Taxonomy & naming
Cordylancistrus daguae was originally described by Carl Eigenmann in 1912, in Indiana University Studies (number 8, page 11), based on specimens from the Río Dagua system, Colombia. The species subsequently appeared in the literature under the names Hemiancistrus daguae, Lasiancistrus daguae, and Pseudoancistrus daguae as generic circumscriptions shifted across the twentieth century. The current valid combination, Cordylancistrus daguae, was established by Isbrücker (1980, page 44).
Eigenmann himself provided a complementary description with illustrations of the holotype in 1922 (page 78, plate 12, figures 1–2). The species is treated in Fisch-Muller (2003, Loricariidae-Ancistrinae, Checklist of Freshwater Fishes of South and Central America, EDIPUCRS) and is accepted by the Catalog of Fishes (Eschmeyer, CAS, species ID 5212).
The genus name Cordylancistrus derives from the Greek kordyle (club or swelling) and agkistron (hook), a reference to the widened head shape; the epithet daguae is a toponym honouring the Río Dagua, the type drainage. No L-number or LDA code has been assigned to this species.
Morphology
FishBase records a maximum length of 3.5 in total length (TL) for C. daguae, making it a small to medium ancistrine. PlanetCatfish gives 3.5 in SL (approximately 3.7 inches), which is consistent with a TL in that range when the caudal fin is included. The body conforms to the standard loricariid plan: dorsoventrally flattened and fully armoured with bony scutes, a suctorial ventral mouth, and broad pectoral fins that function as anchors in flowing water.
Topotype photographs are available on PlanetCatfish (images 20959–20961), which provide the most direct visual reference for the species' coloration and body form. No detailed published coloration description was available from the sources consulted beyond these photographic records.
Sexual dimorphism has not been characterised in the literature available. Given its placement in Hypostominae, some degree of odontode development in males during the breeding season would be expected, but this has not been documented for C. daguae specifically.
Habitat
Cordylancistrus daguae is endemic to the Río Dagua, a short river draining the Pacific slope of the western Andes in the Valle del Cauca department of Colombia. The Dagua discharges into the Pacific Ocean near the port city of Buenaventura — a significantly different biogeographic context from the vast majority of Colombian loricariids, which inhabit the Orinoco or Amazon drainages.
Pacific-slope rivers of the Colombian Andes are typically short, fast-flowing, and characterised by clear to turbid water depending on rainfall and land use upstream. Specific temperature or pH measurements are not available for this species from the sources consulted. The type locality is recorded as Caldas, Colombia, near the Río Dagua. FishBase classifies the species as freshwater, demersal, and tropical.
The restricted endemic range — a single river system — means this species has a naturally limited geographic footprint with no known populations in adjacent drainages.
Feeding
No diet data are available for Cordylancistrus daguae in the published or hobby literature consulted. FishBase records no diet information, and no captive records exist from which feeding behaviour could be inferred.
Based on its placement within Hypostominae and the general biology of ancistrine loricariids, a diet of periphyton (algae and associated organic matter rasped from hard substrates), biofilm, and detritus is the reasonable default expectation. The genus is not known to include confirmed xylivores. In a captive context, algae-based foods, sinking wafers, and fresh vegetables would likely represent appropriate supplementary offerings — but this is inferred from family-level biology rather than any observation of this species.
Mating
No information on the mating behaviour of Cordylancistrus daguae is available. The species has not been maintained in captivity and has generated no hobby literature. No field observations of courtship have been reported.
In the absence of species-specific data, nothing substantive can be stated about how this fish courts or pairs.
Breeding
Cordylancistrus daguae has not been bred in captivity and no breeding report exists in any source consulted. PlanetCatfish notes explicitly that it is unreported in captivity with no registered keepers or field sightings through its system.
The species' narrow endemic range on Colombia's Pacific slope and its apparent absence from the aquarium trade make captive breeding a remote prospect without deliberate collection and import effort. Any future attempt would need to establish basic husbandry parameters from scratch.
In the aquarium
No husbandry information is available for Cordylancistrus daguae. The species is, as far as can be determined from the sources consulted, absent from the aquarium hobby — not maintained, not bred, and not commercially imported with any regularity.
For any hobbyist who acquired specimens, the Pacific-slope origin suggests water conditions that may differ from the Amazonian parameters used for most kept loricariids: the Río Dagua is a short, steep Andean river, likely cooler in its upper reaches and potentially harder and more variable than soft Amazonian blackwater. In the absence of any husbandry record, conditions would need to be assessed empirically, starting with clean, well-oxygenated water, moderate temperature (perhaps 72–79 °F as a starting estimate consistent with Andean foothill rivers), and pH held close to neutral. These are extrapolations from geography, not documented observations.
Careful documentation of any husbandry experience with this species would be a genuine contribution to knowledge of Pacific-slope Colombian loricariids.
Conservation
The IUCN Red List assessed Cordylancistrus daguae as Least Concern in October 2014. The assessment notes a distribution across the Dagua River basin, Pacific slope, Colombia, with no major known threats listed.
However, the Río Dagua catchment is subject to significant environmental pressure. The watershed has experienced substantial deforestation, agricultural runoff, and disturbance associated with road construction (the Buenaventura highway corridor). Gold mining activity in the upper Dagua and its tributaries has caused sediment loading and chemical contamination in parts of the system. These pressures are ongoing and have increased since the 2014 assessment.
A species with a single-river endemic range is inherently more vulnerable to localised disturbance than widespread species. The Least Concern designation reflects a broad distribution within that river at the time of assessment, but the combination of a restricted range and a deteriorating catchment warrants monitoring. No population size data are available.