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Diversitas Ikan pada Ekosistem Terumbu Karang di Perairan Pulau Menjangan, Taman Nasional Bali Barat Hernowo, Rusman; Djumanto, Djumanto; Probosunu, Namastra
Biota Biota Volume 18 Nomor 1 Tahun 2013
Publisher : PBI Yogyakarta

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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.Kata kunci: keragaman, ikan, terumbu karang, Pulau Menjangan, Bali
Komunitas Krustasea di Kawasan Mangrove Desa Jangkaran Kabupaten Kulon Progo Amalia, Sholihat; Djumanto, Djumanto; Probosunu, Namastra
Jurnal Perikanan Universitas Gadjah Mada Vol 19, No 2 (2017)
Publisher : Universitas Gadjah Mada

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Penelitian ini bertujuan untuk mengetahui keanekaragaman dan kemelimpahan krustasea di kawasan mangrove Desa Jangkaran Kecamatan Temon Kabupaten Kulon Progo. Sampling dilakukan setiap dua minggu sekali dari bulan Oktober 2016 sampai Februari 2017 pada enam stasiun yang ditetapkan berdasarkan karakter ekologis. Pengambilan sampel Krustasea dilakukan menggunakan jala tebar, pintur dan hand picking di sepanjang sungai dengan luasan tiap stasiun pengambilan sekitar 10 m2. Sampel krustasea yang tertangkap dibersihkan, disimpan dalam cool box yang diberi es dan dibawa kelaboratorium untuk diidentifikasi dan dikelompokkan sesuai dengan jenisnya, kemudian diukur panjang karapas dan berat individu. Pengamatan lingkungan perairan dilakukan dengan mengukur suhu, kecerahan,  kedalaman perairan, kecepatan arus, pH, salinitas, oksigen terlarut, dan jenis substrat. Hasil pengamatan didapatkan 1 ordo, 7 famili, dan 26 spesies. Famili krustasea yang ditemukan yaitu Coenobitidae, Diogenidae, Grapsidae, Ocypodidae, Palaemonoidae, Penaeidae, dan Portunidae. Jenis Krustasea paling banyak ditemukan adalah udang putih (Penaeus merguiensis) sebanyak 25,06 %, kelomang (Clibanarius sp.) sebanyak 10,85%, dan Uca annulipes sebanyak 10,59%. Jenis krustasea yang paling sedikit ditemukan adalah Varuna Yui sebanyak 0,13% dan Ocypode sp. sebanyak 0,26%. Nilai kemelimpahan 25,4 ind/m2, indeks keanekaragaman 2,60, indeks kemerataan 0,87 dan indeks dominansi 0,18.
kOMPOSISI IKAN HASIL TANGKAPAN JARING INSANG PADA BERBAGAI SHORTENING DI WADUK SERMO Djasmani, Supardjo S.; Djumanto, Djumanto
Jurnal Perikanan Universitas Gadjah Mada Vol 16, No 1 (2014)
Publisher : Universitas Gadjah Mada

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The aim of this study was to determine fi sh capture and composition using gill nets in various of shortening nets, as well as to obtained a suitable size of shortening nets which better productive and sustainable. The study was conducted by fi shing using gill nets 4 sheets, using gill net with mesh size of 2-inch eye openings and various shortening nets, namely 40%, 50%, 60%, and 70%. The setting gill nets were done in the afternoon and hauling the following morning day. Gill net setting were done once a week in September-October 2013. All species of fi sh gilled were collected, then measured the length and weight, as well as on the abdomen was dissected to determine sex. Data on the number and weight of the catch were analyzed descriptively, analyzed using a completely randomized design were subjected to determine the best catches statistically. The results showed that the number of individuals fi sh and the mean weight of fi sh captured in shortening 40%, 50%, 60% and 70% were not signifi cantly different. The most number of fi sh captured was in the nets with shortening of 60%, ie 392.69 (g/ trip), then on shortening of 40%, ie 333.3 g / trip, next on the shortening of 50% as much as 285.9 g/trip and the least in shortening 70% as much as 263.6 g trip. Based on the fi sh species composition, the most dominant of fi sh captured was red devil (52.5%), then tilapia mossambique (27.1%), black tilapia (17.5%), managuin (1.3%), marbel gobby (0.8%), the remaining was consisted of snake head and javain carp (0.8%). Based on sex proportion, the proportion of male fi sh in tilapia mossambique was 63.8%, black tilapia was 53.7%, and red devil was 58.2%, while the remaining was balance between male and female.
INDEK BIOTIK FAMILI SEBAGAI INDIKATOR KUALITAS AIR SUNGAI GAJAHWONG YOGYAKARTA Djumanto, Djumanto; Probosunu, Namastra; Ifriansyah, Rudy
Jurnal Perikanan Universitas Gadjah Mada Vol 15, No 1 (2013)
Publisher : Universitas Gadjah Mada

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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.
REPRODUCTIVE BIOLOGY OF THE YELLOW RASBORA (Rasbora lateristriata) INHABITAT OF THE NGRANCAH RIVER, KULON PROGO REGENCY Djumanto, Djumanto; Setyobudi, Eko; Sentosa, A. A.; Nirwati, N.
Jurnal Perikanan Universitas Gadjah Mada Vol 10, No 2 (2008)
Publisher : Universitas Gadjah Mada

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The purpose of this research was to identify the reproductive biology in the yellow rasbora (Rasbora lateristriata) in habitat of the Ngrancah River. To identify spawning events and embryo development, direct observation was employed during the spawning season in their natural environment, and then fertilized egg was incubated insitu. Spawning seasons underwent correspond to the end of rainy season and early dry season which characterized by clean freshly water and low temperature. The result showed that during spawning season, the broodfish migrated from Sermo Reservoir upward to the main river to find out the spawning site. In the early morning between 03.00 and 05.00 AM, the broodstock moved to the spawning site, then making aggregation and both female and male released their gametes in the shallower place. The aggregations were consisting around of 1 female and 3 males. The fertilized eggs would cleavage, and then embryo developed and yolk sac larval hatched within 23 hours at 27oC. The knowledge about spawning events of yellow rasbora may be used for improved management tools in the future.
PEMANFAATAN DAN LAJU TANGKAP UDANG LOBSTER DI PANTAI SELATAN DAERAH ISTIMEWA YOGYAKARTA Djasmani, Supardjo S; Djumanto, Djumanto; Sukardi, Sukardi
Jurnal Perikanan Universitas Gadjah Mada Vol 14, No 1 (2012)
Publisher : Universitas Gadjah Mada

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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).
PEMBENIHAN NILA MERAH (Oreochromis sp.) MENGGUNAKAN JARING APUNG DI WADUK KEDUNGOMBO Rustadi, Rustadi; Djumanto, Djumanto; Triyatmo, Bambang; Hardaningsih, Ign.; Saksono, Hery
Jurnal Perikanan Universitas Gadjah Mada Vol 1, No 1 (1996)
Publisher : Universitas Gadjah Mada

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The objectives of the research were to know the production of hatchery, survival rate and growth rate of fry. Floating nets  were made for plastics hapa (2 mm mesh size) with 3 different size (5 m2, 10 m2, and 15 m2). The larvae were stocked in different hapa nursery size ( 1 m3, 2 m3, 3 m3) at the rate of 1000 larvae/m3 of water. The fry produced from the first nursery were subsequently reared in waring (mesh size 0,04 cm) at density of 600 fry/m3 of water. The spawning were conducted for 6 months, while larvae rearing were 2 months for each period respectively. The result showed that the hatchery of 15 m2 scale were technically and biologically feasible. During 6 months period it produced 11,870 fingerling of 40 gram, 3,028 fry of 4 gram and 4,290 of larvae. The survival rate and growth rate of fry water not significantly affected by different hapa size either in the first and second nursery. The survival rate of the first nursery was 64.70-72.63% of 5.0-6.8 cm fry, while the second nursery was 97.29-98.30% of 11.5-12.4 cm fry. 
SEBARAN LOKASI PENELURAN PENYU HIJAU (Chelonia mydas) DI PULAU SANGALAKI KEPULAUAN DERAWAN KABUPATEN BERAU Ibrahim, Andi; Djumanto, Djumanto; Probosunu, Namastra
Jurnal Perikanan Universitas Gadjah Mada Vol 18, No 2 (2016)
Publisher : Universitas Gadjah Mada

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Populasi penyu hijau (Chelonia mydas) yang bertelur di kawasan konservasi kepulauan Derawan semakin menurun disebabkan oleh berbagai faktor. Penelitian ini bertujuan untuk mengetahui jumlah peneluran tiap induk penyu hijau dan korelasinya terhadap naungan, lebar pantai berpasir dan fase bulan. Penelitian ini dilakukan pada tanggal 24 Januari–31 Maret 2015 berlokasi di Pulau Sangalaki. Pengamatan induk bertelur dilakukan dengan menyusur pantai tiap malam untuk menemukan induk yang sedang bertelur. Pada induk yang sudah bertelur, maka sarangnya diberi tanda di lokasi tempat bertelur. Pada hari berikutnya dilakukan penggalian sarang, pengambilan telur, dan pengukuran kondisi lingkungan tempat peneluran. Data yang dikumpulkan adalah jumlah telur tiap sarang dan kondisi lingkungan tempat peneluran. Kondisi lingkungan yang diukur meliputi kedalaman sarang, suhu substrat, jarak sarang terhadap naungan dan garis pantai saat surut terendah. Analisis data dilakukan secara deskriptif terhadap jumlah telur dan parameter lingkungan. Hasil penelitian menunjukkan rerata jumlah telur tiap sarang sebanyak 97 butir dengan kisaran 45–127 butir, ukuran panjang karapas 96 cm dengan kisaran 86-107 cm, rerata kedalaman sarang 73 cm dengan kisaran 56-87 cm. Penyu yang bertelur semakin banyak akan menggali sarang semakin dalam, namun tidak ada korelasi antara panjang karapas dengan jumlah telur. Jumlah rerata induk penyu hijau yang bertelur di Pulau Sangalaki adalah 486 ekor/bulan dengan kisaran 168–1085 ekor/bulan. Musim barat dan timur mempengaruhi frekuensi peneluran. Frekuensi peneluran terjadi sepanjang tahun dan frekuensi peneluran paling tinggi terjadi pada bulan Agustus yang bertepatan dengan puncak musim Timur. Frekuensi peneluran pada musim Timur empat kali lebih banyak daripada saat musim Barat. Frekuensi pendaratan penyu hijau tidak dipengaruhi oleh fase bulan. Berdasarkan lokasi penyu hijau bertelur, pantai yang banyak dipilih untuk lokasi bertelur terdapat di sebelah barat laut, timur laut dan selatan Pulau Sangalaki. Sarang penyu hijau lebih banyak ditemukan pada daerah naungan vegetasi (64%) daripada daerah pasir terbuka (36%).
Polikromatik, dimorfisme seksual, dan redeskripsi spesies ikan red devil, Amphilophus amarillo [Stauffer & McKaye, 2002] di Waduk Sermo Yogyakarta Habibie, Sitty Ainsyah; Djumanto, Djumanto; Murwantoko, Murwantoko
Jurnal Iktiologi Indonesia Vol 18, No 1 (2018): Februari 2018
Publisher : Masyarakat Iktiologi Indonesia (MII )

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Red devil has been extensively researched due to extremely high morphometric and chromatophore variations, including the phenomena of polychromatic and trophic polymorphism. The purpose of this study was to identify and observe the phenomenon of sex dimorphism that occurs in polychromatic red devil species which caught in Sermo Reservoir. Fish sample as much as 240 individual was collected from fishermen catch during November 2016-September 2017 by using gill nets, cest nets, and fishing rods. Subsequently, the fish sample was grouped based on color and sex, the namely group of red devil red, red devil black, and red devil reddish black. The morphometric character data of 21 units were measured in each fish sample, whereas the DNA samples were taken from the gill tissue on each species of two individuals. The morphometric character data was analyzed for discriminant distance, while DNA was analyzed by BLAST (Basic Local Allignment Search Tools) from NCBI. The result of the principal component analysis and discriminant function showed the three group of fish can be distinguished by the characters around the head. The T-test of male and female morphometric characters in each fish group showed the phenomenon of sex dimorphism. Canonical and dendrogram diagrams consistently classify the three group of fish as the same species but are segregated by sex so that significantly dimorphism occurs. The mitochondrial sequencing results of the DNA control region show that among the red devil fish group found in the Sermo Reservoir is a species of A. amarillo.AbstrakRed devil telah banyak diteliti karena variasi morfometrik dan kromatofora yang sangat tinggi, termasuk di dalamnya fenomena polikromatisme dan trofik polimorfisme. Penelitian ini bertujuan untuk mengamati polikromatik dan dimor-fisme seksual serta mengidentifikasi spesies red devil di perairan Waduk Sermo Yogyakarta. Contoh ikan sebanyak 240 ekor diambil dari hasil tangkapan nelayan selama bulan November 2016-September 2017 dengan menggunakan jaring insang, jala dan pancing. Selanjutnya contoh ikan dikelompokkan berdasarkan warna dan jenis kelamin, yaitu kelompok red devil merah, red devil hitam, dan red devil merah kehitaman. Data karakter morfometrik sebanyak 21 unit diukur pada setiap contoh ikan, sedangkan contoh DNA diambil dari jaringan insang pada masing-masing kelompok ikan seba-nyak dua ekor. Data karakter morfometrik dianalisis pembedanya, sedangkan DNA dianalisis dengan BLAST (Basic Local Allignment Search Tools) dari NCBI. Hasil analisis komponen utama dan fungsi diskriminan menunjukkan ketiga kelompok ikan dapat dibedakan berdasarkan karakter yang berada di sekitar kepala. Uji t terhadap karakter morfome-trik jantan dan betina pada masing-masing kelompok ikan menunjukkan fenomena dimorfisme seksual. Diagram kanonikal dan dendrogram konsisten mengelompokkan ketiga kelompok ikan tersebut sebagai spesies yang sama, namun terpisah berdasarkan jenis kelamin sehingga sangat nyata terjadi dimorfisme. Hasil sekuensing mitokondria DNA control region menunjukkan seluruh kelompok ikan red devil yang ditemukan di Waduk Sermo merupakan spesies Amphilophus amarillo.
Reproductive biology of largehead hairtails, Trichiurus lepturus Linnaeus, 1758 in the coastal area of Bantul Regency Novianingrum, Praditha; Djumanto, Djumanto; Murwantoko, Murwantoko; Setyobudi, Eko
Jurnal Iktiologi Indonesia Vol 17, No 2 (2017): June 2017
Publisher : Masyarakat Iktiologi Indonesia (MII )

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Largehead hairtail (Trichiurus lepturus) is one commodity fish catches with high production and value in Yogyakarta. The purpose of this research is to analyse reproductive aspects of this fish in coastal area of Bantul Regency. Yogyakar-ta. Those aspects are gonadal maturity level, fecundity, and the length at the first gonadal maturity. Fish samples are taken from the catch of fisherman using gillnet with a mesh sizes of 1.75 and 2 inches in the coastal fishing port of Depok and Samas. The fish collected from January to April 2016 with at least 30 individuals every two weeks. The samples are identified to find their sex and measured to know the length, weight, and gonadal maturity level (TKG). The data analyzed include length distribution, weight, sex ratio, gonadosmoatic index, length at the first gonadal maturity (Lm), fecundity and oocyte diameter. The result shows the fish length varies between 52.8 and 86.2 cm, and weight 115 and 567.2 g. The sex ratio between male and female was 1:0.6. Gonad maturity stage II and III are found every month observation while gonad maturity stage IV found in April. Oocyte diameter in the stage of gonadal ma-turity IV was 0.35-1.02 mm, there were two distribution modus so that the spawning expected partial spawner with fec-undity of 24.601 eggs with range was 12.873-33.534 eggs. Fecundity increased as parent’s body length with equation F= 0,434L2.60. Hairtail expected reaching the length of the first gonadal maturity in 65.55 cm, higher than the average captured, namely 63.4 cm. AbstrakIkan layur (Trichiurus lepturus) merupakan salah satu komoditas hasil tangkapan ikan di Daerah Istimewa Yogyakarta dengan jumlah produksi dan nilai yang tinggi. Penelitian ini bertujuan untuk mengkaji aspek reproduksi yang meliputi: tingkat kematangan gonad, fekunditas, dan ukuran ikan kali pertama matang gonad layur di perairan pantai Kabupaten Bantul, Daerah Istimewa Yogyakarta. Sampel ikan dikumpulkan dari hasil tangkapan nelayan yang menggunakan jaring insang dengan ukuran mata jaring 1,75 dan 2 inci di Tempat Pelelangan Ikan Depok dan Samas. Pengumpulan sampel ikan dilakukan pada bulan Januari hingga April 2016 setiap dua minggu sekali minimal 30 ekor. Sampel ikan diidentifikasi jenis kelamin, diukur panjang, bobot tubuh, bobot gonad, dan tingkat kematangan gonad (TKG). Data yang dianalisis meliputi sebaran panjang, bobot, nisbah kelamin, indeks kematangan gonad, ukuran ikan kali pertama matang gonad (Lm), fekunditas, dan diameter telur. Hasil pengamatan menunjukkan kisaran panjang ikan 52,8-86,2 cm dan bobot 115-567,2 g, nisbah betina dan jantan sebesar 1 : 0,6. TKG II dan III ditemukan pada setiap bulan pengamat-an sedangkan TKG IV banyak ditemukan pada bulan April. Diameter telur ikan TKG IV berkisar 0,35-1,02 mm, terda-pat dua modus persebaran sehingga pemijahan diduga bertahap dan fekunditas sebanyak 24.601 butir dengan kisaran 12.873-33.534 butir. Fekunditas meningkat seiring panjang tubuh induk dengan persamaan F = 0,434L2,60. Ukuran ikan layur kali pertama matang gonad diperkirakan pada panjang 65,55 cm, lebih panjang daripada ukuran rata-rata tertangkap, yaitu pada 63,4 cm.