Cory catfish, are actually pretty closely related to plecos in the sense that they are both catfish
and they both have bony armour. However, corydoras do not have suckermouths in the way plecos do
so they are classified a bit differently. Corydoras is the name of the genus in which
all species of cory catfish are found. There more than 150 different species of corydoras
and they all hail from South America. They are bottom dwellers who prefer small streams, ponds,
swamps, and the banks of rivers and lakes. In the wild they live in groups, called shoals,
that can number up to 1,000 individuals, though smaller amounts are more likely.
They will even shoal with members of differing species, but, again, this is not as typical.
Corydoras can be identified by the three pairs of barbels found on their faces. These act as sensors
to aid in finding food on the floor of the water column. They’re kind of like fingers but on their
faces. You could sort of correlate them to cat whiskers, even. These barbels are sensitive to
sharp or harsh substrate so cory catfish need to be housed in tanks that will not cause damage to
these sensitive face fingers. They food corydoras eat consists of both plant and animal material and
they will focus on worms, invertebrates, algae, and detritus or basically the leftovers of other
animal’s meals, other animal’s waste material, and even decaying flesh. I might think it sounds
gross but to a cory catfish it’s a feast. Or to a seagull..Get out of here, it’s not your week!
Corydoras come in many different colors and patterns.
Here are just a few examples of what this genus has to offer...
In size they can range from right around an inch (2.54cm) at full length to nearly five inches
(12.7cm) from tailfin to nose. This makes them on average much smaller than the aforementioned
pleco species and it’s this fact along with the hardiness of corydoras that they likely make a
much better cleaner fish for beginner aquarium enthusiasts. In fact, corydoras are one of the
most commonly kept fish species. Sure, it’s typically recommended that they be housed in
groups of at least three individuals due to their social nature, but they won’t grow as large as
plecos and usually live longer. If you’ll recall from the pleco episode, the average lifespan of
a pleco is about ten years, but cory catfish can live upwards of twenty years. Though...
I suppose this could technically be a pro or a con depending on how you want to interpret it…
During mating, some species of corydoras display quite the spectacle.
The male and the female form what is commonly known as the “T-position” in which a female
will drink the male’s sperm straight from the source. The sperm are passed through her body
and meet up with eggs she has already prepared. She will lay the now-fertilized and slightly
adhesive eggs in groups on surfaces such as driftwood, plant stalks, or even aquarium walls.
There are usually about 30 eggs laid in this manner and they will hatch approximately five
days later. The length of time it takes them to hatch can depend on water temperature.
It’s been commonly believed that corydoras wink at their owners though this is a bit
of a misconception. Corydoras are not able to close their eyes but they can roll their eyes
downward which causes the pupil and iris to disappear from view of the observant keeper.
This gives the illusion of the fish winking their eye at their owner.
But, while they can’t really offer flirtatious gestures, the fact that owners have even
observed this eye-rolling behavior is in and of itself pretty awesome.
Most catfish are nocturnal thus becoming more active at night, but corydoras are diurnal like
us which gives us ample opportunity to watch their fun and fishy antics. One other cool fact
about corydoras is that they breathe air. While watching them an owner may catch sight of one
quickly swimming to the surface of the tank and then just as swiftly returning the the bottom.
This is because their gills are not designed to take in enough oxygen from the surrounding
water so they have to do this from time to time to quite literally catch their breath.
For more facts on corydoras please take a look at the links in the description.
Have you ever owned a cory catfish? Let us know about it in the comments! As always,
thank you so much for watching and be sure to give a thumbs up for more Animal Fact Files.