Cat-eLog Right Arrow Loricariidae Right Arrow Hypoptopomatinae Right Arrow Otocinclus

Jump to next section Cat-eLog Data Sheet
Scientific NameOtocinclus flexilis  Cope, 1894
Common NamesPeppered Oto
Argentinischer Ohrgitter-Harnischwels (Germany)
Type LocalityRio Jacuhy [Jacuí], Rio Grande do Sul, Brazil.
Synonym(s)Macrotocinclus flexilis, Otocinclus fimbriatus
Pronunciationauto SINK luss - flex ill iss
EtymologyGreek, ous, oto = ear + Latin, cinclus = latticework; in allusion to the holes of the head in the ears. 
Jump to next section Species Information
Size 54mm or 2.1" SL. Find near, nearer or same sized spp.
IdentificationAn easy species of Otocinclus to identify although two colour forms exist. One with a more pronouced darker and lighter "peppering" and one with a more regular pattern. This variance aside, the colouration is the same as the common peppered Cory, Corydoras paleatus. Coloration of individual otos vary with mood. Normal coloration is beige with spots, but this species (in presumed breeding mode) turn darker, and may become almost black.

Other species of Otocinclus which can have a blotched color pattern are O. arnoldi, O. mimulus, and O. xakriaba. O. flexilis is distinguished from O. arnoldi and O. mimulus by having six branched pectoral-fin rays (vs. five branched rays in O. arnoldi and O. mimulus). O. flexilis is distinguished from O. xakriaba by the presence of a triangular pigment mark at the dorsal-fin base of O. flexilis (absent on O. xakriaba).
SexingFemales are considerably larger than males and fuller in girth.
Jump to next section Habitat Information
DistributionSouth America: Middle and lower Paraná/Paraguay, Uruguay and La Plata basins and Atlantic coastal streams of southeastern Brazil.
La Plata, Uruguay (click on these areas to find other species found there)
La Plata, Paraná, Middle Paraná (click on these areas to find other species found there)
La Plata, Paraná, Lower Paraná (click on these areas to find other species found there)
La Plata, Paraná, Paraguay (click on these areas to find other species found there)
La Plata (click on these areas to find other species found there)
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pH6.5 - 7.8
Temperature20.0-25.0°C or 68-77°F (Show species within this range)
Other Parameters2-25 dGH.
Jump to next section Husbandry Information
FeedingNew imports can be tricky to acclimatize to prepared foods, but once this hurdle is overcome (using frozen bloodworm and algae wafers) they feed greedily.
FurnitureLess reliant on plants than other Otocinclus species, nevertheless, tall leaved plants like Vallisneria provide habitat and shade for these species that also appreciate vertical wood surfaces but generally move around the aquarium without preference. Gravel or sand may be used.
CompatibilityA highly social, diurnal and hardy species. Slightly aggressive (more akin to slightly larger loricariids); they defend food albiet half-heartedly, and dominate Corydoras at feeding time but not to the other species detriment.

Also when kept with Corydoras paleatus, the Corys appear fooled by the oto mimics, and often follow them around, gulp air at the same time the otos do, and even male corys display to otos. The otos on the other hand seem aware which fish are conspecifics, as they're noticeably more aggressive towards the corys than to each other. Perhaps the bright white opercular diverticulum serves as a recognition signal for the otos? They have a curious behaviour that they nibble at each other and corys at the base of the dorsal fin, something which is apparently very unpleasant for the receiving fish - it looks like aggressive/dominance behaviour.
Suggested TankmatesKeep in groups (preferably at least six) with any small to mid-sized community fish.
BreedingIt is reported that smaller male fish 'dance' in front of larger fish, 'nudge' the larger fish in the region of the cloaca, and also follow them around very closely. Actual reproduction is unreported.
Jump to next section Further Information
ReferencesProc. Am. Philos. Soc.v. 33 - pp97 - Pl. 8 [7] (figs. 13, 13a-b)
Registered Keepers(1) irshprncsk, (2) alderfish (k: 6), (3) DrunkenPanda (k: 8), (4) SHEAG35 (k: 4), (5) Barbie, (6) Cory Ben.

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Breeding ReportsNone.
Article - CotM 2009 May
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Last Update2017 May 13 01:49 (species record created: 2004 Aug 21 00:00)