Taxonomy & naming
Anablepsoides christinae was originally described as Rivulus christinae by Jean-Henri Huber in 1979, with the type locality recorded as Lake Tupac Amaru (Lago Tupac Amaru) in the upper Madre de Dios river basin near Puerto Maldonado, Puno department, Peru. The authority is presented in parentheses because the species has since been moved out of the genus in which it was first placed. Eschmeyer's Catalog of Fishes (Fricke, Eschmeyer & Fong) records the valid combination as Anablepsoides christinae (Huber, 1979); the transfer from Rivulus to Anablepsoides reflects the broad phylogenetic revision of neotropical rivulines that dissolved the old catch-all genus Rivulus into several more natural lineages.
The genus Anablepsoides is placed within the family Rivulidae (South American rivulines) in the order Cyprinodontiformes. Costa's 2003 Rivulidae checklist is the primary reference for the modern arrangement. Earlier trade and hobbyist literature universally uses the old combination Rivulus christinae, which still appears in works such as Aquarien Atlas Band 5 (1997) and Aqualog 14 (2000); both names refer to the same fish.
The specific epithet christinae is a latinised given name in the feminine genitive, honouring Christine Huber, wife of the describing author — a common eponymic convention in the Rivulidae, where many species carry the names of collectors, colleagues, or family members.
Morphology
FishBase records a maximum total length of 2.5 in for Anablepsoides christinae, placing it at the smaller end of the genus. The body form is typical of the non-annual South American rivulines: elongated and subcylindrical, tapering toward a rounded caudal fin, with the dorsal fin set well back and roughly opposite the anal fin. Scales are moderate and cycloid.
Colouration in males is the primary ornamentation. The flanks typically carry rows of red or orange-red spots on a blue-green to olive-brown ground colour — a pattern shared with several related Anablepsoides species from the Madre de Dios and upper Amazon basin. Females and juveniles are considerably plainer, showing the brownish background with reduced or absent spotting and a small ocellus on the dorsal fin that may serve as a social signal during conspecific interactions. Sexual dimorphism in finnage and body depth is moderate, with males being slimmer and more vividly coloured.
Habitat
Anablepsoides christinae is native to the upper Amazon basin, with a documented range spanning the Madre de Dios river system of southern Peru and extending into adjacent portions of Brazil (Reserva Ducke area near Manaus; Rio Urubui tributary) and Bolivia, where it has been recorded in collections associated with the Bolivian sector of the Madre de Dios drainage. The American Killifish Association database lists fourteen named collection localities, including the Rio Tambopata, the Colorado River tributary, Infierno, Quebrada Philadelphia, and Puente Chorrillo — all in the lowland and foothill forest zone of southeastern Peru.
The IUCN assessment characterises the habitat as inland wetlands, consistent with the permanent forest streams, pools, and small oxbow lagoons typical of lowland Amazonian rivulines. The species is non-seasonal and lives in perennial water rather than the ephemeral seasonally desiccating pools used by annual killifish. IUCN data gives a water pH of approximately 7 and records it as strictly freshwater (salinity 0), indicating broadly neutral rather than strongly acidic blackwater conditions, though individual localities across its range may vary somewhat. FishBase records an ambient temperature range of 72–79 °F, consistent with the warm but not extreme conditions of the foothill Amazon zone.
Feeding
Anablepsoides christinae is a surface- and mid-water opportunist, as is typical of non-annual rivulines occupying forest-stream habitats. In the wild it feeds on small invertebrates, including terrestrial and aquatic insects, insect larvae, microcrustaceans, and other small prey items that fall onto or near the water surface — a foraging niche aided by the upturned mouth characteristic of many rivuline killifish.
In the aquarium the species accepts a wide range of live and frozen invertebrate foods readily: Drosophila (fruit flies), bloodworm, Artemia nauplii and adults, micro-worms, and small aquatic invertebrates all work well. Small dry foods such as fine flake or micro-pellets are also taken, though a diet skewed toward meaty live and frozen items brings out the best colouration in males and supports reproductive condition.
Mating
As a non-annual rivuline, Anablepsoides christinae does not exhibit the explosive seasonal spawning of annual killifish that live in ephemeral pools. Instead, breeding is continuous or near-continuous throughout the year in stable water conditions, and the pair bond and courtship rituals are correspondingly more protracted and elaborate. Males display prominently to females, spreading the dorsal and anal fins to show off the full extent of their coloured spotting and pursuing receptive females through vegetation.
Spawning occurs among fine-leaved plants, floating roots, or artificial spawning mops, where the pair assume a lateral or ventral embrace and deposit one or a few adhesive eggs at a time. The eggs attach to the plant material by filaments and remain submerged throughout incubation — there is no diapause, no drying, and no burying in substrate. Females can produce eggs on successive days over extended periods, so pairs maintained in good condition will spawn repeatedly.
Breeding
Eggs of Anablepsoides christinae incubate in water, hatching in roughly two to three weeks at temperatures in the 72–79 °F range typical of the species' natural habitat. The incubation period can be extended somewhat by lower temperatures. Fry are free-swimming and reasonably large at hatching compared with annual killifish larvae, and they can usually accept Artemia nauplii as a first food shortly after becoming fully active, though infusoria or commercial fry food is appropriate for the very smallest individuals.
The most practical approach in captivity is to keep a group — one male and two or three females in a heavily planted tank with fine-leaved plants (Java moss, hornwort, or floating mops) — and to collect the spawning mop weekly, hatching eggs in a separate container to protect fry from adult predation. Adults do not pursue eggs as aggressively as some egg-scatterers but will consume small fry readily. Water quality during rearing should be clean and well-oxygenated; partial water changes promote growth. Juveniles reach adult colouration and sexual maturity within a few months under good conditions, and the fish are comparatively long-lived relative to annual killifish.
In the aquarium
Anablepsoides christinae has been cultivated in the killifish hobby since at least the early 1990s, and AKA strain records document multiple collection localities maintained by North American hobbyists. It is a manageable species for anyone familiar with small livebearing or egg-laying fish: not as demanding as some rivulines, tolerant of broadly neutral water (around pH 7), and comfortable in the 72–79 °F range that many community fishrooms maintain as a default.
A pair or trio (one male, two females) does well in a well-planted tank of 10–15 US gal, decorated with Java moss, fine-leaved plants, and floating cover. Filtration should be gentle; a sponge filter is ideal. Males can be combative with each other in close quarters, so single-male setups are safest unless space is generous. Because it is a surface-orientated fish and an efficient jumper, a tight-fitting lid is essential.
The species is an excellent entry point into South American rivulines for the killifish beginner: its willingness to spawn without manipulation, its tolerance of ordinary tap water conditioned to neutral pH, and the attractive spotted colouration of males make it a rewarding long-term project. It is regularly available through AKA species auctions and killifish club networks, though it is seldom seen in the general aquarium trade.
Conservation
The IUCN Red List assessed Anablepsoides christinae in April 2014, placing it in the Least Concern category; the assessment was authored by Hernán Ortega Torres of the Museo de Historia Natural, Universidad Nacional Mayor de San Marcos (UNMSM-MHN), Lima. The species' range spans multiple localities across Peru, Brazil, and Bolivia in the broadly intact forest zone of the upper Amazon and Madre de Dios river system, and it is not considered immediately threatened.
Nonetheless, the Madre de Dios basin in southeastern Peru — the core of the species' range — is under increasing pressure from illegal gold mining, road construction, and deforestation associated with agricultural expansion. Puerto Maldonado, near the type locality, is the regional hub for both legal and informal mining activity that has degraded river water quality and floodplain habitats across the basin. Whether these pressures have affected Anablepsoides christinae populations specifically has not been assessed since 2014 and warrants monitoring. As a non-annual species tied to permanent forest streams rather than ephemeral pools, its habitat requirements are more demanding than those of truly annual killifish, and it would be expected to be sensitive to the permanent loss or degradation of forest stream quality.