IDENTIFIKASI IKAN SILI (FAMILI: MASTACEMBELIDAE) BERDASARKAN KARAKTERISTIK MORFOLOGI DAN MOLEKULER GEN COI DI RAWA LAMONGAN

IDENTIFICATION OF SILI FISH (FAMILY: MASTACEMBELIDAE) BASED ON MORPHOLOGICAL AND MOLECULAR CHARACTERISTICS OF COI GENES IN LAMONGAN SWAMP

Ikan sili (Famili: Mastacembelidae) merupakan ikan air tawar yang memiliki nilai ekologis dan ekonomis, namun identifikasi spesiesnya masih menghadapi kendala akibat kemiripan karakter morfologi antarspesies, khususnya dalam genus Macrognathus, variasi pola tubuh dan ocelli yang berpotensi menimbulkan kesalahan identifikasi. Penelitian ini bertujuan untuk mengidentifikasi spesies ikan sili berdasarkan karakter morfologi dan molekuler guna meningkatkan keakuratan penentuan spesies. Sampel diperoleh dari rawa Desa Jabung dan Desa Pesanggrahan, Kecamatan Laren, Kabupaten Lamongan menggunakan metode purposive sampling. Analisis morfologi dilakukan melalui pengamatan karakter kualitatif dan kuantitatif, sedangkan analisis molekuler dilakukan melalui DNA barcoding gen Cytochrome Oxidase Subunit I (COI), meliputi isolasi DNA, amplifikasi, sekuensing, dan analisis bioinformatika.

Hasil penelitian menunjukkan bahwa karakter morfologi yang diamati mengarah pada spesies Macrognathus aculeatus, meskipun ditemukan variasi pada pola warna dan ocelli yang berpotensi menimbulkan ambiguitas. Analisis molekuler menunjukkan tingkat similaritas sekuens yang tinggi (99–100%), jarak genetik yang rendah, serta pengelompokan dalam satu klad monofiletik dengan Macrognathus aculeatus. Hasil ini mengonfirmasi bahwa seluruh sampel merupakan spesies yang sama, serta menunjukkan bahwa variasi morfologi yang teramati bersifat intraspesifik.

Pendekatan integratif antara morfologi dan molekuler terbukti efektif dalam meningkatkan akurasi identifikasi spesies ikan sili, serta memberikan data dasar penting dalam kajian taksonomi dan pengelolaan biodiversitas perairan rawa.

Kata kunci: ikan sili, Macrognathus aculeatus, morfologi, DNA barcoding, gen COI, filogenetik.

The sili fish (Family: Mastacembelidae.) is a freshwater fish of ecological and economic importance; however, species identification remains challenging due to the similarity of morphological characteristics among species, particularly variations in body patterns and ocelli, which can lead to misidentification. This study aims to identify sili fish species based on morphological and molecular characteristics to improve the accuracy of species determination. Samples were collected from the swamps of Jabung Village and Pesanggrahan Village, Laren Subdistrict, Lamongan Regency, using purposive sampling. Morphological analysis was conducted through the observation of qualitative and quantitative characteristics, while molecular analysis was performed using DNA barcoding of the Cytochrome Oxidase Subunit I (COI) gene, encompassing DNA isolation, amplification, sequencing, and bioinformatics analysis.

The results of the study indicate that the observed morphological characters point to the species Macrognathus aculeatus, although variations in color patterns and ocelli were found that could potentially cause ambiguity. Molecular analysis revealed high sequence similarity (99–100%), low genetic distance, and grouping within a single monophyletic clade with Macrognathus aculeatus. These results confirm that all samples belong to the same species and indicate that the observed morphological variations are intraspecific.

An integrative approach combining morphological and molecular data has proven effective in improving the accuracy of species identification in spiny eels, and provides important baseline data for taxonomic studies and the management of wetland biodiversity.

Keywords: spiny-cheeked fish, Macrognathus aculeatus, morphology, DNA barcoding, COI gene, phylogenetics.