Taxonomy & naming
Poecilia sarrafae was described by Pedro H. N. Bragança and Wilson J. E. M. Costa in a paper published in Ichthyological Exploration of Freshwaters (volume 21, pages 369–376), with the species attributed to the authors as Bragança & Costa, 2011. The fish was diagnosed from material collected in the Parnaíba and Mearim river basins of north-eastern Brazil, which together form both the type region and, as far as is currently known, the entire distribution of the species. Eschmeyer's Catalog of Fishes and GBIF both treat Poecilia sarrafae as a valid, accepted name within the genus Poecilia and the family Poeciliidae, the New World livebearers.
The authors hypothesised that P. sarrafae is closely related to two other small Brazilian species, Poecilia branneri and Poecilia minima, with which it shares a suite of eight derived characters. These include conical teeth on the external rows of the dentary and premaxilla (five to seven such teeth), a dorsal fin of eight rays in males and seven in females, an elongated penultimate dorsal-fin ray in males, a black blotch on the posterior caudal peduncle present in both sexes, and vertical pale-grey bars along the mid-flank of males. Within that group, P. sarrafae is set apart by the shape of its post-humeral blotch — round or only slightly elongated vertically — rather than the form seen in its congeners.
The genus name Poecilia derives from the Greek poikilos, meaning varied or many-coloured, a reference to the variegated patterning typical of these fishes. The specific epithet sarrafae is an eponym honouring Alessandra Sarraf Pereira, a Brazilian ichthyologist at the Biological Institute associated with the Federal University of Rio de Janeiro. The English common name recorded for the species is the Jandira toothcarp.
Morphology
Poecilia sarrafae is a small poeciliid, and the original description framed it largely through fine details of dentition, fin-ray counts and pigment pattern rather than through a striking colour scheme. Like other members of its species group it bears conical teeth on the external rows of both the dentary and premaxilla, with five to seven of these teeth, a feature the describers used to align it with P. branneri and P. minima. The dorsal fin carries eight rays in males and seven in females, and in males the penultimate dorsal-fin ray is elongated — a subtle sexual difference characteristic of the group.
The most useful field mark is the species' pigmentation. Both sexes show a black blotch on the rear of the caudal peduncle, while males additionally display a series of vertical pale-grey bars along the middle of the flank. The diagnostic character that separates P. sarrafae from its relatives is its post-humeral blotch — the dark mark sitting just behind the pectoral/shoulder region — which is round or only slightly elongated in the vertical plane, in contrast to the differently shaped marks of its congeners.
Precise maximum size and detailed morphometric measurements for this species are not recorded in FishBase, and the figures in the original description were not captured in the research available here, so an exact standard length is not asserted. As a small wild Poecilia in the branneri/minima group, the species is expected to be a diminutive fish on the order of a few centimetres, with males smaller than females and bearing the modified anal fin (gonopodium) typical of the family. Data are sparse, and a precise length is better confirmed directly from the describing paper than guessed at here.
Habitat
The known range of Poecilia sarrafae is the Parnaíba and Mearim river basins of north-eastern Brazil — the same drainages from which the type material was collected. These are large coastal river systems of the country's north-east, draining tropical lowlands toward the Atlantic, and the species appears to be restricted to this coastal region rather than being widely distributed across South America. FishBase classifies the fish as a freshwater, pelagic, tropical species.
As a small livebearing poeciliid of north-eastern Brazilian coastal basins, P. sarrafae can reasonably be expected to occupy the kinds of small-water and marginal habitats favoured by its relatives — slow stretches, backwaters, vegetated margins, and shallow pools within the larger river systems — in warm, tropical freshwater. The original description and the cached sources do not give detailed measured water parameters for the collection sites, so specific temperature, pH and hardness values for wild populations are not asserted here.
Because the species is documented only from these two basins, its distribution is comparatively narrow, and habitat notes for it remain limited. This is a fish whose ecology has not been studied in the depth applied to the guppy or the mollies; much of what can be said about its environment is inferred from its family and region rather than from dedicated ecological work.
Feeding
No dedicated dietary study for Poecilia sarrafae is available, but FishBase assigns the species an estimated trophic level of about 2.6, which places it as a micro-omnivore — a small fish feeding low on the food web on a mixture of plant and small animal matter. This is entirely consistent with the feeding ecology of small poeciliids generally, which graze on algae, biofilm, detritus and tiny invertebrates.
In practice a fish of this size and trophic position would be expected to take aufwuchs (the film of algae, diatoms and micro-organisms on submerged surfaces), small aquatic invertebrates, insect larvae, and drifting organic particles, shifting its intake according to what is locally available. The estimated trophic level reflects this kind of mixed, opportunistic micro-omnivory rather than any specialised predatory or strictly herbivorous habit.
Direct observations of what wild P. sarrafae eats were not part of the available research, so the dietary picture here is drawn from the FishBase trophic estimate and from the well-understood feeding patterns of related small livebearers. As with much of this species' biology, the specifics are data-sparse.
Mating
Poecilia sarrafae is a member of the Poeciliinae, the live-bearing subfamily of the Poeciliidae, and like its relatives it reproduces by internal fertilisation. The defining male structure of the group is the gonopodium, an intromittent organ formed from modified rays of the anal fin, which the male uses to transfer sperm directly into the female; this is the mechanism that underlies live-bearing across the whole family, and the modified male anal fin is consistent with the sexually dimorphic fin characters noted in the species' description.
The specific courtship behaviour of P. sarrafae has not been documented in the sources available, so the detailed mating routine — whether it relies on the display-based courtship and "sneak" mating tactics so well described in the guppy — is not asserted here. What can be said with confidence is that fertilisation is internal and that males deliver sperm via the gonopodium rather than externally fertilising eggs.
Many poeciliids are capable of female sperm storage, which allows a single mating to fuel several successive broods, and some show superfetation (carrying broods at more than one stage of development simultaneously). Whether P. sarrafae specifically practises superfetation has not been established in the cached research, so it is noted here only as a possibility within the family rather than a confirmed trait of this species.
Breeding
Poecilia sarrafae is viviparous: as a member of the live-bearing Poeciliinae it gives birth to free-swimming young rather than laying eggs. Reproduction in the family is lecithotrophic — the developing embryos are nourished largely by yolk laid down in the egg before fertilisation — and after internal fertilisation via the gonopodium the female carries the developing brood internally through gestation before releasing fully formed fry.
Species-specific reproductive figures for P. sarrafae — gestation length, brood size, and birth interval — are not recorded in FishBase, whose reproduction fields for the species are blank, and the morphometric paper did not supply them in the research available. By analogy with small wild Poecilia, broods are likely to be modest in number, and as in the family generally there is no parental care: the newborn fry are independent at birth and adults do not guard or tend them, so cover for the young matters where they are bred.
The species' resilience is rated High on FishBase, with an estimated minimum population doubling time of under fifteen months, which is consistent with the rapid, repeated reproduction typical of livebearers even where exact brood statistics are unrecorded. Beyond that, the breeding biology of this particular species remains genuinely data-sparse and is best treated as inferred from its family rather than measured.
In the aquarium
Poecilia sarrafae has little to no presence in the aquarium trade. No dedicated hobbyist care page for the species was located in the available research, including among specialist livebearer resources, and it is best regarded as a wild Brazilian poeciliid of interest mainly to ichthyologists and dedicated livebearer specialists rather than a commonly kept aquarium fish.
Where it is kept at all, husbandry can only be inferred from the genus and region: a small, viviparous livebearer of warm tropical fresh water from the coastal basins of north-eastern Brazil. Conditions appropriate to small soft-to-neutral, warm tropical freshwater would be a reasonable starting point, with the usual livebearer provisions of stable, clean water, gentle flow, and dense planting or floating cover to shelter free-swimming fry from adults. A varied micro-omnivore diet of small flakes, micro-foods and tiny live or frozen invertebrates would suit its low trophic position.
Because genuine husbandry data for this species are absent, none of these notes should be read as a tested care protocol. They are extrapolations from related livebearers, offered with the caveat that the species' specific tolerances have not been documented and that anyone keeping it would be working largely from first principles.
Conservation
Poecilia sarrafae is assessed as Least Concern (LC) on the IUCN Red List, under species ID 140651590 (assessment 140651594), with the assessment dated 7 November 2018. The species is not listed under CITES or CMS and is recorded as harmless to humans. Its fishing vulnerability is rated Low (10 out of 100), and its population resilience is rated High, with an estimated minimum doubling time of under fifteen months.
The Least Concern rating reflects an absence of identified species-level threats rather than a large or thoroughly monitored population; this is a fish known from a restricted part of north-eastern Brazil whose ecology has not been intensively studied. Its high resilience and low vulnerability suggest a reproductively robust small fish, but a relatively narrow documented range — the Parnaíba and Mearim basins — means that localised habitat change could matter more for this species than for wide-ranging congeners.
Unlike the guppy, P. sarrafae carries no record of being spread around the world as an introduced or invasive fish; it remains a native species within its home basins. The most useful conservation note for this poorly known fish is simply that its biology deserves further study, since much of what is recorded for it rests on a single description and broad family-level inference rather than detailed population data.