Merry Widow (Phallichthys amates) Care Guide
Phallichthys amates is a hardy, peaceful Central American livebearer reaching about 6 cm, found in still waters from Guatemala to Panama.
Compiled by Aquairi from published sources · Published · Updated
Overview
Phallichthys amates, the Merry Widow, is a small livebearing fish of the family Poeciliidae described by Miller in 1907. It is native to the Atlantic drainages of Central America. The fish has a deep, almost rhomboid grey body with bluish tones and a dark stripe running through the eye to the throat; males bear a notably long gonopodium.
Taxonomy
- Family: Poeciliidae
- Genus: Phallichthys
- Scientific name: Phallichthys amates
- Author: Miller, 1907
Habitat
The species occurs in Atlantic-slope drainages from southern Guatemala through Honduras, Nicaragua and Costa Rica to western Panama. It favours stagnant waters, swamps, creeks and river shorelines over soft bottoms of mud and leaf litter.
Tank requirements
- Minimum tank volume: 60 L
- Temperature: 22-28 °C (72-82 °F)
- pH: 7.0-8.5
- GH: 10-25 °dGH
- Lifespan: 3-5 years
- Water flow: low; soft substrate with plants
Diet
In the wild Phallichthys amates feeds on detritus, ooze and diatoms, with occasional filamentous algae and aquatic insects. As an omnivore in the aquarium it accepts a varied diet including plant matter and small invertebrate foods.
Compatibility
The species is hardy, peaceful and outgoing, swimming mostly in the mid-water column. It suits community aquaria with other peaceful livebearers such as platies and Limia, and aggressive species should be avoided.
Breeding
As a livebearer the female gives birth to 10-80 live fry after roughly four weeks (about 28 days) of gestation. Breeding occurs readily in well-planted aquaria and is suitable for beginners.
Conservation status
IUCN Red List: Least Concern (assessed 2019).
Merry Widow Breeding Guide
Overview
Phallichthys amates, the merry widow, is a livebearing poeciliid from the Atlantic slope of Central America. The nominate subspecies P. amates amates ranges from Guatemala's Motagua River to the rivers near La Ceiba in Honduras, while the subspecies P. amates pittieri occurs from northern Nicaragua to western Panama. Like other Phallichthys it is hardy, peaceful and outgoing. It is named for the conspicuous black band running along the edge of the dorsal fin.
Sexing
There is marked sexual dimorphism: females grow to about 64 mm (2.5 in) while males reach only about 32 mm (1.25 in). The defining male trait is an unusually long gonopodium that reaches the base of the caudal fin, the feature that gives the genus its name. The black-edged dorsal band appears in both sexes and even in newborn fry, so it cannot be used to sex the fish.
Conditioning
In nature the species feeds mainly on detritus, ooze and diatoms, with occasional filamentous algae and aquatic insects, so a diet including vegetable matter and small live or prepared foods conditions adults. Wild habitat temperatures range from 20 to 37 °C, indicating broad thermal tolerance, and the fish remains hardy, peaceful and outgoing across that range, which makes it easy to keep a settled breeding group.
Mating & Gestation
Fertilization is internal via the long gonopodium. Gestation lasts about four weeks or less, shortening at higher temperatures. Females give birth to 10 to 80 live fry depending on female size.
Birth & Fry Care
Fry are born looking exactly like adult fish, including the characteristic dorsal band, and are self-sufficient from birth, taking small foods immediately with no parental care required. As with other livebearers, dense planting or separating the gravid female protects fry from predation by adults, which is the principal factor limiting how many young survive each brood.
Common Challenges
The species is hardy and undemanding, tolerating a wide temperature range, so the main consideration is protecting fry from being eaten by adults. Providing dense cover and a varied diet that includes greenstuff alongside small live and prepared foods keeps a colony productive over successive broods.