Catfish of the Month Right Arrow August 1997 • Article © Julian Dignall, uploaded August 01, 1997



Hoplo, Amazon-pansermalle (Denmark), Armoured Catfish, Gefleckter Schwielenwels (Germany), Prickig Hoplo (Sweden), Spotted Hoplo - Megalechis thoracata   (Valenciennes in Cuvier & Valenciennes, 1840)

Corydoras get a lot of attention, but the family they belong to, Callichthyidae, also has a number of other genus ranging from the similar Aspidoras & Brochis to the more elongate Dianema and Megalechis. All of the Callichthyids possess the dual row of armoured plates along their flanks giving rise to the generic name of Armoured Catfish.

There are a number of new scientific names and genera arising from a revisions of Hoplosternum that will take time to become widely used. You will find these fish in most published literature under previous names; Hoplosternum (recently) or Callichthys (before the 1980s). Essentially the fish commonly known as H. thoractum is now placed in a new genus Megalechis as M. thoracata. The similar M. picta can be differentiated by a vertical black bar in the caudal fin which also has a black edge. As an aside, the other commonly available species affected by this revision is H. pectorale which is placed in a new genus of dwarf armoured cats as Lepthoplosternum pectorale. H. littorale remains as such. Irrespective of the scientific world, the common name Hoplo appears to have stuck.

One of the more active catfish that is seen during the day, Hoplos can be quite a personality in a community aquarium. In fact, their only down-side is their gregarious, boisterous nature. They are commonly bred by hobbyists and a tank of 1" long home-bred youngsters can often be found for sale. These tend to be much more competitively priced than wild-caught fish and are also more hardy."


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Jump to next section Cat-eLog Data Sheet
Scientific NameMegalechis thoracata  (Valenciennes in Cuvier & Valenciennes, 1840)
Common NamesHoplo
Amazon-pansermalle (Denmark), Armoured Catfish, Gefleckter Schwielenwels (Germany), Prickig Hoplo (Sweden), Spotted Hoplo
Type LocalityMana R., French Guiana.
Synonym(s)Callichthys exaratus, Callichthys personatus, Hoplosternum personatus, Hoplosternum thoracatum surinamensis, Megalechis personata
PronunciationMEG ah LEK iss - tho rah KAT ah
EtymologyMegalechis: From the Greek megas, meaning large and lekis, meaning plate; in allusion to the extreme development of the coracoid bones on the breast of fully developed males. 
Jump to next section Species Information
Size 155mm or 6.1" SL. Find near, nearer or same sized spp.
IdentificationCan be distinguished from the similar M. picta by the absence of a conspicuous dark vertical band in the caudal fin. In M . thoracata the caudal fin is all-over greyish.
SexingA sexually mature male exhibits a thickened first pectoral ray which ranges from orange / brown to scarlet in colour.
Jump to next section Habitat Information
DistributionTrinidad, Guyana, Martinique, Venezuela, Brazil, Peru & Paraguay
Amazon (click on these areas to find other species found there)
Orinoco (click on these areas to find other species found there)
La Plata, Paraná, Paraguay, Upper Paraguay (click on these areas to find other species found there)
Guyana Waters, Coastal Rivers of Guyanas (click on these areas to find other species found there)
Trinidad rivers (click on these areas to find other species found there)
Maranhão waters, Itapicurú (click on these areas to find other species found there)
Show it on a map (Click the map-icon to show/hide map of species distribution)
pH5.5 - 8.2
Temperature17.0-28.0°C or 62.6-82.4°F (Show species within this range)
Other ParametersAble to survive in poor water conditions.
Jump to next section Husbandry Information
FeedingNot a fussy eater, most foods are accepted. Bloodworm and sinking catfish tablets are best, but once established will eat flakes at the surface. Larger fish will take cichlid tablets / doromin.
FurnitureMegalechis can be found in South American low-oxygen plant infested pools, almost puddles in some cases, but will happily live in most set-ups.
CompatibilityPeaceful and not predatory, although larger specimens can be downright boisterous at feeding time.
BreedingWell conditioned pairs should spawn readily, but a large water change should prompt spawning of a more reluctant pair. Mature fish are typically 18 months to 2 years old. The male builds a large bubble nest, therefore surface movement from filtration should be kept to a minimum. A mass of floating plants (Wysteria is good) are necessary to anchor the nest. After spawning the male guards the nest. The eggs within should hatch after 4 days. The fry are free swimming after 2 days and should be fed newly hatched brine shrimp. They will grown rapidly and should be fed small amounts frequently for the first 6 - 8 weeks during which they can attain sizes of up to 1.5''.
Jump to next section Further Information
ReferencesHistoire naturelle des poissons v. 15, pp309, Pl. 443.
Registered Keepers(1) MatsP (p: 2, k: 2), who also notes: "Quick growth from two inches to almost four in about half a year. Very active and eats ANYTHING.", (2) TP (k: 10), (3) Iwona (k: 2), (4) Stephen, (5) ali12345 (k: 6), (6) hoplo (k: 994), who also notes: "Spawned 15/11/07 1 male with 2 females Hatched 19/11/07 1456 young from that spawning ", (7) Daniel Machado, (8) Chrysichthys (k: 6), (9) CptnSpaulding, (10) ivokilli, (11) CatBrat, (12) fish fodder (k: 2), (13) mikelouth, (14) lazymf, (15) chrismarkham1982, (16) woofess, (17) Redcatman (k: 2), who also notes: "I live in a soft water area. The only water quality parameter measured regularly is pH which is kept between 6.5 and 7.0. Ammonia and nitrite are usually zero when I do occasionally measure it. Nitrate controlled by parial water changes every 2-3 weeks. The tank is filtered using an old (40 years!)Eheim external filter which has been in continuous use since it was purchased. Contains various Eheim filter materials also bought 40 years ago. Only material replaced is a layer of filter wool. Filter is cleaned out when water flow drops which is usually every 2-3 months.", (18) ani-mal-lvr (k: 4), (19) amiidae, (20) Carp37 (p: 2, k: 7), who also notes: "3 females from Birelys on 28/6/07, plus 2 males from Hoplocat 14/07/08.", "Fish bred by Hoplocat- bought at SVAS auction. Originally had 4 in this tank- one female died 2009, most likely after getting stuck among wood decor; the second female had poorly developed fins and died April 2012.", (21) sherry44 (k: 6), who also notes: "arrived 26th sept 2007", (22) kagal, (23) irshprncsk, (24) Mrs.JP, (25) zenyfish (k: 3), (26) janev, (27) myrheksa (k: 8), (28) corydoras, (29) teddyman5 (k: 6), (30) Loracidlover (k: 2), (31) Pungen (k: 8), (32) Birger Amundsen, (33) joe.juice13, (34) SalmonAfrica, (35) aledk85, (36) rayrich (k: 3), (37) kubastanik, (38) launcap (k: 3), (39) chalkvandam, (40) MADRacing (k: 8), (41) geekshow, (42) le_fish, (43) Cornuta, (44) drgold (k: 8), (45) Phoxinus (k: 2), (46) Nick44 (k: 4), who also notes: "2 Pairs grown on from babies", (47) Chlngr (k: 3), (48) Kampfer, (49) theonetruepath, (50) GW_NL (k: 2), (51) thejudgement (k: 4), (52) kiwiplymouth, (53) fischkringli, (54) Reginator (k: 2), (55) dbrzz, (56) Birger (k: 9), (57) Juha (k: 5), (58) L number Banana (k: 2), who also notes: "Added purple beech leaves 4/22/09. PH at. 7.4 Spiral Vals, wisteria. Gravel from old tank, no filter, daily WC's at 10-15%. Airstone, AM sunlight. WC down to 15-20% weekly. Making bubble nest 08/18/2009. Update: No spawning occured. One died without the cause being identified. The other two are doing great. Size is approximate. Update winter 2012 - no changes in the habits but no spawning. Still hand feed when I feel like it - wonderful fish!", (59) eoibio, (60) walshy317, (61) paul, (62) Cory_lover (k: 2), who also notes: "Been keeping these awesome fish for close to 2 years now, and they just spawned for me last night! My first ever Hoplo spawning!! woo hoo! :)", (63) Komolaj1, (64) Jools (k: 6), who also notes: "Being kept in slow water with duckweed, beech leaves and low light.", (65) drpleco (k: 5), (66) jacobhayes79 (k: 2), (67) Back, (68) pickles4601 (p: 2), (69) Bloodywertzie, (70) markhinch, (71) Hikarixz (k: 2), (72) highoctane500 (k: 4), (73) Phyllonemus, (74) mummymonkey (k: 52), (75) ketteringta, (76) MattP (k: 3), (77) PeterUK (k: 2), (78) chubbikins, (79) TurnedTo, (80) tijani (k: 3), (81) Noturus, (82) therealpigdog (k: 4), (83) Richard B (k: 14), (84) andysfishhouse, (85) Dee (k: 2), (86) Mowin (k: 11), (87) Shaun (k: 2), (88) Lars Jamne (k: 102), who also notes: "Got one adult pair, breeds every 6-8 weeks.....", (89) Buddiechrist, (90) JamesStuddart (k: 7), (91) snowball (k: 2), (92) arapaimag (k: 9), (93) linden09, (94) Draco Spectrum (k: 4), (95) browny85, (96) Void (k: 2), (97) N0body Of The Goat, who also notes: "Very friendly, regularly eat food from my fingers", (98) nurglespuss, (99) minkweir, (100) Lilredbeaver, (101) s0llem, (102) anthonyking, (103) Catfish freak (k: 44), (104) james gilbertson, who also notes: "By far the most gentle cat i ever had, this is big bad barry as named by my son,", (105) diikis, (106) francistrus (k: 3), (107) transporter42, (108) Jason.G, (109) Fruityscone, (110) slimrs, (111) Greatguy, (112) yogi88, (113) Doras, (114) Dotty66, (115) Woodza73 (k: 5), (116) dav (k: 3), (117) Sarajute, (118) stealth77, (119) wirikwiri, (120) Iiriva (k: 4), (121) miguel mitchel (k: 2), (122) mikemaes (k: 2), (123) lizimal, (124) andrebelg, (125) WhiteLomu (k: 2), (126) characinfan, who also notes: "The adult male is thriving. He is very gentle but goes crazy when I approach the tank because he *loves food.* He will suck worms from my fingers. Every spring he tries to build a bubble nest. The little guy who never grew at all died on March 2, 2014.", (127) Catfishfingers, (128) nmatt (k: 2), who also notes: "I have had my pair for over 4 years now and they appear to be be thriving. I often see a bubble nest appear on the surface but I don't think they have ever spawned. I Love these fish they are real characters very friendly and active especially at feeding time. Very easy going and a gentle nature.", (129) Xandoz, (130) p44236, (131) summoner2183, (132) simonkirby1985, (133) wobbler (k: 4), (134) Silurius, (135) coelacanth, (136) Jacksta, (137) katgermain, (138) HUNdani (k: 9), (139) chriscoli, (140) Nikita (k: 6), (141) camillajakobsen93 (k: 3), (142) Catfishy, (143) TKL, (144) CL27, (145) dethmann, (146) Ciryluk3g (k: 3), (147) Tau, (148) Csababá, (149) scandicman (k: 3), (150) TheDoctor, who also notes: "A heater malfunctioned and now I only have one small Hoplo cat left the malfunction also cost me 2 angelfish :(", (151) Steven Jansen 72, (152) Garfield1969, (153) flatdog, (154) Madhouse5, (155) rizla75, (156) rcbows (k: 2), who also notes: "Small, 1 to 1/2", doing fine", (157) aqua_maniacs, (158) KetkuFIN, (159) pokemonrange, (160) SimenAndre, (161) Jordanlewis100 (k: 2), (162) Fishybotany, (163) MarcW, who also notes: "Last remaining fish of a trio. Very curious and a little clumsy!", (164) Sabaji, (165) Evy, (166) kenjarle, (167) MBX, (168) protopterus, (169) ADiack, (170) Flatdog, (171) KeXx, (172) Marshal, (173) Zakqary, (174) Gulper, (175) Aquaticus, (176) Gertbl (k: 6), (177) Chilo_glanis (k: 2).

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Breeding Reports(1) Lars Jamne (b: 53), (2) HUNdani (b: 12), (3) Nikita (b: 8).
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Last Update2017 Oct 30 13:49 (species record created: 1997 Aug 01 11:22)

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