IJA Volume 54, Issue 1, 2002
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ItemEpitopes Of Tilapia Red Blood Cells. I. Species-Specific Antibodies For The Control Of Tilapia Breeding Stocks(Israeli Journal of Aquaculture - BAMIGDEH, 2002)Specific antisera against red blood cells of some tilapia species were obtained by reciprocal inter- specific and intergeneric immunizations. The antisera were used to confirm co-dominant expres- sion of epitopes in F1 interspecific hybrids and to identify the parental origin of three red tilapia strains. The antisera in all hybrids (Oreochromis niloticus x O. mossambicus, O. aureus x O. horno- rum, O. niloticus x S. galilaeus and O. niloticus x O. aureus) were positive to both parental strains. However, while all F1 hybrids of O. mossambicus x O. hornorum were positive to anti-O. mossambi- cus antiserum, only 50% were positive to anti-O. hornorum antiserum. In most cases, these results point to co-dominant expression of the species-specific epitopes in hybrids. In addition, the triple parental origins of the Philippine red tilapia (positive for O. aureus, O. mossambicus and O. niloticus epitopes) and of mossambicus red tilapia (positive for O. hornorum, O. mossambicus and O. niloticus epitopes) were assessed. The O. niloticus red tilapia, described as a purebred red variant of O. niloticus, was positive for both anti-O. niloticus and anti-O. aureus antibodies, with a significantly more intense reaction to the latter. A possible genetic basis of this last finding is discussed.
ItemUse of Melanophore Patterns On The Ventral Side Of The Head To Identify Fry Of Grey Mullet (Teleostei: Mugilidae)(Israeli Journal of Aquaculture - BAMIGDEH, 2002)Examination of fry of five species of grey mullet revealed that the shape of the lower jaw and the melanophore patterns along the edge of the lower jaw and the ventral side of the head are species-specific. Mugil cephalus is characterized by an acute angle of the dentary symphysis and lightly pigmented ventro-opercular and gular regions of the head. In Liza aurata, the mandibular region has spots of pigment at the corners of the mouth, the gular region is lightly pigmented with a single row of melanophores, the ventro-opercular region of the head has two rows that form a distinct arch and, in specimens over 20 mm TL, at least one of these rows extends to the posterior ventro-opercular region. In Liza ramada, the pigmentation is darkest in the mandibular and gular regions of the head, the melanophores in the mandibular region in specimens of 30-40 mm TL are concentrated around the anterior tip of the jaw and the corners of the mouth, and the anterior ventro-opercular region usually has a single row of melanophores that may extend into the posterior ventro-opercular region. In Chelon labrosus, there are two rows of melanophores in the ventro-opercular region and one or two rows in the gular region which usually extend beyond the eye into the posterior sector. In Liza saliens, there are two rows of melanophores in the ventro-opercular region and two in the gular region which rarely extend beyond the eye to the posterior sector. These observations were used to create a key which may be useful for identifying fry of grey mullet species grown in aquaculture in the Mediterranean region.
ItemAquaculture In Turkey(Israeli Journal of Aquaculture - BAMIGDEH, 2002)Marine and freshwater aquaculture in Turkey have grown substantially. The first trout farm was established in the 1960s and the first marine cage farm for sea bream and sea bass in 1985. From the beginning of the 1970s to 1999 the number of licensed fish farms increased from two to 1,444. Since 1995, the number of cage farms has grown to 57 and production reached 4,100 tons in 1999. Total aquaculture production grew from 3,075 tons in 1986 to 63,000 tons in 1999. Production is dominated by inland production, mainly of trout (Oncorhynchus mykiss), which supplies 60% of the total. From 1995 to 1999, marine production increased from 8,494 tons to 25,230 tons. The major contributors are sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax). Because of the rel- atively high temperatures in the Black Sea, Atlantic salmon (Salmo salar), cultured from the late 1980s to 1997, is no longer grown; only rainbow trout (O. mykiss) in floating net cages is produced. Because of the growing demand caused by increased population and export, aquaculture pro- duction and consumption in Turkey are expected to grow. New fish and shellfish species, mainly marine, are being developed. The bureaucracy involved in licensing fish farms, especially in marine environments, is complicated, time-consuming, and suffers from a lack of technical knowl- edge and insufficient exchange of know-how and cooperation concerning new developments. * Corresponding author. Present address: Istanbul Universitesi, Su Ürünleri Fakültesi, 34470 Laleli, Istanbul, Turkey; e-mail: email@example.com
ItemIn Memoriam Professor Boaz Moav (1938-2002)(Israeli Journal of Aquaculture - BAMIGDEH, 2002)On January 28, 2002, Professor Boaz Moav passed away after a long and valiant struggle with his ailment. We have lost both a good friend and a dedicated scientist who contributed greatly to the scientific aspects of fish culture.
ItemCommercial Culture Of Oreochromis Spilurus In Open Seawater Cages And Onshore Tanks(Israeli Journal of Aquaculture - BAMIGDEH, 2002)Trials were conducted to establish commercial-scale production of all stages of Oreochromis spilurus. Fry were produced in a tank using recycled fresh water. Fingerlings were grown in full strength sea water either in cages in the open sea or in onshore tanks filled with water from the sea. Very promising results were obtained in terms of fish growth, survival and product quality, opening up significant new opportunities for the expansion of tilapia culture in tropical and sub- tropical seas.
ItemGrowth And Survival Of The White Leg Shrimp (Litopenaeus Vannamei) Reared Intensively In The Brackish Water Of The Israeli Negev Desert(Israeli Journal of Aquaculture - BAMIGDEH, 2002)Juvenile shrimp, Litopenaeus vannamei (initial weight 0.019±0.009 g), were reared at den- sities of 2000/m3 and 5000/m3 in brackish (2.5-3.0 ppt) geothermal (~40°C at the source) water from beneath the Israeli Negev desert in a recirculating system for 72 days. The shrimp grew significantly faster (p<0.01) at the lower density than at the higher density. The weekly mean weight and specific growth rate in the low density were 0.57 g and 8.68 and, in the high density, 0.404 g and 8.02. The feed conversion ratio was 2.01 in the lower density and 2.36 in the higher. The survival rate was 87% and 63.5% in the low and high densities, respectively. Data obtained in this study, particularly at the low density, are comparable to favorable published results for L. vannamei in marine waters. The present study is the first experimental attempt to evaluate the potential of mass culture of high quality, healthy L. vannamei in the brackish, geothermal water of Israel’s Negev desert. This water, which is free of pollutants and marine pathogens, has been found to be highly suitable for the culture of a number of species of fish and aquatic organisms.