In the present study, fish meal (FM) was replaced by pea (Pisum sativum) protein (PP) in diet for Rainbow trout (Oncorhynchus mykiss) at levels of 0% (PP0), 25% (PP25), 50% (PP50), 75% (PP75) and 100% (PP100), and the effect of dietary PP level on the digestive system tracts and liver was investigated by micromorphological and histopathological evaluations. Morphometric measurements (mm 100g fish −1 ) of the liver width and stomach length in rainbow trout were found to be significantly larger (p <0.05) in fish with high-level pea protein as the main protein source (PP75, PP100) compared to the low-level PP replacement group (PP25). No significant differences were found in morphometric measurements for pyloric caecum and intestines among treatment groups, whereas the number of the caecum of fish fed the PP25 diets significantly increased over the control (PP0) (p<0.05). In the histological examination of the liver, mild hydropic and vacuolar degeneration was observed in all experimental groups except PP0 and PP25. The measurements of pyloric caecum fold height, enterocyte length and width of tunica muscularis of the high-level pea protein groups of PP75 and PP100 were significantly higher (p <0.05) compared to the control group. In conclusion, 25% substitution of PP can be suggested for FM in trout diets, because the findings of the present study provided evidence that the digestive system improved by increasing the number of pyloric caecum at this replacement level.

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In this study, the effects of gibel carp meal (GFM) application as a protein source on growth performance, fillet composition, feed digestion and haematological and serum biochemical indices of rainbow trout (Oncorhynchus mykiss) were evaluated. Replacement of anchovy fish meal (AFM) with GFM was performed at 0%, 50% and 100% levels (GFM0, GFM50 and GFM100). After 60 days of feeding the best nutritional performance was obtained in the GFM100 group. There was no significant difference in crude moisture, crude protein, crude lipid or crude ash contents in fish fillet between the GFM0, GFM50 and GFM100 groups. No side effects were observed in hematological and serum biochemical indices of rainbow trout. Dry matter, crude protein and crude lipid digestibility coefficients did not differ significantly in experimental groups. As a conclusion, the results of the study suggested that the GFM could be used totally as a replacer of AFM in diets for rainbow trout without the adverse effects on growth performance, feed use, feed digestion, hematological and serum biochemical parameters of fish.

A new species Surirella caljoniana sp. nov. is described from a unique microenvironment in the mountainous region of Türkiye. The taxon was found in a small soda spring which is an important water source for the Kızılırmak River. Surirella caljoniana is similar to Surirella brebissonii Krammer & Lange-Bertalot, S. brebissonii var. kuetzingii Krammer and Lange-Bertalot, S. lacrimula J.D.English, S. neglecta Reichardt and S. subsalsa W.Smith in morphology and shape. Unlike the other taxa, S. caljoniana has an oval-elliptic, slightly heteropolar outline, larger length/width ratio and a narrowly rounded, slightly protracted foot pole. Over the striae, distinct fimbriate silica protrusions are evident and similar to some marine species within the Pinnatae.

Tarhana is a traditional food produced by different traditional methods and the materials used in production are changing from a region to another region. The total yeast and molds, total mesophilic aerobic bacteria, Escherichia Coli and enterococci bacteria count of wet dough Kastamonu tarhana and dry powdered tarhana samples were investigated in this study. All microorganisms examined in our study were detected in one of the wet dough tarhana samples. The highest total yeast and molds, total mesophilic aerobic bacteria, Escherichia coli and enterococci bacteria counts were determined for the wet dough tarhana samples to be 2.2×106, 6.6×107, 1.2×106 and 1.9×106 cfu/g, respectively. No growth of microorganism capable of reproduction was observed in the powdered tarhana produced industrially. In addition, the Escherichia coli and enterococci bacteria were not detected for any of the dry powder tarhana samples. It was seen that the microbial load of the wet tarhana produced at home in Kastamonu was higher than the powdered tarhana. The reason for this situation was thought to be due to poor production and hygiene conditions. The presence of Escherichia coli and enterococci bacteria in samples indicates that there is possible fecal contamination of the raw materials used in wet dough tarhana production. Electron microscope images of molds obtained in our study are similar to molds producing mycotoxins. These results show that the wet dough tarhana have a greater risk for microorganism development and human health compared to dry powder tarhana.