Taxonomy & naming
Harttia surinamensis was described by Marinus Boeseman in 1971 and is recognised as a valid species by the Catalog of Fishes (Eschmeyer, CAS). It belongs to the subfamily Loricariinae, the whiptail catfishes.
The genus name honours Charles Frederick Hartt (1840–1878), the Canadian-born geologist and naturalist who accompanied the Thayer Expedition to Brazil. The species epithet refers to Suriname, the country at the heart of the species' Guianan range and the source of the type material.
Morphology
Harttia surinamensis is a comparatively large member of its genus, reaching about 7.5 in standard length — more than twice the length of some of its small Brazilian congeners. It has the classic Loricariinae build: a strongly depressed head and body, a ventral suckermouth, and a long, slender caudal peduncle, the whole encased in overlapping bony plates. The flattened, hydrodynamic form is well suited to holding position against rock in strong current.
No separate published account of sexual dimorphism is available for this species, though Harttia males typically develop hypertrophied odontodes on the head and pectoral spines in breeding condition.
Habitat
Harttia surinamensis occurs in the coastal rivers of the Guianas, ranging from the Suriname River in the west eastward to the Approuague River, spanning Suriname and French Guiana. It is a freshwater, demersal fish of tropical rivers and is reported to be very abundant in zones of swiftly flowing, plunging water — rapids and torrents over rock.
This is a rheophilic, hard-substrate specialist: the well-oxygenated, fast water of Guianan shield rapids is its core habitat. No detailed in-situ water-chemistry figures have been published for the species beyond this characterisation.
Feeding
No dedicated dietary study of Harttia surinamensis has been published. As a benthic loricariine of rocky rapids, it is presumed to graze biofilm — algae, diatoms, detritus, and associated micro-invertebrates — from rock surfaces with its ventral suckermouth, in keeping with the feeding habits of the subfamily.
Mating
No courtship or mating behaviour has been documented specifically for Harttia surinamensis. In the genus generally, breeding males develop pronounced odontodes and guard a spawning site, but no species-specific observations have been published.
Breeding
There are no published breeding records for Harttia surinamensis, in the wild or in captivity. Loricariinae are typically substrate egg-layers with paternal care, the male guarding and tending the clutch, but no data has been published confirming the reproductive mode or fecundity of this species.
In the aquarium
Harttia surinamensis is not a fixture of the aquarium trade and has no established husbandry record. As a rheophilic rapids fish, it would require pristine, strongly oxygenated water with vigorous flow, a rocky substrate, and warm, stable temperatures, along with a tank large enough to suit its near-7.5 in adult size. It is best regarded as a fish of scientific interest rather than a hobbyist subject.
Conservation
The IUCN Red List assessed Harttia surinamensis as Least Concern in 2023, reflecting its wide distribution across the Guianan coastal rivers and its reported abundance in suitable rapids habitat. The species faces no immediate range-wide threats severe enough to warrant a higher category, though, as with all rheophilic specialists, localised pressures such as gold-mining sedimentation, deforestation, and any future damming of Guianan rivers could affect particular populations dependent on clean, fast water.