Orinoco Festivum (Mesonauta egregius) Breeding Guide
Breeding Mesonauta egregius, an Orinoco festivum: a biparental substrate spawner that lays eggs on a cleaned flat surface.
Overview
Mesonauta egregius is a festivum endemic to the Meta and Vichada river basins, both tributaries of the Orinoco in Colombia, reaching a standard length of up to 8.2 cm. It is typically found near aquatic plants in shallow water. Species-specific breeding accounts are scarce, so the reproductive behaviour here follows the closely related Mesonauta festivus.
Sexing
In Mesonauta, the male is generally larger and shows longer extensions to the dorsal and anal fins; otherwise sexing is unreliable, so allowing a group to pair off is the usual approach.
Conditioning
Keep a small group and condition prospective breeders on a varied omnivorous diet. Soft, slightly acidic water in keeping with its Orinoco range helps bring fish into spawning condition.
Breeding Setup
- Soft, slightly acidic water reflecting its natural range
- A flat stone or broad surface as a spawning site
- Planted cover and a quiet, undisturbed location
Spawning Behavior & Trigger
In Mesonauta the pair prepares a flat stone or similar area, after which the female deposits the eggs and the male fertilises them. Over 200 eggs may be laid in a single spawn, hatching in about 2-3 days.
Egg & Fry Care
Both parents guard the eggs, move the fry to a pit and the larvae become free-swimming roughly 3-4 days after hatching. Newly hatched brine shrimp and powdered fry foods are suitable until the young can take larger items.
Common Challenges
Mesonauta are easily spooked, which can lead nervous parents to eat their fry; a quiet location and minimal disturbance, or rearing the fry separately, improve survival.