EFFECTS OF DIFFERENT pH SETTINGS ON GROWTH AND SURVIVAL OF COMMON CARP RAJADANU STRAIN

pH is one of the important water quality parameters in aquaculture. This study aimed to observe the growth performance and survival rate of common carp (Cyprinus carpio) Rajadanu strain reared in culture media with different pH levels. Fish (length: 3.60 ± 0.18 cm; weight: 1.68 ± 0.18 g) were stocked in nine aquariums (40 cm x 40 cm x 30 cm) for 10 days with a stocking density of 25 fish per aquarium. The treatments used were (A) pH 4-5, (B) pH 5-6, and (C) pH 6-7, with three replications. A commercial feed containing 28% protein was given daily and as much as 3% of the total biomass. The observed data were analyzed using variance analysis (ANOVA), followed by Duncan test. The results showed that the pH treatments did not affect the growth (length and weight) and survival rate of common carp Rajadanu strain (P>0.05). The best growth was achieved by the fish group reared in water with a pH range of 6-7 (length = 0.38 cm; weight = 0.17 g). The highest survival was attained by the fish group reared in water with a pH range of 5-6 (90.66%)

COMPENSATORY GROWTH OF Oreochromis niloticus SELECTED STRAIN FROM BOGOR, WEST JAVA

Inefficient feed management strategy in aquaculture will increase the fish production cost. One of the most effective strategies to solve this problem is through a better understanding of the compensatory growth of cultured fish. O. niloticus BEST tilapia strain (total length: 7.23 ± 0.11 cm mean ± SD; Body weight: 7.04 ± 0.08 g mean ± SD) were reared in aquariums at 26.3 ± 1.4oC for 10 weeks. During the experiment, the control group was fed twice a day. The other two groups were deprived of food for one and two weeks and then fed twice a day during refeeding period. At the end of the experiment, the fish deprived for one week had a body weight, biomass and specific growth rate that were not significantly different from the control group. The body weight, biomass and specific growth rate of fish deprived for two weeks were significantly lower than the other groups. This study revealed that concentrations of ash and lower concentrations of protein and lipid on the deprived groups were higher compared to those without feed deprivation. Mortality of fish was lower than 9% and not significantly different among the treatments. Fish aggressive behavior was the main reason for injuries and death. Given the results, BEST tilapia strain was only able to reach complete growth compensation not longer than one week deprivation period. The results of the present study could be applied as basic information for further research on feeding management of BEST tilapia strain.

METABOLIC RATES (SMR, RMR, AMR, AND MMR) OF Oplegnathus fasciatus ON DIFFERENT TEMPERATURE AND SALINITY SETTINGS

The metabolic rate of aquatic animals is closely related to oxygen concentration and influenced by internal and external factors. Despite its high value as marine fish species in South Korea, information on rock bream Oplegnathus fasciatus metabolism is scarcely available. This study observed the standard metabolic rate (SMR), routine metabolic rate (RMR), and active metabolic rate (AMR) of rock bream Oplegnathus fasciatus subjected to different temperature settings. Another observation was performed to find out the maximum metabolic rate (MMR) on rock bream subjected to different salinity settings. Fish (TL: 26.86 ± 0.29 cm and BW: 469.40 ± 38.21 g for SMR, RMR, and AMR measurement; TL: 26.7 ± 0.4 cm and BW: 451.0 ± 44.4 g for MMR measurement) were observed using respirometer (dimension = 30 cm × 20 cm × 20 cm; volume: 10.4 L) inside a recirculation systems. SMR, RMR, and AMR were measured at 15°C, 20°C, and 25°C. Meanwhile, MMR was measured at 15, 25, and 35 psu. The results showed that SMR, RMR, and AMR increased linearly by increasing the temperatures (SMR: 58.7 ± 3.2, 102.7 ± 4.3, and 157.1 ± 4.1 mg O2/kg/h at 15°C, 20°C, and 25°C, respectively; RMR: 66.0 ± 8.6, 112.6 ± 10.2, and 175.2 ± 21.3 mg O2/kg/h at 15°C, 20°C, and 25°C, respectively; AMR: 73.4 ± 7.4, 122.0 ± 6.3, and 196.7 ± 15.4 mg O2/kg/h at 15°C, 20°C, and 25°C, respectively), whilst MMR decreased by lowering salinity (48.5 ± 5.2, 61.1 ± 5.5, and 89.3 ± 14.7 mg O2/kg/hour at salinity of 15, 25, and 35 psu, respectively)

COMPENSATORY GROWTH OF Oreochromis niloticus SELECTED STRAIN FROM BOGOR, WEST JAVA

In efficient feed management strategy in aquaculture will increase the fish production cost. One of the most effective strategies to solve this problem is through a better understanding of the compensatory growth of cultured fish. O. niloticus BEST tilapia strain (total length: 7.23 ± 0.11 cm mean ± SD; Body weight: 7.04 ± 0.08 g mean ± SD) were reared in aquariums at 26.3 ± 1.4oC for 10 weeks. During the experiment, the control group was fed twice a day. The other two groups were deprived of food for one and two weeks and then fed twice a day during refeeding period. At the end of the experiment, the fish deprived for one week had a body weight, biomass and specific growth rate that were not significantly different from the control group. The body weight, biomass and specific growth rate of fish deprived for two weeks were significantly lower than the other groups. This study revealed that concentrations of ash and lower concentrations of protein and lipid on the deprived groups were higher compared to those without feed deprivation. Mortality of fish was lower than 9% and not significantly different among the treatments. Fish aggressive behavior was the main reason for injuries and death. Given the results, BEST tilapia strain was only able to reach complete growth compensation not longer than one week deprivation period. The results of the present study could be applied as basic information for further research on feeding management of BEST tilapia strain

REPRODUKSI IKAN BAUNG (Hemibagrus nemurus) DENGAN PERLAKUAN DOSIS HORMON GnRH-a BERBEDA

Ikan baung (Hemibagrus nemurus) memiliki prospek bagus untuk dikembangkan sebagai komoditas budidaya di Indonesia karena citarasa daging yang enak banyak diminati konsumen. Dewasa ini, peningkatan produksi benih dapat dilakukan melalui pemijahan buatan dengan manipulasi hormonal. Penelitian yang dilakukan bertujuan untuk mengevaluasi produksi induk ikan baung melalui pemijahan buatan dengan dosis penyuntikan GnRH-a berbeda. Penelitian dilakukan di Instalasi Riset Plasma Nutfah Perikanan Air Tawar, Cijeruk, Bogor pada bulan November 2017. Induk betina ikan baung yang digunakan berukuran 465,0 ± 71,8 g; dan induk jantan 426,3 ± 46,8 g. Induksi dilakukan dengan penyuntikan hormon GnRH-a dengan tiga dosis yang berbeda pada induk betina (0,3; 0,5; dan 0,7 mL/kg bobot badan), dan ikan jantan dengan dosis 0,4 mL/kg bobot badan. Masing-masing perlakuan terdiri atas tiga ekor induk betina sebagai ulangan. Hormon disuntikkan secara intramuskular, diberikan dua kali penyuntikan 35% dari dosis total pada penyuntikan pertama, dan 65% diberikan pada penyuntikan kedua, dengan interval waktu penyuntikan delapan jam. Parameter yang diamati yaitu jumlah telur ovulasi, derajat pembuahan, derajat penetasan, dan sintasan larva selama tujuh hari. Hasil penelitian menunjukkan bahwa dosis penyuntikan hormon GnRH-a 0,5 mL/kg pada induk ikan baung saat proses pemijahan buatan menghasilkan derajat penetasan yang lebih tinggi dibandingkan dosis 0,3 dan 0,7 mL/kg; serta sintasan larva yang lebih baik dibandingkan dosis 0,7 mL/kg. Sedangkan nilai jumlah telur yang berhasil ovulasi dan derajat pembuahan yang relatif lebih baik ditemukan pada perlakuan dosis 0,7 mL/kg dibandingkan dengan dosis 0,3 dan 0,5 mL/kg.Asian redtail catfish (Hemibagrus nemurus) has a good prospect to be developed as aquaculture commodity in Indonesia. It was proved by the demand of consumers regarding to its delicious flesh taste. Recently, efforts to increase seedling production could be implemented through artificial spawning with hormonal manipulation. This study was conducted to evaluate the production of broodstocks through artificial spawning with different doses of GnRH-a. Study was conducted at Research Institute for Freshwater Fisheries Germplasm, Cijeruk, Bogor in November, 2017. The broodstock used in this study was 465.0 ± 71.8 g for females, and 426.3 ± 46.8 g for males. Induction was performed by injection of GnRH-a hormone with three different doses on female broodstocks (0.3, 0.5 and 0.7 mL/kg of body weight), and male broodstocks with a dose of 0.4 mL/kg of body weight. Each treatment consisted of three females as replications. The hormone was injected intramuscularly, given twice injection: 35% of the total dose is given at the first injection, and the remaining 65% was given at the second injection, with an injection time interval of eight hours. The results showed the observed parameters of number of the ovulated eggs, fertilization rate, hatching rate, and larval survival for seven days, treatment dosage of 0.5 mL/kg showed better results (P<0.05) than the dosage of 0.3 mL/kg and 0.7 mL/kg. Parameters observed were number of ovulated eggs, fertility rate, hatching rate, and survival rate for seven days. The results showed that the dosage of 0.5 mL/kg GnRH-a injection to the broodstock during artificial spawning resulted in higher hatching rate compared to 0.3 and 0.7 mL/kg and better larval survival rate than the dosage of 0.7 mL/kg. Meanwhile, the number of ovulated eggs and fertility rate was relatively better in the treatment of 0.7 mL/kg compared with the dosage of 0.3 and 0.5 mL/kg

PENGARUH STRESSOR SUHU DAN SALINITAS TERHADAP PERKEMBANGAN EMBRIO IKAN NILEM (Osteochilus hasselti)

Effects of Temperature and Salinity as Stressors on Embryo Development of Hard-Lipped Barb (Osteochilus Hasselti)          Exposure to environmental stressors on fish is an aspect of concern to researchers because its effects can be detrimental to metabolism, growth, disease resistance, reproductive ability, health, and survival of the fish. Although, according to the researchers that stress can be bad for the fish, but this stress phenomenon remains to be studied more deeply. Based on this information, this paper is made to assess the effects of environmental stressors on fish, especially in hard-lipped barb (Osteochilus hasselti) on the embryonic developmental stages. The data collected comes from the results of research conducted at Institute for Freshwater Aquaculture Research and Development (IFARD), Bogor. This paper discussed about temperature and salinity as environmental stressors related to development of early life stage of hard-lipped barb. Hatching, mortality, and survival rates were the indicators of environmental stressors decisive influence on the development of the embryo. In addition, the observation of embryonic development through the microscope is also used as supporting data. Based on research data, it was concluded that environmental stressors such as temperature and salinity beyond the limits of tolerance could interfere with embryonic development of fish nilem. The stressor temperatures for the embryonic development of hard-lipped barb were 25oC and 31oC, while the salinity stressor for hard-lipped barb embryos was above 5 ppt. The results of this study could be used as reference in fish farming activities of hard-lipped barb to optimize seedling production.Key Words:  Osteochilus hasselti, embryo development, environmental stressors, temperature, salinity ABSTRAK          Paparan terhadap stressor lingkungan pada ikan merupakan aspek yang menjadi perhatian bagi peneliti karena efeknya dapat merugikan metabolisme, pertumbuhan, ketahanan terhadap penyakit, kemampuan reproduksi, kesehatan, dan kelangsungan hidup ikan. Meskipun menurut para peneliti bahwa stress dapat berakibat buruk bagi ikan, namun fenomena stress ini masih perlu dipelajari lebih dalam lagi. Berdasarkan informasi tersebut, tulisan ini dibuat untuk mengkaji pengaruh stressor lingkungan terhadap ikan, khususnya pada spesies ikan nilem (Osteochilus hasselti) pada fase perkembangan embrio. Data yang dikumpulkan berasal dari hasil penelitian yang dilaksanakan di BPPBAT, Bogor. Jenis stressor lingkungan yang akan dibahas pada tulisan ini yaitu suhu dan salinitas. Derajat penetasan, mortalitas, dan tingkat kelangsungan hidup merupakan indikator penentu pengaruh stressor lingkungan terhadap perkembangan embrio. Selain itu, pengamatan perkembangan embrio melalui mikroskop juga dijadikan sebagai data pendukung. Berdasarkan data penelitian, dapat disimpulkan bahwa stressor lingkungan berupa suhu dan salinitas di luar batas toleransi dapat mengganggu perkembangan embrio ikan nilem. Suhu yang bersifat stressor bagi perkembangan embrio ikan nilem yaitu 25oC dan 31oC, sedangkan stressor salinitas bagi embrio ikan nilem yaitu di atas 5 ppt. Hasil dari studi ini dapat dijadikan sebagai acuan dalam kegiatan budidaya ikan nilem untuk mengoptimalkan produksi benih.Kata Kunci: Osteochilus hasselti, Perkembangan embrio, stressor lingkungan, suhu, salinita

LOW WATER TEMPERATURE AND ITS EFFECTS ON STRESS RESPONSE OF GREY MULLETS Mugil cephalus ACCLIMATED IN FRESHWATER

Grey mullet (Mugil cephalus) can adapt to saline and freshwater. Although belonged to euryhaline species, but information regarding their stress response on low temperature. Environmental disturbance such as low water temperature may effect their physiological condition. These information can be useful for aquaculture development of this species in freshwater. Therefore, the purpose of study was to investigate the effects of low water temperature on the stress response of grey mullets Mugil cephalus acclimated in freshwater. The blood samples of experimental fish (TL: 28.2±1.1 cm, BW: 198.6±25.9 g) were collected during winter season when the water temperature of controlled rearing system was stable at 25°C and uncontrolled rearing system slowly dropped until 12°C. Their stress response on both rearing systems was observed. The results showed that low temperature affected to lower the behavior activity and increase the stress response of grey mullets. The breath frequency of grey mullet regarding their opercular movement at 12°C was 74-97 breath/min., while at 25°C it was 95-114 breath/min. Hematocrit (Ht) and hemoglobin (Hb) were shown higher values of 43.5% and 9.5 g/dL, respectively at 25°C than 12°C (28.0% and 7.1 g/dL, respectively). The tendencies of cortisol and glucose level increased with the lowering temperature, showing higher value of 264.8 ng/mL and 35.5 mg/dL in 12°C than 5.5 ng/mL and 32.7 mg/dL in 25°C. The chemical properties of blood in grey mullets showed same tendency comparing between 12°C and 25°C, there was no significant different between each temperature, except for chloride (P<0.05). Chloride value was higher at 25°C, while other blood components such as osmolality, sodium, potassium, and magnesium were showing no significant differences. However, the results showed lower values at 12°C in every blood components, except for chloride. In conclusion, lowering water temperature to 12°C had impact as stressor to the behavior and stress response of grey mullets acclimated in freshwater

LAJU RESPIRASI INDUK IKAN BLACKHEAD SEABREAM Acanthopagrus schlegelii PADA SUHU PEMELIHARAAN YANG BERBEDA

Laju respirasi hewan akuatik memiliki hubungan yang erat dengan metabolisme. Tingkat metabolisme hewan merupakan variabel yang dapat dipengaruhi faktor dalam maupun luar, salah satunya adalah suhu. Pada ikan, proses metabolisme juga berkorelasi dengan suhu. Salah satu jenis ikan yang perlu dikaji laju respirasinya adalah ikan blackhead seabream Acanthopagrus schlegelii yang merupakan spesies ikan laut yang popular di Korea Selatan, sehingga diperlukan lebih banyak informasi lagi mengenai laju respirasi ikan ini untuk mengoptimalkan metabolisme ikan ini dan berdampak kepada produktivitas budidaya. Penelitian ini bertujuan untuk mengevaluasi laju respirasi induk ikan blackhead seabream pada beberapa tingkatan suhu. Ikan blackhead seabream (panjang total 29,3 ± 2,2 cm dan bobot tubuh 538,3 ± 43,0 g) diteliti menggunakan respirometer dalam sistem resirkulasi. Tiga kelompok percobaan dilakukan untuk mengukur laju respirasi berdasarkan perubahan suhu pemeliharaan (15°C, 20°C, dan 25°C). Hasil penelitian menunjukkan bahwa kecenderungan laju respirasi meningkat secara linier dengan peningkatan suhu perlakuan, dengan nilai tertinggi sebesar 164,8 ± 30,7 mg O2/kg/jam pada 25°C dan nilai terendah sebesar 72,4 ± 8,1 mg O2/kg/jam pada 15°C. Sementara itu, frekuensi pernapasan berkorelasi positif terhadap kenaikan suhu. Berdasarkan penelitian ini, dapat disimpulkan bahwa perubahan suhu dari 15°C ke 25°C menyebabkan peningkatan laju respirasi pada induk ikan blackhead seabream.It is well known that a close relationship exists between respiration rate and metabolism in aquatic animal. In fish, the metabolic rate is influenced by internal or external factors, such as temperature. This research observed the respiration rate of blackhead seabream, Acanthopagrus schlegelii, which is one of the popular marine fish species in South Korea. Despite the fish popularity, very few information are available about the fish’s respiration rate which is important in order to optimize its metabolism and increase its aquaculture productivity. This study aimed to evaluate the respiration rate of adult blackhead seabream reared in media with different temperature settings. The fish (total length of 29.3 ±2.2 cm and body weight of 538.3 ± 43.0 g) were observed using a respirometer placed inside the recirculation systems. Three groups of experiments were set up to measure the fish’s respiration rate according to different rearing temperatures (15°C, 20°C, and 25°C). The results showed that there was a tendency of respiration rate increased linearly with the increase of temperature. The highest respiration rate was 164.8 ± 30.7 mg O2/kg/hour at 25°C and the lowest value was 72.4 ± 8.1 mg O2/kg/hour at 15°C which indicated that the respiratory rate positively correlated to the change in temperature. According to this study, it can be concluded that temperature changes from 15°C to 25°C led an increase in respiration rate of adult blackhead seabream 

GROWTH AND EARLY REPRODUCTION DEVELOPMENT OF THE FIRST GENERATION OF SHEATFISH, Ompok miostoma (Vaillant, 1902) REARED IN CONTROLLED CONCRETE TANKS

This study was conducted to observe the growth and reproductive biology of wild sheatfish in controlled concrete tanks. The research was carried out from January to November 2020 at the Research Station for Freshwater Fisheries Germplasm, Cijeruk, Bogor. Sampled fish were captured from Cilala Lake in Bogor and Cipanas River in Sumedang, West Java. The collected fish were 14.6 ± 2.24 cm in length and 21.5 ± 9.19 g in weight. Growth and reproductive biology parameters were measured every 30 days. Cortisol, estradiol, vitellogenin, testosterone, glucose, and hemoglobin were also determined as the supporting parameters for gonadal maturity. Measured water quality parameters were temperature, pH, dissolved oxygen, ammonia, and alkalinity. The results showed that sheatfish grew with a specific growth rate of 0.4 ± 0.15%/day, FCR of 3.2 ± 0.26, and survival rate of 100%. Observation on the gonad maturity found that the fish studied were in the level-I and II. There are no significant differences regarding the supporting parameters (P>0.05) on the fish examined, despite the tendency of decreasing cortisol, and increasing testosterone. Based on the results, this study concludes that the observed fish can adapt, grow, and start to mature their gonads in their new environment, with temperature as one of the possible key factors influencing its gonad development

PEMANFAATAN LIMBAH PRODUKSI KAKAO UNTUK PAKAN BENIH IKAN NILA (Oreochromis niloticus)

Utilization of Waste Production of Cocoa for Tilapia Fish (Oreochromis niloticus) Seed Feed           Problems often arise in fish farming is the cost of artificial feed (pellets) which is expensive. The availability of local feed ingredients are still very limited and reliance on imports causing feed prices to rise. Therefore we need research to find alternative raw materials that can substitute fish meal price is relatively cheaper, widely available, and do not compete with cattle and human needs. Raw materials include cocoa shell waste derived from cocoa plantations. This study aimed to evaluate the use of cocoa shell waste for growing out of  tilapia fish (Oreochromis niloticus). The study was conducted at the Center for Research and Development of Freshwater Aquaculture, Bogor. When the study will be conducted over two months. The fish used were tilapia fish 7-8 cm size were maintained on media aquarium measuring 50 × 40 × 40 cm. In addition, the feed given that the result of the fortification of rind cocoa powder, cocoa seed shell powder, rice bran, tapioca flour, water and salt. Commercial feed was also used in this study as a comparison. Feed given as much as 3% of the total biomass of fish in each aquarium. Every two weeks the data  collection of body length and weight of fish seeds were measured. The data would be observed that the length and absolute weight, specific growth rate (SGR), increase biomass and fish survival rate. The results of this study indicated that tilapia fish fed the formulation of cocoa waste could not achieve the growth of fish with commercial feed. Further studies on cocoa waste hopely be better to produce fish seeds which same growth with the growth of fish fed by commercial feed.Key words: Feed, waste of cocoa, tilapia, Oreochromis niloticus ABSTRAK         Permasalahan yang sering muncul pada usaha budidaya ikan yaitu biaya pakan buatan (pellet).yang mahal. Ketersediaan bahan baku pakan lokal masih sangat terbatas dan ketergantungan pada impor menyebabkan harga pakan meningkat. Oleh karena itu diperlukan penelitian untuk mencari alternatif  bahan baku yang dapat menjadi substitusi tepung ikan dengan harga yang relatif murah, banyak tersedia, dan tidak bersaing dengan kebutuhan ternak dan manusia. Bahan baku tersebut antara lain limbah kulit kakao yang berasal dari perkebunan kakao. Penelitian ini bertujuan untuk mengevaluasi pemanfaatan limbah kulit kakao untuk pembesaran benih ikan nila (Oreochromis niloticus). Penelitian dilakukan di Balai Penelitian dan Pengembangan Budidaya Air Tawar, Bogor. Waktu penelitian akan dilaksanakan selama 2 bulan. Ikan yang digunakan yaitu benih ikan nila ukuran 7-8 cm yang dipelihara pada media akuarium berukuran 50 × 40 × 40 cm. Selain itu, pakan yang diberikan yaitu hasil fortifikasi dari serbuk kulit buah kakao, serbuk kulit biji kakao, dedak padi, tepung tapioka, air, dan garam. Pakan komersil juga digunakan dalam penelitian ini sebagai pembanding. Pakan diberikan sebanyak 3% dari total biomassa ikan pada masing-masing akuarium. Tiap 2 minggu dilakukan pengambilan data panjang dan bobot tubuh benih ikan yang diuji. Data yang akan diamati yaitu pertambahan panjang dan bobot mutlak, laju pertumbuhan spesifik (SGR), pertambahan biomass, dan sintasan ikan uji. Hasil penelitian ini menunjukkan bahwa benih ikan nila yang diberi pakan formulasi dari limbah kakao belum dapat mencapai pertumbuhan yang setara dengan pakan komersial. Perlu penelitian lebih lanjut mengenai formulasi pakan limbah kakao yang lebih baik lagi agar mampu menghasilkan pertumbuhan benih ikan yang seimbang dengan pertumbuhan ikan yang diberi pakan komersial.Kata Kunci: Pakan, Limbah kakao, Nila, Oreochromis niloticu