Scleromystax macropterus Breeding Guide
Breeding notes for the subtropical sailfin cory Scleromystax macropterus, a cool-water egg-depositor from south-eastern Brazil.
Overview
Scleromystax macropterus is a subtropical cory-relative reaching about 8.7 cm, ranging from Sao Paulo to Santa Catarina, Brazil, with some records from upper Parana tributaries. According to Wikipedia it lays eggs in dense vegetation and the adults do not guard them. As a cool-water Scleromystax, the well-documented breeding pattern of its close relative S. barbatus is the most reliable guide.
Sexing
Wikipedia does not document sexing for this species. In Scleromystax, mature males typically develop more pronounced head bristles and pattern while females become rounder and broader when gravid; this is presented as a genus-level expectation rather than a species-specific record.
Breeding Setup
- A spacious, well-oxygenated tank over fine sand
- Cool subtropical water: Wikipedia reports about 18-21 C and pH 6.0-8.0
- Hardness about 2-25 dGH (Wikipedia)
- Fine-leaved plants, clean glass and spawning mops as egg sites
Spawning Behavior & Trigger
Wikipedia documents only that the species scatters eggs in dense vegetation without parental care. Following the pattern of the closely related S. barbatus, a large water change with cooler water plus increased oxygenation and flow, repeated daily, is the usual spawning stimulus; this is offered as a genus-level approach.
Egg & Fry Care
Because the adults do not guard the eggs, the clutch should be protected from being eaten or moved to a separate hatching container. As with S. barbatus, fungus control and high water quality help survival; once free-swimming, fry are reared on small live foods. Detailed species-specific data is not published.