Taxonomy & naming
Farlowella henriquei was described by the Brazilian zoologist Alípio de Miranda Ribeiro in 1918, and later redescribed by Retzer and Page in 1997 as part of their revision of the genus. The Catalog of Fishes (Eschmeyer, CAS) recognises Farlowella henriquei Miranda Ribeiro, 1918 as the valid name.
The species belongs to the subfamily Loricariinae, the lineage of typically elongate, depressed-bodied loricariids that includes the whiptail and twig catfishes. The genus name Farlowella honours the American botanist William Gilson Farlow of Harvard University, while the epithet henriquei commemorates Captain Henrique Silva, who collected the holotype in Brazil.
Morphology
Farlowella henriquei reaches a maximum recorded length of about 6.5 in standard length (SL). Like all members of its genus, it is an extremely slender, elongate fish with a long, narrow rostrum (snout) and a stick-like body that provides exceptional camouflage among twigs and fine branches — the basis for the common name 'twig catfish'. The body is armoured in the bony plates typical of the family, and the ventral suckermouth is set beneath the elongated head.
No detailed sexual-dimorphism data specific to this species is available in the accessible literature; in many Farlowella, breeding males develop odontodes along the snout margins, but this has not been confirmed for F. henriquei specifically.
Habitat
Farlowella henriquei is recorded from the Araguaia River basin of Brazil. FishBase characterises it as a freshwater, demersal, tropical species. Members of the genus typically inhabit slow to moderate stretches of clear and blackwater rivers and streams, resting against submerged branches, root tangles, and marginal vegetation where their twig-like form blends in.
The genus is noted for facultative air-breathing, an adaptation useful in warm, oxygen-poor backwaters. Detailed water-chemistry and depth data for F. henriquei specifically have not been published.
Feeding
Farlowella henriquei is an algae and detritus grazer, consistent with its low trophic level of approximately 2.5 reported on FishBase. Using its ventral suckermouth, it rasps the biofilm of algae and fine organic matter coating submerged wood, leaves, and rock. No detailed species-specific feeding study has been published, but the genus is uniformly herbivorous-detritivorous and depends on a steady supply of aufwuchs rather than animal prey.
Mating
No data has been published on the courtship or mating behaviour of Farlowella henriquei specifically.
Breeding
No species-specific reproductive data has been published for Farlowella henriquei. Twig catfishes of the genus Farlowella are generally egg-layers that deposit adhesive eggs on firm surfaces — including aquarium glass and broad leaves — with the male guarding the clutch, but no documented spawning records exist for this particular species to confirm clutch size or care for F. henriquei.
In the aquarium
Farlowella henriquei is not commonly distinguished in the aquarium trade, where Farlowella are usually sold simply as 'twig catfish' without firm species identification. The genus as a whole is regarded as delicate: these fish need mature, well-oxygenated water, a steady supply of algae and biofilm (and supplementary blanched vegetables and quality vegetable foods), and gentle tankmates. They are sensitive to deteriorating water quality and to competition for grazing surfaces. Species-specific husbandry for F. henriquei is undocumented, and any keeping guidance is general to the genus rather than confirmed for this species.
Conservation
The IUCN Red List assessed Farlowella henriquei as Data Deficient (DD) on 7 November 2018, and the species is Not Evaluated under CITES. A Data Deficient listing reflects insufficient information on distribution, population size, and trends to assign a threat category. The Araguaia basin faces pressures from agricultural expansion, deforestation, and altered flow regimes, but the specific impact of these on F. henriquei is unknown.