The Corydoras Reclassification Explained: New Names, New Genera, and What It Means for You

April 09, 2026

By Bob Steenfott

If you’ve been in the aquarium hobby for any amount of time, you’ve probably noticed something… weird.

All of a sudden:

Corydoras sterbai became Hoplisoma sterbai
Corydoras aeneus became Osteogaster aeneus
Brochis splendens still being Brochis splendens — but now in a framework where Brochis is back as a valid genus

And the entire hobby collectively went:

“Yeah… I’m still calling them Corys.” (Ok, maybe that was just me)

So what actually happened here?

Did scientists just wake up one day and decide to rename everything for fun?
Did your fish suddenly become something different overnight?
And most importantly—what should you actually call them?

Let’s break it all down.

What Changed?

For decades, nearly all armored catfish in this group were lumped into one massive genus: Corydoras.

This genus included:

Over 160 species
Everything from tiny pygmy Corys to larger, bulkier fish
A massive range of body shapes, behaviors, and habitats

The problem?

👉 They weren’t actually all that closely related.

The New Genera

Based on modern research using both genetics and physical traits, the old “Corydoras” group has now been reorganized into multiple genera that better reflect how these fish are actually related.

Here are the ones that matter most to hobbyists:

🟢 Hoplisoma (The Big One)

This is where most of your familiar Corydoras went.

Examples:

Hoplisoma sterbai (formerly Corydoras sterbai)
Hoplisoma paleatum (formerly Corydoras paleatus)
Hoplisoma panda (formerly Corydoras panda)

👉 Translation:
If you’ve owned Corydoras before, you’ve probably owned a Hoplisoma.

🔵 Corydoras (The “True” Corydoras)

This genus still exists—but it’s now much more restricted.

These tend to be:

Smaller-bodied
Sometimes more delicate
Often a bit more specialized

🟡 Brochis (Not Just “Big Corys”)

This is where things often get misrepresented.

Brochis is now recognized as a valid genus within this group—but that does not mean these fish were simply Corydoras that got renamed.

For example:

Brochis splendens was not originally described as a Corydoras species

These fish are generally:

Larger
Thicker-bodied
Equipped with more dorsal fin rays

👉 Think of them as a distinct lineage, not just oversized Corys.

🟣 Aspidoras

Already separate, but part of the same broader group.

Traits:

Smaller size
More streamlined bodies
Faster, more darting movement

🔴 Scleromystax

Also already distinct.

Known for:

Strong sexual dimorphism
Elongated fins in males
Slightly different behavior patterns

⚫ Other Genera You May Hear About

There are a couple additional genera that show up in more technical discussions:

Osteogaster
Gastrodermus

🟤 Osteogaster

This group includes species from the classic “bronze Cory” lineage.

Most notably: Osteogaster aeneus (formerly Corydoras aeneus)
These are some of the hardiest and most widespread Cory-type fish in the hobby
Found in a wide range of environments, which explains why they’re so adaptable

👉 If you’ve kept Bronze Corys, Albino Corys, or Green Corys… you’ve kept an Osteogaster.

⚪ Gastrodermus

Unlike most of their former Corydoras relatives, these fish don’t have coracoid bones enclosing the ventral region.

Examples:

Gastrodermus pygmaeus (formerly Corydoras pygmaeus)
Gastrodermus hastatus (formerly Corydoras hastatus)

These represent deeper splits in the group, but for most hobbyists, you’ll mainly encounter Hoplisoma, Corydoras, and Brochis.

Why Did This Happen?

Short answer:

👉 Science caught up.

For a long time, fish were classified based on:

Body shape
Fin structure
External appearance

And for a while, that worked well enough.

But once genetic analysis became more advanced, it became clear that:

Fish that look similar are not always closely related.

The Problem With the Old System

The traditional Corydoras genus had effectively become:

A catch-all category
Grouping fish that looked similar
But didn’t necessarily share close ancestry

It was convenient—but not accurate.

What Scientists Did

They reorganized the group based on:

Genetic relationships
Skeletal differences
Fin ray counts
Evolutionary lineage

The result:

👉 A more accurate family tree

👉 And a bit of chaos for the hobby

What This Means for Hobbyists

Alright, here’s the part you actually care about.

1. Your Fish Didn’t Change

Let’s get this out of the way:

👉 Your Corydoras did not magically evolve overnight.

Same fish
Same care
Same behavior

Only the name changed.

2. Care Requirements Stay the Same

Whether you call it:

Corydoras sterbai
OR Hoplisoma sterbai

…it still needs:

Soft substrate
Clean, well-oxygenated water
A group of its own kind
Stable parameters

👉 The reclassification does NOT change care.

3. The Hobby Is in a Weird Middle Phase

Right now:

Scientists use the new names
Stores mostly use the old names
Hobbyists use whatever they feel like that day

You’ll see:

Old labels
New labels
Both on the same tank

👉 Completely normal.

4. This Actually Helps Long-Term

Even though it’s messy right now, this change is good for the hobby.

Why?

Better understanding of species relationships
More accurate breeding knowledge
Clearer identification of similar species

👉 Long-term, this makes everything more precise.

What Should You Actually Call Them?

This is the real-world question.

The Honest Answer

👉 Call them Corydoras.

Everyone knows what you mean.

The Practical Answer

If you want to be accurate without sounding like a scientist at a party, here’s the move:

When you first mention the fish, you can say something like:
Hoplisoma sterbai (better known as Corydoras sterbai)
After that, just call them Corys like a normal human being

That way:

You’re technically correct
You’re not confusing anyone
And you don’t sound like you’re trying to prove a point

The Reality

The hobby is not switching overnight.

And honestly?

👉 It probably never fully will.

Will the Names Change Again?

Short answer:

👉 Probably… but not like this.

Here’s Why

Taxonomy evolves over time as new information becomes available:

New genetic data
Newly discovered species
Re-evaluation of existing groups

But This Was a Big One

This reclassification was a major correction, not a routine update.

👉 These names are likely to stick for a long time.

What Could Still Change?

Some species placements may shift
Lesser-known species may be reassigned
CW-number fish may eventually get formal names

But the overall structure?

👉 That’s probably here to stay.

Final Thoughts

Yes, the Corydoras reclassification is confusing.

Yes, the new names feel weird.

And yes, the entire hobby is going to keep saying “Cory” for pretty much everything.

But underneath all that, this change represents something important:

👉 A more accurate understanding of one of the most popular fish groups in the hobby.

And once you understand it, it stops feeling like chaos…

…and starts making sense.

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