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.

POTENTIAL APPLICATIONS OF DIETARY Moringa oleifera LEAVES AS GROWTH MODULATOR AND IMMUNOSTIMULANT AGAINST Aeromonas hydrophila FOR FARMED Oreochromis niloticus

Herbal medicine, including moringa (Moringa oleifera), is widely used as dietary supplementation to enhance growth performance and increase disease resistance in aquaculture. This study aimed to investigate the effects of supplementing moringa leaves on growth performance, hematology and disease resistance of nile tilapia (Oreochromis niloticus) against Aeromonas hydrophila. Fish (38.05 ± 0.83 g) were fed with a commercial feed supplemented by moringa leaves at 0%, 15%, 20%, and 25%, ad libitum, twice a day for eight weeks. Results revealed that 15% moringa leaves supplemented diet gave the highest weight gain, while the specific growth rate was statistically significantly different (p<0.05) among the treatments. Fish fed with 25% supplementation had the highest total red blood cell count and total white blood cell count. All experimental groups had higher values of red blood cells and white blood cells than the control group. The challenge test with A. hydrophila showed that the fish fed with the 25% moringa leaves supplementation diet had the highest relative percentage survival rate. There were no significant differences among the treatment groups. However, the treatment groups had a statistically significant difference with the control group (p<0.05). Results of the present study indicated that supplementation of 15% moringa leaves in diet gave optimal growth performance, while supplementation of 25% moringa leaves in the diet showed the best results in terms of the health of nile tilapia. Moringa leaves supplemented in nile tilapia diet enhanced growth performance and increased disease resistance against A. hydrophila.

VIRULENCE GENE PROFILING AND PATHOGENICITY OF Streptococcus agalactiae ISOLATED FROM TILAPIA, Oreochromis niloticus FARMS IN INDONESIA

Streptococcosis caused by Streptococcus agalactiae has become a major disease problem in tilapia culture in Indonesia. This study aimed to detect virulence genes of S. agalactiae during streptococcosis disease outbreaks in several tilapia farms in Indonesia and evaluate the correlation between biotype and virulence genes to bacterial virulence. The presence of virulence genes was determined in 10 strains of S. agalactiae isolated from farm-raised tilapia. Polymerase chain reaction (PCR) protocol was used to determine genes for cylE, hylB, lmb, bib A, PI-2b, fbs A, fbs B, gap, PI-1, and cfb in the template DNA. Pathogenicity test was carried out by intraperitoneal injection of 24 hour-cultured S. agalactiae to tilapia with 108 CFU/fish. Four isolates have seven of virulence genes (cylE, hylB, bibA, PI-2b, fbs A, fbs B, and gap genes), three isolates have six virulence genes (hylB, bib A, fbs A, fbs B, gap, cfb genes), one isolate has four virulence gene (hyl B, bib A, fbs, and cfb genes), and one isolate has one virulence gene (PI-2b gene). None of the isolates has lmb or PI-1 genes. Bacteria with more virulence genes showed higher pathogenicity post injection. Mortality of tilapia injected with b-hemolytic bacteria was 100% within the period of 14-19 hours, while non-hemolytic bacteria was 53.3%-86.6% on 14 days post-injection. Pathological changes associated with the infection by either isolate included melanosis, slow response, anorexia, ocular opacity, gasping, erratic, C-shape, and whirling. It can be concluded that S. agalactiae with more virulence genes show a higher level of pathogenicity. The presence of a virulent gene has the potential to be used as a basis for selecting candidate isolates and designing vaccine compositions as an effort to prevent streptococcosis infection in tilapia in Indonesia.

OVARY DEVELOPMENT, FSH AND LH GENES EXPRESSION OF INDONESIAN LEAFFISH, Pristolepis grootii (Bleeker, 1852), INJECTED WITH LUTEINIZING HORMONE-RELEASING HORMONE ANALOG

Indonesian leaffish, Pristolepis grootii (Bleeker, 1852), is an undomesticated freshwater fish species native to the rivers, flooded swamps, and tributaries of Indonesia. The fish is mainly captured for consumption. In order to prevent its extinction and supply its growing demands, the artificial breeding of the fish should be developed. The purpose of this study was to determine the optimum dose of luteinizing hormone-releasing hormone analog (LHRHa) for stimulating the female P. grootii gonadal development at a dosage of 0, 1, 10, and 50 µg kg-1 of fish. Female fish (20.0 ± 0.6 g) were adapted for 30 days in the rearing environment and then separated into 12 aquariums with six fish per aquarium. Fish were then reared for another 21 days and fed with Tubifex sp. The LHRHa injection was conducted twice on day-7 and 14. Fish bodyweight, gonadosomatic index, gonad histology, blood estradiol-17â, and FSH-â and LH-â gene expression were evaluated at day 0, 7, 14, and 21. The results showed that the injection of the LHRHa hormone stimulated the development of fish gonads and was better achieved with a higher concentration of LHRHa. The best treatment was observed by the administration of 50 µg kg-1 of LHRHa that produced the fastest development among all treatments. This study demonstrated that the LHRHa induction could potentially stimulate the gonadal development of the newly domesticated fish. To our knowledge, this is the first study that reported the success of the induction of female gonad development in the Indonesian leaffish P. grooti.KEYWORDS:

GROWTH AND EXPRESSION PATTERN OF GROWTH-RELATED GENES IN THE FAST-GROWING GIANT GOURAMI Osphronemus goramy

Growth improvement of the giant gourami through molecular assisted selection offers a breakthrough solution regarding the slow growth problem in culturing the fish species. However, gene molecular expression studies and gene mapping information are scarce for this species. This study aimed to evaluate the growth, expression of the growth-related genes and compare the gene expressions between fast-growing (FG) and slow-growing (SG) fish. The polymorphism screenings were also conducted within the GH sequence of the FG and SG populations. Fish growth was analyzed by measuring length and weight once a month. The expression levels of GH, IGF1, AMPK, ARS-I, ALT, and AST genes were analyzed using real-time PCR. Twenty-five days old fish were reared for 30 days. The fish were continuously reared separately based on their body weight (BW) for 85 days until reaching 140 days old. At the end of the rearing period, the BW growth rate of the FG population was 1.569-fold higher, and body length (BL) growth was 1.056-fold higher than the SG population. FG fish have higher gene expression than the SG fish, indicating the important role of gene expression in fish growth. The polymorphisms screening within the GH sequences showed no significant difference between FG and SG fish of giant gourami. These research results provide valuable information in developing the marker-assisted selection for growth traits in giant gourami.

SUBSTITUTION OF FISH OIL WITH PALM KERNEL OIL IN DIETS OF Oreochromis niloticus FRY: EFFECTS ON GROWTH, FEED UTILIZATION AND ECONOMIC ESTIMATES

This study assessed the impact of replacing fish oil with palm kernel oil (PKO) in the diet of Oreochromis niloticus fry on growth, feed efficiency and proximate composition. Three isonitrogenous (30% crude protein) and isolipidic (10% crude lipid) diets were formulated using palm kernel oil as a substitute for fish oil at 0% (PKO-0), 50% (PKO-50), and 100% (PKO-100). Two hundred O. niloticus fry with initial weight of 0.80± 0.25g were purchased from Water Research Institute Upper West, Ghana and transported to the Spanish Laboratory of University for Development Studies (Ghana) where they were kept and fed two times a day on commercial diet from Ranaan feed for two weeks. The fry was then stocked in triplicate groups in 60 L tanks (50 cm x 40 cm x 40 cm) at 20 fry per tank. At the end of the eight weeks feeding trial, there was a significant difference amongst the three treatments with respect to final weight, weight gain, feed conversion ratio, and specific growth rate. It was observed that the least mean values for feed intake, protein productive value, protein efficiency ratio, and protein intake occurred in fish fed PKO-0. There was a trend of increasing whole body moisture content as palm kernel oil increased. Fish fed PKO-0 recorded the lowest lipid content (7.48 ± 1.13%) in the whole body. From the economic analysis, it is evident that palm kernel oil is a cheaper source of lipid for tilapia. This study therefore recommends palm kernel oil as a substitute for tilapia diet.

DETERMINING THE OPTIMUM TEMPERATURE FOR GROWTH, FEED EFFICIENCY AND SURVIVAL OF DOMESTICATED INDONESIAN MAHSEER, Tor soro LARVAE

Temperature plays a pivotal role in the success of larvae production. Evaluation of the effects of different temperatures on growth, feed efficiency, and survival of domesticated Indonesian mahseer (Tor soro) larvae was carried out to determine an optimum rearing temperature. Five different temperature settings of 22°C, 24°C, 26°C, 28°C, and 30°C were used as the treatments arranged in triplicates, in indoor closed recirculating systems. The larvae were stocked in a rectangular glass tank with a stocking density of 150 larvae per tank and fed with a commercial feed (30% protein content) three times a day, about 10% per body weight over 61 days of observation. Measured parameters included the specific growth rate of total weight (SGRTW) and length (SGRTL), feed efficiency (FE), and survival rate (SR). The result showed that the treatments of different temperatures significantly affected the growth performance and feed efficiency of the larvae. The growth performance and feed efficiency of mahseer larva were much better at rearing temperature from 24°C to 28°C compared with those at 22°C and 30°C. There were no significant differences in SR in different temperatures tested. The SR was found to range from 86.44% to 100% in all treatments. Maintaining temperature ranging from 24°C to 28°C is the best rearing condition to achieve the optimum growth and feed efficiency of mahseer during the larval rearing period. The findings from this research could be set as a standard technique in larval rearing of Indonesian mahseer (Tor soro).

STRESS RESPONSES OF THREE SPECIES OF CYPRINID: COMMON CARP (Cyprinus carpio), BONYLIP BARB (Osteochilus hasselty), AND TORSORO (Tor soro) SUBJECTED TO OXYGEN DEPLETION

Fish in stressed conditions will show symptoms of a decreased physiological function. These symptoms include changes in the respiration system (gills, breathing frequency) and blood hemoglobin. Cyprinid fish are active fish that require high oxygen levels. In a minimum oxygen condition, cyprinid fish are easy to get stressed. Despite the extensive literature on cyprinid biology, comparison of declined physiological functions due to oxygen depletion in cyprinid are few and far between. The purpose of this study was to determine the physiological reactions and organ responses of three species of Cyprinidae, common carp (Cyprinus carpio), nilem carp (Osteochilus hasselti), and Torsoro carp (Tor soro) challenged to oxygen depletion. The study was conducted using 18 fishes for each species with an average body weight of 48.11 ± 4.24 g. Oxygen depletion challenge was done by placing the test fish in closed and non-aerated aquaria (40 cm x 20 cm x 20 cm). The dissolved oxygen level in each aquarium was measured every 30 minutes. Fish breathing frequency was calculated by the frequencies of mouth movement every 30 minutes. Histological examination of gills and blood was taken from healthy fish (at the beginning of treatment) and at LC50 (lethal concentration). The results showed that oxygen depletion reduced blood hemoglobin levels down to 5.1 ± 1.4 gram%, 3.3 ± 1.15 gram%, and 1.5 ± 0.71 gram% for goldfish, nilem, and torsoro, respectively. The respiratory rate varied from normal to depleted conditions. When depletion occurred, the respiratory rate increased and decreased again when the fish started to get weak. In normal conditions, the breathing frequency of goldfish was 60 beats/minute, nilem was 108 ± 20.8 beats/minute, and Tor soro was 144 ± 31.7 beats/minute. The highest respiration frequency occurred in tor soro fish in the 150th minute with a value of 216 ± 0.0 beats/minute. The fastest mortality at LC50% occurred in torsoro at 245.00 ± 17.32 minutes.

BIOCHEMICAL RESPONSES AND GENETIC EXPRESSIONS OF SYNTHETIC COMMON CARP POPULATIONS EXPOSED TO HIGH-AMMONIA REARING ENVIRONMENT

Carp is one of the leading freshwater aquaculture commodities in Indonesia. Further improvement of carp strains by the Research Institute for Fish Breeding (RIFB), Sukamandi, Indonesia, has produced a synthetic F2 carp. The strain is assembled from different strains of carps and has shown better growth and health characteristics. Considering that high environmental ammonia (HEA) has affected most carp grow-out systems, this study aimed to determine the performance of the synthetic carp populations in a high ammonia rearing environment. The treatments were rearing media of the synthetic carp seed populations added with and without (control) 200 mg/L NH4Cl arranged in three replicates. A total of 30 fish seeds/aquarium, weighed 10-15 g/fish, was used in the study. Dissolved oxygen levels were maintained above 2 mg/L using aeration. This study shows that higher tolerant carp populations had red blood cells of 232.66 ± 17.24 cells/mL, indicating a direct effect of high ammonia on red blood cell count (p<0.05). Cortisol levels of 80.90 ± 6.35 ng/mL in resistant carp indicate significant differences (p<0.05). The relative expressions of the HSP70 gene in the liver (Log10) ranged between 0.72 and 2.80. The values demonstrate that high ammonia-resistant synthetic carp have a higher relative expression ratio of the HSP70 gene than the less resistant group. This research concluded that the populations of synthetic F2 carp showed a degree of resistance against high-ammonia rearing conditions. When it is ready for aquaculture, this synthetic carp strain could be farmed in high density using intensive systems in HEA-affected artificial lakes and reservoir