fish prefer intermediary salinities especially "how salinity influences growth?" Paper ID:

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1 external environmental conditions (Brett, ). Different external factors effect on fish that temperature and environment s important of them (Brett, 1979). Man demonstrated the influence of external sa capacities in fish (see Table1). It is importan that have migration between different locati salinity considered because the fish that men not influenced by salinity changes during t and growth are rare. In other study it determ fish prefer intermediary salinities especially (Boeuf et al., 2001).So the question that can "how salinity influences growth?"

2 2010), but they are limited in freshwater Bombata and Busari, 2003; Albert et al., ). It has shown that some freshwater te incubated and hatched in 5ppt salinity but hatching rate of freshwater teleost decrease (Gbulubo and Erondu, 1998).The other rep than 5ppt salinity tolerance in Zebrafish (B (Sawant et al., 2001). Rockwell (1956) r mortality in Pacific salmon, Oncorhynchus keta 19 to 40 days after incubation period but, salinity less than 6ppt has not very leth species. Rubin (1994) Also showed, (For found in the Baltic Sea), a small negative inf Table 2: The effects of different salinity tre s Treatments 0.5 Gastrula 2.56±0.6 a S- type heart formation 5.56±2.4 a

3 Figure 2: Different abnormalities samples incubation period of s-type heart format embryonic developmental stages according Ginsburg, 1992). A: the normal embryo i formation stage. B: retarded embryo. C: notochord formation. D: deformity in head a E: lack of head and fore part of body and d deformity in head (lengthened than norma embryo with deficiency in back bone Khato

4 substantial enough to increase growth. however, fail to show isotonic salinity maximal growth in salrnonids; growth rate fresh water in studies by Shaw et al. (197 (l981), McKay and Gjerde (1985). A theor the energetic cost of osmoregulationins a that it would be very low, being less than metabolism (Eddy1982). Accordingly, chan rate of that magnitude would be very dif accurately. Studies such as that of Bulliv reported no significant differences betwee rates of yearling chinook salmon(bncorhync reared in fresh water, half strength sea wate seawater, support those theoretical estimates Few studies have made simultaneous m growth and metabolic rates of salmonid salinity. Here, we focus on a study thatmo conducted. John et al. (1991) examined g rates, and ionic regulation in juvenile rainb

5 ± ± ±0.0 Stellhead trout ± ± ± ± ±0.01 Stellhead trout ± ± ± ± ±0.01 As results, salinity had a negative effect on three species, particularly at salinities ab level. These findings are in agreement w (1975), Clarke et al. (1983) and McKay an

6 species, such as rainbow trout, steelhead tr salmon fry were optimum in fresh water, th at this life stage. Isotonic salinity did not pro growth advantages in the present stu hypothesis that it would provide the demands for ion-osmoregulation. Compa studies indicated that optimal salinities metabolic rates were influenced by specie season. Although the oxygen consumption d the energetic cost of ion-osmotic regulatio salinity, attempts to quantify this cost were by other metabolic processes which respo salinity. As one contributing factor in salinity adapt growth hormone (GH) and insulin-like grow 1) has been frequently emphasized in teleo trutta and rainbow trout, Oncorhynchus my Bern 1992; Shimizu et al. 2007), and seve species such as tilapia, Oreochromis mossam

7 on the development of Pe CoregonuslavaretusmaraenoidesPoljako AnnalesZoologiciFennici..41, [3] Almeida, D. V., C. D. G. Martins, M. F. C. Lanes, A. Bianchini, and L. F Growth hormone transgenesis affects os energymetabolism in zebrafish, Danio Research 22: [4] AristizabalAbud, E.O., Effects weight on routine metabolism in the MicropogoniasfurnieriŽDesmarest , [5] BATHR,. N., AND h;. B. EDDY balance in rainbow trout QSalmog transferred from fresh water to seawater [6] Beckman, B. R Perspectives on discordant relations between insulin-lik

8 on the viability of Persian sturgeon, A embryos during different develo Scientific Journal of Animal Science, 2( [35] Laurent, P., Dunel-Erb, S., 1984.T morphology and function. In: Hoar, W Physiology, 10B. Academic Press, [36] Likongwe, J.S., Stecko, T.D., Stauffer, R.F., Combined effects of water salinity on growth and feed utilization tilapia OreochromisniloticusŽLinne 146, [37] LISTERD,.B., AND C. E. WALKER1 of flow control on freshwater survivd o chinook salmon in the Big Qualicum Cult.37: [38] Madsen, S.S., Bern, H.A., Antago and growth hormone: impact on seawa

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