Sorubim lima
Duckbill Catfish
Classification
Pimelodidae
Distribution
A very widespread species that has been recorded from Venezuela, Ecuador, Colombia, Peru, Brazil, Bolivia, Paraguay, Uruguay and Argentina. It occurs in numerous river basins most notably the rios Amazon, Orinoco, Paraná, Parnáiba and Tocantins. It’s an important source of food across much of this range and is fished on a commercial basis.
Habitat
Has been collected from both open, flowing sections of rivers/tributaries and quieter habitats such as floodplain lakes and oxbows but mostly inhabits turbid white-water rivers. Juveniles often form aggregations around thickets of grasses and reeds or among submerged woody structures such as tree roots.
Maximum Standard Length
400 – 501 mm.
Aquarium SizeTop ↑
An aquarium with base dimensions of 200 cm x 75 cm or more is necessary to maintain this species long-term.
Maintenance
This species is nocturnal and a dimly-lit tank with substrate of soft sand suits it best. Other décor need consist only of some decent-sized roots and branches which can be arranged to form sheltered areas although plants can also be added should you wish.
Water should be well-oxygenated and free of organic pollutants. An enormous and reliable filter system should therefore be considered mandatory if maintaining adults as they will produce considerable waste, and a maintenance regime comprising weekly water changes of 30-50% is also required.
Water Conditions
Temperature: 74 – 86°F/23.3 – 30°C
pH: 6.0 – 7.5
Hardness: 1 – 20°H
Diet
Almost exclusively carnivorous preying on smaller fishes, crustaceans, invertebrates, etc. in nature. In the aquarium most individuals can be weaned onto dead foods over time although some seem to find it trickier to adjust than others and may refuse to feed initially. A period of starvation may be necessary, especially when acclimatising recently-transported adult specimens.
Once acclimatised juveniles relish a protein-rich diet comprising live or frozen bloodworm, Tubifex, chopped earthworms, prawns and similar. Adults should be fed correspondingly larger items, such as whole mussels, cockles, prawns, chopped squid, whitebait and earthworms. Once the fish reaches adult size it need only be fed two or three times a week.
This species should not be fed large amounts of mammalian/avian meat such as beef heart or chicken. Some of the lipids contained in these meats cannot be properly metabolised by the fish, and can cause excess deposits of fat and even organ degeneration. Similarly there is no benefit in the use of ‘feeder’ fish such as livebearers or small goldfish which carry with them the risk of parasite or disease introduction and at any rate tend not have a high nutritional value unless properly conditioned beforehand.
Behaviour and CompatibilityTop ↑
Anything that can fit inside its mouth should not be considered but it’s otherwise quite peaceful. Good tankmates include adequately-sized, less-territorial loricariids, cichlids, larger characins and cyprinids with other large Pimelodids or territorial bottom-dwellers less suitable.
Juveniles are actively gregarious and while adults are less so they’re not aggressive towards one another and can be maintained together in large aquaria.
Sexual Dimorphism
Unreported.
Reproduction
Little has been established regarding the reproductive biology of Sorubim spp. though they’re known to spawn at the onset of the rainy season as with so many other Amazonian fishes.
NotesTop ↑
This species is also known by the vernacular names “Hockey Stick Catfish”, “Lima Shovelnose”, “Chiripira”, “Chucharón” and “Pico de pato”.
The genus Sorubim currently contains five recognised species. Of the others S. cuspicaudus is recorded from the parts of the Rio Essequibo, Rio Orinoco, Amazon and Lake Maracaibo basins, S. elongatus from the Rio Essequibo, Rio Orinoco Rio Mamore and Amazon and S. maniradii from the mid-to-upper Amazon. Only three specimens of S. trigonocephalus have ever been collected and it’s known only from the Rio Madeira and Rio Tapajós, while S. lima is distributed as above.
All appear superficially similar with S. elongatus sometimes being imported and sold as S. lima though none of the other species are thought to be traded at present. S. lima is the type species and was redescribed by Littmann (2007) with distinguishing morphological features given as:
“Distinguished from S. elongatus by having modally 9 pectoral rays; 21 anal-fin rays; 16 gill rakers; large vomerine tooth patches, almost always fused; a more robust, deeper head and body; body somewhat compressed laterally; mental barbels equal or anterior to gular apex. Differs from S. cuspicaudus in having rounded caudal fin lobes and more robust body; from S. trigonocephalus by premaxillary tooth patch length being 1.5 to 2.5 times its width; trenchantly differs from S. maniradii in having only 13-18 gill rakers. Additionally, other distinguishing characters include, pelvic fins that contact or nearly reach anal fin origin when depressed and presence of thin plates or ossicles (highly variable in shape) extending vertically on anterior lateral line in most large adults.”
“Head, body and caudal peduncle deeper than in other species of Sorubim.”
“Juveniles more heavily pigmented than adults. Posterior-most rays on dorsal, anal, and pelvic fins heavily speckled with chromatophores, speckling reduced in adults. During development, relative length and amount of pigmentation is reduced on lower caudal lobe until specimen reaches ~ 100mm SL (Reid 1986).”
Sorubim spp. often swim in a characteristic, vertically-orientated posture with the head pointing downwards and caudal fin uppermost. This is thought to be a form of camouflage used for concealment when the fish is among submerged plant leaves or tangles of roots and branches. When adult the fish tend to exhibit a more pelagic lifestyle and the cryptic behaviour and patterning become reduced.
The genus Sorubim is differentiated from other members of the family Pimelodidae by the following combination of characters: head very depressed head; upper jaw long and projecting over lower jaw; premaxillary tooth patch covered by minute, villiform teeth and exposed ventrally; eyes positioned laterally and usually visible from below; black lateral stripe of variable width extending from snout to distal tip of median rays on caudal fin.
Phylogenetic analyses by Lundberg (2011) revealed Sorubim to form a monophyletic group but its closer relationships within the family Pimelodidae were not fully-resolved though it appears most closely-related to the genera Pseudoplatystoma and Sorubimichthys.
References
- Ferraris, C. J., Jr. 2007 - Zootaxa 1418: 1-628
Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types. - Littmann, M. W. 2007 - Zootaxa 1422: 1-29
Systematic review of the neotropical shovelnose catfish genus Sorubim Cuvier (Siluriformes: Pimelodidae). - Lundberg, J. G. 2011 - Proceedings of the Academy of Natural Sciences of Philadelphia 161: 153-189
Phylogenetics of the South American catfish family Pimelodidae (Teleostei: Siluriformes) using nuclear and mitochondrial gene sequences - Ortega, H. and R. P. Vari. 1986 - Smithsonian Contributions to Zoology 437: iii + 25 p.
Annotated checklist of the freshwater fishes of Peru. - Penha, J. M. F., L. A. F. Mateus and G. Barbieri. 2004 - Brazilian Journal of Biology 64(1): 125-134
Age and Growth of the Duckbill Catfish (Sorubim cf. lima) in the Pantanal.
