Taxonomy & naming
Brochiloricaria chauliodon was described by Isbrücker in 1979 (published in Revue française d'Aquariologie et Herpétologie volume 5, number 4, for 1978, pages 90 and 102, figures 15–17). The holotype (ZSM 23342) was collected at Isla El Dorado, Paraná Guazú, approximately 37 mi northwest of Villa Ballester, Entre Ríos Province, Argentina. The genus Brochiloricaria was erected in the same work, with chauliodon as the type species.
The Catalog of Fishes (Eschmeyer, CAS) recognises Brochiloricaria chauliodon as the valid name; no synonyms are listed. The genus contains two species: B. chauliodon and B. macrodon (the second species described later). The former is the more widely distributed, occurring across the La Plata system, while B. macrodon is known from the Paraguayan portion of the Paraguay River.
Covain & Fisch-Muller (2007) placed Brochiloricaria in the Loricaria group of tribe Loricariini (subfamily Loricariinae), closely associated with Loricaria, Paraloricaria, and Ricola. The genus is morphologically very similar to Loricaria, differing most conspicuously in the protruding dentition that gives the type species its name. Within the family Loricariidae, it falls in the subfamily Loricariinae as recognised by Armbruster (2004).
Morphology
Brochiloricaria chauliodon is one of the larger whiptail catfishes in the La Plata system, reaching a maximum of 11 in SL (Ferraris 2003; PlanetCatfish records 11 in SL). The body is strongly depressed, broader at the pectoral-fin base and tapering progressively to a long, slender caudal peduncle. The caudal fin in large specimens bears elongated upper and lower filamentous rays. The dorsal surface is covered with bony keeled scutes; the ventral surface features the typical abdominal cover of flattened platelets.
The diagnostic character alluded to in the species name is the protruding ('gaping' or 'bloated') teeth. The specific epithet chauliodon derives from the Greek chaulios (gaping, or here conveying prominence) and odon/odous (tooth), referring to the noticeably prominent teeth. Scotcat (after the ETYFish Project) renders chaulios as 'gaping or bloated, but probably used here to mean prominent'. In photographs, the teeth are visibly exposed at the mouth in resting adults, giving the fish a distinctive 'open-mouthed' appearance unusual among whiptails.
Coloration is brownish dorsally with variable darker mottling or irregular darker bands; the ventral surface is pale. Males and females are distinguishable: males typically have a broader head, more pronounced odontodes (dermal denticles) on the snout and pectoral spines, and structural differences in the urogenital region. PlanetCatfish images document well-separated male and female morphology from Río Paraná at San Pedro, Argentina.
Habitat
Brochiloricaria chauliodon occurs throughout the La Plata River basin, including the Paraná River and its tributaries in Argentina, Uruguay, and parts of Paraguay (Covain & Fisch-Muller 2007; FishBase). The type locality, Isla El Dorado on the Paraná Guazú near Entre Ríos Province, is in the braided lower Paraná delta, a mosaic of river channels, flooded islands, oxbow lagoons, and seasonally inundated floodplain.
FishBase does not record specific water parameters for this species. Scotcat gives temperature 68–73 °F, pH 6.5–7.2, which reflects the subtropical character of the lower Paraná basin, where water temperatures are distinctly cooler than tropical South American rivers and undergo a pronounced seasonal cycle. These are warm-temperate to subtropical conditions, with winter minima sometimes approaching 59 °F in the more southerly parts of the range.
The species is likely benthic and associated with fine sandy to silty substrates in the lower Paraná floodplain, including riverbanks, lagoons, and flooded channels. Meaty food items dominate in captive diet accounts, suggesting at least partial carnivory in the wild, perhaps feeding on invertebrates in addition to biofilm and detritus. Scotcat notes that aquaria for this species should use sand substrate and subdued lighting.
Feeding
Dietary information for Brochiloricaria chauliodon in the wild is not documented in the published literature. Captive accounts (Scotcat; Evers & Seidel 2005) note that meaty foods are preferred: frozen bloodworm and brine shrimp are readily accepted, suggesting the species is more carnivorous or omnivorous than strictly algae-grazing whiptails.
This aligns with the morphology: the protruding, prominent teeth of B. chauliodon may be more effective at handling invertebrate prey (chironomid larvae, oligochaetes, microcrustaceans, small molluscs) than at fine-scraping algal biofilm. In the productive lower Paraná floodplain, benthic invertebrates are seasonally abundant, and opportunistic predation on them would be energetically advantageous.
In captivity, a diet combining high-quality carnivore sinking pellets, frozen bloodworm, frozen Artemia, and occasional blanched vegetables is recommended. Pure vegetable-based feeding is probably insufficient for long-term health; the food requirements are closer to those of Loricaria than to strictly algivorous whiptails such as Farlowella.
Mating
Brochiloricaria chauliodon is an abdomino-lip brooder, reproducing in a manner analogous to the genus Loricaria (Evers & Seidel 2005; Covain & Fisch-Muller 2007). This reproductive mode, also described in Scotcat as 'lip breeding', involves the male carrying or guarding the egg mass in close association with the ventral lip region — a distinctive paternal care strategy among loricariid catfishes.
Sexual differences in the species are visible externally: PlanetCatfish images from the Río Paraná population at San Pedro document adult males and females side by side, showing the broader head and more prominent snout odontodes of males. Females tend to have a broader body when gravid, as is typical across whiptail genera.
Spawning in the La Plata basin is likely seasonal, correlated with the spring temperature rise following the austral winter. In closely related Loricaria species, spawning is often triggered by rising temperatures and falling water levels after wet-season flooding. An annual temperature cycle in the aquarium — cooler conditions in winter months followed by a gradual spring warm-up — is recommended to condition adults for breeding.
Breeding
Captive breeding of Brochiloricaria chauliodon has been achieved, though reports are sparse. Scotcat documents reproduction as follows: the male carries the eggs until they hatch, with an incubation period of approximately 12 days. Fry should be fed protein-rich foods such as Artemia nauplii (brine shrimp larvae).
This incubation period is consistent with abdomino-lip brooding in Loricaria, where the male fans and guards the egg mass — pressed beneath the lip region — for a comparable duration at subtropical temperatures. The relatively short incubation (compared with cave-spawners such as Panaqolus) reflects the exposed, flow-buffered nature of the brooding site.
Fry of whiptail catfishes in the Loricariinae are typically well-developed at hatching, bearing the full armoured body plan of adults in miniature. They begin feeding quickly on microfoods; Artemia nauplii, microworms, and finely crushed sinking foods are suitable starter diets. No clutch size data have been published for this species; clutch sizes in comparable Loricaria species typically range from a few dozen to over one hundred eggs, depending on female size and condition.
In the aquarium
Brochiloricaria chauliodon is not commonly seen in the trade but is occasionally available from specialists in South American catfishes, particularly in Europe and South America. It carries no L-number. At up to 11 in SL, it is a large whiptail requiring spacious quarters: a minimum tank of 59 in length is advisable for adult fish, with 71 in preferable if the intention is to attempt breeding.
Water conditions must reflect the subtropical La Plata origin: temperature 68–75 °F, pH 6.5–7.2, soft to moderately hard water. This species must not be kept at tropical temperatures; persistent exposure above 79 °F risks chronic stress. A winter cool-down to 64 °F is beneficial and may be necessary for triggering reproductive readiness. Clean, well-oxygenated water with moderate current is preferred; the lower Paraná is a large, flowing river and the fish are not adapted to stagnant conditions.
A fine sand substrate is important. Scotcat specifically states that sand is 'a must'. Subdued lighting and some cover (driftwood, rocky shelves) will encourage natural behaviour. Diet should skew towards meaty foods: bloodworm, Artemia, high-protein sinking pellets, with occasional vegetable matter as a supplement.
Brochiloricaria chauliodon is appropriate for experienced keepers of loricariid whiptails who can provide the space, the temperature regime, and the live/frozen food variety the species requires. It is not a fish for casual community setups.
Conservation
The IUCN Red List assessed Brochiloricaria chauliodon as Least Concern in 2020 (Salvador 2023 assessment confirmed in IUCN 2025 database). The assessment notes a wide distribution across the La Plata basin and no apparent threats severe enough to meet threatened thresholds, though available population data are limited.
The La Plata basin is under heavy anthropogenic pressure. The Paraná River is impounded by numerous major dams including Itaipú and Yacyretá, whose reservoirs have permanently inundated large sections of floodplain habitat and altered the thermal and hydrological dynamics downstream. Floodplain wetlands have been extensively drained for agriculture (particularly soy cultivation) and urban expansion in Argentina and Paraguay. Pollution from agricultural runoff and industrial discharge affects water quality throughout the lower basin.
For a large benthic whiptail with a subtropical temperature requirement, habitat degradation and the alteration of natural seasonal flood pulses are the most relevant threats. The loss of connected floodplain wetlands reduces available benthic habitat and food resources during the critical wet-season period. Continued monitoring of population trends in the lower Paraná system would improve confidence in the species' conservation status.
The species is not known to be collected for the ornamental trade in significant numbers, so harvesting pressure is unlikely to be a meaningful threat.