Taxonomy & naming
Rineloricaria strigilata was described by Reinhold Hensel in 1868 in the Archiv für Naturgeschichte (volume 34, part 1, page 368) from a stony brook near Santa Cruz in the Laguna dos Patos drainage, Rio Grande do Sul, Brazil — a type locality recorded on PlanetCatfish. The combination was originally published as Loricaria strigilata; Rineloricaria is the currently accepted genus, and the Catalog of Fishes (Eschmeyer, CAS) recognises Rineloricaria strigilata (Hensel, 1868) as the valid name.
The genus received its modern limits largely through the systematic revisions of Isbrücker and, later, Rodriguez and Reis. Rodriguez and Reis (2008) published a taxonomic review of Rineloricaria from the Laguna dos Patos drainage that formally placed R. strigilata within a recognisable species group characterised by a fully plated abdomen and vermiculated colour pattern — the "strigilata group". That same paper described two additional new species from the same system.
Within Loricariidae the genus Rineloricaria belongs to the subfamily Loricariinae, the whiptail catfishes, whose members are characterised by a strongly depressed, elongated body, a protruding lower lip, and the elaborate filaments that extend from the caudal fin in many species.
Morphology
Rineloricaria strigilata reaches approximately 5.5 in standard length (SL) per FishBase (Ref. 75788); PlanetCatfish records a figure of 4.5 in SL, and the higher FishBase value likely reflects the full adult size of larger specimens or a difference in the reference series used.
The body follows the characteristic loricariin plan: strongly depressed and elongated, broadest across the pectoral region and tapering steadily to a long, whip-like caudal peduncle. The snout bears a distinctive globular protuberance of naked skin at its tip — a diagnostic feature noted in the species diagnosis. The abdomen is fully plated, typically with four to five series of plates between the lateral abdominal plate rows, distinguishing R. strigilata from congeners with a naked or partially unplated ventral surface.
Coloration consists of numerous dark vermiculated (worm-like) spots and lines on a light brown background — the pattern by which this species is separated from all congeners in Rodriguez and Reis's (2008) diagnosis. The arrangement of these markings is irregular and fine, giving the fish a streaked or grooved appearance that likely inspired the specific epithet.
Sexual dimorphism follows the general loricariin pattern. Adult males develop hypertrophied odontodes along the snout margin and on the pectoral spines during the breeding season, giving experienced males a bristled appearance. Females remain odontode-smooth and tend to be wider-bodied when gravid.
Habitat
Rineloricaria strigilata occurs in the Laguna dos Patos drainage of Rio Grande do Sul, Brazil, and in adjacent waters of Uruguay — confirmed by photographic records from Laguna de Arnaud, Treinta y Tres Department, Uruguay (PlanetCatfish). The Laguna dos Patos system is the largest coastal lagoon complex in South America, and its tributary streams range from slow, murky sluggish channels to faster-flowing, clearer watercourses over sandy and muddy substrates.
FishBase places the species in slow to fast-flowing watercourses with clear to brown water and sandy or muddy bottoms (Ref. 75788). This breadth of habitat types within a single drainage is consistent with the genus as a whole — most Rineloricaria are substrate generalists that exploit open sandy runs and leaf-litter margins equally well. The species is classified as a temperate freshwater fish, reflecting the seasonally cool conditions of the subtropics of southern Brazil and Uruguay, where winter temperatures can drop considerably below those of tropical loricariid habitats further north.
Facultative air-breathing has been recorded in the genus (FishBase Ref. 126274), an adaptation likely relevant in the shallow, sometimes oxygen-depleted lagoon margins the species may inhabit during dry or warm periods.
Feeding
FishBase assigns R. strigilata a trophic level of 2.5, placing it among low-level consumers. Like other Rineloricaria, the species is a benthic grazer, scraping biofilm, diatoms, fine organic detritus, and algal films from sandy and muddy substrates using its ventrally positioned sucker mouth. The species is not a wood-feeder in the manner of the xylophagous plecos.
In the aquarium, the diet should reflect this detritivore–algivore profile: algae wafers, spirulina discs, sinking pellets, and blanched soft vegetables (courgette, cucumber, spinach) are accepted. Fine-grained substrate in the aquarium, ideally sand, allows natural sifting behaviour. Supplementary protein in the form of small live or frozen invertebrates (bloodworm, daphnia) can be offered occasionally.
Mating
Breeding behaviour in Rineloricaria follows the general pattern documented across the genus in captivity. Males become territorial during the reproductive period, defending a chosen cave or tube site against rival males. The interopercular and pectoral odontodes that develop on breeding males are used in both display and physical contests — males present their bristled snouts and spines toward each other in lateral threat displays.
Females ripe with eggs develop a noticeably wider body profile when viewed from above. A receptive female is guided by the male into the prepared spawning site, where egg deposition and fertilisation occur within the cavity. The male's role shifts immediately to brood guardian once eggs are laid.
Breeding
Rineloricaria strigilata is a cavity spawner with paternal brood care, consistent with the reproductive mode documented across Loricariinae. In captivity, most Rineloricaria spawn in open-ended tubes or similar narrow cavities — PlanetCatfish notes that no formal breeding report specific to this species is on file, but the general genus pattern is well established.
The male fans the egg mass continuously with his pectoral and pelvic fins, maintaining oxygen flow and removing any infertile or fungused eggs. Incubation typically takes several days at subtropical temperatures; fry emerge as miniature adults and begin foraging independently soon after dispersal. The cooler water temperatures characteristic of the Laguna dos Patos region suggest that seasonal temperature drops may play a role in triggering spawning in this species, analogous to the cool-season breeding cycles documented in other temperate loricariids.
In the aquarium
Rineloricaria strigilata is an undemanding whiptail suited to mid-sized aquaria of 20 US gal or more. Its elongated body and preference for open substrate mean that floor space matters more than tank height. A sand or very fine gravel bottom is strongly preferred and allows natural foraging posture. Smooth river pebbles, driftwood, and flat slate provide both visual cover and resting surfaces.
As a temperate species from southern Brazil and Uruguay, R. strigilata is comfortable at lower temperatures than most tropical loricariids. Temperatures of 64–75 °F are appropriate; the species can tolerate brief dips below this range without distress, making it compatible with cooler-water community fish. A moderately soft to moderately hard, neutral-to-slightly-acidic water chemistry suits it well.
The fish is peaceful and can be kept with other non-aggressive species. Males may skirmish over cave sites; providing two or three tube or cavity options per male reduces conflict. The species is not a plant-eater and is safe with most aquatic vegetation. Because it is a low-light, benthic fish, tankmates should not monopolise the substrate.
Conservation
The IUCN Red List assessed Rineloricaria strigilata as Least Concern, with the assessment completed on 7 November 2018. The species' range is restricted to the Laguna dos Patos drainage in Rio Grande do Sul, Brazil, and adjacent drainages in Uruguay — a relatively limited geographic footprint by loricariid standards.
The Laguna dos Patos coastal system faces ongoing pressures from agricultural runoff, wetland drainage, and urbanisation around Porto Alegre and smaller cities. Sedimentation of shallow sandy watercourses poses the most direct habitat risk to benthic substrate specialists like Rineloricaria. At present these pressures are not considered sufficient to threaten the species' overall status, but localised population declines in the most degraded tributaries of the system cannot be excluded.