This study aims to describe the appendicular skeleton morphology (ossa appendicularis) of Thai mahseer’s (Tor tambroides Bleeker, 1854). The samples were obtained from fish traders in the Tangse River area of Pidie district, fish weight about 5 kg and length of 65 cm. The axial skeleton preparations conducted at the Laboratory of Mathematics and Natural Sciences, Almuslim University, Bireuen district. The skeleton terminology identification was done at Integrated Biology Laboratory, Biology Department, Faculty of Science and Technology, Ar-Raniry Islamic State University. The preparation of Thai mahseer’s axial skeleton was done by physically and chemically processed. Axial skeleton was arranged into a single piece to analyze every part of it. Documentation every part of axial skeleton was using Canon EOS 700D camera and processed by Adobe Photoshop CS3. The structure of fish constituent was named based on some published papers. The results showed that appendicular skeleton of Thai mahseer belonging to a pair of pectoral fin (pinna pectoralis), a pair of abdominal fins (pinna pelvis), the dorsal fin (pinna dorsalis), anal fin (pinna analis) and the caudal fin (pinna caudalis). Thai mahseer has similar morphological characters of appendicular skeleton compared to its family (Cyprinidae) but has some difference when compared to other families (Osphronemidae, Zaproridae, dan Tetraodontidae).AbstrakPenelitian ini bertujuan untuk mendeskripsikan morfologi tulang anggota gerak (ossa appendicularis) ikan keureling (Tor tambroides Bleeker, 1854). Contoh ikan diperoleh dari pedagang ikan di wilayah sungai Tangse Kabupaten Pidie dengan bobot 5 kg dan panjang 65 cm. Tahapan pembuatan preparat tulang dilakukan di Laboratorium Matematika dan Ilmu Pengetahuan Alam, Universitas Almuslim Kabupaten Bireuen, sedangkan identifikasi terminologi tulang anggota gerak ikan dilakukan di Laboratorium Terpadu Biologi, Program studi Biologi, Fakultas Sains dan Teknologi, Univer-sitas Islam Negeri Ar-Raniry. Pembuatan tulang anggota gerak dilakukan secara fisik dan kimiawi. Pemotretan setiap bagian tulang dilakukan dengan menggunakan kamera Canon EOS 700D dan diolah dengan menggunakan Adobe Photoshop CS3. Penamaan setiap bagian tulang anggota gerak dilakukan dengan cara membandingkan kemiripan bentuk dan letak setiap bagian tulang anggota gerak ikan yang telah diteliti sebelumnya, baik dari famili yang sama maupun dari famili yang berbeda. Hasil penelitian menunjukkan bahwa tulang anggota gerak (ossa appendicularis) ikan keureling terdiri atas sepasang sirip dada (pinna pectoralis), sepasang sirip perut (pinna pelvis), sirip punggung (pinna dorsalis), sirip anal (pinna analis), dan sirip ekor (pinna caudalis). Karakteristik sirip ikan keureling relatif sama pada famili sejenis (Cyprinidae), namun terdapat perbedaan apabila dibandingkan dengan ikan dari famili lainnya (Osphronemidae, Zaproridae, dan Tetraodontidae).

<em>The habitat ontogeny of arfak rainbowfish (Melanotaenia arfakensis) in Nimbai and Aimasi streams, Prafi river system were studied from June to December 2007.&nbsp; Sampling was carried out monthly in four different habitat types using hand net. Slow littoral and medium littoral are two habitat types which characterized by slowly water velocity, availability of submerged vegetation and warmer temperature, however the run and pool areas have higher water velocity and dissolve oxygen. The former habitats are essential for all developed stages, i.e. feeding, spawning and nursing of this species. On the other hand, the later habitat types particularly were only for young and adult fish, due to their swimming abilities as well as maximize of oxygen uptake. In order to maintain the population of this species, conservation is needed to all of their natural habitats for continuing their life cycles.</em>

Ikan oskar (Amphilophus citrinellus) merupakan ikan asing di Waduk Ir. H. Djuanda yang saat ini merupakan ikan yang paling banyak tertangkap di waduk tersebut. Penelitian ini dilakukan pada Oktober 2011–Januari 2012 di Waduk Ir. H. Djuanda, Jawa Barat, dengan tujuan untuk mengetahui beberapa aspek yang berkaitan dengan pemijahan ikan oskar. Contoh ikan ditangkap menggunakan jaring insang. TKG diamati secara visual dan fekunditas dihitung menggunakan metode gravimetrik. Total ikan contoh yang tertangkap selama penelitian berjumlah 460 ekor yang berasal dari enam stasiun pengamatan. Hasil penelitian menunjukkan panjang total dan bobot tubuh ikan berkisar antara 62–210 mm dan 4,81–187,18 gram. Rasio kelamin ikan seimbang. Ukuran ikan jantan dan betina terkecil yang ditemukan matang gonad adalah 125 mm dan 121 mm. Ikan yang matang gonad paling banyak ditemukan pada bulan Desember untuk ikan betina dan Januari untuk ikan jantan. Fekunditas total berkisar antara 729–3.299 butir. Ikan oskar merupakan ikan pemijah bertahap.

It is extensively recognized that seagrass meadows have been defined as nursery ground for fish. In this study, we investigated species composition and abundance of small fishes in seagrass beds of Karang Congkak Island, Kepulauan Seribu National Park from November 2018 to March 2019. In total, about 10,000 individuals of 46 fish species belonging to 26 families were captured using a seine net at four fix stations. The major families graded by species number were Labridae, Apogonidae, Gobiidae, Siganidae, and Atherinidae. More than 90% of fish was juvenile and mostly economically important species and reef-associated fish. Majority of fish juveniles inhabit seagrass beds were categorized as temporary resident and regular visitors. It was observed that the top five ranked fish species in abundance were Spratelloides gracilis (33.4%), Stenatherina panatela (19.5%), Siganus canaliculatus (13.2%), Gerres oyena (11.8%) and Siganus spinus (5.9%). There was a propensity that species richness and diversity were higher in areas with higher seagrass coverage. However, two-way ANOSIM revealed fish abundance was not significantly different spatially and temporally (p>0.05). Predominant trophic function of fish were zooplanktivores and crustacivores. The present study, therefore, identified seagrass beds of Karang Congkak Island as feeding habitats and shelter for fish juveniles.

<p align="center"><strong>ABSTRACT</strong></p><p align="center"> </p><p>This study aimed to analyze the effect of water temperature on the physiological condition and growth performance of freshwater eel elver<em> Anguilla bicolor bicolor </em>(McClelland, 1844). This study was conducted in March 2017 at the Physiology Laboratory of Aquatic Animal, Faculty of Fisheries and Marine Sciences, Bogor Agricultural University. The study used a completely randomized design with five different levels of temperature (22^°C, 24^°C, 26^°C, 28^°C, and 30^°C) as treatments with two replications. The size of elver was 2‒3 g. Fish were fed with 1 mm pellet containing 45% of protein. The feeding level was 7 % of fish biomass and the feeding frequency was two times a day. The results showed that temperatures range from 24‒30^°C could be used for freshwater eel elver rearing and 28‒30^°Cwere the best temperatures to support survival and growth performance of eel elver. A temperature of 24^°C was the best temperature that could reduce the metabolism rate and did not cause stress on the elver.</p><p> </p><p>Keywords: elver, physiological conditions, growth performance, metabolism, temperature</p><p> </p><p> </p><p align="center"><strong>ABSTRAK</strong></p><p align="center"><strong> </strong></p><p>Penelitian dengan tujuan menganalisis pengaruh suhu terhadap kondisi fisiologis dan kinerja pertumbuhan <em>elver</em> ikan sidat (<em>Anguilla bicolor bicolor</em> McClelland, 1844) telah dilakukan pada bulan Maret 2017 di Laboratorium Fisiologi Hewan Air FPIK IPB. Penelitian menggunakan rancangan acak lengkap dengan lima perlakuan suhu berbeda (22^°C, 24^°C, 26^°C, 28^°C, dan 30^°C) dengan masing-masing dua ulangan. Ukuran benih yang digunakan 2‒3 g. Pakan yang diberikan berupa pellet berukuran 1 mm dengan kadar protein 45%. Jumlah pakan yang diberikan (FR) adalah 7% dari biomassa ikan dan diberikan dua kali sehari. Hasil penelitian menunjukkan bahwa kisaran suhu 24‒30^°C dapat digunakan dalam pemeliharaan <em>elver</em> ikan sidat, dan suhu 28‒30^°C merupakan suhu yang sangat baik untuk mendukung kelangsungan hidup dan pertumbuhan <em>elver</em> ikan sidat. Suhu media 24^°C adalah suhu terbaik yang dapat menekan laju metabolisme dengan tidak menyebabkan stres pada <em>elver </em>ikan sidat.</p><p> </p><p>Kata kunci: <em>elver</em>, kondisi fisiologis, kinerja pertumbuhan, metabolisme, suhu</p><p> </p><p> </p>