², Narongrit Muangmai^1,*

¹Department of Fishery Biology, Faculty of Fisheries, Kasetsart University, Bangkok 10900, Thailand
²School of Biological Science, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand

*Corresponding Author

Narongrit Muangmai, Tel: +66-2-942-8701, Fax: +66-2-942-8702,
Email: ffisnrm@ku.ac.th

Received: February 1, 2022; Accepted: June 4, 2022. Published online: June 21, 2022.

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

ABSTRACT

Genetic diversity and distribution patterns of marine macroalgae are increasingly being documented in Southeast Asia. These studies show that there can be significant levels of genetic diversity and isolation between populations on either side of the Thai-Malay Peninsula. Bostrychia tenellla is a common filamentous red seaweed in the region and the entity is represented by at least two cryptic species. Despite being highly diverse and widespread, genetic variation and population structure of this species complex remains understudied, especially around the Thai-Malay Peninsula. We analyzed genetic diversity and inferred the phylogeographic pattern of specimens identified as B. tenella using the plastid RuBisCo spacer from samples from the Andaman Sea and the Gulf of Thailand. Our genetic analysis confirmed the occurrence of the two cryptic B. tenella species (B and C) along both coasts. Cryptic species B was more common in the area and displayed higher genetic diversity than species C. Historical demographic analyses indicated a stable population for species B, but more recent population expansion for species C. Our analyses also revealed that both cryptic species from the Andaman Sea possessed higher genetic diversity than those of the Gulf of Thailand. We also detected moderate to high levels of gene flow and weak phylogeographic structure of cryptic species B between the two coasts. In contrast, phylogeographic analysis showed genetic differences between populations of both cryptic species within the Andaman Sea. Overall, these results suggest that cryptic B. tenella species around Thai-Malay Peninsula may have undergone different demography histories, and their patterns of genetic diversity and phylogeography were likely caused by geological history and regional sea surface current circulation in the area.

Key words: connectivity; cryptic diversity; dispersal; macroalgae; Sundaland