Taxonomy & naming
Farlowella isbruckeri was described by Retzer and Page in 1997, as part of their systematic revision of the stick catfishes of the genus Farlowella, and is recognised as valid by the Catalog of Fishes (Eschmeyer, CAS). The genus belongs to the subfamily Loricariinae, the whiptail and twig catfishes of the family Loricariidae.
The genus name Farlowella honours the Harvard botanist William Gilson Farlow (1844–1919). The species epithet isbruckeri honours the Dutch ichthyologist Isaäc J. H. Isbrücker, a leading authority on South American armoured catfishes.
Morphology
Farlowella isbruckeri reaches a maximum recorded length of about 5.5 in standard length (SL), making it one of the smaller members of the genus. It shares the genus's hallmark form: an extremely slender, elongate, twig-like body with a long, thin snout and a depressed, plated trunk that closely resembles a submerged stick. The mouth is a ventral sucker typical of loricariids.
No information on live coloration or on sexual dimorphism specific to this species has been published in the sources consulted, although male Farlowella in general develop snout odontodes.
Habitat
Farlowella isbruckeri occurs in the upper Paraguay River basin of South America. It is a tropical freshwater, demersal fish. As with other members of the genus, it is a facultative air-breather, an adaptation suited to warm, slow, sometimes oxygen-poor waters where twig catfishes cling to wood and submerged vegetation.
Specific data on water temperature, pH, hardness, or depth at the collection localities has not been published in the sources consulted.
Feeding
Farlowella isbruckeri is a grazer of algae and aufwuchs, the biofilm of algae and microorganisms coating submerged surfaces, and is placed at a low trophic level (approximately 2.5) consistent with a largely herbivorous diet. No detailed study of its specific diet has been published, and finer dietary detail is not asserted here.
Mating
No information on the courtship or mating behaviour of Farlowella isbruckeri specifically has been published in the sources consulted.
Breeding
No breeding observations specific to Farlowella isbruckeri have been published in the sources consulted. Twig catfishes of the genus are generally egg-depositors with paternal care of clutches laid on firm surfaces, but the reproductive details of this species are undocumented and are not asserted here.
In the aquarium
Farlowella isbruckeri is not a regularly identified species in the ornamental trade, and no husbandry data specific to it has been published in the sources consulted. Twig catfishes as a group are considered delicate, needing clean, well-oxygenated water and plentiful grazing surfaces; no keeping or breeding account exists for this species to draw on, and none should be inferred as established practice.
Conservation
The IUCN Red List assessed Farlowella isbruckeri as Data Deficient (DD), with the assessment dated 7 November 2018 (Red List version 2025-2). The Data Deficient listing reflects a lack of information sufficient to evaluate extinction risk rather than evidence of security or of decline.