Morphological variations and phylogenetic analysis of Oryzias nigrimas Kottelat, 1990 (Rice fish) from Lake Poso, Central Sulawesi, Indonesia

NOVALINA SERDIATI (Faculty of Animal Husbandry and Fisheries, Universitas Tadulako. Jl. Soekarno-Hatta Km. 9, Tondo, Mantikulore, Palu 94148, Central Sulawesi Indonesia)
DIANA ARFIATI (Faculty of Fisheries and Marine Science, Universitas Brawijaya. Jl. Veteran No.16, Malang 65145, East Java, Indonesia)
MAHENO SRI WIDODO (Faculty of Fisheries and Marine Science, Universitas Brawijaya. Jl. Veteran No.16, Malang 65145, East Java, Indonesia)
TRI JOKO LELONO (Faculty of Fisheries and Marine Science, Universitas Brawijaya. Jl. Veteran No.16, Malang 65145, East Java, Indonesia)
SAMLIOK NDOBE (Faculty of Animal Husbandry and Fisheries, Universitas Tadulako. Jl. Soekarno-Hatta Km. 9, Tondo, Mantikulore, Palu 94148, Central Sulawesi, Indonesia)
RUDY SARANGA (Department of Fishing Technique, Politeknik Kelautan dan Perikanan Bitung. Jl. Tandurusa, Bitung 95526, North Sulawesi, Indonesia)

Biodiversitas Journal of Biological Diversity
Vol. 21 No. 3 (2020)

Abstract. Serdiati N, Arfiati D, Widodo MS, Lelono TJ, Ndobe S, Saranga R. 2020. Morphological variations and phylogenetic analysis of Oryzias nigrimas Kottelat, 1990 (Rice fish) from Lake Poso, Central Sulawesi, Indonesia. Biodiversitas 21: 882-888. Rice fish (Oryzias nigrimas Kottelat, 1990) is a well-studied species endemic to Lake Poso, Sulawesi and identified as scarce. This study aims to identify the Rice fish of Lake Poso, Central Sulawesi based on morphological characters (15 morphometric characters and 5 meristic counts) and phylogenetic analysis using maximum-likelihood (ML) method based on mtDNA, CO1 gene. Based on the morphological analysis, it was showed that the meristic counts show significantly different only on the lateral line scale. However, the morphometric measurements show significantly different characteristics on postorbital distance, body depth, and length of jaw. Our phylogenetic analysis also showed that our samples are indeed a species of O. nigrimas. We suggest that the endemicity of this Rice fish on Lake Poso is greatly influenced by the well-maintained genetic structure of the population.