Betta mandor — Breeding & Rearing (Scientific Profile)
| Category | Details |
|---|---|
| Taxonomy |
Order: Anabantiformes Family: Osphronemidae Genus: Betta Complex: Coccina group Species: Betta mandor (Tan, 2006) |
| Natural Habitat |
Endemic to Mandor region, West Kalimantan, Borneo. Peat swamp forest, leaf‑litter micro‑pools, root‑tangle cavities. pH 3.8–5.0, conductivity 15–40 µS/cm, dissolved humic acids, extremely low irradiance. Seasonal hydrology: shallow ephemeral pools during wet season; hypoxic microhabitats. |
| Adult Morphology |
Standard length 45–55 mm (males). Mahogany‑red pigmentation with iridescent opercular scaling. Sexual dimorphism: males with elongated anal/dorsal rays; females with reduced fin extension and visible ovipositor. Gill morphology adapted to hypoxic blackwater; labyrinth organ moderately developed. |
| Breeding Triggers |
Conductivity reduction to <40 µS/cm via rainwater dilution. pH shift to 4.0–4.8 through botanical loading. Temperature 25–27°C with slight nocturnal drop. Photoperiod suppression to simulate canopy closure. High‑protein live‑food conditioning (10–14 days). |
| Courtship Behaviour |
Male lateral display with iridescent opercular flashes. Female initiates approach to micro‑cavity. Pre‑spawn embraces repeated with gradual gamete release. Low‑aggression ethology compared to splendens‑type bettas. |
| Spawning Method |
Cave‑associated bubble‑nesting. Nest constructed within leaf tubes, coconut cavities, or root hollows. Bubble matrix small, fragile, stabilised by mucous secretions. Male performs exclusive brood care. |
| Egg Development |
Fecundity: 20–40 ova. Incubation: 36–48 hours at 26°C. Larvae remain in nest until yolk absorption (72–96 hours). High susceptibility to fungal colonisation outside acidic, low‑TDS water. Male retrieves displaced eggs. |
| Larval Stage |
Larvae exhibit limited motility; remain aggregated in nest. First feeding window opens day 3–4 post‑hatch. Mouth gape extremely small; requires micro‑planktonic prey. Photophobic behaviour; avoid direct illumination. |
| Fry Rearing |
Initial diet: infusoria, rotifers, paramecium. Artemia nauplii introduced day 10–12. Maintain pH <5.0 for first 4 weeks to stabilise microbial community. Daily 5–10% drip water changes using ultra‑soft water. Zero current; sponge filtration optional at minimal flow. |
| Juvenile Development |
Pigmentation onset at 6–7 weeks. Sexual differentiation visible at 10–12 weeks. Juveniles require dense structural complexity (leaf litter, roots). Moderate intraspecific aggression; group rearing possible with space. |
| Genetic Considerations |
Maintain locality‑specific lineage integrity. Avoid hybridisation with sympatric coccina species. Outcross every 3–4 generations to prevent inbreeding depression. Monitor for loss of wild‑type traits under captive selection. |
| Health & Disease |
Sensitive to bacterial blooms, elevated TDS, pH >5.5, and mechanical filtration. Blackwater conditions suppress pathogenic bacterial load. Avoid chemotherapeutics unless essential; fry highly vulnerable. |
| Production Scaling |
Moderate reproductive output for coccina group. Best maintained as multiple isolated breeding pairs. Suitable for conservation‑focused ex‑situ programmes. Growth rate slow; commercial scaling limited. |
Rearing Protocol Summary
Conditioning Adults
- Blackworms, grindal worms, mosquito larvae
- TDS <40 ppm
- Botanical‑rich water (catappa, oak, peat fibre)
Spawning Setup
- 15–25 L system
- Leaf tubes, coconut caves, root tangles
- 5–10% light intensity
- Water depth 12–18 cm
Fry First Foods
- Infusoria
- Rotifers
- Paramecium
- Microworms (minimal)
Growth Management
- Daily micro‑changes
- No current
- Weekly botanical replenishment
- Sex separation at 10–12 weeks
Notes for Keepers
Betta mandor requires soft, acidic, tannin‑rich water, low light, and micro‑cavity spawning structures. Ideal for conservation‑grade breeding programmes.
