IJA Volume 59, Issue 4, 2007

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    Masculinization of African Catfish (Clarias gariepinus) Treated with Gokshura (Tribulus terrestris)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2007) Turan, Funda ; Cek, Sehriban
    The present paper describes the effects of Tribulus terrestris, a masculinization agent, on the sex reversal of African catfish, Clarias gariepinus. One-day-old hatchlings were immersed in water containing an extract of T. terrestris at a rate of 0, 3, 6, or 9 g/30 l water for 30 days. The 9 g treatment resulted in 80.42% male populations. Morphological and histological examinations of the gonads in all groups revealed no intersex fish. Histological examination of fish treated with T. terrestris revealed no damage to the testes or ovaries. Despite differences in sex ratio, growth rate, ovaries, and testes, fish treated with T. terrestris were histologically similar to fish from the control groups. Survival ranged from 72% in the 3 g group to 80% in the 9 g during treatment and did not significantly differ from the control (p>0.05). The best growth was obtained in the 9 g treatment.
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    Effects of a Probiotic Bacterium, Lactobacillus acidophilus, on the Growth and Survival of Pearl Oyster (Pinctada margaritifera) Spat
    (Israeli Journal of Aquaculture - BAMIGDEH, 2007) Subhash, S.K. ; Lipton, A.P.
    The present study investigated the effect of a probiotic bacterium, Lactobacillus acidophilus, on the growth and survival of pearl oyster, Pinctada margaritifera, spat. The probiotic bacteria was fed together with a microalgal feed at 1:1 or 2:1 while control groups received no probiotic sup- plementation. The probiotic groups had significantly higher survival (78.7±8.1 and 85.7±2.9%, respectively) than the control groups (60.7±1.2%). Weight and length also increased significant- ly. The weight gains in the probiotic groups were 349.8±0.44 mg (1:1 level) and 396.8±0.49 mg (2:1 level) mg, compared to 300.9±0.51 mg in the control. The increases in dorso-ventral mea- surement were 20.08 mm (1:1 level) and 21.04 mm (2:1 level) in the probiotic groups, compared to 14.22 mm in the control.
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    Embryonic and Pre-Larval Development of Shabbout (Barbus grypus H.)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2007) Sahinoz, Erdinc ; Dogu, Zafer ; Aral. Faruk
    As a preliminary step towards assessing its aquaculture potential, egg development and artificial breeding in shabbout (Barbus grypus Heckel 1843) was studied. Artificial insemination was achieved by mixing eggs and a sperm-testes extract. The fertilization rate was 60%. Diameters of fertilized eggs ranged 2.58-2.70 mm. The perivitelline space formed 20 min after insemination and contained no oil droplets. A blastodisc split two blastomeres of nearly equal size 80 min after insemination and first cleavage occurred 4-4.5 h after insemination. The gastrula stage was completed after 12.5 h and the embryonic body formed after 14 h. The first somites were observed at 28 h and the first heartbeat at 72 h. The first hatched larva appeared at 84 h and all eggs hatched within 92 h. The mouth opening occurred after 188 h. Head pigmentation was nearly complete together with the formation of the tail fin by 480 h, after which the tail fin gained its homocercal formation and the pigmentation spread throughout the body.
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    Reproductive Performance of Wild and Hatchery-Reared Black Sea Salmon
    (Israeli Journal of Aquaculture - BAMIGDEH, 2007) Sahin, Temel ; Akbulut, Bilal ; Cakmak, Eyup ; Cavdar, Yahya
    Spawning period, total fecundity, egg size, and fertilization and hatching rates of wild and hatch- ery-reared Black Sea salmon (Salmo trutta labrax Pallas, 1811) were investigated. Wild brood- stock consisted of 15 females (4-5 years old) with a mean weight of 1773.2±1014.4 g. Hatchery- reared broodstock consisted of 28 females (3 years old) with a mean weight of 869.5±319.6 g. The spawning period lasted from mid-November to the beginning of January. Mean total fecun- dity was 3524.6±2106.9 and 1931.3±915 eggs/female for wild and hatchery-reared broodstock, respectively, and mean egg diameters were 5.2±0.20 and 5.0±0.24 mm. Fertilization and hatch- ing rates were 98.4±1.71% and 88.1±8.78% for wild broodstock and 97.9±1.84% and 83.1±15.77% for hatchery-reared. The reproductive parameters of wild and hatchery-reared Black Sea salmon in northeastern Turkey were similar to those of other salmonid species.
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    Color Enhancement in the Ornamental Dwarf Cichlid Microgeophagus ramirezi by Addition of Plant Carotenoids to the Fish Diet
    (Israeli Journal of Aquaculture - BAMIGDEH, 2007) Harpaz, Sheenan ; Padowicz, Daniel
    The present research examined the effects of adding carotenoids from oleoresin paprika to fish feeds for ornamental dwarf cichlid, Microgeophagus ramirezi. The growth rate, survival, carotenoid accumulation level, and color intensity were evaluated. Post larvae and near-adult (three months old) fish were tested to determine when carotenoids are better assimilated. The addition of carotenoids had no effect on the growth rate or survival in either life stage, however, they had a clear effect on color enhancement. After 45 days, near-adult fish that consumed carotenoid-supplemented diets at 60, 120, or 240 mg/kg had significantly higher levels of carotenoids (72.19±4.55, 84.81±5.29, and 86.55±4.50 μg/g dry matter, respectively) than con- trol fish (33.69±1.06 μg/g), with no significant differences between treatments. After 75 days, post larvae that consumed 240 mg/kg carotenoids accumulated significantly more carotenoids in their body (59.34±3.93 μg/g dry matter) than fish that consumed only 60 mg/kg carotenoids (40.53±2.37 μg/g dry matter) or no supplemental carotenoids (29.18 μg/g dry matter). Visual examination revealed a strong correlation between level of pigment accumulation and color appearance in the fish. Results indicate that addition of 60 mg oleoresin paprika per kg diet is sufficient to obtain good coloration in M. ramirezi.
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    Effects of 2,2-Dichlorovinyl Dimethyl Phosphate (DDVP) on Hsp70 Gene Expression in Rainbow Trout
    (Israeli Journal of Aquaculture - BAMIGDEH, 2007) Erdogan, Orhan ; Atamanalp, Muhammed ; Sisman, Turgay ; Aksakal, Ecrument ; Alak, Gonca
    2,2-Dichlorovinyl dimethyl phosphate (DDVP) is used to control insects on crops, household, and stored products, and treat external parasitic infections in farmed fish, livestock, and domestic animals. Ectoparasitic copepods can cause severe skin damage in fish that may lead to death through osmoregulatory failure or infection by opportunistic pathogens. There is considerable uncertainty about whether or not DDVP is implicated in cancer, and the wider environmental con- sequences of its use. In general, and specifically in developing countries and fish farming, less hazardous alternatives are available. The present experiment studied the effects of DDVP at a daily dose of 1.6 mg/l for 21 days on the expression of the heat shock protein (Hsp) 70 gene in rainbow trout (Oncorhynchus mykiss). Hsp70 from control and DDVP-exposed fish was ampli- fied for 20-40 PCR cycling. After the fortieth PCR cycle, the Hsp70 level in mRNA was very low in the control fish and very high in the DDVP-exposed fish, with a statistical difference of p<0.01.
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    Genetic Diversity of Gilthead Seabream (Sparus aurata) Broodstocks as Determined by RAPD-PCR
    (Israeli Journal of Aquaculture - BAMIGDEH, 2007) Bilgen, Guldehen ; Akhan, Suleyman ; Arabaci, Muhammed ; Oguz, Ismall
    The objective of this study was to determine the genetic diversity in gilthead seabream brood- stocks from two hatcheries on the northern Aegean Coast of Turkey by RAPD-PCR. Forty primers were tested for each broodstock. Twenty-five produced scorable RAPD bands in stock from the Seferihisar hatchery and 28 in stock from the Aliaga hatchery. Nineteen revealed pat- terns with scorable amplified primers in both broodstocks. Depending on primer, the number of bands varied 3-16, ranging in size from 438 to 2520 base pairs (bp). The average genetic simi- larity within stocks was 0.466 for the Seferihisar stock and 0.617 for the Aliaga. The average genetic similarity between the two broodstocks was 0.420, lower than the values within the broodstocks, and the genetic distance between the two broodstocks was 0.245.
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    Use of PCR-RFLP Analysis of mtDNA Cytochrome-b Gene to Determine Genetic Differences in Capoeta spp.
    (Israeli Journal of Aquaculture - BAMIGDEH, 2007) Aksakal, Ecrument ; Erdogan, Orhan
    Genetic differences between Capoeta capoeta capoeta, Capoeta capoeta umbla, and Capoeta tinca were determined using PCR-RFLP of mtDNA cytochrome-b (Cyt-b) by amplifying approxi- mately 400-500 bp of this region from each of the three subspecies. The restriction enzymes SpeI and HinfI did not indicate genetic differences but AluI and HpaII did. Thus, PCR-RFLP of the mtDNA was used to distinguish between closely related subspecies without having to ana- lyze the entire DNA sequence of specimens. Use of this technique demonstrated that the Cyt-b regions of the three subspecies have different base sequences. The similarity between C. c. capoeta and C. c. umbla is 71.4% while C. tinca is more distant (50% for C. c. umbla and 33.3% for C. c. capoeta). The Cyt-b similarity is consistent with morphological and taxonomical similar- ities. PCR-RFLP can serve as a tool for genetically identifying subspecies of fish in nature and in aquaculture.