Perawatan Fresh Water Cooler Pada Sistem Pendinginan Mesin Diesel Penggerak Generator Listrik Di Kapal Navigasi Milik Distrik Navigasi Kelas I Ambon

Mesin diesel merupakan mesin yang paling banyak digunakan sebagai sumber energi mekanisdiatas kapal. Mesin diesel adalah salah satu mesin pembakaran dalam yang menghasilkan energi gerak danenergi panas. Panas berlebihan pada mesin mengakibatkan kerusakan mesin. Untuk mencegah panas yangberlebihan pada mesin diesel maka diperlukan pendinginan yang tepat, salah satu komponen yang bertugassebagai pendingin mesin adalah fresh water cooler (FWC) berupa heat exchager. Gagalnya FWC untukmendinginkan air tawar sebagai media pendingin mesin mengakibatkan kerusakan mesin. Perawatan FWCmerupakan tindakan untuk mengembalikan kemampuan FWC pada kondisi yang prima untuk mendinginkanfresh water dan mencegah terjadinya kegagalan mesin akibat temperatur mesin yang melebihi batas yangditentukan. Adapun tujuan penelitian ini adalah untuk mengetahui bagaimana tindakan perawatan yangdilakukan pada FWC sistem pendinginan mesin diesel penggerak generator listrik menggunakan metode studikasus yang pada kapal navigasi, hasil penelitian dipaparkan secara diskriptif. Kesimpulan penelitian iniperawatan FWC pada kapal navigasi sudah berjalan dengan baik, dilaksanakan sesuai instruksi kerja petunjukmesin, sesuai jadwal, hasil perawatan didapat temperatur mesin kembali sesuai dengan yang diharapkan

DYNAMICS OF GEARS, FLEETS, CATCH AND FISHING SEASON OF SMALLSCALE TUNA FISHERIES IN LABUHAN LOMBOK, WEST NUSA TENGGARA

In Indonesia, about 80% of fishing activities are small-scale and play major role both economically and socially. Previous studies mostly concentrated in Java, while in eastern part of Indonesia the information still scarce and limited. The study was conducted from January to December 2013, describes in detail the gears, fleets and catch dynamics of the small-scale tuna fisheries operating based in Labuhan Lombok Coastal Fishing Port (PPP. Labuhan Lombok). Small-scale tuna fishery in Labuhan Lombok are characterized by the small boats less than 10 GT, operating both troll line and hand line simultaneously, targeting large tuna, skipjack tuna and small tuna. Fishing season starts from April to August and influence by southwest monsoon wind and the presence of middleman as the connector between fishers and the market are the main character of the small-scale fisheries business in this area

INDONESIAN HATCHERY REARED SEABASS LARVAE (Lates calcarifer), ASSOCIATED WITH VIRAL NERVOUS NECROSIS (VNN)

Mass tuortality atuongs seabass larvae, Lates calcarifer, reared in hatcheries in East and Bali due to viral nervous necrosis were investigated. outbreaks of the disease occured from August to Novetnber 1997

SEX DIFFERENTIATION AND GROWTH PERFORMANCE TRIALS OF TWO GENOTYPES OF TILAPIA ADMINISTERED WITH ANDROGENIC HORMONE

The aim of this study was to know the effect of dietary administration of androgenic hormone methyltestosterone on two sex genotypes of Nile tilapia i.e. XX and XY genotype, especially to sex ratio, growth rate, survival rate, food conversion ratio and harvest yield. XX genotype was obtained from XX male matted with XX normal female, and XY genotype was obtained from YY super-male matted with XX normal female. Methyltestosterone was administered seven days after larvae hatching for 28 days. After that, the fish were reared in hapas for 60 days and then placed in growout ponds for 120 days period. As check population, mixed sex genotype was used consisting of 50% XX genotype and 50% XY genotype. The result showed that dietary administration of methyltestosterone in XX genotype significantly increased male proportion about 82.42%, compared with control XX population (7.55%). The same treatment in genotype XY did not significantly increase the proportion of male (85.13%), compared with control XY population (79.81%). In grow-out ponds, all male population (XY genotype and sex reversed from XX genotype) have better growth rate than all female and mixed sex populations. Dietary administration of methyltestosterone in both of XX and XY genotypes increased growth rate of these populations resulting in the increased of total biomass at harvest time

Meteorological and physical conditions of Salt Pan Areas with Filtering-Threaded Technology (TUF) in Cirebon Regency, Indonesia

Salt pans in Indonesia are commonly set in batch operation and highly depend on the meteorological condition. Moreover, the common salt pans are considerably limited in the area (averagely 0.5-1 Ha) as it is not organized by industries or governments; local farmers instead. However, with such confinement, there are some salt pans particularly with filtering-threaded technology system (TUF system) that successfully produce salt with high production (>100 tons/Ha/season) and grade-1 quality. The present study was aimed to get insight on the meteorological condition at the salt pans using TUF system and the physical condition of the sea brine obtained from the TUF in the local salt pans in Cirebon Regency. Measurements on temperatures (air, brine and soil), humidity, wind direction and speed, brine conductivity, brine density and salinity were conducted at the pre-crystallizer pond, brine storage pond, channels, the condenser, and the reservoir. The meteorological parameters were recorded hourly using Automatic Weather Station and the data were taken during 49 hours ly, from August 26-28, 2014 started at 04.00 pm. Meanwhile, the physical parameters of the brine were measured every three hours using water quality meter. The results showed that the meteorological condition, brine physical condition, and the process occurred during salt production were still in agreement and met the theoretical condition or modeling. Even though the relative humidity and some wind speed in the present study area were out of the standard criteria recommended (5m/s for wind speed), the study showed that salt still can be produced in condition of relative humidity (52-88%), wind speed (0.2-5.7 m/s), and ambient temperature (23.2-32.4 oC). Interestingly, it is found that brine thickness and volume could be adjusted to get an optimum temperature of brine (reached 36.2 oC), in order to enhance the evaporation process. The highest soil temperature (34.7 oC) was found at 15.00 in the pre-crystallizer ponds. Meanwhile, the lowest temperature (26.7oC) was found early morning at 04.00 in the reservoir pond. Brine in the pre-crystallizer had highest thermal storage capacity during daytime (06.00-16.00), whereas soil in the pre-crystallizer tended to store heat during the nighttime (18.00-22.00). Brine and soil temperature fluctuation indicate that solar irradiation and convection process transferring heat energy from soil to brine occurs and also took an important part in the evaporation process. It therefore can be concluded that by understanding the condition of meteorology at the salt pan areas and the brine characteristic obtained, the appropriate technology resulting high-quality and quantity salt production could be devised

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

MICROSATELLITE GENETIC VARIATION IN CULTURED POPULATIONS OF AFRICAN CATFISH (Clarias gariepinus) IN INDONESIA

African catfish, Clarias gariepinus, is one of economically important farmed species in Indonesia. To support the development of aquaculture industry, high genetic quality of both broodstock and seeds is required and breeding program is considered as viable option. Information on genetic variation of the populations being considered to form a base population may give insight toward the appropriate strategy to be implemented in breeding program. This study was aimed to assess genetic variation in farmed populations of catfish in Indonesia using microsatellite markers with special emphasis on their use to develop breeding program. Three populations of farmed catfish, namely Dumbo, Paiton, and Sangkuriang were collected. Fifteen individuals representing each population were screened for microsatellite variability using seven primer sets (cga01, cga02, cga03, cga05, cga06, cga09, cga10). Results found that with exception of two loci (cga01 and cg02) which had a slight increase, the other four loci showed reduction in the number of alleles ranging from 35% to 80% depending on loci. Farmed populations also showed heterozygote deficient and inbreeding level, being the highest was found in Sangkuriang and the least was observed in Dumbo population. Individuals within populations contributed most (95%) while interpopulation variation accounted for only 5% of the total genetic variation. Populations of Dumbo and Sangkuriang were genetically similar while populations of Paiton were genetically different from both Dumbo and Sangkuriang. Viewed from genetic perspective, by combining all information emerging from this study, the best possible strategy to establish a base population with broad genetic base and less inbreeding would be to combine all the populations into a synthetic base population

EMBRYONIC AND LARVAL DEVELOPMENT OF A RED STRAIN OF THE EGYPTIAN AFRICAN CATFISH (Clarias gariepinus Burchell, 1822)

Egyptian African catfish is one of several African catfish (Clarias gariepinus) strains introduced to Indonesia. Several breeding activities using that strain in Sukamandi resulted in some individuals with redish-yellow body colour (a red strain). Biological informations related to aquacultural aspects of that red strain were still scarce. The present study aimed to elucidate the embryonic and larval developments of the red strain compared to those of the black (normal coloured) one, using the progenies obtained from artificial spawning of each red and black coloured brooders. Results of the present study revealed that embryonic developments of the red and black strains were similar. Their larval development were also quite similar, however, both larvae could be distinguished based on the pigmentation. The red strain larvae were golden-red-yellowish in colour, while the black strain larvae were greyish covered with dense melanophores. Total length of the red strain larvae tended to be lower than those of the black strain

CHARACTERISTICS OF VIRAL PROTEIN, VP-15, OF WHITESPOT SYNDROME VIRUS ISOLATED FROM INFECTED TIGER SHRIMP Penaeus monodon (Fabricius, 1798)

White spot syndrome virus (WSSV) has caused mass mortality on tiger shrimp (Penaeus monodon) culture and adversely affects prawn industry worldwide including Indonesia. It is well known that the protein structure of WSSV plays an important role in the virus infection and morphogenesis process. A viral protein structure called VP-15 is located in the nucleocapsid of virion virus. The protein structure involves in the life cycle of WSSV in host cells. A gene encoding VP-15 could be involved in constructing the RNA interference (RNAi), so it is needed to isolate and characterize for RNAi technology purpose. The study was aimed to isolate and characterize the VP-15 from the infected WSSV tiger shrimp. The characterization of VP-15 was undertaken through assessment of nucleotide sequence, amino acid deduction, alignment nucleotide/protein searches using Genetyx and BLAST program, and dendrogram construction analysis. The results showed that VP-15 was successfully isolated in form of ORFDNA with a fragment size of 243 bp. The phylogenetic tree analysis revealed three clusters corresponding to the time (year) of isolates collection. The VP-15 consisted of 80 amino acids, two start codons (ATG), one stop codon (TAA), and one Kozak context (AAAATGG). Hydrophilic amino acid was the highest composition (44.2%), followed by neutral (31.2%) and hydrophobic (24.6%) amino acid groups. The VP-15 was rich in amino acid of lysine (21.3%), arginine (22.9%) and serine (24.6%). The successful isolation of VP-15 is a very important step in providing a basic yet suitable material in constructing the dsRNA vaccine to control shrimp diseases in aquaculture