Taxonomy & naming
Rineloricaria jaraguensis was described by Franz Steindachner in 1909, originally in the genus Loricaria — the reason its authority is cited parenthetically as (Steindachner, 1909). The Catalog of Fishes (Eschmeyer, CAS) recognises the valid combination Rineloricaria jaraguensis (CoF species id 5383).
The species belongs to the subfamily Loricariinae, the whiptail catfishes, one of the major lineages within the suckermouth-armoured catfish family Loricariidae. Rineloricaria is a large and taxonomically difficult genus of slender, depressed-bodied whiptails distributed widely across South America. The genus was treated in the Loricariinae checklist by Ferraris (2003) in the Check List of the Freshwater Fishes of South and Central America (CLOFFSCA).
Morphology
Rineloricaria jaraguensis reaches a maximum recorded length of about 7.5 in (total length, male/unsexed) — a comparatively large whiptail within the genus. Like other Rineloricaria, it has the elongated, dorsoventrally flattened body and tapering caudal peduncle typical of the whiptail loricariins, with the body sheathed in rows of bony scutes and a ventral suckermouth.
Detailed morphometric and meristic diagnostics specific to this species are not reproduced in the available reference data, and no reliable description of its live coloration is published here. Sexual dimorphism is undocumented in the available sources; many Rineloricaria males develop hypertrophied odontodes on the head and pectoral region during breeding condition, but this has not been confirmed for R. jaraguensis.
Habitat
The species is endemic to the Jaraguá River basin in Santa Catarina, southern Brazil, a coastal drainage of the Atlantic slope. It is a freshwater, demersal (bottom-associated) fish of temperate-to-subtropical waters.
Members of the genus are typically found in flowing watercourses, often associated with rocky or sandy bottoms, and are facultative air-breathers able to use atmospheric oxygen when dissolved oxygen is low. Specific microhabitat data — substrate, current, water chemistry — for R. jaraguensis are not published in the available sources.
Feeding
No direct feeding study for Rineloricaria jaraguensis is available. FishBase lists a trophic level of approximately 2.5, consistent with the omnivorous-to-detritivorous habits typical of whiptail loricariins, which graze biofilm, algae, small invertebrates, and organic detritus from hard surfaces using the rasping suckermouth. Captive dietary requirements have not been documented for this species.
Mating
No data on courtship or mating behaviour have been published for Rineloricaria jaraguensis.
Breeding
No breeding records exist for Rineloricaria jaraguensis in the available sources. Across the genus, whiptail catfishes are generally substrate- or cave-spawners with paternal care, the male guarding and fanning a clutch of adhesive eggs — but this has not been confirmed for this species and should not be assumed.
In the aquarium
Rineloricaria jaraguensis is not an established aquarium species, and husbandry information is essentially absent from the available data. General care of large Rineloricaria whiptails involves well-oxygenated, clean water, a fine sandy substrate, gentle to moderate current, and ample biofilm and algae grazing surfaces, but no species-specific guidance can be offered responsibly here.
Conservation
The IUCN Red List assessed Rineloricaria jaraguensis as Least Concern on 7 November 2018. As a freshwater species restricted to a coastal southern-Brazilian basin, it is potentially exposed to localised pressures such as habitat alteration and water-quality decline, but it is not currently considered threatened.