II. LITERATURE REVIEWA. Biology Tilapia (Oreochromis niloticus)1. MorphologyTilapia have morphological characteristics that radius loud, pelvic fins thoracic, layout and taper-shaped subterminal mouth. Additionally, other marks that can be seen from the tilapia is a black body color and somewhat whitish. Part gill cover is white, while the local tilapia white somewhat blackish even yellow. Tilapia fish scales large, rough and neatly arranged. One third of scales back side of the front cover. Her body has a line linea lateralis that the disconnect between the top and bottom. Linea lateralis upper part extending from the gill cover to the back of the dorsal fin to the base of the tail fin. The size of the relatively small head with its mouth was at the head end and has a great eye (Kottelat et al., 1993).Body shape of tilapia (Oreochromis niloticus) is flat to the sides lengthwise. Having a vertical line on the body as much as 9-11 pieces, while the stripes on the fins red fruit numbered 6-12. On the dorsal fins are also oblique stripes. Eyes protruded andrelatively large eyes with white edges. Body relatively thick and sturdy compared tilapia fish. The lateral line (lateral line in the middle of the body) left off and continued with the line that lies further down (Susanto, 2007).The difference between male and female fish can be seen in the genital hole and secondary sex characteristics. In male fish, in addition to the anus is a hole in the form of genital small bulge tapering as a spending urinary tract and sperm. Body of male fish are also darker in color, with a jaw bone extends to the rear to give a solid impression, while females usually on the big belly (Suyanto, 2003).Morphological characteristic differences between male tilapia fish with tilapia females can be seen in Figure 1.Figure 1. Tilapia Tilapia males and females (Suyanto, 2003).Tilapia small size relatively quickly adapt, to the increase of salinity compared with indigo large size. Operational enlargement of tilapia have to pay attention to the time factor, land preparation and production facilities, enlargement method (Popma, 2005).In general, tilapia is very resistant to disease, which is caused by viruses, bacteria, fungi and excess tilapia with intensive system very guarantee of tilapia is not attacked by the disease, given the replacement of water continuously performed every day at least 20% (Pullin et al., 1992 ).2. TaxonomyTilapia originated from Eastern Africa. Tilapia has a flattened body shape in the vertical direction (compress). The position is located in the tip of the nose mouth (terminal) and can disembulkan (Suyanto, 2003).According Saanin (1984), tilapia (Oreochromis niloticus) hasclassification as follows:Kingdom: AnimaliaPhylum: ChordataClass: OsteichthyesSub-class: ActinopterygiiOrder: PercomorphiSub-order: PercoideaFamily: CichlidaeGenus: OreochromisSpecies: Oreochromis niloticus3. GrowthAccording to Effendi (1997), a growth of length or weight gain in units of time, whereas the growth in a population is a growing number. Growth in the individual is the result of tissue accretion mitotic cell division. According Dwijoseputro (1986), the future growth is the addition of the size and the number of cell bodies.Throughout his lifetime fish isometric and allometric growth. Isometric growth is proportionally to changes in the body that is the length of the body, accompanied by weight gain, whereas the allometric growth is temporary growth as well as weight gain due to the maturation of the gonads (Effendi, 1997).Fish growth is influenced by two factors: internal factors and external factors. Internal factors are factors originating from within the body, some of which included internal factors including heredity, age, resilience of the body, as well as the ability to digest food. What is meant by external factors ie factors that come from outside the body of the fish. Some of which include external factors include the amount of food, the number of population,the nutritional content of food, as well as environmental parameters (Lagler, Bardach, and Miller, 1962).The rapid growth in tilapia obtained from fish are male, male tilapia grow faster with an average growth of 2.1 g / day compared with, tilapia females only grew an average of 1.8 g / day, then more economical, if in a pond just stocked tilapia fish are male (Thomas, 2005).Table 1. Solid Spreading, Growth and Production TilapiaNo.Age / Size SeedsSize / Solid TebarProduction resultPond conditions12-3 g / head(3 weeks)100,000 / ha20-40 g(70,000)nursery Pond220-40 g / tail(5-8 weeks)6000-8000 / ha(tail)6000-8000 / ha(tail)400 g(5-6 months)700 g(8-9 months)Natural feed of traditional farmsNatural feed of traditional farms320-40 g(5-8 weeks)20000-28000 / hahead / ha20000-28000 / hahead / ha20000-28000 / hahead / ha200 g / tail(3-4 months)400 g / tail(5-6 months)700 g / tail(8-9 months)Intensive additional feed.Substitution water 20%Intensive additional feed.Substitution water 20%Intensive additional feed.Substitution water 20%Source: Popma (2005).The rapid growth, other than specified by fish lower osmotic work also depends on the efficiency of feed utilization. At the time of heavy rainfall, for example the growth of a variety of aquatic plants will be reduced so that disrupt the growth of the water and are not directly interfere with the growth of tilapia. Tilapia will also be faster growth if maintained in a shallow pool of water, because in a shallow pond plants and algae growth is faster than in a deep pool. There are others that pool at the time of manufacture using organic fertilizer or manure will also make the growth of aquatic plants better and tilapia also be more rapid growth (Ferraris et al., 1986).4. HabitatTilapia generally live in fresh waters, such as rivers, lakes, reservoirs, swamps, paddy fields and irrigation canals, but a wide tolerance to salinity so that tilapia can live and breed in brackish waters with salinity preferably between 0-35 ‰. Freshwater tilapia can be moved to brackish water, with a gradual adaptation process of tilapia are still small 2-5 cm, more resistant to changes in the environment of the fish was great. Displacement sudden stress can cause the fish to die even (Kordi, 2000).Tilapia has a good ability to adapt to its surroundings. These fish have a high tolerance for the environment, so it can be maintained in the watery lowlandsbrackish or high ground to low temperature (Trewavas, 1982).Tilapia are able to live at a temperature of 14 - 38oC with the best temperature is 25-30oC and with a pH value between 6 to 8.5. It is most influential to the growth is the number of salinity or salt content 0-29% as the maximum levels to grow well. Although tilapia can live dikadar salt to 35%, but the fish have been unable to grow properly (Suyanto, 2003).5. ReproductionTilapia is bred and fast growth. In addition, these fish have a high tolerance to salinity changes to 30 PROMIL. Tilapia can reach adulthood at the age of 4-5 months and will achieve maximum growth for childbirth until aged 1.5 - 2 months. At the time of tilapia is older than 1 year about - about weighing up to 800 g and is currently tilapia can be issued from 1200 to 1500 larvae each time spawning, and can last for 6-7 times a year. Before the fish spawn male tilapia always nest in the bottom waters, the area will be maintained, and a territorial areas themselves. Tilapia males become aggressive during the breeding season. male fish are growing faster and larger than females. Spawning process begins with the manufacture of the nest by the male fish in the form of a round indentation with a diameter comparable to the size of her body at the base of the territorial waters (Suyanto, 1988).Female fish are ready to spawn will release the eggs in a hole that has been prepared by the male and the eggs will be fertilized by the male fish. Once the egg is fertilized, the eggs will be collected by the female fish and incubated in the mouth until they hatch. Old hatch in the mouth ranged between 1-2 weeks depending on the water temperature does spawning places. After the larvae released by females, the larvae will return to the mouth of the mother if there was danger. Calm water conditions will be favorable to the growth and breeding of tilapia. In an effort to obtain an optimum level of spawning, tilapia are polygamous, the sex ratio is recommended 1 male for 2 females on an area of ​​10 m2 (Djarijah, 1994).Theoretically, tilapia can breed naturally, semi-made and artificial. Spawning naturally are spawning naturally in the container / spawning without any provision of hormonal stimulation. Semi-artificial spawning is spawning with hormonal stimulation process but the process of ovulation occurs naturally in the container / spawning. Artificial spawning occurs with administration of hormonal stimulation and ovulation and fertilization done artificially. Spawning tilapia for production purposes should be done naturally and semi-made, this is due to biological spawning and hatching eggs of tilapia are more likely to do naturally (Djarijah, 1994).In natural spawning, spawning is done by pairing with a male parent females with a ratio of 1: 3, stem density is 1-2 breeding females per square meter to about 50 cm into the pond. To induce spawning should dilakuakn environmental manipulation that is by draining the pool, a new water flow into the pond and the provision of sandy mud on the bottom of the pond that used to be easy to make a nest parent. Feature spawning has occurred is warps spherical bottom of the pool with a diameter of 30-50 cm. The duration of spawning until the seeds separated from maternal care is approximately 14 days (Djarijah, 1994).6. Feed the fishAccording to Amri and Khairuman (2003), tilapia fish belonging eating everything (Omnivore), so that it can consume food, in the form of animals and plants. Tilapia larvae food is, zooplankton such as Rotifera sp., Daphnia sp., As well as algae or moss attached to the objects in his habitat. When has grown tilapia can be given additional food, fine bran, coconut cake, pellets, pulp and others.Zonnevald et al. (1991) said that the optimum level of protein in fish feed required for growth is 2-3 times higher, than warm-blooded animals. Omnivorous fishes such as tilapia, require the protein content in the feed of 35% - 45% in its infancy.Table 2. Number and Frequency Feeding Fish Seed Based on AgeMonthFeed Percentage (%)Frequency of FeedingI15-253 timesII6-103 timesIII2-54-5 timesIV2-54-5 timesSource: DG Fisheries, 1990.Table 3. Feed Protein Needs of Some Species Tilapia (Oreochromis niloticus)Fish speciesProtein Needs (%)Size (gr)Oreochromis niloticus361.5 to 7.5Oreochromis niloticus25fingerlingOreochromis aureus342.5 to 7.5Oreochromis aureus30fingerlingOreochromis zilli35fingerlingOreochromis mossambicus400.5 to 1.0Source: Lovell (1988), Tacon (1987), NRC (1983)Yuwono, Nganro, and Sahri (1996) states in the cultivation to meet the needs of feed each day required types of artificial feed (pellets). Pellets are widely used in the cultivation as required by fish such as proteins, fats, and carbohydrates that have been adapted to the needs of the fish. Pellets also contain vitamins, minerals, and other additives. Additionally pellets is also practical to use because it is available in various sizes and can be stored for a long time.Pellets are used should have a nutrient content according to the needs of fish and in good condition. Feed must not endanger the lives of juvenile maintained, does not containtoxic, does not pollute the environment, and does not act as a host organism and pathogen (Isnansetyso and Kurniastuti, 1995).Table 4. Composition of nutrients in artificial feed (pellets)No.ParameterPercentage (%)1protein50.132Fat9:153Carbohydrate17.814Fibers (Row)1:065Ash15:366Water6:49Source: Sahwan (2001).B. Organic OsmolitOrganic Osmolit is one type of amino acid, if this organic osmolit accumulates in the cell will act as osmoprotektif compound (Campbell et al., 2004).Taurine contains amino groups, but does not have a carboxyl group necessary to form a peptide bond. This causes the molecule to function as builders of the structure of proteins. Taurine is an amino acid derivative compounds for non-essential human nutrient because it internally can be synthesized from the amino acid methionine or cysteine ​​and pyridoxine (vitamin B6). In certain circumstances, such as during development, taurine is necessary, so that taurine is found in milk, eggs, meat, and fish. In human metabolism, taurine has two roles, namely as a neurotransmitter and as part of the emulsifying bile acids. Taurine serves as osmoprotektifin the process osmoregulasi ie as a supplier of energy in the process osmoregulasi (Strange and Jackson, 1997).Taurine has an important role in metabolism, particularly in the brain. Besides active function in tissues such as the brain and heart to help stabilize cell membranes, taurine also has the function of the gallbladder, eyes and blood vessels and seems to have some antioxidant and detoxifying activity. Taurine can help the movement of potassium, sodium, calcium, and magnesium in and out of cells and thus helps generate nerve impulses. Taurine is also an inhibitory neurotransmitter (Resep.web, 2009).Taurine with bile acid conjugation give significant effects to dissolve cholesterol and increase its excretion. Medically, taurine is used to handle cases of heart failure, cystic fibrosis, diabetes, epilepsy, and several other conditions (Resep.web, 2009).According to Strange and Jackson (1997), organic osmolit a small organic molecule that works as an intracellular effector. This solution plays an important role in cellular osmoregulation and osmoprotektif process. In mammalian cells, organic osmolit divided into three major groups namely polyols (sorbitol, myo-inositol), amino acids and derivatives (taurine, proline, alanine), and metilalamin (betaine, gliserofosforilklorin).Taurine is a free amino acid derivative of the most important in the body. Taurine is a sulfur-containing compound β amino acids with molecular formula H2NCH2CH2SO3H. Taurine is not including the group of proteins, but taurine is essential for the metabolism of the body and found in high levels in the brain, heart, and retina of the eye which provides several important functions (Gaull, 1986).Figure 2. Structure of taurine (3dchem, 2012)Taurine is an organic compound containing cluster osmolit sulfihidril and helps protect cells from hypertonic. Taurine can be as a source of carbon, energy, and nitrogen (Lie et al., 1999).Scientists in China have discovered that taurine plays an important role in the function of leucocytes, white blood cells that are the backbone of the immune system. Two other recent studies highlight the ability of taurine as an antioxidant (NaturalNews, 2009).C. Level of Maturity gonadsGonad maturity is a certain stage of gonadal development before and after spawning. During the reproduction process, some of the energy usedfor gonadal development. The weight of the fish gonads will reach a maximum instantaneous fish to spawn and then will decline rapidly during the spawning process goes on until completion. According to Effendi (1997), generally female fish gonad weight gain during the mature stage of the gonads can reach 10-25% of the weight of the body and the male fish of 5-10%. Further stated that the rneningkat maturity level of gonads, the diameter of the eggs in gonads will become greater. This opinion is reinforced by Kuo et al. (1974) that sexual maturity in fish characterized by the development of the average diameter of the eggs and through the distribution of the size distribution of the eggs.Damandiri (2009) states in outline, fish gonad development can be divided into two stages, namely stage gonad growth of fish until the fish become mature sex and the next is the maturation of gametes. The first phase took place from hatching fish to reach sexual maturity, and the second phase begins once the fish reach adulthood, and continues to develop during the reproductive function is still running normally. Further said that mature gonads in particular fish is influenced by two factors: environmental factors and internal factors. Environmental factors, among others influenced by temperature and the presence of the opposite sex, internal factors include differences in the species, age and other physiological properties.The characteristics of the male parent and a female parent who has a mature gonads (Damandiri, 2009) are as follows:1. Parent Malesa. When distripping white spermb. Having a body color is black or dark redc. White on the chind. On the genitals tapered with a clean white colore. At the end of the tail fin and dorsal fin bright red.f.2. Femalesa. Genital pavila mature female gonad is red, upright position against the ventral part.b. The genitals are rounded and reddishc. When distripping issued amber colored eggs.d. When distripping issued amber colored eggs.e. Belly bulge or a little bit wide.f. Body color black or dark red.g. On the chin slightly tinted whiteh.According Dadzie and Wangila (1980), the level of maturity of the gonad of tilapia are classified into five levels as to which is presented in Table 5.Table 5. Maturity Level gonads Male and Female NilaNo.TKGHistologyFemaleMale1IThe ovary is still small, transparent, and young oocytes are only visible under a microscopeTestis such as yarn, shorter, ends in the body cavity, clear colorTable 5. Maturity Level gonads ... (continued)2IIOvarian bright yellow, and oocytes can be seen with the eyeTesticular size larger, milky white coloration, shape more clearly than TKG 14IVOvary large, brown, many oocytes that are up and easily separated.As TKG III seems clearer, testes the more solid and more full body cavity, a milky white color5VOvarian bright yellow, size, reduced because the eggs that have been cooked was removed.Testicular the back flat and the part near the discharge still dryIn adult fish, the ovaries are generally numbered pair. oocytesevolving located in the follicle lining. Follicle lining consists of the inner layer of cells (granulosa) and the outer layer (theca cells). Oocyte develops as a result of the accumulation of yolk (vitelogenesis) in the cytoplasm. Vitelogenesis will thrive in full and then undergoes maturation and ovulation due to the influence of environmental and hormonal. After ovulation then the next will occur division process and oocytes has been egg perfectly and ready to be fertilized (Murua and Kraus, 2003).In one gonad maturity level (TKG), the composition of the eggs contained is not uniform, but consists of a wide variety of eggs. Eggis the beginning for a living creature, that its formation process is already started on phase differentiation and oogenesis namely the accumulation vitelogenin into follicles (vitelogenesis).The development of the egg diameter increases with increasing TKG (Murua and Kraus, 2003).D. Specific Growth Rate / Specific Growth Rate (SGR)According Wahyuningsih and Barus (2006), the growth can be defined as a form of long growth in the size and weight at a certain time or a change in calories stored as somatic and reproductive tissues. In the process the growth rate will exceed the rate of catabolism anabolism. According to Effendi (2002), the growth is a complex biological process which will be influenced by many factors where the growth will indicate the length, weight in a unit of time.According Lagler, Bardac, and Miller (1962), influenced the growth of two factors, namely:1) Internal FactorsIs a factor derived from the body difficult to control, among them is heredity, sex, and age.2) External FactorsThe main external factors that affect the growth was the food, the number of population, parasites, disease, and environmental water quality parameters.Specific Growth Rate / Specific Growth Rate (SGR) can be determined by calculation through the formula (Asmawi, 1983):SGR = T(LnWt - LnWo)× 100%Information:SGR = Specific Growth Rate (Specific Growth Rate)Wo = Weight (weight day 0 (g))Wt = Weight day t (g)T = Length Maintenance (days)





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