ABSTRAKUpaya meningkatkan produktivitas lahan tambak dapat dilakukan dengan meningkatkan padat penebaran disertai dengan pemberian akuinput yang prima serta dukungan teknologi yang memadai. Tiga padat penebaran yaitu 750; 1.000; dan 1.250 ekor/m 2 , diaplikasikan pada tambak dengan luasan 1.000 m 2 dengan kedalaman air 1,8 m dilengkapi dengan sistem aerasi berupa kincir dan root blower, pompa submersible, automatic feeder, central drain dan collector drain serta Instalasi Pengolah Air Limbah (IPAL). Kapasitas sistem aerasi adalah 500 kg biomassa udang/HP. Udang dipelihara selama 105 hari. Hasil penelitian menunjukkan bahwa padat penebaran yang diaplikasikan menghasilkan bobot akhir udang yang relatif sama berkisar 15, 48-16,30 (15,78±0,45)

One effort to increase dissolved oxygen concentration in pond waters is by applying bottom aeration system. The number of aeration point in the pond bottom allegedly affects oxygen solubility and shrimp farming performance. This study utilized two concreted ponds of 1000 m 2 each equipped with two bottom aeration systems built by 100 cm long of rubber diffuser, totaling 140 pieces (Treatment A) and 70 pieces (Treatment B). The PL-9 of L. vannamei were stocked with density of 600 ind/m 2 and reared for 70 days. Treatment A resulted dissolved oxygen of 3.04-10.36 (6.60±1.07) mg/L which were higher than Treatment B where the range of dissolved oxygen were 2.77-7.92 (6.08±0.95) mg/L. In contrast, nitrite, total nitrogen, phosphate and dissolved organic matter were lower within treatment A. Shrimp production, survival rate and feed conversion ratio in Treatment A were5, 620 kg, 93.6% and 1.12, respectively; whereas in treatment B were 4,000 kg, 80.7% and 1.51. Treatment A resulted in a better the L. vannamei farming compared to treatment B. To increase the supply of dissolved oxygen in the pond, a rubber diffuser can be used which is connected to a blower. ABSTRAKSalah satu upaya untuk meningkatkan oksigen terlarut di perairan tambak dapat dilakukan melalui sistem aerasi dasar. Jumlah titik aerasi dasar diduga mempengaruhi kelarutan oksigen dan berdampak pada performa budidaya udang di tambak. Penelitian ini menggunakan dua petak tambak beton masing-masing 1.000 m 2 dilengkapi dengan sistem aerasi dasar yang terbuat dari rubber diffuser sepanjang 100 cm, berjumlah 140 buah (Perlakuan A) dan 70 buah (Perlakuan B). Benur udang vaname PL-9 ditebar dengan padat penebaran 600 ekor/m 2 dan dipelihara selama 70 hari. Perlakuan A menghasilkan kelarutan oksigen 3,04-10,36 (6,60±1,07) mg/L lebih tinggi dibandingkan perlakuan B dengan kisaran oksigen terlarut 2,77-7,92 (6,08±0,95) mg/L. Sebaliknya parameter nitrit, total nitrogen, phosphat dan bahan organik terlarut lebih rendah di perlakuan A. Produksi, sintasan, dan rasio konversi pakan pada perlakuan A masing-masing 5.620 kg, 93,6% dan 1,12 dan perlakuan B masing-masing 4.000 kg, 80,7% dan 1,51. Perlakuan A menghasilkan performa budidaya lebih baik dibandingkan perlakuan B. Untuk meningkatkan pasokan oksigen terlarut di tambak dapat digunakan rubber diffuser yang dihubungkan dengan blower.Kata kunci: rubber diffuser, aerasi dasar, udang vaname

The purpose of this experiment was to evaluate the effects of using seaworm meal in artificial diet as partial substitution of freshfeed for maturation of tiger shrimp. This experiment started by growing-out tiger shrimp with initial weight around 60 g for four months until reaching maturation phase where shrimp weight were over 90 g for female. Tiger shrimp was selected and stocked into 10 ton concrete tank with stocking density of 50 shrimps with ratio of female : male of 1:1. Dietary treatments were different levels of seaworm meal at 0% (SW0), 10% (SW10) and 20% (SW20). SW0 was positive control without seaworm meal but breeder was fed with frozen seaworm. Test diets were fed as a combination of 60% test pellet and 40% fresh feed. Artificial insemination was carried out for all females before ablation to obtain fertile eggs. Results showed that after ablation, number of female matured was highest in group fed SW10 (13 breeders) and the lowest in female fed control group (7 breeders). Number of female spawned was also highest in female fed SW10 and the lowest was in positive control. Fecundity was very low in all treatments ranged from 12,000-79,700 eggs/spawn. Even though female bearing spermatophore through insemination, number of spawning hatched was very low, only three spawned in each of SW0 and SW10 and two spawned in SW20. Based on number of breeders matured and spawning rate, breeder fed with SW10 gave better performance than other two diets. Technique of artificial insemination needs to be improved to increase the number of fertile eggs.

Very low naturally mating rate of pond-reared tiger shrimp broodstock is probably due to the slow maturation of the male stock. The aim of this study was to evaluate the salmon gonadotrophin releasing hormone analoque (sGnRHa) in stimulating the gonadal maturation of male stock of pond-reared tiger shrimp. The treatments were three dosages of sGnRHa at 0.1 (OV-1), 0.2 (OV-2), and 0.3 (OV-3) mL/kg of shrimp weight and control was eye stalk ablation (AB). The sGnRHa was administered via injection three times with one week interval. Male stocks with average initial body weight of 82.1 g were randomly distributed into four of 10 m3 concrete tanks, 26 males for each tank. Variables observed were performances of spermatophores and profiles of amino acid and fatty acid of muscle of the male stocks. After induction, number of male maturing indicated by spermatophores releasing from terminal ampullas was higher in shrimp induced with OV-1 (80.8%) compared to control which was only 46.1%. Furthermore, shrimp treated OV-2 had the highest spermatophore weight of 0.16 g compared to control (0.11 g) and other two groups. Amino acid profiles improved as the dose of sGnRHa increased up to 0.2 mL/kg from 61.23% for ablated male becoming 71.27% for OV-2. Total fatty acid also tended to improve by increasing the dose of hormone injection, however, the ablated male had higher total fatty acid content than that of OV-1. The present finding demonstrated that the dose of sGnRHa to stimulate the gonadal maturation of pond-reared male tiger shrimp could be applied at range between 0.1-0.2 mL/kg of shrimp weight.

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