Hydrobiological Research

Effect of dietary supplementation with olive leaf extract on growth performance, hematological parameters and resistance against Yersinia ruckeri in rainbow trout, Oncorhynchus mykiss

2024-05-31T12:43:40+03:00

This study investigated effects of dietary olive leaf extract (OLE) on growth performance, hematological parameters and resistance against Yersinia ruckeri in rainbow trout. Four groups were designed including a control diet and OLE added in fish feed at 0.5, 1.0, and 1.5 ml/100 g feed, which were administered for 30 days. The weight gain (WG), specific and absolute growth rate (SGR and AGR), feed conversion ratio (FCR) and feed efficiency ratio (FER) of rainbow trout fed with OLE were found to be significantly (p < 0.05) differed compared with control. Fish fed 1.0 ml/100g feed OLE supplemented diet significantly improved (p < 0.05) WG, AGR and SGR. The lowest FCR was observed with 1.0 ml OLE/100 g diet. An enhancing effect of OLE on hematological parameters occurred, as shown by the significant increase in red blood cell (RBC), white blood cell (WBC) and haematocrit (Ht) parameters in fish fed with 1.0% OLE. Haemoglobin (Hb) level of fish fed the 1.5% added OLE diet was significantly lower than those fed the 0.5 or 1.0% added OLE diet and control groups. Mortality at 14-day post-challenge with Y. ruckeri significantly decreased at all the dietary OLE groups. Dietary OLE at the level of 1.0 and 1.5 ml/100 g feed showed significantly (P < 0.05) higher relative percentage survival (RPS) (73.91 and 78.26%, respectively) against Y. ruckeri infection. The present results suggest that diets supplemented with OLE feed level positively enhance the growth parameters and affords protection from Y. ruckeri.

The effect of Coriandrum sativum extract supplementation diets on lipid, carbohydrate and protein levels of rainbow trout, Oncorhynchus mykiss

2024-05-31T14:26:01+03:00

This study was conducted to investigate the effect of coriander (Coriandrum savitum) extract on protein, lipid and carbohydrate levels of rainbow trout (Oncorhynchus mykiss). For this purpose, trout with an average weight of 40-45 g were used. Coriander was added to the feed as 0, 0.5, 1.0, 2.0 mg% and experimental groups were formed. The prepared feeds were weighed daily as 2% of the fish weight and fed in the morning and evening. Liver, spleen, kidney and muscle tissues were removed from the fish on the 42nd day of the first feeding and protein, carbohydrate and lipid levels were determined. Liver protein contents of fish fed the 1.0 and 2.0% supplemental C. sativum extract diet were statistically similar but were significantly lower than those fed the control diet. Liver lipid level significantly decreased in fish fed 2% C. sativum extract but did not differ among the groups fed lower dietary levels (0, 0.5 and 1.0% C. sativum extract). Dietary treatments did not significantly affect carbohydrate values of all tissues.

Comparative molecular characterization of Diplozoon species from fishes

2024-06-28T18:39:13+03:00

In this article, it was aimed to isolate Diplozoon species from naturally infected carp fish from Elâzığ region and to determine their morphological and microscopic characteristics and molecular identification. As a result of the study, it was observed that parasite isolation was realized in all samples of carp fish sampled. It was observed that the isolated parasites were 33-55/27.3-51.3-51.2/24-45 mm in size. DNA isolation and PCR analysis were performed by selecting the most morphologically and different sized samples. In the preliminary identification analysis by Real-Time PCR, both primer sets and DNA interaction were checked. Then, blast results obtained from the sequence data obtained as a result of PCR analysis performed in the thermal cycler device, it was observed that they showed 98% similarity with Diplozoon paradoxum and the closest similarity with Paradiplozoon homoion and Paradiplozoon skrjabini with a maximum similarity of 96%. Phylogenetic analysis of Diplozoon species using sequence data and Neighbor Joining (NJ) methods showed that they occur in 2 different branches. In line with these results, it was observed that 3 different groups were formed in the parasites with the lowest morphological and microscopic similarity. It is thought that genetic differences are the main reasons why Diplozoon parasite species cause different levels of infestation, virulence and mortality in fish.

Diplozoon species in fish are a common cause of infestation worldwide and diplozoon species are also common in the study area. Intraspecific differences in diplozoon species and changes in the host-parasite relationship lead to differences in virulence and pathogenicity, and as a result, cause diseases and economic losses. Knowing the species differences of parasites regionally has an important place in fish diseases for taking prophylactic measures and treatment processes.

Some aquatic plants and their characteristics that can be used for biological ponds to be created in cold climate regions

2024-04-02T13:09:17+03:00

Water has been the most necessary and valuable resource since mankind began to cultivate the earth. Water has a special place in all cultures and belief systems with its purifying, renewing and life-enhancing properties. In this study, some aquatic plants that can withstand cold climatic factors (-5°C to -15°C) and are utilized in biological ponds were investigated. This is a compilation study prepared with the aim of evaluating these plants in landscape areas and biological ponds by taking into account the climatic conditions, positively affecting the psychology of the people living in the place where they are used with their pleasant appearance and flowers, and enriching these areas visually.

Occupational health and safety hazards in aquaculture

2024-07-11T13:37:07+03:00

The growing aquaculture industry is expected to have a more pronounced impact on the lives and economies of rural coastal communities worldwide. Both in private production and products, there is a guarantee to provide employment opportunities in the production of aquatic products in a healthy and safe manner. However, this temperature, which is an important preventive measure, has not yet started to be systematically investigated in occupational health and safety (OHS) research. This review, with special emphasis on aquaculture production, presents a detailed outline of the industry from feed production to feed processing, identifying potential OHS hazards at each stage and providing recommendations for current research and actions.