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Purpose. Studies of the growth and survival of Oriental river prawn (Macrobrachium nipponense) larvae depending on water temperature and salinity during cultivation. Methodology. Experimental studies were carried out at the Aquatic Department of Aquatic Bioresources and Aquaculture of the Odesa State Ecological University in 2020-2021. Brood Oriental river prawns (Macrobrachium nipponense) were caught in the lower Dniester river and placed into a 0.8 m3 RAS. The larvae were stocked in separate aquariums with automatically maintained specified temperature regime. The first series of experiments in fresh water investigated the influence of water temperatures of 20–22, 22–24, 24–26, and 28–31 ℃ on the growth of shrimp larvae (from the 1st stage to the Pl stage). Cultivation in water with a salinity of 5, 7, 12 ‰ was carried out at a temperature of 20–22, 22–24, 28–31 ℃. Ten prawn larvae were measured daily under a binocular microscope (MBS-10) using an eyepiece-micrometer. The stage of larval development and the survival rate were determined. Water salinity was determined using an ATAGO-100 refractometer, and an Azha-101M thermal oximeter was used to determine the oxygen content in water. Statistical processing of data was carried out in Microsoft Excel. Findings. It was established that at a temperature of 24–26 ℃, the duration of the transition from one stage of larval development to another in Oriental river prawn (Macrobrachium nipponense) increased as the larvae grew and developed. It lasted 4–5 days in the first stages (1-3), then stages from 6 to 9 days in the later stages. High temperature stimulated the growth of larvae and accelerated their development. In fresh water at a temperature of 29–31 ℃, the length of postlarvae (Pl) reached 6.69±1.15 mm in 28 days of rearing. Cultivation at high temperature resulted in a significant variation in larval sizes (from 4.4 to 8.6 mm CV–25,27). At lower temperatures (25-27, 22-24 and 20-22 ℃), the average sizes of prawn postlarvae were smaller (5.83±0.78, 4.56±0.15, 4.43±0.15), and the survival rates increased (46, 49 and 54%, respectively). Survival of larvae was inversely dependent on temperature r = –0.89. It was minimal (32%) at a temperature of 29–31 ℃. The higher the growing temperature, the lower the output of postlarvae. Water salinity, like temperature, significantly affected the growth, survival and size uniformity of postlarvae. In water with a salinity of 5‰, postlarvae reached their maximum length (6.56±0.15 mm) at a temperature of 29-31 ℃. At temperatures of 20-22 and 22-24 ℃, the size of the postlarvae did not reliably differ among themselves. The maximum survival of postlarvae (52%) was noted at a temperature of 22-24 ℃. Regardless of water temperature, salinity of 5‰ ensured high uniformity of larvae size (CV: 6.11–9.09). At a salinity of 7‰, the maximum length of postlarvae was reached at a temperature of 29-31 ℃, and the highest survival rate of prelarvae (34%) was noted at a temperature of 20-22 ℃. The size of the larvae and their survival at other growing temperature conditions did not differ significantly (Р

Purpose. To analyze major biological characteristics of pike (Esox lucius L., 1758) stock in the lower Dnieper River in the conditions of transformed flow. Methodology. Collection of the ichthyological material was carried out in the lower Dnieper River from commercial fishing gears, including beach seines, drag seines, fyke-nets. Field, laboratory processing of samples and mathematical analysis of the obtained results were carried out according to generally accepted methods and guidelines with some assumptions regarding the duration of pike fattening directly in the lower Dnieper River. Findings. Recent years, there is an increase in the specific weight of younger age groups in the pike stock in the lower Dnieper River. Analysis of linear growth indicates on satisfactory environmental conditions for pike. Current commercial contingent of pike is based on size classes of 46–50 cm versus 22–32 cm in the first half of the last century. Reproductive properties of pike, in particular fecundity, egg size and maturity coefficients did not virtually change compared to those of the last century. Depending on linear sizes, the absolute fecundity is 32.3–155.8 thousand eggs and the maturation coefficient is 11.1–15.7%. Morphologic variability of pike in the lower Dnieper River during the period from 1980s to the present time was observed for plastic features, which characterized fin sizes. Sexual dimorphism in current conditions was observed only for maximum body depth. No significant differences for other plastic features between males and females of pike in the lower Dnieper River. Originality. The data on biological characteristics of pike stock from the lower Dnieper River have been updated. Current fecundity of females of different size groups recorded in commercial catches was been determined. An analysis of morphological variability of major plastic features of pike in the process of the transformation of the Dnieper River flow has been carried out. Practical value. The determined peculiarities of pike linear growth will allow optimizing commercial harvest for preserving the most productive part of the stock. Such measures will contribute to an increase in the commercial stock of this valuable predatory fish of the Dnieper-Bug mouth system that in turn will ensure appropriate regulation of the number of coarse non-commercial fish. This is highly important for the balanced trophic strain for valuable commercial species at early stages of their development.

The paper contains results of brown trout (Salmo trutta) growing in industrial conditions of the fish farm “Ishkhan” during three years. It was found that linear growth and weight accumulation of fish after reaching the one-year age increased and were superior in comparison with natural populations.

The article provides results of investigations of linear growth of mixed bred pigs (large white x Landrace) with different duration of embryonic development. It was established, that mixed bred pigs with different duration of the embryonic period have differences in terms of linear growth. Thus, newborn pigs with reduced duration of embryonic development had a greater chest girth, when compared to control ones, indicating a high rate of growth of their axial skeleton. Animals with reduced and average period of embryonic development had higher blockiness index, when compared to those with longer period. [ABSTRACT FROM AUTHOR]

Results of research of linear growth parameters of pigs of the Large White breed with various length of embryonic development. It has been proved that newborn piglets with shortened duration of embryonic period had larger body length and heart girth as compared to the control, which indicates on higher growth intensity of their axial skeleton. Experimental piglets with shortened and medium duration of embryonic development had higher longevity index, whereas pigs with prolonged duration of embryonic period had higher index of body blockiness. [ABSTRACT FROM AUTHOR]