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Ribogospod. nauka Ukr., 2026; 1(75): 178-209
DOI: https://doi.org/10.61976/fsu2026.01.178
UDC 639.371.7

Received: 25.11.2025
Received in revised form: 04.03.2026
Published: 31.03.2026

Reproductive biology of Hypancistrus zebra Isbrücker & Nijssen, 1991 (Siluriformes: Loricariidae) under controlled conditions

O. Marenkov, This email address is being protected from spambots. You need JavaScript enabled to view it. , ORCID ID 0000-0002-3456-2496, Oles Honchar Dnipro National University, Dnipro
V. Sarman, This email address is being protected from spambots. You need JavaScript enabled to view it. , ORCID ID 0009-0007-0550-9446, Oles Honchar Dnipro National University, Dnipro

Purpose. To investigate the reproductive biology of Hypancistrus zebra (Isbrücker & Nijssen, 1991) under controlled conditions and, based on the obtained data, to improve the breeding protocol for this species in aquarium culture. Special attention was given to identifying the optimal parameters that best reproduce the natural habitat conditions of the Xingu River basin (Brazil), which is crucial for maintaining ex-situ populations.

Methodology. Experiments were conducted in laboratory aquaria with controlled water parameters simulating natural biotopes. A mixture of 90 % reverse-osmosis and 10 % tap water was used (total hardness < 1 mmol/L, pH 6.8–7.4, temperature +28–30°C, nitrates < 2 mg/L). To induce spawning, partial (30%) water changes with cooler and softer water were performed to simulate the onset of the rainy season. Observations included behavioral responses, spawning frequency, fecundity (number of eggs), and spawning success coefficient (k).

Findings. It was found that H. zebra reaches sexual maturity at about two years of age under optimal feeding and stable hydrochemical conditions – approximately six months earlier than in wild populations. The highest spawning activity was recorded at +29°C in soft, slightly acidic water. Fecundity ranged from 10 to 20 eggs per spawn, with the spawning success coefficient (k) varying between 7 and 12 (mean = 8.7). The feeding technique involving food applied to rock substrates proved efficient and safe, ensuring good water quality and absence of diseases.

Originality. For the first time under laboratory conditions, the complete developmental cycle of H. zebra – from spawning to the rearing of viable juveniles was documented. The study experimentally demonstrated a 0.5-year reduction in age at first spawning due to optimized diet composition and stabilization of hydrochemical parameters. The influence of temperature and water chemistry on embryonic development rates was clarified.

Practical Value. The developed rearing conditions and spawning-induction protocol can be implemented in aquaculture practice for propagation of rare Loricariidae catfish. The results are valuable for biodiversity conservation programs, establishment of captive backup populations, and reduction of anthropogenic pressure on Amazonian ecosystems.

Keywords: fish reproductive biology, Hypancistrus zebra, artificial spawning, aquarium breeding, fish behavior, species conservation, breeding methods, aquaculture, water quality, fecundity, spawning.

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