Megalechis picta
Bar-tailed Hoplo
SynonymsTop ↑
Callichthys pictus Müller & Troschel, 1849; Callichthys sulcatus Kner, 1855; Hoplosternum oronocoi Fowler, 1915
Etymology
Megalechis: from the Greek μέγας (mégas), meaning ‘big, large’, and λεκίς (lekis), meaning ‘small shield’, in reference to the greatly enlarged coracoid bones in adult males.
picta: from the Latin pictus, meaning ‘decorated, painted, coloured’, presumably in reference to the banded caudal-fin.
Classification
Order: Siluriformes Family: Callichthyidae
Distribution
Widely distributed east of the Andes mountains in Brazil, Venezuela, and Guyana with records existing from the Amazon, Orinoco and upper Essequibo river systems plus some minor coastal rivers of northern Brazil.
It’s absent from Suriname and French Guiana.
Type locality is given simply as ‘Britisch-Guiana’, corresponding to modern day Guyana.
Habitat
An adaptable species that has been observed in a wide range of habitats and can even tolerate hypoxic conditions.
Maximum Standard Length
100 – 120 mm.
Aquarium SizeTop ↑
Minimum base dimensions of 120 ∗ 45 cm or equivalent are recommended.
Maintenance
Ideally use a substrate of fine sand, although rounded gravel is an acceptable alternative provided it’s kept scrupulously clean.
Other décor is largely down to personal choice, but some cover should be provided to give the fish security and floating vegetation is appreciated as well.
Water Conditions
Temperature: 18 – 28 °C
pH: 5.0 – 7.5
Hardness: 268 – 357 ppm
Diet
Megalechis spp. are foraging omnivores and will accept most sinking dried foods, as well as small live and frozen varieties such as bloodworm, Tubifex, etc.
Once settled they will even take floating foods, rising the surface to do so.
Under no circumstances should they be expected to survive on ‘left-overs’ from other inhabitants of the aquarium or relied on to ‘clean’ the aquarium.
Behaviour and CompatibilityTop ↑
Peaceful and hardy, although perhaps a little boisterous for communities containing much smaller or less robust species.
It’s an ideal resident of the larger South American-themed set-up alongside comparable to larger-sized characids, cichlids, loricariid catfishes, etc.
Sexual Dimorphism
Adult males develop greatly enlarged pectoral-fin spines and grow larger than females.
Reproduction
Bubblenester.
The nest is constructed by the male and it’s useful if floating plants are included in the breeding set-up as they’re typically incorporated into the structure.
The female can be removed post-spawning as the male guards the nest and may begin to behave aggressively towards her.
The eggs hatch in 48-72 hours and it’s recommended to remove the male at this point since he may eat his offspring once they are mobile.
The fry are free-swimming 3-4 days later and able to accept Artemia nauplii and suchlike immediately.
NotesTop ↑
This species was previously referred to as M. thoracata, but that name is now applied to the species with a relatively short dorsal-fin spine which was itself formerly known as M. personata.
M. picta can be told apart from M. thoracata by presence of a dark vertical bar in the caudal-fin, a comparatively longer dorsal-fin spine (52.0-64.0% vs. 32.0-48.0% of dorsal-fin base in specimens measuring 90 mm SL or larger), anal-fin with five (rarely four) branched rays (vs. anal-fin with six, rarely five, branched rays).
References
- Ferraris, C. J., Jr., 2007 - Zootaxa 1418: 1-628
Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types. - Reis, R. E., P.-Y. Le Bail and J. H. A. Mol , 2005 - Copeia 2005(3): 678-682
New arrangement in the synonymy of Megalechis Reis, 1997 (Siluriformes: Callichthyidae). - Reis, R. E., S. O. Kullander and C. J. Ferraris, Jr. (eds), 2003 - EDIPUCRS, Porto Alegre: i-xi + 1-729
Check list of the freshwater fishes of South and Central America. CLOFFSCA.
