Taxonomy & naming
Hypostomus lamberti was formally described by Penido, Pessali & Zawadzki in 2023 and published in Zootaxa (volume 5361, number 1, pages 103–113) under the title 'A new tiny-spotted species of Hypostomus (Siluriformes: Loricariidae) from the upper Rio Tocantins basin, Goiás State, Brazil.' The Catalog of Fishes (Eschmeyer, CAS) recognises the name as a valid species of Hypostomus.
The species epithet honours Mauro César Lambert de Brito Ribeiro, a Brazilian ichthyologist who made significant contributions to knowledge of fish diversity on Brazil's central plateau (Planalto Central) — the very region from which H. lamberti was collected. This kind of eponymous naming is a longstanding convention in Neotropical ichthyology, acknowledging researchers whose regional work laid the groundwork for subsequent discoveries.
Hypostomus is the largest genus in Loricariidae and one of the most species-rich suckermouth genera globally; it has historically served as something of a catch-all for medium to large plated catfishes without the diagnostic characters of more specialised loricariid lineages. H. lamberti was distinguished from all congeners primarily by its 'tiny-spotted' colour pattern combined with specific tooth and body proportions.
Morphology
Adults reach a maximum recorded standard length of 7 in SL, placing H. lamberti in the upper-medium size range for Hypostomus. The body is covered in the characteristic loricariid armour of keeled bony scutes arranged in longitudinal and transverse rows. The dorsal fin has 2 spines and 7 soft rays; the anal fin has 4 soft rays.
The defining diagnostic characters, as given in the original description, are the extremely small, densely distributed dark spots on the body — the 'tiny-spotted' condition referenced in the paper's title. This spotting pattern was the primary character separating H. lamberti from related congeners in the upper Tocantins region. Additional distinguishing features include bicuspid teeth with elliptic (rather than rounded or elongate) medial cusps, and a long, low caudal peduncle. Like other members of the genus, H. lamberti is a facultative air-breather, capable of surfacing to gulp atmospheric oxygen when dissolved oxygen in the water is insufficient.
Habitat
Hypostomus lamberti is known from the upper rio Tocantins basin, Goiás state, in central Brazil. The Tocantins rises on the Planalto Central — the elevated interior plateau that forms part of the Cerrado biome — and flows northward to meet the Amazon system. The upper reaches where this species was collected are characterised by clear to moderately turbid water over rocky substrates, typical of Cerrado headwater streams.
No water chemistry parameters (temperature, pH, hardness) have been published for the specific collection sites of H. lamberti. The broader upper Tocantins basin in Goiás typically experiences a marked wet-dry seasonality: rains from October to April raise water levels substantially, while the dry season (May to September) leaves many streams at low water over exposed rock. Demersal suckermouth catfishes in these systems tend to occupy rocky runs and cascade pools where current keeps substrates clean of fine sediment.
Feeding
No feeding studies specific to H. lamberti have been published. As a Hypostomus with a ventrally positioned rasping mouth and small teeth, the species is expected to be a periphyton and algae grazer — scraping biofilm, attached algae, diatoms, and associated organic material from hard substrates such as rock surfaces and submerged wood.
This dietary mode is shared across the vast majority of Hypostomus and is consistent with the demersal, hard-substrate habitat the species occupies. In an aquarium context, spirulina-based foods, algae wafers, and blanched vegetables would be appropriate staples, supplemented occasionally with invertebrate foods.
Mating
No mating observations have been published for H. lamberti. Given that the species was described only in 2023 and does not appear to have entered ornamental trade in meaningful numbers, no aquarium observations exist.
General Hypostomus biology suggests that males occupy and defend rock crevices or suitable hollow sites, developing interopercular odontodes and engaging in territorial display. In the seasonally variable rivers of the upper Tocantins basin, spawning is likely linked to the onset of the wet season, when rising water temperatures and increased river flow create cues for reproductive activity — a pattern observed across many rheophilic loricariids in Cerrado drainages.
Breeding
No captive breeding of H. lamberti has been recorded. The species is a 2023 description and has not, to date, been documented in ornamental aquaculture or established hobby collections.
By comparison with other medium to large Hypostomus, a cave-spawning reproductive mode with paternal brood care is the most plausible expectation: a male guarding adhesive eggs deposited in a hard-surfaced hollow, fanning them through incubation and continuing to protect newly hatched fry until they are free-swimming. Confirmation of this mode awaits either field study or captive observation.
In the aquarium
Hypostomus lamberti is not established in the hobby as of writing, and the information required to give detailed husbandry guidance — water chemistry preferences, temperament data, specific dietary observations — has not been published. Aquarists who obtain this species should treat it as a medium to large Hypostomus (up to approximately 8–8.5 in total length) with the requirements typical of the genus: a spacious tank with hard substrates for grazing, efficient filtration, a varied plant-based diet, and water quality consistent with a tropical Cerrado river.
Given the upper Tocantins origin, slightly acidic to neutral water (pH 6.5–7.2) and warm tropical temperatures (75–82 °F) are a reasonable starting point in the absence of specific field data. The species should be housed with sufficient space to avoid territorial conflict with other large benthic catfishes.
Conservation
Hypostomus lamberti has not been evaluated by the IUCN Red List as of 2026. The species was described only in October 2023, and newly described species typically require several years before being formally assessed.
The upper Tocantins basin in Goiás state is subject to significant anthropogenic pressure. The Cerrado biome — one of the world's biodiversity hotspots — has been heavily converted for soybean and cattle agriculture, and its headwater streams face sedimentation, altered hydrology, and water abstraction. The Tocantins main stem was dramatically altered by the Tucuruí Dam (completed 1984), one of the largest hydroelectric projects in the world; while H. lamberti occurs in the upper basin above the influence of that reservoir, smaller hydroelectric and irrigation infrastructure in Goiás poses localised risks. The apparently restricted distribution of H. lamberti within the upper basin merits monitoring as land-use change continues in the region.