REKAYASA PAKET TEKNOLOGI PRODUKSI PAKAN ALAMI COPEPODA PADA SISTIM KULTIVASI PEMBENIHAN IKAN KERAPU ( Epinephelus sp. ) SKALA " BACKYARD "

Abstract

The aim of the research is to obtain the copepod stock from the natural resources as the natural feed for grouper ( Epinephelus sp. ) in the backyard hatchery scale. The research was conducted from April to December 2005 at the Jepara Waters and Laboratory of Biological Oceanography, UNDIP. There were six stations were established as the research site area. The monthly samplings were done during the research. Copepod were collected vertically using the 100 1.1.M planktonnet, by filter a total of I m3 sea water vertically into 1 liter water sample. The samples were conserved by the addition of formalin 4 %. The identification and numerical account were done in the laboratory. The diversity, eveness and dominance were done to describe the copepods population structure. The water quality such as temperature, salinity, pH, current and transparancy, were observed in the same time. The horizontal collections were also conducted between the stations to obtain the dominant copepod source as the seed for hatchery cultivations. The dominant copepods Acartia sp and Calanus sp., were cultivated in the 2000 ml and 20 1 media, fed on Tetraselmis chuii andChlorella sp. The grazing rate and growth of copepods were observed for 6 month continuously. There were 18 genus of copepods determine at the Jepara, consist of 3 ordo Calanoid ( 13 genus ), Cyclopoid ( 2 genus ) and Harpacticoid ( 3 genus ). Copepods density at Jepara water show a range of 5 — 546 ind / 1, with average 316 ± 85, diversity 2,3259 — 2,3594, eveness 0,8047 — 0,8163 and dominancy 0,1837 — 0,1953. Two genus Acartia sp and Calanus sp. were dominantly identified. Copepods grazing rate to fed on Tetraselmis chuii show a range of 7.87 — 28.53 cell / ml ; with average 14.318 ± 7.9685 ( media 20 1 ) and 25.04 — 91.21 cell / ml ; with average 45.53 t 25.6972 ( 2 1 ). Copepods grazing rate to fed on Chlorella sp. show a range of 18.61 — 140.69 cell / ml with average 61 t 60.2952 ( media 20 1 ) and 40.94 — 229.61 cell / ml with average 96.0933 ± 78.1445 ( media 21 ). Copepod grown fed on Tetraselmis chuii show a range of 258 — 303 ind. ! 2 1 with average 267 ± 25 ( media 2 1 ) and 2534 — 3808 ind. / 20 1 with average 3061 t 550 ( media 20 1). Copepod grown fed on Chorella sp. show a range of 297 — 377 ind. / 2 1 with average 341 ± 31 ( 2 1) and 3241 — 4824 ind. / 20 I with average 3866 t 694 ( 20 1 ). Penelitian ini bertujuan untuk mendapatkan stock pakan alami Copepoda dominan dad alam serta jenis-jenisnya yang dapat dijadikan unggulan sebagai pakan alami bagi ikan Kerapu. Penelitian ini dilaksanakan dari April hingga Desember 2005 di perairan Jepara dan Laboratorium Biologi Oseanografi UNDIP. Sejumlah 6 stasiun ditetapkan di perairan Jepara untuk sampling dad alam yang dilakukan sebulan sekali. Sampling copepoda dilakukan dengan planktonnet 100 Ism, dengan menyaring air sejumlah 1 m3 secara vertikal dari dasar perairan utnuk identifikasi srtuktur populasi. Sampel diperoleh diawetkan dengan formalin 4 Vu. Identifikasi jenis dan kelimpahan dilakukan di laboratorium. Keanekaragam, keseragaman dan dominansi juga dianalisis untuk mengetahui struktur populasi copepoda. Pengukuran parameter kualitas air yang meliputi suhu, salinitas pH, anus dan kecerahan dilakukan secara bersamaan dengan sampling. Sampling copepoda secara horizontal antar stasiun berjarak 300 meter dilakukan dengan planktonnet 100 ism, untuk mendapatkan benih copepoda yang akan dikultur di laboratorium. Copepoda basil sampling yang dominan, jenis Acartia sp dan Calanus sp. dengan pemberian pakan alami Tetraselmis chuii dan Chlorella sp pada media beker 2000 ml dan 20 I. Tingkat Konsumsi dan Pertumbuhan ( Kelimpahan ) Copepoda diamati secara berkelanjutan selama 6 perioda. Hasil pengamatan menunjukkan 18 genus copepoda Jenis copepoda yang dijumpai di perairan Jepara terdiri dad 3 ordo dan 18 genus copepoda, yang masing — masing adalah Ordo Calanoida terdiri dari 13 genus, Ordo Cyclopoida terdiri dad 2 genus dan Ordo Harpacticoida terdiri dad 3 genus. Kelimpahan copepoda di perairan Jepara menunjukkan kisaran 5 — 546 ind / 1, dengan rata — rata 316 f 85, keanekaragaman 2,3259 — 2,3594, keseragaman 0,8047 — 0,8163 dan dominansi 0,1837 — 0,1953, dengan dominansi pada jenis Acartia sp dan Calanus sp. Tingkat konsumsi copepoda terhadap Tetraselmis chuii berkisar 7.87 — 28.53 sel / ml ; rata — rata 14.318 t 7.9685 ( media 20 1) dan 25.04 — 91.21 sel / ml ; rata — rata 45.53 ± 25.6972 ( 2 1 ). Tingkat konsumsi copepoda terhadap Chlorella sp. berkisar 18.61 — 140.69 sel / ml dengan rata — rata 61 ± 60.2952 ( media 20 1 ) dan 40.94 — 229.61 sel / ml dengan rata — rata 96.0933 t 78.1445 ( media 2 1). Pertumbuhan ( kelimpahan ) copepoda dengan pemberian Tetraselmis chuii sebesar 258 — 303 ind. / 2 1 dengan rata — rata 267 t 25 untuk media 21 dan 2534 — 3808 ind. / 20 1 dengan rata — rata 3061 ± 550 untuk media 20 1.. Pertumbuhan ( kelimpahan ) copepoda ( ind. / 2 1 ) dengan pemberian Chorella sp. berkisar 297 — 377 ind. / 21 dengan rata — rata 341 t 31 untuk media 21 dan 3241 — 4824 ind. / 201 dengan rata — rata 3866 ± 694 untuk media 20 1.