Judul: First Domestication Efforts of Nomorhampus sp. Endemic  to Lake Lindu, Sulawesi
Abstrak: Sulawesi merupakan pusat biodiversitas spesies akuatik endemik dari genus Nomorhamphus (Zenarcophteridae) atau halfbeak, diantaranya berada di kawasan Taman Nasional Lore Lindu, Sulawesi Tengah. Spesies Nomorhamphus di kawasan ini merupakan ikan yang baru ditemukan dan belum dideskripsikan setelah penemuan oleh tim Ekspedisi Riset Akuatika (ERA) pada 2017. Ikan ini memiliki warna yang indah dan bentuk tubuh yang unik serta bernilai history karena endemisitasnya sebagai komoditas ikan hias lokal yang keberadaannya mulai langka. Pelestarian spesies endemik dapat dilakukan melalui budidaya di luar habitatnya yang sekaligus dapat bermanfaat secara ekonomi, mengurangi ketergantungan penangkapan di alam, serta berguna untuk restocking. Oleh karena itu kajian upaya domestikasi Nomorhamphus sp. penting untuk diteliti sebagai dasar kegiatan budidaya ikan hias. Secara umum, penelitian ini bertujuan untuk memperoleh data dasar untuk domestikasi ikan Nomorhamphus sebagai ikan hias dan pelestarian plasma nutfah. Penelitian dilakukan di Laboratorium Budidaya Perairan, Universitas Sultan Ageng Tirtayasa dengan sistem resirkulasi. Wadah penelitian menggunakan akuarium berukuran 100 cm × 50 cm × 40 cm dengan volume 150 L sebagai wadah aklimatisasi ikan dari alam. Wadah plastik berukuran 35 cm × 25 cm × 15,5 cm dengan volume air 9 L sebagai wadah pemeliharaan ikan untuk uji adaptasi, tingkah laku pemijahan induk bunting dari alam, dan ontogeni larva-juvenil. Induk diberikan pakan alami yaitu Daphnia sp., Tubifex sp., jentik nyamuk, dan cacing darah. Larva diberikan pakan nauplii artemia. Penelitian pertama bertujuan menganalisis karakter genetik, biometrik, dan habitat Nomorhamphus sp. Lindu. Karakter genetik diamati menggunakan gen Cytochrome b (Cyt b). Karakter biometik yang dianalisis yaitu morfometrik dan meristik. Karakteristik habitat yang dimati adalah fisik dan kimia air di habitat alami. Nomorhamphus sp. dikoleksi dari Danau Lindu dibandingkan dengan Nomorhamphus versicolor yang berasal dari hulu sistem Sungai Palu dan N. celebensis dari Danau Poso, Sulawesi Tengah. Hasil analisis genetik Nomorhamphus sp. Lindu jantan dan betina memiliki panjang rata-rata urutan nukleotida 853bp. Halbeak Lindu dan N. versicolor memiliki jarak genetik yang dekat (0,4-0,6%). Karakter biometrik (meristik) yang diperoleh yaitu jumlah jari jari sirip anal berkisar 14-15, jari-jari sirip punggung: 11, jari-jari sirip dada: 13, dan jari-jari sirip perut: 6. Karakteristik habitat berada pada ketinggian >1.000 mdpl, kedalaman sungai maksimal 50 cm dengan air jernih mengalir perlahan, suhu 18,9-22,7°C, oksigen terlarut 7,5-7,6 mg L-1 , pH 7,73-8,50, serta substrat dasar berupa pasir dan kerikil dengan serasah daun. Penelitian kedua bertujuan untuk mengevaluasi aspek reproduksi Nomorhamphus sp. Lindu. Parameter pengamatan meliputi seksual dimorfisme, karakteristik organ reproduksi, status gonad, karakteristik spermatozoa, potensi jumlah larva, dan tingkah laku melahirkan larva. Ikan uji yang digunakan ii sebanyak 30 ekor jantan dan betina dengan ukuran 4-9 cm. Karakterisasi tingkat kebuntingan menggunakan ikan betina pada kisaran panjang total 4-8 cm. Nomorhamphus sp. Lindu jantan dan betina dapat dibedakan berdasarkan adanya organ andropodium pada individu jantan. Nomorhamphus sp. yang dapat digunakan sebagai induk jantan berukuran 4,3-5,7 cm dan betina berukuran 5,7- 8,5 cm. Sperma Nomorhamphus sp. Lindu memiliki karakteristik panjang total 41,89 µm dengan panjang kepala 2,94 µm, lebar kepala 2,00 µm, panjang leher 1,06 µm, dan panjang ekor 37,89 µm. Betina bunting memiliki indeks kebuntingan 0,40-0,42 pada kisaran panjang total 6,5-7,5 cm. Potensi satu ekor ikan betina berukuran panjang
Keyword: Cytochorome-b, domestication, morphomeristic, Nomorhamphus, pregnancy

Judul: Morphogenesis and Biometric Characteristics  of Early Life Development of Nomorhamphus sp. Endemic to Lindu, Central  Sulawesi
Abstrak: Nomorhamphus sp. is endemic ornamental fish from Lindu, Sulawesi Tengah. Nomorhamphus sp. is viviparous fish and it has unique body shape and color. Several of Nomorhamphus species have been sold as ornamental fish commodities. But, production of Nomorhamphus still relies from wild catches. Overfishing will threat Nomorhamphus sp. sustainability. Other threats are anthropogenic, agricultural waste and invasive fish in Lindu. Aquaculture can be potential solution for sustainable Nomorhamphus sp. production. Aquaculture begins from domestication. Domestication is an adaptation of fish from nature to a controlled environment. This process requires basic biology information of fish life. Biological information of Nomorhamphus sp. used to determine step of aquaculture management, conservation, and development. Critical point of fish life is larval stage. Information of larval stage can obtain from morphogenesis and biometric information on early life of Nomorhamphus sp. This study aimed to study of morphogenesis and biometric on early life stage as basic information of Nomorhamphus sp. culture. This study contained morphometric and meristic characters, mouth width, morphogenesis and feeding behavior. Morphometric was measured using caliper and analyzed based on standard length ratio. Meristic was measured using microscope to count fins rays. Mouth width was identified for feed size. Mouth width was measured based on 90° angle form of upper jaw. Morphogenesis was observed by development and growth of fish body on larval and juvenile stages. Feeding behavior was observed based on body shape and lower jaw length. Result showed that new born Nomorhamphus sp. larva had 13,57 – 14,42 mm standard length, 15-days-old had 16,53 – 17,55 mm standard length, 25-days-old had 16,87 - 18,38 mm standard length and 30-days-old had 20,4 – 23,32 mm standard length. Morphometric characters ratio showed growth of body length and fin length. morphometric characters ratio showed a transition between larvae and juveniles on day 15 and day 25. Larvae had proportional body shape on 30-days-old. Juvenile body was growth in between pectoral fin and anal fin. Fin rays meristic characters showed no difference between larva and juvenile stage. Fin rays meristic were 14-15 anal fin rays (A.14-15), 11 dorsal fin rays (D.11), 13 pectoral fin rays (P.13), dan 6 ventral fin rays (V.6). New born Nomorhamphus sp had cream body color, yellow jaw, and transparent silver color on their belly. Swim bladder was developed after birth. Nasal barbel were found on their head. Larvae had cream color, silver belly and orange pattern ventral and caudal fins on 15-days-old. Then, yellow jaw was faded. 25-days-old had cream and silver color body. Their body morphology was like adult-age. Juvenile stage has started 25-days-old. Male’s Andropodium was developed as secondary sexual dimorphism on 25-days-old. Sexual dichromatism was identified by brighter orange strip kaudal fin in males. 30-days-old had similar character with 25-days-old. Newborn larvae are motionless at bottom of water and try to swim to the surface because their swim bladder was not filled yet. Newborn can moved after their swim bladder were filled. Nomorhamphus sp. can find their feed in water column and bottom.
Keyword: Domestication, Early life development, Morphology, Nomorhamphus  sp.

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
Keyword: