Appropriate Usage Level of Shrimp Waste Meal as Chitin Source for Feeding Young Crayfish (Astacus leptodactylus Esch. 1823)

This study was conducted to determine effects of shrimp waste meal as natural chitin source at different rates (0 (control), 10, 20, 30 and 40% ) on growth, feed conversion ratio (FCR), survival of young crayfish (1.61±0.04 g and 3.74±0.03 cm) for 60 days. Fifteen glass aquariums (70x30x40 cm) were used in the experiment and 20 individuals were stocked per aquarium (95/m2). The highest of final weight and weight gain were obtained in feed with 10% shrimp waste meal group (3.29±0.23 and 1.66±0.23 g), while the lowest of final weight and weight gain was obtained in fed with 40% shrimp waste meal group (2.75±0.35 and 1.18±0.37 g), respectively. However, non-significant differences were found between final weight, weight gain, specific growth rate, final total length, feed conversion ratio, survival percentage among groups at the end of experimental period. It was concluded that shrimp waste meal as natural chitin source can be used in young crayfish diets up to 40% without adverse effect influence on growth

Chitin-Chitosan Yield of Freshwater Crab (Potamon potamios, Olivier 1804) Shell

In this study, freshwater crab (Potamon potamios, Olivier 1804), economically unevaluated, was used to obtain chitin-chitosan. Chitin-chitosan was extracted with standardized modified chemical method. Chitosan was extracted with demineralization, deproteinization, decoloration (chitin) and deacetylation (chitosan). Grinded shell was obtained as 60% after boiling, drying and grinding processes. Chitosan yield of crab shell was determined as 4.65% from grinded crab shell after demineralization (yield is 34.32%), deproteinization (yield is 7.25%), decoloration (yield is 6.83%) and deacetylation processes. Moreover, freshwater crab stock was estimated with catch per unit effort (CPUE) data in Eğirdir Lake for calculation of quantity of chitosan. Population size was estimated between 12.85±11.88 and 23.86±25.39 tones and freshwater crab was determined as an appropriate crustacean to obtain chitin-chitosan

Effects of Enzyme-Producing Probiotic Bacteria Isolated from the Gastrointestinal Tract of Trout on the Growth Performance, Survival, and Digestive Enzyme Activity of Rainbow Trout Fry (Oncorhynchus mykiss)

In this study, we investigated the effects of enzyme-producing probiotic bacteria isolated from the gastrointestinal tract of rainbow trout on the growth performance, feed conversion ratio, and digestive enzyme activity, of fry (Oncorhynchus mykiss). Three isolates (G8/2013, T7/2013 and U5/2013) of candidate bacteria elicited the highest protease, lipase, and amylase activities, respectively. Isolates were identified as Aeromonas sp., Bacillus sp. and Citrobacter braakii by morphological, physiological, biochemical characterizations as well as 16S rRNA gene sequence analysis. The fry basal diet was supplemented with probiotics at varying concentrations; G8 group, Aeromonas sp. 1.72 x 108 CFU/g; U5 group, Bacillus sp. 3.01 x 108 CFU/g; T7 group, C. braakii 2.96 x 108 CFU/g and a mixed group (same bacterial concentrations), and control group (no bacteria). The rainbow trout fry were fed ad libitum in triplicate treatments with supplemented and non-supplemented probiotic diets for 70-days. The total bacterial count in the intestine was significantly higher in the mixed group (30th and 50th days) and U5 group (50th and 70th days) compared with the control group. However, there was no significant difference in weight gain, specific growth rate (SGR), feed conversion ratio (FCR), nutrient digestibility, or digestive enzyme activity among the groups.

Effects of Feed Additive Containing Yeast (Saccharomyces cerevisiae) and Lactic Acid Bacteria on Growth Performance, Body Composition and Nutrient Digestibility of Carp

Bu çalışmada, sazan (Cyprinus carpio, L. 1758) balıklarının yemine % 0,1 oranında maya (S. cerevisiae) ve laktik asit bakterisi (YKM) içeren yem katkı maddesi ilavesinin büyüme performansı, yem dönüşüm oranı, besin madde sindirilebilirliği, vücut kompozisyonu, yaşama oranı, hepatosomatik indeks ve visero somatik indeks değerleri üzerine etkileri araştırılmıştır. Sazan balıkları, 90 gün süren denemede, % 32 protein ve 3200 kcal kg-1 enerjiiçeren deneme yemleri ile beslenmişlerdir. Deneme sonunda final ağırlık, ağırlık kazancı, spesifik büyüme oranı, yem dönüşüm oranı yemlere YKM ilavesi ile istatistiksel olarak önemli derecede etkilenmemiştir (P0,05). Bununla beraber, en yüksek final ağırlık, ağırlık kazancı ve spesifik büyüme oranı YKM ilaveli deneme yemleri ile beslenen deneme grubundan elde edilmiştir. Yeme YKM ilavesi ile kuru madde, protein ve yağ sindirilebilirliği, vücut kompozisyonu, hepatosomatik indeks ve yaşama oranı da etkilenmemiştir (P0,05)In this study, the effects of feed additive containing % 0.1 mix of yeast (S. cerevisiae) and lactic acid bacteria to diets on growth performance, feed conversion ratio (FCR), nutrient digestibility, body composition, survival rate, hepatosomatic index and vissero somatic index of carp (Cyprinus carpio, L. 1758). were investigated. Carp diets contained 32% protein and 3200 kcal kg-1 energy, and carp were fed with this trial diets during 90 days. At the end of the experiment, final weight, weight gain, specific growth rate and feed conversion ratio were not significantly affected by feed additive (P 0.05). However, higher the final weight, weight gain and specific growth rate were obtained from the group fed with feed additive. Dry matter, protein and fat digestibility, body composition, hepatosomatic index and survival rate were also not affected by feed additive (P 0.05

New Bythinella (Gastropoda, Bythinellidae) species from western Turkey

Bythinella anatolica sp. n., Bythinella istanbulensis sp. n., Bythinella magdalenae sp. n., and Bythinella wilkei sp. n. from western Turkey are described herein. Illustrations of the shell and genitalia of the newly described taxa, together with comparisons with previously known Bythinella taxa and a key to the species from western Turkey, are also provided

Effect of Different Feed and Stocking Density on Survival and Growth Performance of Astacus leptodactylus (Esch., 1823) Juveniles

The aim of this study was to investigate the combined effects of two stocking densities (650 and 1300 juveniles/m2 ) and diets  (live feed - Daphnia magna and commercial trout feed) on survival rate and growth performance of Astacus leptodactylus juveniles. Juveniles in the second developmental stage were used in the experiment. Final survival rate and growth paremeters of juveniles were evaluated at the end of experiment (90 days). The results of this study indicated that diets were not found effective on survival rates, though increasing stock densities reduced survival rates. The best final survival rate as 21.99 %, was achieved in the group fed with live feed and kept under the 650 juveniles/m2 stocking density, whereas the lowest survival rate values as 10.84 % was obtained in the group fed with trout pellet and kept under the 1300 juveniles/m2 stocking density. At the end of experiment, the highest final body weight was found in group of at 650 juveniles/m2 stocking density and fed with trout feed. The result of our study also revealed that stocking density had a significant effect on survival rates of crayfish juvenile fed with both feeds