SEBARAN SPASIAL PLANKTON DI PERAIRAN BAWEAN

The presence of phytoplankton in the water is very important because it serves as a primary producer that is often used as an indicator of aquatic fertility. The objective of the research was to determine the species, density and spatial distribution of plankton in the Bawean waters, Gresik regency. Baruna Jaya VIII research vessel was used for sampling on 29-30 April 2009. Sampling locations were set up in two stations on the position of 06°05'S, 112°36'E and 06°05'S, 120°12'E, and water samples were taken at depths of 0m, 20m, 40m and 60m in each station. Water was collected using water samplers at amounts of 10 liters each depth, thenwas filtered using plankton net, and then preserved with formalin 4%. Identification of genus plankton was carried out in the laboratory.The results showed that there were 20 genus of phytoplankton and 38 genus of zooplankton which were spread outin each depth of the water column unevenly. Plankton density was as much as 2330 cells / liter, while the density of zooplankton was as much as 507 individuals / liter. The highest density of phytoplankton was found in the water column depth of 20 m, while the lowest was found at the depth of 60m. The highest density of zooplankton was found in the surface, then decreases as the depth of waters. The dominant genusof phytoplankton were Pleurosigma sp., then Rizosolenia sp., Skeletonema sp., and the least was Actinocyclus sp. The dominant species of zooplankton are Ceratium sp. then Tintinopaial sp., and nauplius sp

FOOD HABITS OF THE YELLOW RASBORA, Rasbora lateristriata, (FAMILY: CYPRINIDAE) BROODFISH DURING MOVING TO SPAWNING GROUND

The purpose of this research was to clarify the food habits of yellow rasbora (Rasbora Iateristiata) when moving into spawning site during spawning season. Specimens of yellow rasbora were collected between July and August, 2007 from spawning site surveys during spawning season in their natural environment which run yearly from April to August. There were 628 individual fish collected from spawning ground, and 30 of them were selected to analyze the gut content. Samples were preserved in alcohol solvent until identified their gut content in laboratory. The results showed that yellow rasbora broodfish fed plankton continuously both in the day and night while moving into the spawning site. Percent Index of Relative Importance values indicated the most important prey items of yellow rasbora were phytoplankton (68.43%), and then zooplankton (29.79%), leaf cut (0.02%), little caterpillar (0.01%), insect larva (0.15%), and unidentified items (1.60%), respectively. Chrysophyta and protozoa was found the most dominant of phytoplankton and zooplankton in the gut content, respectively. Based to the ratio between gut length and total length, and the feeding mode, R. lareritriata is categorized to an omnivorous feeder

Komunitas Krustasea di Kawasan Mangrove Desa Jangkaran Kabupaten Kulon Progo

The objective of this study was to determine the diversity and abundance of krustaseans in the mangrove area of Jangkaran Village, Temon District, Kulon Progo Regency. Sampling was done bi-weekly from October 2016 to February 2017 on six stations defined by ecological character. Krustasean sampling was done using cest net, trap net and hand picking along the river with the extent of each collection station about 10 m2. The captured krustasean samples were cleaned, stored in ice-cooled boxes and transported to the laboratories to be identified and grouped according to species, then measured by carapace length and individual weight. Observation of aquatic environment was done by measuring temperature, brightness, water depth, current velocity, pH, salinity, dissolved oxygen, and substrate type. The results of the observation obtained 1 order, 7 families, and 26 species. The family krustaseans found were Coenobitidae, Diogenidae, Grapsidae, Ocypodidae, Palaemonoidae, Penaeidae, and Portunidae. The most dominant species of krustaseans were white shrimp (Penaeus merguiensis) as much as 25.06%, hermit crab (Clibanarius sp.) as much as 10.85%, and Uca annulipes as much as 10.59%. The fewest species of krustaseans found were Varuna yui of 0.13% and Ocypode sp. as much as 0.26%. The abundance value was 25.4 ind / m2, indices of diversity 2.60, richess index 0.87 and index of dominance 0.18

PEMANFAATAN DAN LAJU TANGKAP UDANG LOBSTER DI PANTAI SELATAN DAERAH ISTIMEWA YOGYAKARTA

Penelitian ini bertujuan untuk mengetahui potensi sumberdaya lobster, laju tangkap dan peluang pengembangannya. Metode penelitian yang digunakan dalam pengumpulan data adalah metode survei. Data dianalisis dengan metode surplus produksi metode Schaefer. Hasil penelitian menunjukkan lobster yang ada di pantai selatan DIY sebagian besar dari jenis udang pasir (Panulirus homarus), udang batu (Panulirus penisilatus), udang mutiara (Panulirus ornatus), udang bambu (Panulirus polyphagus) dan udang batik (Panulirus longipes). Produksi udang lobster berfl uktuatif baik secara musim dan tahunan dengan musim panen mulai bulan Oktober sampai dengan bulan Februari dan produksi tertinggi pada tahun 2007. Analisis mengenai jumlah perahu optimum foptimum adalah 723 unit perahu/th dengan potensi lestari maksimum (CMSY) sebesar 12.322,66 kg/th dan tangkapan total yang diperbolehkan (TAC) adalah 9.858,13 kg/th sedangkan aktual tingkat pemanfaatan sebesar 10.721,42 kg/th dengan laju tangkap adalah 17,05 kg/perahu/tahun. Upaya jumlah trip optimum diperoleh f(optimum) 13.324,39 trip/th dengan potensi maksimum lestari (CMSY) sebesar 13.914,6 kg/trip dan hasil tangkapan total yang diperbolehkan (TAC) adalah 11.136,7 kg/th, sedangkan aktual tingkat pemanfaatan mencapai 11.859,2 kg/th dengan laju tangkap pemanfaatan lobster sebesar 1,04 kg/trip. Hasil penelitian menunjukkan bahwa tingkat pemanfaatan sumberdaya lobster sudah lebih besar dari pada tangkapan total yang diperbolehkan (TAC) dan mendekati potensi lestari maksimum (MSY)

FOOD HABITS OF THE YELLOW RASBORA, Rasbora lateristriata, (FAMILY: CYPRINIDAE) BROODFISH DURING MOVING TO SPAWNING GROUND

The purpose of this research was to clarify the food habits of yellow rasbora (Rasbora lateristiata) when moving into spawning site during spawning season. Specimens of yellow rasbora were collected between July and August, 2007 from spawning site surveys during spawning season in their natural environment which run yearly from April to August. There were 628 individual fish collected from spawning ground, and 30 of them were selectedto analyze the gut content. Samples were preserved in alcohol solvent until identified their gut content in laboratory. The results showed that yellow rasbora broodfish fed plankton continuously both in the day and night while moving into the spawning site. Percent Index of Relative Importance values indicated the most important prey items of yellow rasbora were phytoplankton (68.43%), and then zooplankton (29.79%), leaf cut (0.02%), little caterpillar (0.01%), insect larva (0.15%), and unidentified items (1.60%), respectively. Chrysophyta and protozoa was found the most dominant of phytoplankton and zooplankton in the gut content, respectively. Based to the ratio between gut length and total length, and the feeding mode, R. lareritriata is categorized to an omnivorous feeder

INDEK BIOTIK FAMILI SEBAGAI INDIKATOR KUALITAS AIR SUNGAI GAJAHWONG YOGYAKARTA

The purpose of this research was to determine water quality level of Gajahwong River, Yogyakarta with the present of macroinvertebrate as biologycal indicators. The sampling was conducted in the Gajahwong River fl ow from Pakem subdistrict in Sleman regency to Pleret subdistrict in Bantul regency. There were six sampling stations, and sampling was conducted once a week for two months from mid October to December 2011. Samples of macroinvertebrate were collected by poking substrate in front of surber net mouth so that macroinverterbrate were drifted into surber and trapped in pocket net. Samples were preserved in 5% formaldehide solution then identifi catifi ed and anlyzed in the laboratory.The species number of macroinvertebrate were analyzed as biotic index, such as diversity index, evenness index, dominance index and biotic family index (BFI). Environment parameter measured include physical and chemical properties. The physical parameter collectednamely subtrate type, river depth and stream width, fl ow velocity, temperature and total suspended solid (TSS). The chemical parameter collected namely dissolved oxygen, free CO2, alcalinity,organic matter and pH. The results showed that fl ow rate was varied 0.51-0.80 m/det decrease to downstream direction.The water depth was ranging from 19.9 to 49.8 cm tend to increase downstream direction. Total suspended solid (TSS) was ranging from 8.5 to 14.2 mg/l and tend to be higher in the central city of Yogyakarta. Dissolved oxygen concentration was 6.0-7.2 mg/l while CO2 was 0.7-1.9 mg/l. Organic matter was 22.8-25.1 mg/l and pH was in the range of neutral. The density of macroinvertebrate was 88 individual/m2, the taxa number in each station was 7-12 species, diversity index was 1.48-2.09, evenness index 0.76-0.85 and dominance index was 0.10-0.27, and there was not found dominance organism among the stations samplings. The highest density was Limnaea tranculata and Potamopyrgus jenkinsi. Index biotic family ranging from 5.95 to 6.64 showing the water environment was poor and there has been pollution caused by garbage disposal of communities surround the river also waste disposal from resident along the watershed

UPAYA PEMBUAHAN TELUR LELE LOKAL (Clarias batrachus)PADA BERBAGAI PASCA OVULASI VIABILITY OF ASIAN CATFISH (Clarias batrachus) EGGS FERTILIZED AT VARIOUS OVULATION INTERVAL

ABSTRACT: The purpose of this research was to determine the viability of Asian catfish (Clarias batrachus) eggs which were fertilized at various post ovulation periods. Initially, the gravid female broodstocks were stimulated by injection of LHRHa hormone. The broodstocks then were stripped by gently pushing from abdomen to the genital pore to expel some eggs (around 1-2 ml). Eggs subsequently were fertilized with sperms, which were prepared before. Then, the fertilized eggs were distributed into a small scoop net which were immersed in the hatching tank. Those procedures were done every 2 hours and completed in 12 hours after ovulation. The experiment was done by completely randomized design with three replicates Result of the research showed that fertilization of Asian catfish eggs could be done until 12 hour after ovulation.The highest percentage of embryo development was found at 8 hours delaying of fertilization and hatching rate as well as. Dissolved oxygen concentration was decreased drastically at the time of eggs hatching which lead to kill almost all larvae. Further experiments are needed to find out an oxygen consumption of eggs and longer delaying of fertilization. Key words : Clarias batrachus, ovulation, and LHRH

Diversitas Ikan Pada Ekosistem Terumbu Karang Di Perairan Pulau Menjangan, Taman Nasional Bali Barat

Tujuan penelitian adalah mengkaji keragaman ikan-ikan karang dan mengetahui penutupan terumbu karang di perairan Pulau Menjangan, Taman Nasional Bali Barat. Penelitian dilaksanakan dari akhir bulan April sampai awal bulan Mei 2012 di perairan Pulau Menjangan. Jumlah stasiun pengamatan ditetapkan sebanyak 8 lokasi berdasarkan perbedaan habitat. Pengukuran kondisi lingkungan dan pengambilan sampel dilakukan dengan penyelaman pada kedalaman 3 dan 10 m. Jumlah dan jenis ikan yang berada pada jangkauan 2,5 m dari transek sepanjang 50 m disensus dengan metode Underwater Visual Census. Jenis ikan karang diidentifikasi secara langsung insitu. Jenis dan luas penutupan karang dicatat dengan metode Line Intercept Transect. Pencatatan jenis terumbu karang yang dilewati transek didasarkan pada bentuk pertumbuhan (lifeform), sedangkan luas penutupan terumbu karang menggunakan Lifeform Report. Data yang diperoleh dianalisis secarakuantitatif berdasarkan indeks biologis. Hasil dari penelitian diperoleh nilai indeks keanekaragaman ikan (H’) berkisar antara 0,8499–2,1360, keseragaman (E) antara 0,36–0,73 dan indeks dominansi (C) berkisar antara 0,163–0,647. Cacah individu ikan sebanyak 5753 ekor dari 62 genus yang berasal dari 32 suku, sedangkan kemelimpahan ikan (D) berkisar antara 0,756–2,680 ekor/m2. Jumlah individu dan suku ikan mayor dominan pada semua lokasi. Tutupan terumbu karang berada pada kisaran 0,66–67,34% yang dikategorikan pada kondisi sedang hingga baik