Otocinclus Anatomy
Basic Anatomy
Here I'll describe the basic Otocinclus anatomy. Most fish have similar fins and
other body parts as the oto, just not in the same places. Either way, the otocinclus is
like other catfish in the family Loricariidae (Suckermouth catfishes) so this could also
describe the other species, such as pleco, paraotocinclus, and farlowella.
| Picture Key |
| 1 |
Dorsal Fin |
6 |
Pectoral Fin |
| 2 |
Eye |
7 |
Pelvic Fin |
| 3 |
Nares (Nostril) |
8 |
Anal Fin |
| 4 |
Mouth |
9 |
Caudal Peduncle |
| 5 |
Gills |
10 |
Caudal (Tail) Fin |
Interesting Anatomy
Sure we could keep up the scientific analysis of scales and gill plates, and other such
stuff. But I'm interested in what makes these otocinclus catfish so COOL! Lets have a
look at the parts of the otocinclus which make them interesting.
Nostrils
What? Does this poor fish have "hole in the head" disease? No... they're nostrils! Otocinclus use
their nostrils to locate food from across the tank. It's most likely that your oto is SMELLING the
algae tablet you placed in one corner, rather than seeing it right away.
Ventral Fins
This picture isn't flipped... that is an otocinclus hanging upside down by its ventral
fins! The oto uses these fins as little hands to hold it steady on thin leaves (such as
the pygmy chain swords pictured above.) It will also sometimes rest on these fins so its
stomach doesn't touch the gravel or plant leaf... almost like a balancing act!
Mouth
A closeup of an otocinclus mouth shows you the two "whiskers" of the catfish. This also shows
the closest thing you'd ever find on an otocinclus that resembles teeth. It takes those four
mouth parts and rubs them against the surface to remove the algae, kind of like a scrubby pad.
Hairs?
Fish have hairs? Well, the otocinclus do! They have these small hair-like protrusions from the skin. They're
called odontodes, and they are actually made of bone material. I'm still trying to find out what they are used
for (probably deterring predators and maybe mating), but I know that these hairs can cause the
otocinclus to get stuck in a fishnet, so be careful!
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