Taxonomy & naming
Spatuloricaria terracanticum was described by Londoño-Burbano, Urbano-Bonilla, Rojas-Molina, Ramírez-Gil, and Prada-Pedreros in 2018 in Copeia (volume 106, issue 4, pages 611–621; DOI: 10.1643/CI-18-087). The holotype (IAvH-P 7685) was collected from the Upía River, a tributary of the upper Meta River, in the municipality of Sabanalarga, Casanare, Colombia. FishBase records the species under accession 69176.
The description is notable on biogeographic grounds: prior to 2018, no Spatuloricaria species had been recorded from the Orinoco basin. The genus had been known from the La Plata system south through Argentina and Uruguay, from the São Francisco basin, and from drainages extending as far north as Panama — but the Orinoco record extended the genus's known range significantly and raised new questions about colonisation routes across the Orinoco–Amazon divide.
Spatuloricaria belongs to subfamily Loricariinae within Loricariidae. The genus is defined by a notably elongated, spatula-like snout and the exceptionally long filament on the upper edge of the caudal fin, a character conspicuous in both field and aquarium observation. The Catalog of Fishes (Eschmeyer, CAS) recognises Spatuloricaria terracanticum as a valid species.
Morphology
Adults of Spatuloricaria terracanticum reach approximately 11.5 in standard length (SL) — the largest individual measured by Aquarium Glaser GmbH was 11 in SL — making this one of the more substantial members of its genus. The body follows the strongly depressed, elongated plan of all Loricariinae, narrowing to a slender caudal peduncle with a prominent filamentous extension on the upper lobe of the caudal fin; this filament is a diagnostic feature of the entire genus.
A broad, curved saddle marking sits behind the head on the dorsal surface, forming a distinctive pale sash across the anterior trunk — a colour feature noted in published descriptions of this species. The rest of the dorsal surface is typically dark brown with the cryptic mottling common in substrate-dwelling whiptails. Ventral surfaces are paler.
The upper jaw bears long, curved fang-like teeth, which according to observations from the aquarium trade appear to be used to extract snail bodies from their shells — an unusual dietary specialisation if confirmed. During the breeding season, males develop an elaborate growth of enlarged odontodes (dermal denticles) described as an 'enormous whisker' that covers the head and snout region; this ornamental growth regresses substantially after breeding is complete. Outside the reproductive period, the two sexes are similar in external appearance, though females are typically broader across the body when gravid.
Habitat
Spatuloricaria terracanticum is recorded from the Orinoco River basin in Colombia, with the type locality at the Upía River, a left-bank tributary of the Meta River, in the Sabanalarga area of the Casanare department. The Meta River drains the Colombian Llanos — a vast savanna plain east of the Andes — before joining the Orinoco at the Colombian-Venezuelan border.
FishBase records water chemistry parameters from collecting sites: pH 6.4–8.2, water temperature 73–83 °F, and conductivity 30–302 µS/cm. This wide range reflects the variable hydrology of the Llanos, where seasonal rainfall produces dramatic shifts in water volume, chemistry, and current speed across the wet and dry seasons. The species inhabits moderate-slope rivers over rocky and sandy substrates, consistent with the riffle and run habitats where spawning-site boulders and flat stone slabs are available.
The Colombian Llanos lend the species its name. The original description notes that terracanticum derives from the Latin terra (earth) and canticum (song), honouring the cantos de vaquería — the work songs of the cattle herders (llaneros) of the Colombian and Venezuelan plains, a musical tradition with roots in the 16th century.
Feeding
FishBase records a trophic level of 2.4 for Spatuloricaria terracanticum, indicative of a predominantly herbivorous and detritivorous diet. Most Loricariinae feed by scraping algae, diatoms, fine detritus, and associated microorganisms from hard and soft substrates.
Spatuloricaria terracanticum appears to supplement this baseline diet with animal prey. Aquarium observations indicate that the species will accept animal-based foods with preference, and the curved fang-like teeth of the upper jaw are reportedly used to extract snail bodies from their shells in natural conditions — a behaviour that, if confirmed, is unusual among loricariid catfishes and would represent a degree of molluscivory rare in the family.
In captivity, the species accepts mixed feeding: sinking pellets, algae wafers, spirulina-based foods, and blanched vegetables provide the plant-based component, while live or frozen invertebrates (bloodworm, snails, small shrimps) can be offered to satisfy the apparent preference for animal protein. A varied diet is recommended for long-term conditioning and reproductive health.
Mating
Breeding males of Spatuloricaria terracanticum undergo a remarkable seasonal transformation: the head and snout become densely covered in elongated odontodes — the 'enormous whisker' growth described by importers — that are conspicuously displayed during courtship and territorial interactions with rival males. This odontode development is a reversible seasonal investment; after spawning is complete the whiskers regress, and out-of-season fish show a much smoother head profile.
Males select and defend flat, stone-slab sites, presumably advertising them to ripe females through posturing and the display of breeding odontodes. The species is a substrate-contact spawner rather than a lip-brooder, placing its eggs in a concealed space beneath the selected stone. Females gravid with eggs show a noticeably broader body profile. Conditioning both sexes with animal protein and providing flat stones or ceramic spawning slabs in the aquarium are practical steps toward encouraging courtship.
Breeding
Spatuloricaria terracanticum is a cave-like substrate spawner. Breeding accounts documented in the German aquarium press (Amazonas, 2007) describe the species spawning on the underside of flat stone slabs, with eggs deposited on the concealed lower surface of the stone — effectively using the stone as a roof over a spawning cavity. This microhabitat choice is consistent with rock-riffle habitat in its native Llanos rivers, where flat sandstone or granite slabs resting on the riverbed provide natural spawning chambers.
The male guards the egg mass after spawning, remaining beneath the stone slab throughout incubation. Specific clutch sizes and incubation durations are not available in the published literature for this species, though related genus members incubate for one to three weeks depending on temperature. Fry emerge as miniature adults and take benthic diets from an early stage.
In the aquarium
Spatuloricaria terracanticum is an uncommon import, occasionally available through specialist South American catfish dealers. Its adult size of close to 11.5 in SL demands a spacious aquarium: a tank of 50 US gal or more with a generous footprint is appropriate for a single adult or a pair, as the fish requires open substrate area for foraging and flat stone territory for breeding.
The substrate should be fine to medium sand — whiptails of this group press their ventral mouths against the riverbed and are stressed by coarse gravel. Flat stones or slate pieces should be provided as potential spawning sites and resting positions. The tank need not be heavily planted; a more open, riverine décor with some driftwood and leaf litter is more appropriate to the species' Llanos river habitat.
Water parameters based on field data: pH 6.4–8.2, temperature 73–83 °F, conductivity 30–302 µS/cm. The wide tolerances suggest the species can adapt to a range of tap-water conditions without elaborate chemistry adjustment, provided the water is clean and ammonia and nitrite are kept at zero. Regular partial water changes replicate the dilution effect of wet-season rains and are important for maintaining the high oxygen levels these active catfishes require.
The species is peaceful toward dissimilar tankmates. Males may show territorial behaviour around flat-stone sites, particularly during the breeding season when odontode growth is at its peak. Compatible tankmates include peaceful mid-water species of appropriate size; very small fish may be at risk given the apparent molluscivorous tendency, but this is largely speculative. The seasonal breeding transformation — males growing and shedding elaborate odontodes — is one of the most visually striking phenomena observed in loricariid keeping.
Conservation
The IUCN Red List assessed Spatuloricaria terracanticum as Least Concern in 2020. The species was described only in 2018, and its full range within the Orinoco basin of Colombia is likely broader than the type locality alone. The Llanos rivers of Colombia face pressures from agricultural runoff, cattle ranching, and petroleum extraction in the Casanare department, which can affect water quality, sedimentation rates, and the structural integrity of rocky riffle habitats that the species depends on for spawning.
No captive-breeding population is established in the hobby, so the species is dependent on wild collection for aquarium trade supply. Given its recent description and limited collecting history, further survey work in the Colombian Orinoco tributaries would help establish a more complete picture of its distribution and abundance.