Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Siluriformes
(Catfish) > Lacantuniidae
Etymology: Lacantunia: Named for Rio Lacantún in Chiapas, the tributary river of Rio Usumacinta inhabited by the new catfish; enigmatica: From the Latin name 'enigmatica' = baffling or inexplicable, for the unexpected discovery, obscure relationships and origin.
Environment / Climate / Range
Freshwater; pelagic; depth range 0 - 18 m (Ref. 54757). Tropical
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 42.7 cm SL male/unsexed; (Ref. 54757); 40.6 cm SL (female)
Morphology | Morphometrics
spines: 0. Lacantunia is distinguished from all other siluriforms by five uniquely derived
and anatomically complex characteristics.
1) Fifth infraorbital bone relatively wide and thick-walled, boomerang-shaped and anteriorly
convex, and remote from a markedly prominent sphenotic process (Fig. 4). A long, naked span of the infraorbital sensory canal traverses the bone-free gap between IO5 and the sphenotic process. Primitively in catfishes the infraorbital sensory canal is almost completely surrounded by thin tubular ossicles separated by short gaps, the largest infraorbital bone (fifth or sixth) posterior to eye is simple and anteriorly concave, contacting or close to the sphenotic process that is small or lacking (Lundberg 1982, Mo 1991).
2) Lateral margin of skull thickened along frontal bone and adjacent parts of lateral ethmoid and sphenotic bones at origins of much enlarged adductor mandibulae and levator arcus palatini muscles (Fig. 4). Also, skull roof medial to muscle origins severely constricted, flat, lacking crests and fossae. Most catfishes have smaller jaw and hyoid arch muscles with limited cranial attachments (Lundberg 1982, Grande & de Pinna 1998) and broader, arched skull roofs across the frontals and sphenotics. Other catfishes with enlarged jaw and hyoid arch muscles (e.g. diplomystids, modern ictalurids,
most cetopsids, some amblycipitids, bagrids, clariids and heptapterids) have different patterns of muscle arrangement and attachment sites dorsally on skull roof (Arratia 1987, de Pinna & Vari 1995, Grande & de Pinna 1998, Bockmann 1998).
3) Pair of cone-shaped "pseudo-pharyngobranchial" bones at anterior tips of enlarged accessory cartilages medial to first and second epibranchials (Fig. 5). Many catfishes
have small, paired accessory cartilages medial to the cartilaginous caps on the epibranchials
(Bockmann 1998), but without ossification. The "pseudo-pharyngobranchial" bones and accessory cartilages of Lacantunia are not homologous with first or second pharyngobranchials that are primitively retained in a few siluriforms as rod-shaped bones anteriorly adjacent and parallel to their companion epibranchials (Arratia 1987).
4) Hypertrophied, axe-shaped uncinate process on third epibranchial (Fig. 5). Primitively the third epibranchial of catfishes lacks an uncinate process. Some catfishes have a low process or, if enlarged, a process of markedly different shape (de Pinna 1993).
5) Gas bladder with paired spherical, unencapsulated diverticulae protruding from
anterodorsal wall, each extending dorsad before anterior limb of fourth transverse process,
lateral to first centrum and anterior limb of tripus, and posterior to occiput and ossified Baudelot's ligament (Fig. 6). Diverticulae walls of tough connective tissue containing silvery guanine crystals as in wall of main gas bladder chamber; without heavy vascularization. Catfishes primitively lack gas bladder diverticulae, though a few have different unpaired or multiple diverticulae posterior or lateral to main bladder (Chardon 1968).
North America: Mexico.
Inhabits deep river channels and pools with rocks and strong eddy currents. sometimes taken in stream mouths; collected in both high and low water seasons, and generally during the night. Food include fishes, crabs, prawns, and large and tough seeds (Ref. 54757).
Rodiles-Hernández, R., D.A. Hendrickson, J.G. Lundberg and J.M. Humphries, 2005. Lacantunia enigmatica (Teleostei: Siluriformes) a new and phylogenetically puzzling freshwater fish from Mesoamerica. Zootaxa 1000:1-24. (Ref. 54757)
IUCN Red List Status (Ref. 90363)
CITES (Ref. 94142)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 1.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00389 (0.00180 - 0.00842), b=3.12 (2.94 - 3.30), based on all LWR estimates for this body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.3 ±0.54 se; Based on food items.
Resilience (Ref. 69278
Vulnerability (Ref. 59153
): Moderate vulnerability (41 of 100) .