<![CDATA[ABSTRACTHybridization between female striped catfish (Pangasianodon hypophthalmus) and male nasutus catfish (Pangasius nasutus) has been conducted in Indonesia and Malaysia. However, only limited characteristics of the hybrid already reported. The present study aimed to elucidate the morphological differences between the hybrid and both parental species. Each 35 fish specimens of seven months old were examined through the measurement of 35 morphometric caharacters and the count of five meristic characters, as conducted by previous workers. Additionally, the morphology of gill rakers, mouth, snout, eye, maxillary and palatal dentitions, swim bladder, adipose fin and the body colouration were observed. The results revealed that the hybrid was morphometrically similar to the striped catfish and slightly differed from the nasutus catfish. For meristic characters, the hybrid could be practically differentiated from both parental species based on the number of pelvic fin rays. Morphologically, the hybrid differed from the striped catfish in terms of gill rakers, swim bladder, mouth, snout, maxillary and palatal dentitions, adipose fin and the body colouration. While, the hybrid was morphologically different from the nasutus catfish in terms of mouth, snout, eye position, maxillary and palatal dentitions, swim bladder and the body colouration. Key words: morphology, morphometric, meristic, hybrid, striped catfish (Pangasianodon hypophthalmus), nasutus catfish (Pangasius nasutus) ABSTRAKHibridisasi antara ikan patin Siam (Pangasianodon hypophthalmus) betina dengan patin nasutus (Pangasius nasutus) jantan telah dilakukan di Indonesia dan Malaysia. Namun demikian, karakteristik yang sudah dilaporkan masih terbatas. Penelitian ini bertujuan menguraikan perbedaan morfologi antara ikan patin hibrida tersebut dibandingkan kedua spesies induknya. Masing-masing 35 ekor spesimen berumur tujuh bulan diteliti melalui pengukuran 35 karakter morfometrik dan penghitungan lima karakter meristik, sebagaimana telah dilakukan oleh peneliti-peneliti terdahulu. Selain itu, morfologi tapis insang, mulut, moncong, mata, deretan gigi rahang atas dan gigi langit-langit mulut, gelembung renang, sirip lemak dan warna tubuh juga diamati. Hasil penelitian ini menunjukkan bahwa karakteristik morfometrik ikan patin hibrida serupa dengan ikan patin Siam, dan agak berbeda dari ikan patin nasutus. Secara meristik, ikan patin hibrida dapat dibedakan dengan mudah dari kedua spesies induknya berdasarkan jumlah jari-jari lemah sirip perut. Ikan patin hibrida berbeda dari ikan patin Siam dalam hal karakteristik morfologi tapis insang, mulut, moncong, deretan gigi rahang atas dan gigi langit-langit mulut, gelembung renang, sirip lemak dan warna tubuh. Selanjutnya, ikan patin hibrida berbeda dari ikan patin nasutus dalam hal karakteristik morfologi mulut, moncong, posisi mata, deretan gigi rahang atas dan gigi langit-langit mulut, gelembung renang dan warna tubuh. Kata kunci: morfologi, morfometrik, meristik, hibrida, patin Siam (Pangasianodon hypophthalmus), patin nasutus (Pangasius nasutus)]]>
