Aktivitas Pemijahan, Perkembangan Awal, dan Pertumbuhan Larva Ikan Pelangi Arfak dalam Kondisi Laboratorium: Studi Pendahuluan untuk Penangkarannya

Comprehensive information regarding the reproduction, early development, and growth of larvae is very important in the efforts of captive breeding and reintroduction of endangered fish species. One of the species that is starting to be threatened is the Arfak rainbowfish, Melanotaenia arfakensis which is already in the vulnerable category and its information is still relatively limited. Therefore, this study was conducted to describe the spawning activity, early development, and growth of the larvae of this rainbow fish species under laboratory conditions. Experiments on a laboratory scale were carried out in March-September 2017. The fish used came from the Nimbai Stream. A total of three pairs of individual males and females ranging in size from 46.5 to 60.1 mm were selected for treatment. However, only one pair was successfully observed spawning activity completely. Spawning takes place between morning and noon in three spawning periods. In each period, spawning lasts between 8 and 11 days. Between spawning periods takes 14 to 22 days. After fertilization, the eggs are attached with filaments to the spawning substrate and placed at a depth of 7.3-24.3 cm from the surface of the water. One group of eggs spawned consists of 78-116 eggs with a diameter range between 1.05 and 136 mm. The eggs hatch in a period of 4 to 10 days. The body length of the newly hatched larvae ranges from 4.13-4.40 mm and will reach a size of 7.85 mm with a survival rate of 48.1% after 41 days. The results of this study found several advantages from the characteristics of spawning and growth in the early stages that are useful for captive breeding efforts and reintroduction of this rainbowfish to their natural habitat. Thus, its population in the Prafi River system can be maintained.Informasi yang lengkap mengenai reproduksi, perkembangan awal, dan pertumbuhan larva menjadi sangat penting dalam upaya penangkaran dan reintroduksi spesies ikan yang terancam punah. Salah satu di antara spesies yang mulai terancam adalah ikan elangi Arfak, Melanotaenia arfakensis yang sudah berada dalam kategori rentan dan informasinya masih sangat terbatas. Oleh karena itu, penelitian ini dilakukan dengan tujuan untuk mendeskripsikan aktivitas pemijahan, perkembangan awal, dan pertumbuhan larva spesies ikan elangi ini dalam kondisi laboratorium. Percobaan dalam skala laboratorium dilaksanakan pada bulan Maret-September 2017. Ikan yang digunakan berasal dari Sungai Nimbai. Sebanyak tiga pasang individu jantan dan betina dengan kisaran ukuran 46,5 sampai 60,1 mm dipilih untuk perlakuan. Namun, hanya satu pasangan yang berhasil diamati aktivitas pemijahannya secara lengkap. Pemijahan berlangsung di antara waktu pagi hari sampai siang hari dalam tiga periode pemijahan. Dalam setiap periode, pemijahan berlangsung di antara 8 dan 11 hari. Antarperiode pemijahan membutuhkan waktu 14 sampai 22 hari. Setelah dibuahi, telur dilekatkan dengan filamen pada substrat pemijahan dan diletakkan pada kedalaman 7,3-24,3 cm dari permukaan air. Satu kelompok telur yang dipijahkan terdiri atas 78-116 butir dengan kisaran diameter di antara 1,05 dan 136 mm. Telur menetas dalam periode 4 sampai 10 hari. Panjang tubuh larva yang baru menetas berkisar 4,13-4,40 mm dan akan mencapai ukuran 7,85 mm dengan tingkat sintasan 48,1% setelah 41 hari. Hasil penelitian ini menemukan beberapa kuntungan dari karakteristik pemijahan dan pertumbuhan tahap awal yang bermanfaat untuk upaya penangkaran dan pelepasliaran ikan ini ke habitat aslinya. Dengan demikian, populasinya di sistem Sungai Prafi dapat tetap dilestarikan

Biologi Reproduksi Ikan Kiper, Scatophagus argus (Linnaeus, 1766) di Teluk Pabean, Indramayu

The spotted scat, Scatophagus argus (Linnaeus, 1766) is a component of the estuarine ecosystem with little reproductive information. Therefore, this study was conducted with the aim of describing aspects of the reproductive biology of this fish species through sex ratio, size at first sexual maturity, and spawning season. The collection of fish samples from the waters of Pabean Bay was carried out every month between January and December 2015. The fishing gear used were sero and gill nets. A total of 428 individuals were collected consisting of larval, juvenile, pre-adult, and adult stages. The ratio of the number of male and female individuals is relatively balanced (1.00 : 1.05). The size of the male individual's first sexual maturity at a total length of 102.95 mm and 112.44 mm in female individuals. The composition of gonadal maturity level and gonadal maturity index value indicated that there was reproductive activity that lasted throughout the year and increased in January-February and September-November. Information on reproductive aspects obtained in this study can be used as a basis for the management of this fish resource, including through recommendations for closing locations and fishing times.Ikan kiper, Scatophagus argus (Linnaeus, 1766) adalah salah satu komponen pada ekosistem estuari yang masih sedikit informasi reproduksinya. Oleh karena itu penelitian ini dilakukan dengan tujuan untuk mendeskripsikan aspek biologi reproduksi jenis ikan ini melalui rasio kelamin, ukuran pertama kali matang kelamin, dan musim pemijahan. Pengumpulan contoh ikan yang berasal dari perairan Teluk Pabean dilakukan setiap bulan di antara Januari dan Desember 2015. Alat tangkap yang digunakan adalah sero dan jaring insang. Sebanyak 431 individu berhasil dikumpulkan yang terdiri atas tahap larva, yuwana, pradewasa, dan dewasa. Perbandingan jumlah individu jantan dan betina relatif seimbang (1,00 : 1,05). Ukuran pertama kali matang kelamin individu jantan pada ukuran panjang total 102,95 mm dan 112,44 mm pada individu betina. Komposisi tingkat kematangan gonad dan nilai indeks kematangan gonad menunjukkan adanya aktivitas reproduksi yang berlangsung sepanjang tahun dan meningkat pada Bulan Januari-Februari dan September-November. Informasi mengenai aspek reproduksi yang diperoleh dalam penelitian ini bisa menjadi dasar dalam pengelolaan sumberdaya ikan ini, di antaranya melalui rekomendasi untuk penutupan lokasi dan waktu penangkapan

Utility of Batang Toru River (North Sumatra, Indonesia) for fishery activities of the local communities: a study on fisheries socioeconomic condition

Batang Toru River is a river that crosses several sub-districts in North Tapanuli and South Tapanuli Regency and has social and economic benefits for the community. This study aimed to determine the fisheries' socio-economic condition of the community around the river. Study was carried out in August 2019, on the communities around the river in five districts, namely Sipirok district (Luat Lobang and Aek Batang Paya Village), Marancar District (Marancar Julu, Pasar Sempurna, Simaninggir, and Huraba Village), Batang Toru District (Sipenggeng and Hapesong Baru Village), Muara Batang Toru District (Bandar Hapinis Village), and Simangumban District (Simangumban Jae Village). The data collected were analyzed descriptively. Based on the study, the local communities usually used the river for fishing, although fishing was not their main occupation. The fish caught were generally for their consumption or sold in the surrounding village

Development potential of native fish in Batang Toru Watershed, North Sumatra, Indonesia: discussion on the impact of dam development and aquaculture efforts

As one of the sizable rivers in the Sumatra region, the Batang Toru River is a habitat for various fish species, some of which are potential to be developed as cultured fish. This study was carried out in April, July, and October 2019 in the Batang Toru River watershed of South Tapanuli Regency, North Sumatra, to evaluate a potential development of the riverine fish for aquaculture development. The methods used were fisheries surveys and discussions with various communities and related agencies in the South Tapanuli Regency. The data obtained were presented descriptively. Based on the result of data analysis collected in the field, there were several potential fish species to be cultured in this study, including mahseer (Tor tambroides, T. tambra, Neolissochilus soro), catfish (Hemibagrus spp.), and eel (Anguilla bicolor). Some people in the area have also developed the culture of several fish species, such as mahseer and catfish. However, there has been no eel rearing until now, although some locations around the Batang Toru River are suitable for freshwater fish aquaculture activities