Taxonomy & naming
Poecilia hondurensis was described by Fred N. Poeser in 2011, in the journal Copeia, from material collected on the Atlantic (Caribbean) slopes of Honduras. The species had in fact been recognised earlier in manuscript form: the epithet "hondurensis" originated in unpublished notes by Robert Rush Miller and Manuel Cruz, who had delimited the range of this Honduran molly, and Poeser retained their name in his formal description to honour the two earlier workers. Eschmeyer's Catalog of Fishes — the governing authority for valid fish names — accepts Poecilia hondurensis Poeser, 2011 as valid, placing it in the genus Poecilia within the family Poeciliidae.
Within Poecilia the species is assigned to the subgenus Mollienesia, the short-finned mollies, a group of New World livebearers that also includes the familiar sailfin and black mollies of the aquarium trade. Poeser diagnosed the species against other Poecilia that share an inner row of tricuspid teeth in each jaw, distinguishing it by two features of the male gonopodium: the absence of a spinal hook on gonopodial ray 5 and an extremely reduced membranous hook on gonopodial ray 3. These gonopodial characters — fine structures of the modified anal fin used in mating — are the standard currency of poeciliid taxonomy, where externally similar species are routinely separated by the architecture of the male copulatory organ.
The genus Poecilia is large and has been repeatedly revised, and several of its subgenera have at times been treated as full genera. The description of P. hondurensis is part of a broader ongoing effort to resolve the diversity of Central American mollies, many of which had long been lumped under a few wide-ranging names before careful comparison of regional populations revealed them to be distinct.
Morphology
Poecilia hondurensis is a small, fusiform molly with the normal body shape of its subgenus rather than any exaggerated finnage. FishBase records a maximum length of about 1.5 in standard length for males and unsexed fish and about 2.5 in standard length for females, figures drawn from Poeser's original description. As is usual for the family, the female is the larger and deeper-bodied sex.
The most taxonomically important features are in the male. Like all poeciliid males the fish bears a gonopodium — an intromittent organ formed from modified rays of the anal fin — and the precise form of that organ is what defines the species. Poeser noted the absence of a spinal hook on gonopodial ray 5 and an extremely reduced membranous hook on gonopodial ray 3, together with the inner row of tricuspid teeth shared with related Poecilia. Detailed live-colour descriptions for the species are sparse in the accessible literature; in keeping with the editorial caution this atlas applies, no colour pattern is asserted here beyond the generalised molly form, and aquarists should treat coloration as data-sparse rather than rely on guesswork.
Habitat
The species is endemic to Honduras and, more specifically, to the Caribbean (Atlantic) slope drainage basins of the eastern part of the country — the type and known range lie in eastern Honduras. FishBase classes it as a freshwater, pelagic species of tropical Central America, and GBIF, which accepts the name and cites Poeser's 2011 description, holds only a small number of occurrence records, consistent with a narrowly distributed and not heavily collected endemic.
Beyond the drainage-basin assignment, specific habitat detail — the size of streams it favours, substrate, vegetation or seasonal behaviour — is not well documented in the readily available sources, and is treated here as data-sparse. Precise water-parameter figures (temperature range, pH, hardness) are likewise not given on the FishBase summary or in the other cached sources, so this atlas does not assign them; aquarists may reasonably extrapolate from the warm, hard-water preferences typical of Central American mollies, but those values are inferred from the group rather than measured for this species.
Feeding
No species-specific dietary study is available, but Poecilia hondurensis carries the low trophic level — about 2.6 on FishBase — characteristic of mollies, indicating a diet weighted toward plant and detrital matter. In practice that means the typical molly regime: grazing on algae and aufwuchs (the film of algae, micro-organisms and detritus on submerged surfaces), supplemented with detritus and small invertebrates taken from the substrate and water column.
In captivity a fish of this kind would be expected to thrive on a varied omnivore's diet with a strong vegetable component — good-quality flake or micro-pellets with algal content, blanched vegetable matter, and small live or frozen foods such as Daphnia and brine shrimp to round out animal protein. Frequent small feedings suit a continuous grazer better than occasional large meals. These husbandry notes are extrapolated from the biology of the molly group rather than from records specific to P. hondurensis, which remains poorly documented in aquarium literature.
Mating
Reproduction in Poecilia hondurensis follows the poeciliid pattern of internal fertilisation. The male's gonopodium — the rod-like organ built from modified anal-fin rays — is swung forward and used to transfer sperm directly into the female; there is no external spawning. The very characters that diagnose the species (the configuration of hooks on gonopodial rays 3 and 5) are functional parts of this copulatory apparatus, and in mollies generally such structures help mediate the mechanics of mating and may contribute to reproductive isolation between similar species.
Molly males typically court more or less continuously rather than defending territories, alternating display toward females with attempts at insemination, and females of many poeciliids can store sperm internally to fertilise successive broods from a single mating. Whether and to what degree these specific behaviours apply to P. hondurensis has not been documented in the accessible sources, so the detail here reflects the general biology of the subgenus Mollienesia rather than direct observation of this species.
Breeding
As a member of the subfamily Poeciliinae, Poecilia hondurensis is viviparous: after internal fertilisation the female carries the developing embryos and gives birth to live, free-swimming young rather than laying eggs. In the short-finned mollies the young are nourished from yolk reserves (lecithotrophy) rather than through a true placenta, and these mollies typically carry a single brood at a time rather than overlapping broods.
Specific reproductive figures for this species — gestation length, brood size, and size or maturity at birth — were not extracted from the cached sources and should be regarded as data-sparse; the cache notes explicitly that no superfetation (the simultaneous development of broods at different stages, seen in some other poeciliids) is reported for it. By analogy with related mollies one would expect a gestation on the order of several weeks, varying with temperature, and broods of fully formed fry that can swim and feed immediately, but these expectations are not substituted here for measured values specific to P. hondurensis.
In the aquarium
Poecilia hondurensis is not a fixture of the ornamental trade, and dedicated husbandry accounts are scarce; it is most likely to be encountered through specialist livebearer keepers and collectors of wild Central American Poecilia rather than in general aquarium shops. As such, the keeping notes below are inferred from the requirements of the molly group rather than tested specifically on this species.
Mollies in general are robust, active, sociable fishes that do best in groups, in warm water with good filtration and stable, well-oxygenated conditions; many appreciate harder, more alkaline water than soft-water tetras or rasboras. A skewed sex ratio favouring females helps spread the persistent attentions of courting males. Because firm temperature, pH and hardness figures for this species are not available in the cited sources, an aquarist should approach it with the general molly profile in mind while watching the fish's own response, rather than relying on precise parameters that have not been published for P. hondurensis.
Conservation
The IUCN Red List assesses Poecilia hondurensis as Least Concern, with the assessment dated 3 February 2020. Despite being a Honduran endemic restricted to the Caribbean-slope drainages of the east of the country, it is regarded as a widely distributed and not currently threatened molly — a contrast with many narrowly ranged livebearers, such as the imperilled goodeids of Mexico, that share its general way of life but face severe pressures.
FishBase rates the species' fishing vulnerability as low and describes it as harmless to humans, and the small number of occurrence records reflects limited collecting rather than documented rarity. As with any range-restricted freshwater endemic, the long-term outlook depends on the health of its native drainages, and continued monitoring is warranted; for now, however, the species is not flagged as being at risk.