Sex-Based Morphological Differentiation and Stock Homogeneity of Rasbora arundinata (Lumbantobing, 2014) in the Krueng Lanca River, Aceh, Indonesia

Mu'amar Abdan (Department of Aquaculture, Faculty of Agriculture, Gajah Putih University, Simpang Kelaping-Lukup Badak-Belang Bebangka Street. Pegasing District, Takengon, Central Aceh, Aceh, 24560)
Sulistiono Sulistiono (Department of Aquatic Resources Management, Faculty of Fisheries and Marine Sciences, IPB University, FPIK Building, Agatis Street, Dramaga Campus, Bogor 16680)
Mohammad Mukhlis Kamal (Department of Aquatic Resources Management, Faculty of Fisheries and Marine Sciences, Bogor Agricultural University, Bogor, 16680)
Ali Mashar (Department of Aquatic Resources Management, Faculty of Fisheries and Marine Sciences, Bogor Agricultural University, Bogor, 16680)
Nurlisa Alias Butet (Department of Aquatic Resources Management, Faculty of Fisheries and Marine Sciences, Bogor Agricultural University, Bogor, 16680)
Fazril Saputra (Department of Aquaculture, Faculty of Fisheries and Marine Science, Universitas Teuku Umar. Jl. Alue Peunyareng, Gunong Kleng, Meureubo, West Aceh 23681, Aceh)
Iwan Hasri (Department of Aquaculture, Faculty of Agriculture, Gajah Putih University, Simpang Kelaping-Lukup Badak-Belang Bebangka Street. Pegasing District, Takengon, Central Aceh, Aceh, 24560)

Journal of Aquaculture and Fish Health
Vol. 15 No. 3 (2026): JAFH Vol 15 No 3 September 2026

Sexual dimorphism and spatial variation in morphometric and meristic traits provide important insights into population structure and biological differentiation in freshwater fishes. This study investigated sexual dimorphism and spatial variation in Rasbora arundinata from the Krueng Lanca River, Aceh, Indonesia. A total of 76 individuals, consisting of 40 males and 36 females, were examined. Twenty-three morphometric and ten meristic characters were measured and analyzed using univariate analysis of variance and principal component analysis. The results showed that only four morphometric characters—body width, pectoral fin base length, pelvic fin base length, and standard length—differed between males and females, while the remaining characters were similar between sexes. Females generally exhibited larger body size and greater body robustness than males, indicating subtle sexual dimorphism mainly associated with size- and fin-related traits. Principal Component Analysis supported these findings by revealing partial separation between male and female individuals, with body width and pectoral fin base length contributing most strongly to overall morphometric variation. Meristic analysis also revealed sex-related differences, particularly in lateral line scale counts and fin ray numbers. Females tended to have higher lateral line scale counts, whereas males showed greater variability in several fin ray characters. Spatial analysis based on sampling stations revealed no clear morphological separation among locations, indicating limited spatial variation and suggesting that R. arundinata in the Krueng Lanca River represents a single, morphologically homogeneous stock. Overall, morphological variation in R. arundinata appears to be driven more strongly by sex-related biological factors than by spatial environmental differences.