Taxonomy & naming
Harttia novalimensis was described by Osvaldo T. Oyakawa in 1993 and is recognised as a valid species by the Catalog of Fishes (Eschmeyer, CAS). It belongs to the subfamily Loricariinae, the whiptail and twig catfishes, characterised by their depressed bodies and long, tapering caudal peduncles.
The genus Harttia commemorates Charles Frederick Hartt (1840–1878), the Canadian-born geologist and naturalist who travelled with the Thayer Expedition to Brazil. The species epithet refers to Nova Lima, the municipality in Minas Gerais state from whose waters the type material was drawn. Beyond the original description, published taxonomic and biological literature on this species is sparse.
Morphology
Harttia novalimensis is one of the smaller species in its genus, reaching about 3 in standard length. Like other Loricariinae, it has a strongly depressed (dorsoventrally flattened) body and head, a ventral suckermouth, and a long, slender caudal peduncle that gives the group its 'whiptail' character. The body is encased in the overlapping bony plates typical of the armoured catfishes.
Detailed published accounts of live coloration and meristics for this species are limited to the original description; no data on sexual dimorphism specific to H. novalimensis has been published, though males of the genus typically develop hypertrophied odontodes along the head and pectoral spines during breeding condition.
Habitat
The species is endemic to the Rio das Velhas basin, a major tributary in the upper São Francisco drainage of Minas Gerais, Brazil. It is a freshwater, demersal fish of tropical headwater streams. Members of the genus Harttia are generally associated with clear, well-oxygenated flowing water over rocky or gravel substrate, where the flattened body lets them cling to the bottom in current.
No detailed in-situ water-chemistry data has been published specifically for H. novalimensis; the broader Rio das Velhas headwaters are typical Brazilian-shield streams with moderate temperatures and generally soft to moderately hard water.
Feeding
No dedicated dietary study of Harttia novalimensis has been published. Like other small Loricariinae, it is presumed to be a benthic grazer, rasping the biofilm — algae, diatoms, and associated micro-invertebrates and detritus — from rock and gravel surfaces with its suckermouth. The ventral mouth and flattened body are well suited to feeding on hard substrates in flowing water.
Mating
No courtship or mating behaviour has been documented for Harttia novalimensis. In the genus more broadly, breeding males develop pronounced odontodes on the head and pectoral spines and defend a spawning site, but no observations specific to this species have been published.
Breeding
There are no published breeding records for Harttia novalimensis, in the wild or in captivity. Loricariinae as a group are typically substrate egg-layers with paternal care, the male guarding and fanning the clutch, but no data has been published confirming the reproductive mode of this particular species.
In the aquarium
Harttia novalimensis is not a species established in the aquarium trade, and no husbandry record exists for it. Any care expectations would be inferred from related riffle-dwelling Harttia, which require clean, highly oxygenated water with strong flow, a substrate of rock and gravel, and stable, cool-to-moderate temperatures. Given its small size and restricted range, it is best regarded as a fish of scientific rather than hobbyist interest.
Conservation
The IUCN Red List assessed Harttia novalimensis as Least Concern in 2022. Despite its restricted endemic range in the Rio das Velhas basin, it was not considered to face threats severe enough to warrant a higher category at the time of assessment. The Rio das Velhas has historically suffered from mining, urban, and industrial pressures around the Belo Horizonte metropolitan region, so continued monitoring of headwater water quality is prudent for range-restricted endemics of this drainage.