Taxonomy & naming
Loricaria catirina was described by Ananda C. Serejo-Saraiva, Nivaldo M. Piorski, Felipe P. Ottoni, Mark H. Sabaj and Sergio M. Q. Lima in 2026, in the Journal of Fish Biology (volume 108, issue 6, pages 2080–2097), as part of an integrative taxonomic revision of Loricaria in the coastal river basins of northeastern Brazil. The work is registered in ZooBank under the publication LSID urn:lsid:zoobank.org:pub:363E1F46-4FAC-49D3-9CD6-E969DE3FD47C, and the species-level act carries the LSID urn:lsid:zoobank.org:act:ED216331-095C-4A9C-9177-F06EE90865F7.
Before this study, specimens from the Munim River had been recorded in the literature simply as Loricaria cf. cataphracta (Vieira et al., 2023). A linear discriminant analysis of 239 northeastern Loricaria specimens, combined with a mitochondrial cox1 phylogeny and four independent species-delimitation methods (ABGD, ASAP, bPTP and GMYC), recovered the Munim-basin population as a distinct, reciprocally monophyletic lineage, morphologically and genetically separate from both true L. cataphracta and its closest coastal relatives. Genetic (cox1, K2P) distances placed L. catirina 2.2% from L. parnahybae, 3.0% from its sister-described L. teteae, and 4.1% from L. turi — divergences consistent with other recognised species pairs in the genus.
The Catalog of Fishes (Eschmeyer, CAS) recognises Loricaria catirina Serejo-Saraiva, Piorski, Ottoni, Sabaj Pérez & Lima, 2026 as a valid species in the genus Loricaria Linnaeus, 1758, subfamily Loricariinae. The holotype is MNRJ 56152, a 7.14 in SL male collected 25 March 2011 from Povoado Cedro, Chapadinha Municipality, Maranhão State, Brazil (03°50'19.25"S, 43°19'44.80"W), with paratypes deposited at CICCAA, CPUFMA and UFRN.
Morphology
Loricaria catirina reaches at least 8 in standard length (SL) in the examined series (n = 18, range 6.05–7.99 in SL; the 7.14 in SL holotype is a male). Like other members of the genus it has the classic loricariine whiptail build: an elongated, dorsoventrally depressed body, a long, flattened caudal peduncle, and a body sheathed in bony dermal plates arranged in odontode-bearing ridges, broken by naked skin over the ventral head, part of the pectoral girdle, the pelvic-fin base, and a V-shaped patch around the anus.
The species is diagnosed chiefly by its plating pattern: the central abdominal region carries polygonal, clearly separated plates interspersed with bare skin, and the pectoral girdle is covered by large, widely spaced plates rather than a continuous sheet — a combination shared with only a handful of congeners (L. coximensis, L. holmbergi, L. lundbergi, L. nickeriensis, L. parnahybae, L. pumila, L. spinulifera and L. turi) and absent in its closest relative L. teteae, which has both regions fully plated. A shallow, rounded postorbital notch (rather than the deep, angular notch of L. teteae) further separates the two Maranhão sister species.
Total lateral plates number 32–34 (mode 34); anterior lateral plates 16–20 (mode 18); posterior lateral plates 14–16 (mode 16); post-anal plates 18–20 (mode 19). The upper lip carries numerous elongate fringes and the lower lip long marginal filaments; premaxillary teeth are bicuspid, 2–4 per ramus, with 14–16 buccal papillae behind them arranged in three rows. Preserved specimens are dark to light brown dorsally and pale yellow to cream ventrally, with a narrow dark middorsal stripe running from the dorsal-fin base to the end of the caudal peduncle, an irregular dark-and-pale mottled head, and faint reddish-orange pigmentation on the pelvic-fin spine.
Habitat
Loricaria catirina is known only from the middle and lower course of the Munim River, Maranhão State, Brazil, within the Cerrado savanna region of the state — a freshwater, demersal (bottom-associated) fish per the Catalog of Fishes habitat designation. Specific water-chemistry data (temperature, pH, hardness) have not been published for the species.
The describing authors calculated an extent of occurrence of roughly 149 km2 for the known Munim River population — a figure that, taken alone against IUCN Criterion B1 thresholds, would qualify as threatened, even set against the basin's total area of 15,918 km2. The Munim basin sits within the MATOPIBA agricultural frontier (spanning Maranhão, Tocantins, Piauí and Bahia), a zone undergoing rapid soybean-driven deforestation, riparian-forest loss and rising agrochemical use.
Feeding
No dietary study has been published for Loricaria catirina. Like other members of the genus, it has fine bicuspid premaxillary and dentary teeth and dense fringing papillae on the lips, an anatomy consistently associated across Loricariinae with grazing biofilm, periphyton and fine organic detritus from submerged surfaces using its ventral suctorial mouth. This inference is drawn from the genus and subfamily, not from direct observation of L. catirina.
Mating
The type series includes documented sexual dimorphism: of the individuals examined, 10 were identified as males, distinguished by a thicker pectoral-fin spine and modified teeth with smaller, rounded cusps, compared to the longer, more pointed tooth cusps of females and juveniles — a pattern shared with other Loricaria species. No courtship behaviour has been observed or published for this species.
Breeding
No breeding data — wild or captive — have been published for Loricaria catirina, which has never been recorded in the aquarium trade. Like other Loricaria, the genus is broadly documented as practising lip-brooding, in which the male carries the fertilised egg mass adhered to an enlarged, pad-like lower lip until the fry hatch. This is a genus-level inference, not a direct observation for L. catirina, and clutch size, incubation period and fry development remain undocumented for the species.
In the aquarium
Loricaria catirina was described only in 2026 and has no history in the ornamental trade; it is not a species aquarists can currently obtain. Were it ever collected for the hobby, its restriction to Cerrado coastal-river channels suggests the general whiptail-catfish care template used for the genus — a fine sand substrate to protect the delicate ventral plates and barbels, driftwood and leaf litter, well-oxygenated flowing water, and a spacious, sand-bottomed aquarium — would be a reasonable starting point. This is a genus-level extrapolation offered with no captive experience behind it, not documented husbandry guidance for this species.
Conservation
Loricaria catirina has not yet been formally assessed by the IUCN Red List; its status there is Not Evaluated, as is expected for a species described in 2026. In the original description, the authors calculated the species' extent of occurrence at roughly 149 km2 and, applying IUCN (2024) guidelines, proposed classifying it as Data Deficient (DD) — noting that geographic restriction alone does not establish that the species is declining, but that no population, abundance, or environmental-tolerance data yet exist to assess its risk properly.
The Munim River basin lies within the MATOPIBA agricultural expansion zone, where riparian-forest clearance, rising agrochemical use, and general land-use pressure associated with soybean cultivation are intensifying. The authors treat this as a reason for caution rather than a basis for a threatened listing, given the total absence of demographic data for the species.