Intensive rearing of European catfish larvae (Silurus glanis L.) at different stocking densities and their effect on fish production parameters

Vasilka Krasteva, Maria Yankova, Tania Hubenova

Abstract: During the present research, two studies are conducted (Study I and Study II), in two consecutive
years, by applying the same scheme of stocking density. Each study has duration of 16 days. The object
of the experiment is European catfish larvae reared in tubs with continuous water flow (0.7 l.min-1).
Throughout the experimental period, all fish are fed with „Ocean nutrition” – Canada (0.8–1.0 mm) to
satiation, three times per day. At the beginning and at the end of each study, weight assessments are
performed using 50 randomly selected individuals from each stocking density variant. The average
weight of the larvae at the start of Study I is in the range of 50.7 ± 11.9 mg to 86.2 ± 20.1 mg and at the
start of Study II – from 182.5 ± 58.0 mg to 199.3 ± 70.9 mg. The number of larvae used in Study I is
2400 and in Study II – 3600. The scheme of stocking density consists of three variants: Variant A (5
ind.l-1), Variant B (10 ind.l-1) and Variant C (15 ind.l-1). In Study I, each variant of stocking density is
applied with one repetition, whereas in Study II – with two repetitions for better statistical analysis.
The results from the study demonstrate that the weight gain (IWG, mg) and the survival rate (SR,
%) are strongly affected by the variant of stocking density, with a significant difference being established
(P ≤ 0.05). Both parameters have the highest values for the lowest stocking density (Variant A
– 5 ind.l-1). The established values for the growth rates (AWG, DGR, SGR), for Study I and Study II,
indicate that they are significantly affected by the different variants of the stocking density (P ≤ 0.05).

Keywords: European catfish; larvae; stocking density

Date published: 2021-02-26