BIOLOGICAL CHARACTERISTICS OF PIKE (ESOX LUCIUS LINNAEUS, 1758) OF THE LOWER DNIEPER RIVER IN CURRENT CONDITIONS / БІОЛОГІЧНА ХАРАКТЕРИСТИКА ЩУКИ (ESOX LUCIUS LINNAEUS, 1758) ПОНИЗЗЯ ДНІПРА В СУЧАСНИХ УМОВАХ
Journal Title: Рибогосподарська наука України - Year 2015, Vol 31, Issue 1
Abstract
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.
Authors and Affiliations
K. Geina, P. Kutishchev
Tilapia (Tilapini) as one of the main objects of modern aquaculture. Experience of cultivation in Israel (review) / Тиляпія (Tilapini) як один з основних об’єктів сучасної аквакультури. Досвід культивування в Ізраїлі (огляд)
Purpose. The State of Israel, for a short period in 1948, despite the difficult political and climatic and geographical conditions, demonstrates a stable development of aquaculture. In this regard, the Israeli experience...
RESULTS OF REARING THE MULTIPLE AGE GROUPS OF CHANNEL CATFISH (ICTALURUS PUNCTATUS RAFINESQUE) WITH THE USE OF PROBIOTIC FEED SUPPLEMENTS NUPRO® AND BIO-MOS® / РЕЗУЛЬТАТИ ВИРОЩУВАННЯ РІЗНОВІКОВИХ ГРУП КАНАЛЬНОГО СОМА (ICTALURUS PUNCTATUS RAFINESQUE) З ВИКОРИСТАННЯМ ПРОБІОТИЧНИХ КОРМОВИХ ДОБАВОК NUPRO® ТА BIO-MOS®
Purpose. To study the effect of feed supplements NUPRO® and BIO-MOS® on the results of rearing the multiple age groups of channel catfish (Ictalurus punctatus Rafinesque). Methodology. The study of effect of feed supple...
Effect of mineral betonit on chemical composition of carp (Cyprinus carpio Linnaeus, 1758) muscles / Вплив мінералу бентоніт на хімічний склад м’язів коропа (Cyprinus carpio Linnaeus, 1758)
Purpose. To study the effect of bentonite mineral added to the basic diet of age-1 carps on the content of lipids and their individual classes as well as on the chemical composition of muscles to establish the efficiency...
Correction of algocenosis by the preparation of komplezim in experimental ponds of fish-farm Nyvka / Корекція альгоценозу препаратом «Комплезим» у ставах дослідного господарства «Нивка»
Purpose. To investigate the effect of the bacterial preparation "Komplezim", which is recommended for the prevention of mass reproduction of blue-green algae through algocoenosis correction, water cleaning and sanitary r...
PECULIARITIES OF THE GENETIC STRUCTURE OF RAINBOW TROUT (ONCORHYNCHUS MYKISS) GROUPS AT THE FISH FARM “SLOBODA BANILOV”, CHERNIVTSI REGION / ОСОБЛИВОСТІ ГЕНЕТИЧНОЇ СТРУКТУРИ ГРУП РАЙДУЖНОЇ ФОРЕЛІ (ONCORHYNCHUS MYKISS) ГОСПОДАРСТВА «СЛОБОДА БАНИЛІВ» ЧЕРНІВЕЦЬКОЇ ОБЛ.
Purpose. Study of the peculiarities of the genetic structure based on genetic-biochemical markers in age-1+ and 2+ rainbow trout of the fish farm “Sloboda Banilov”, Chernivtsi region Methodology. We used the methods of...