Vol. 64, 2025

Genome-wide SNP Analyses Reveal High Gene Flow of Endemic Smallscale Croaker (Boesemania microlepis) in the Lower Mekong Basin

Quyen Dang Ha Vu¹, Christopher E. Bird², Oanh Thi Truong¹

, Ellen E. Biesack³, Amanda S. Ackiss³, Kent E. Carpenter^3,*, and Binh Thuy Dang^1,*

¹Department of Biotechnology, Institute for Biotechnology and Environment, Nha Trang University, 02 Nguyen Dinh Chieu, Nha Trang, Vietnam. *Correspondence: E-mail: binhdt@ntu.edu.vn (Dang)
E-mail: quyenvdh@ntu.edu.vn (Vu); oanhtt@ntu.edu.vn (Truong); sangtq@ntu.edu.vn (Tran)
²Department of Life Sciences, Texas A&M University– Corpus Christi, Corpus Christi, TX 78412, USA. E-mail: chris.bird@tamucc.edu (Bird)
³Department of Biological Sciences, Old Dominion University, Norfolk, Virginia 23529 -0266, USA. *Correspondence: E-mail: kcarpent@odu.edu (Carpenter)
E-mail: ebies001@odu.edu (Biesack); aacki002@odu.edu (Ackiss)

(Received 30 July 2024 / Accepted 6 April 2025 / Published -- 2025)
Communicated by Jen-Pan Huang

The Smallscale Croaker, Boesemania microlepis, is a valuable fishery resource in the Mekong River basin that lacks clear biological data to understand its basic ecology and conservation management priorities. This species is common in the southernmost floodplain of the Mekong which extends from Tonlé Sap in Cambodia to the Mekong Delta in Vietnam. This floodplain is of particular biodiversity conservation concern because of the many upstream dams that restrict water flow in an ecology that relies heavily on a flood-pulse cycle. The literature regarding the biology B. microlepis in this region contains conflicting ideas that populations are both highly localized and exhibit extensive migratory behavior. We used restriction-site associated DNA to test the hypothesis that localized populations exist in the southernmost floodplain of the Mekong basin. Our data indicates high connectivity among eight sites sampled in this region supporting overall panmixia. Our results suggest a potential upstream source of propagules for this floodplain and the need for further research to clarify mechanisms driving gene flow.

Keywords: Boesemania microlepis, EzRAD, Lower Mekong Basin, Gene flow, Population genetics

Citation: Vu QDH, Bird CE, Truong OT, Tran SQ, Biesack EE, Ackiss AS, Carpenter KE, Dang BT. 2025. Genome-wide SNP analyses reveal high gene flow of endemic Smallscale Croaker (Boesemania microlepis) in the Lower Mekong Basin. Zool Stud 64:18.

Supplementary materials: Fig. S1丨Fig. S2丨Fig. S3丨Fig. S4丨Fig. S5丨Table S1丨Table S2