Ten-spotted Livebearer Care Guide
Cnesterodon decemmaculatus is a tiny, cool-tolerant South American livebearer with black flank spots, suited to small unheated planted tanks.
Compiled by Aquairi from published sources · Published · Updated
Overview
Cnesterodon decemmaculatus, the ten-spotted livebearer, is a very small poeciliid from temperate South America, marked with a row of dark spots along each flank. It is notably tolerant of cooler water and is one of the smallest commonly kept livebearers.
Taxonomy
- Family: Poeciliidae
- Genus: Cnesterodon
- Scientific name: Cnesterodon decemmaculatus
Habitat
According to FishBase, the species inhabits the lower Uruguay, Laguna dos Patos, Negro and Salado river basins, plus western drainages of Argentina and small coastal drainages of Uruguay and Argentina. It occurs in fresh and brackish waters with relatively cool temperatures.
Tank requirements
- Minimum tank volume: 30 L
- Temperature: 16-26 °C (61-79 °F)
- pH: 6.5-8.0
- GH: 5-18 °dGH
- Lifespan: 2-3 years
Diet
The species is an omnivore. In the aquarium it accepts small dried foods alongside live and frozen items, and grazes on biofilm and algae. Small frequent feedings suit its size.
Compatibility
The ten-spotted livebearer is peaceful and well suited to small, planted community tanks with other tiny, gentle species. Its small size and tolerance of cooler temperatures make it unsuitable for tanks with larger fish that could prey on it.
Breeding
Cnesterodon decemmaculatus is viviparous, giving birth to live young (FishBase). Males possess a modified anal fin (gonopodium) and the species exhibits distinct pairing; reproduction occurs readily in the aquarium, and dense planting offers cover for the fry.
Conservation status
IUCN Red List: Least Concern (assessed 2020), per FishBase.
Ten-spotted Livebearer (Cnesterodon decemmaculatus) Breeding Guide
Overview
Cnesterodon decemmaculatus is a tiny South American livebearer of the family Poeciliidae found in Bolivia, Brazil, Paraguay, Uruguay and Argentina. It inhabits calm, well-vegetated shallow streams and drainage ditches and is unusually tolerant of cooler water, which makes it a hardy nano species. Like other poeciliids it bears live young rather than laying eggs.
Sexing
Males carry an angled, anteriorly placed gonopodium formed from the anal fin and remain slender. Females are plumper and their body bulges progressively as gestation advances. The species is small overall, so a magnifier helps when sorting young breeders.
Conditioning
Condition adults on small live and frozen foods such as daphnia and microworms alongside fine prepared food. The fish accepts a wide temperature band and breeds well in moderately warm water; aquarium temperatures of around 27 °C are reported, and it can endure water heated to about 30 °C in the warmest season while also tolerating cool conditions.
Breeding Setup
A small, densely planted species tank with calm water mimics its natural ditches and streams. Provide thickets of fine-leaved and floating plants so newborns can escape predation. The peaceful temperament means a small group of one or more males with several females will breed continuously without aggression.
Spawning Behavior & Trigger
Fertilisation is internal. After a gestation of about 24 days the female releases five to ten, and rarely up to fifteen, fully formed young measuring roughly 2 to 2.5 mm. The fry are large enough to take microworms, baby brine shrimp and powdered foods at once. Sexual maturity follows after the third or fourth month, allowing rapid colony growth.
Common Challenges
Because broods are small and the fry are minute, the chief challenge is protecting young from being eaten and providing food fine enough for their tiny mouths. Dense planting and frequent small feedings of infusoria-grade food give the best survival.