IMPROVEMENT IN NUMBER AND QUALITY PRODUCTION OF SEED GROUPER FISH BY NATURAL FEED ENRICHMENT

ABSTRACT Some researches on grouper seed production have been conducted and their results have been adopted by the farmer. Currently, grouper seeds for mariculture purposes can be provided from hatchery. However, seed abnormality is still the major problem in the hatchery.  Therefore, an improvement for survival rate and quality of grouper seed production is very important. The aim of this study was to improve the production and reduce the abnormalities on grouper seed stock through enrichment of larvae feed (rotifer and artemia) with DHA and EPA, Vitamin and Calcium. The larvae of humpback grouper (Cromileptes altivelis) were reared with and without enrichment. The experiment were held in concrete tank with volume of 10 m3 filled with sea water 7-8 m3. Grouper eggs were stocked at a density of 10 eggs/l, larval were reared until the juvenile age of 45 days.  Treatment were repeated three times. The data was analysed with descriptive statistic. The results showed that humpback grouper larvae reared with enriched rotifers and artemia produced better survival rate (26.81%), lower seed abnormality (26.10%), and better percentage of bigger size of seeds with grade A (20.3 %), B (39.2%), and C (40.5%).  Meanwhile, treatment without feed enrichment produced lower survival rate (17.57%), higher abnormality (40.20%), and lower percentage of big size of seeds with grade A (9.7%), B (26.0%), and C (64.3%). Keywords: groupers, quality, enrichment, improvement, productio

THE EFFECTS OF FASTING DURATION AND DIFFERENT DENSITIES OF GROUPER SEED TRANSPORTED IN CLOSED SYSTEM

Indonesia is an archipelagic country with many locations suit for aquaculture. Grouper hatcheries are still concentrated in a few locations. Therefore, appropriate technology to transport live grouper seed is needed to ensure the survival and health of the seed. This study aimed to determine the duration of fasting before transportation and the optimum density of grouper seed during transportation. Transportation was conducted in closed system, transported using a car, for 24 hours. Grouper seed used for the experiment was cantik hybrid grouper, a cross-breed between female tiger grouper (Epinephelus fuscoguttatus) and male marbled grouper (Epinephelus microdon) with an average of size 7.0±0.32 cm. There were 2 experiments in this study. Experiment 1 was different durations of fasting before transprotation: A. 12 hours, B. 24 hours, C. 36 hours and D. 48 hours with the density of 150 seeds/boxes. The result of the first experiment was used to determine the experimental design of experiment 2, which consisted of 4 different densities per boxes: A. 125 seeds, B. 150 seeds, C. 175 seeds and D. 200 seeds. Both of the experiments were conducted in triplicates. The seeds were packed in plastic bags with a thickness 0.08 mm, length 120 cm x width 53 cm, filled with 10 liters of sea water. The results showed that the duration of fasting from 36 to 48 hours had the highest survival rate. Polinomial relation y = -0.0439x2 + 3.7696x + 17.075 with the value of R² = 0.966 illustrated that the optimum duration of fasting was 44 hours. There was a significant difference in densities of seeds during transportation (P<0.05), where the higher density lead to the lower survival rate. The density of 125 seeds/boxes resulted in the highest survival rate, 99.0 ± 1.0%

IMPROVEMENT OF SEED PRODUCTION AND QUALITY GROUPER BY HYBRIDIZATION PROGRAM

Several types of grouper hybrid seeds can now be massively produced in a hatchery. Hybrid seeds can increase diversification of aquaculture species and potential to increase fish production.  Therefore, an  improvement in hybrid seed production both in high quantity and quality is very important. This research was conducted to produce massively cantik grouper hybrid seeds i.e.,a crossbreed between female tiger grouper (Epinephelus fuscoguttatus) and male marbled grouper (Epinephelus microdon). This research examined the cantik grouper seed production compared with the production of tiger grouper and marbled grouper fingerlings. The research results showed that cantik hybrid grouper seeds production had higher survival rate (24.59%) than tiger grouper (17.44%) and marbled grouper (4.63%). The total length of the seed at the age of 45 days for cantik grouper  was 3.59 ± 0.21 cm, tiger 3.24 ± 0.55 cm, and batik 2.61 ± 0.42 cm, respectively. Seed abnormality for cantik grouper was 4.13%, tiger grouper 30.21%, and marled tiger 0.57%, respectively. Based on genetic variation analyses, the cantik grouper had a closer genetic relationship with the marbled grouper compared with the tiger grouper. Keywords: Marbled grouper, hybridization program, seeds production, qualit

PENGARUH KEPADATAN Nannochloropsis sp. PADA PEMELIHARAAN LARVA KERAPU BEBEK (Cromileptes altivelis) SECARA TERKONTROL

Pembenihan kerapu bebek (Cromileptes altivelis) sudah berhasil dikembangkan di tingkat petani secara massal, namun terdapat beberapa kendala. Salah satu kendala pada saat pemeliharaan larva adalah seringnya terjadi kematian setelah penambahan plankton Nannochloropsis sp. Kematian tersebut disebabkan pemberian plankton yang tidak tepat baik kualitas maupun kuantitasnya sehingga menyebabkan turunnya kualitas air pada tangki pemeliharaan larva. Penelitian ini bertujuan untuk mengetahui penambahan optimal Nannochloropsis sp. sehingga diperoleh jumlah kepadatan Nannochloropsis sp. yang tepat sebagai green water dan persediaan pakan rotifer pada bak pemeliharaan larva. Perlakuan yang dicoba adalah penambahan Nannochloropsis sp. dengan kepadatan yang berbeda yaitu: A. Tanpa Nannochloropsis sp.; B. 100.000 sel/mL; C. 300.000 sel/mL; dan D. 500.000 sel/mL. Hasil yang diperolehpada perlakuan D (penambahan Nannochloropsis sp. 500.000 sel/mL) menghasilkan sintasan 26,8%; lebih tinggi dari perlakuan yang lain, berikut perlakuan C, B, dan A masing-masing 19,5%; 14,2%; dan 3,5% sedangkan panjang total larva umur 45 hari relatif sama antara 2,47-2,53 cm

PERTUMBUHAN DAN KANDUNGAN NUTRISI IKAN KERAPU SUNU Plectropomus leopardus PADA PEMELIHARAAN DI KARAMBA JARING APUNG, TAMBAK DAN BAK

Nursery of groupers is often perfomed in concrete tanks and hatcheries, however it is also possible to be conducted at the sea in cages or in earthen ponds.  This study aimed to evaluate growth and nutrition contents of coral trout under 3 different environments: sea cage, pond and tanks. Coral trout with the average size of 6.56±0.52 cm and weight of 4.48±1.04 gwere reared with the density of 50 fish/cage. The volume of the cage was 1x1x1 m with the mesh size of 4 mm. The treatments were reared of coral trout in sea cages (A), in ponds (B) and in tanks (C) with the duration of 90 days. Commercial pellet containing protein 48% was fed to the fish twice a day, morning and afternoon. The results showed that survival and growth of total length the fish nursed in those 3 different environments were not significantly different (p>0.05). However, growth of weight was significantly different among treatments with the highest growth from treatment C (23.12±2.9 g), then followed by treatment A (8.43±2.13 g) and B (12.58±2.58 g). Protein contents of fish among treatments were not significantly different. Calorie contents of fish, both treatment C and B were significantly higher than those of treatment A. To sum up, nursery of coral trout in controlled tanks was likely to increase weight 1,84 times than pond 2.74 times than sea cage.Pendederan kerapu banyak dilakukan di bak-bak semen dan hatchery, tetapi usaha pendederan juga dapat dilakukan di laut dengan menggunakan karamba jaring apung (KJA) maupun di tambak.  Penelitian ini bertujuan untuk menganalisa pertumbuhan, dan kandungan nutrisi pada kerapu sunu yang dipelihara pada lingkungan berbeda yaitu di KJA, tambak dan bak hatchery.  Benih ikan kerapu sunu berukuran panjang total 6,56±0,52cm dan berat 4,48±1,04 g dengan kepadatan 50 ekor/jaring dipelihara dalam jaring berukuran 1mx1mx1m dengan ukuran mata jaring 4 mm yang ditempatkan dalam KJA di laut (A), tambak (B) dan bak hatchery (C) sebagai perlakuan percobaan. Penelitian menggunakan rancangan acak lengkap dengan tiga perlakuan dan diulang 3 kali. Penelitian dilakukan selama 90 hari pemeliharaan, dan benih ikan kerapu sunu diberi pakan buatan komersial dengan kandungan protein 48%. Frekuensi pemberian pakan 2 kali sehari pada pagi dan sore hari.  Hasil penelitian menunjukkan bahwa pemeliharaan pada lingkungan berbeda tidak berpengaruh terhadap sintasan dan pertumbuhan mutlak panjang total namun berpengaruh terhadap pertumbuhan mutlak bobot benih (P<0,01). Pertumbuhan mutlak benih terbaik pada pemeliharaan di bak hatchery yakni 23,12±2,91 g, KJA 8,43±2,13 g dan tambak 12,58±2,58 g.  Kandungan protein benih ikan kerapu sunu tidak dipengaruhi oleh lingkungan pemeliharaan, namun kandungan kalori benih pada pemeliharaan di bak hatchery dan tambak lebih tinggi dibandingkan dengan yang di KJA.  Benih ikan kerapu sunu yang didederkan dalam bak hatchery memiliki pertumbuhan bobot mutlak 1,84 kali lebih tinggi dibandingkan dengan yang di tambak atau 2,74 kali dari yang  di KJA

PERKEMBANGAN MORFOLOGI DAN PERILAKU LARVA IKAN KERAPU HIBRIDA CANTIK PADA PRODUKSI MASSAL

Ikan kerapu cantik merupakan hibrida antara betina kerapu macan E. fuscoguttatus dan jantan kerapu batik E. microdon. Penelitian ini bertujuan untuk mengamati perkembangan dan tingkah laku larva ikan kerapu cantik agar bisa diambil langkah-langkah untuk perbaikan pada pemeliharaan larva sehingga dapat meningkatkan produksi. Penelitian dilakukan di Balai Besar Riset Budidaya Laut dan Penyuluhan Perikanan Gondol, Bali Tahun 2016. Larva dipelihara pada tiga buah  bak semen ukuran 10 m3  yang diisi telur dengan kepadatan 50.000 butir/bak, dipelihara hingga juvenil umur 40 hari (D40). Pemeliharaan larva diulang tiga kali dengan waktu yang berbeda, yaitu siklus 1: Januari-Maret; siklus 2 : Mei-Juli dan siklus 3 : September-Nopember. Pengamatan perkembangan dan tingkah laku larva dilakukan pada setiap siklus yang   dibagi menjadi 4 kelompok umur, yakni: 1) D1 sampai D10; 2). D11 sampai D20; 3). D21 sampai D30; dan 4). D31 sampai D40. Hasil menunjukkan larva ikan kerapu cantik mulai buka mulut dan makan pada D3, aktif berenang setelah tumbuh sirip punggung dan dada yaitu D4, sirip terus berkembang menjadi duri memanjang. D7 kondisi larva terlihat padat dilakukan penjarangan. Duri punggung dan dada mulai memendek, berubah menjadi sirip mulai D30, selanjutnya menjadi juvenil dilakukan grading untuk menekan kanibalisme, D40 dengan ukuran panjang total sekitar 3 cm larva ikan kerapu cantik seluruhnya menjadi juvenil. Perkembangan dan tingkah laku larva ikan kerapu cantik berpengaruh terhadap hasil produksinya

THE DIGESTIVE TRACT DEVELOPMENT OF THE TIGER GROUPER Epinephelus fuscoguttatus LARVAE TREATED WITH THYROXINE HORMONE

Thyroxin administration in tiger grouper larval rearing was conducted to determine its effect on development of digestive tract of the larvae. Newly hatched larvae were treated with 0 mg/L (control), 0.1 mg/L, and 0.2 mg/L of thyroxin for 2 hours in a 30 L tank before were transferred into a 1 m3 rearing tank. Samples were collected daily until 10 DAH and every 3 days until 40 DAH. Development of digestive tract was observed using histological method. For all treatments, the digestive tract was the same on 1 DAH and 2 DAH. The digestive tract of 1 DAH larvae was still closed and still in the form of a simple tube. The mouth, buccopharynx, liver, pancreas, and rectum were found on 2 DAH. On 3 DAH, the esophagus, stomach, intestines, and anus started to develop. At this stage, the digestive tract of larvae treated with and without thyroxin started to become distinguishable. Several goblet cells were noticed in the rectum of the treated larvae but not in the control. Digestive tract developed earlier in treated larvae compared to the control group, such as appearance of tongue, gill raker, fundic, and cardiac stomach development, formation of pharyngeal tooth, and gastric gland. Metamorphosis of larvae into juvenile on treated larvae occurred than that the control larvae earlier

APLIKASI VAKSIN BIVALEN (VNN dan GSDIV) PADA PEMELIHARAAN LARVA Ikan Kerapu Sunu, Plectropomus leopardus

Beta-nodavirus sebagai agen penyebab VNN (virus nervous necrosis) dan infeksi GSDIV (grouper sleepy disease iridovirus, isolat dari genus Megalocytivirus) merupakan penyakit yang menyebabkan mortalitas yang tinggi pada larva dan juvenil ikan kerapu dan kakap di Indonesia. Pencegahan infeksi virus tersebut menjadi prioritas utama dalam budidaya ikan tersebut. Tujuan dari penelitian ini adalah untuk mengetahui efektivitas vaksin bivalen dalam mencegah infeksi virus VNN dan GSDIV pada pemeliharaan larva ikan kerapu sunu, Plectropomus leopardus. Sebanyak 5 mL vaksin bivalen (kombinasi antara vaksin protein rekombinan VNN dan GSDIV dengan rasio 1:1 v/v) di bio-enkapsulasi ke dalam 30 liter pakan alami Rotifera dan Artemia (2 x 104 individu/mL). Aplikasi vaksin pada larva ikan kerapu sunu dilakukan melalui pakan alami Rotifera dari umur 5-24 hari dan Artemia dari umur 25-50 hari. Hasil penelitian menunjukkan bahwa vaksin bivalen tidak berpengaruh terhadap pertumbuhan dan sintasan larva kerapu sunu (panjang: 1,8-2,2 cm dan sintasan: 1,05%-4,07%). Hasil uji tantang dengan VNN dan GSDIV menunjukkan bahwa vaksin tersebut dapat menginduksi gen imunitas larva (MHC-I).Beta-nodavirus as the causative agent of VNN (viral nervous necrosis) and GSDIV infection (grouper sleepy disease iridovirus, isolate from the genus Megalocytivirus) has caused high mortality of cultured grouper and sea bass larvae and juvenile in Indonesia. The prevention of this virus infection on grouper and sea bass culture has become one of the national priority. The purpose of this research was to study the effectiveness of the bivalent vaccine in preventing VNN and GSDIV infections to seed of coral trout grouper, Plectropomus leopardus reared in hatchery. Applications of bivalent vaccine (a combination of protein recombinant VNN and GSDIV vaccine with a ratio of 1:1 v/v) were done by bio-encapsulation using the fish natural diet, Rotifera and Artemia, with a dose of 5 mL vaccine in 30 liters of natural diet (2 x 104 ind./mL). Vaccines were given once a day from the larval age of 5-24 days after hatching using Rotifera and 25-50 day after hatching using Artemia. The results showed that the bivalent vaccine did not influence the growth and survival rate of coral trout grouper larvae (ranged of total length: 1.8-2.2 cm and survival rate: 1.05%-4.07%). The challenge test with VNN and GSDIV revealed that the vaccine had positively induced gene related immunity of larvae MHC-I

Effects of Dietary Mannan-Oligosaccharide (Mos) and Multi-Species of Bacillus on Growth and Feed Utilization in Leopard Coral Grouper Plectropomus leopardus Juvenile

This study assessed the growth and feed utilization in leopard coral grouper Plectropomus leopardus juvenile fed dietary prebiotic mannan-oligosaccharide (MOS) and multi-species of probiotic bacteria (Bacillus cereus BS6, B. subtilis BS3, and B. amiloliquefaciens BS4). The experiment was performed by feeding four replicates groups of juveniles weighing 3.61±0.60 g on four experimental diets, and each diet included: only MOS (PRE); the multi-species of Bacillus (PRO); a combination of MOS and the multi-species of Bacillus (SYN) and without supplementation (CON). When MOS (PRE) or the multi-species of Bacillus (PRO) was included in the diet solely, the growth of the fish was fairly good, although there was no significant difference with the control diet (p>0.05). Unexpectedly, the combined inclusion of MOS and the multi-species of Bacillus (SYN) did not increase the growth and feed utilization in Plectropomus leopardus juvenile. Presumably, MOS did not exert any favorable effects on the multi-species of Bacillus. This study suggested that no advantage was obtained when MOS and the multi-species of Bacillus were included in the diet simultaneously. In addition, the inclusion of MOS in higher levels may be necessary for better feed utilization and growth in leopard coral grouper Plectropomus leopardus

QUANTITATIVE HISTOPATHOLOGICAL ANALYSIS OF ENLARGED CELLS DERIVED FROM HUMPBACK GROUPER, Cromileptes altivelis INFECTED WITH GROUPER SLEEPY DISEASE IRIDOVIRUS (GSDIV)

Pathognomonic sign of grouper sleepy disease iridovirus (GSDIV) was proposed to be the formation of enlarged cells and necrotic cells, in which under electron microscope, it is revealed to be the inclusion body bearing cells (IBCs) and necrotic cells containing GSDIV viral particles. Spleen and kidney tissues are the major sites for formation of enlarged cells. This paper described the result of histopatological analysis of enlarged cells found in the spleen and kidney of moribund fish after GSDIV challenge. A pathogenicity test was conducted on fish stocked in two tanks for infected groups and the other two tanks for uninfected control groups (15 fish per tank). The infected groups were injected intramuscularly with 0.1 ml of the viral inoculum. The uninfected groups were injected with the same amount of EMEM-2. The GSDIV-infected humpback grouper began to die after 6 days post infection and all died after 7 dpi, excluding one fish which had survived until the end of experimental infection periods (93% to 100% mortality). All of the diseased fish showed massive formation of enlarged cells in their spleen, head kidney and trunk kidney. The largest number of enlarged cells was observed on head kidneys and subsequently followed by spleens, trunk kidney (2.0-200.3/field of view). This result suggested that the number of enlarged cells in the affected organs was not the direct factor that led to the mortality of fish