Corydoras spp.
1 to 3 in
inches, adult, as recorded
Bottom
No photograph yet. The bar is the recorded adult length, to scale.
Freshwater fish · care record

Corydoras spp.

A genus, not a species, so the figures below are only as true as a summary can be. The species table on this page is where the answer actually is.

Scroll to descend
Smallest tank
10 galDwarf species only. Most varieties are given twenty.
Temperature
72 to 82 °FAcross the genus. No single species is recorded across all of it.
Adult size
1 to 3 in30 mm for the salt and pepper, 75 mm for the bronze.
Lifespan
20+ yrCaptive, on one source. Five to seven in the wild.
01

This is a genus, not a species

Every other record on this site describes one animal. This one describes a shelf of them, and the fields below are only true in the way a genus can be true.

Aquarium Co-Op puts the corydoras catfish sold in the hobby at 1 to 3 inches long and gives one set of numbers for all of them. Seriously Fish publishes a page per species, and those pages do not agree with each other: the pygmy wants 72 to 79 °F, the panda 72 to 77, sterbai 75 to 82. Three species, and the window they share is two degrees wide.

So this record carries the genus figures where a source states them for the genus, and prints the species table underneath, because that is where the answer actually is. If you already know which corydoras you are buying, read the table and ignore the summary.

One number is the same everywhere and it is the one people break: a group is six of the same species. Aquarium Co-Op says it plainly, all of the same species, and Seriously Fish repeats a minimum of four to six per page with ten or more preferred for the dwarfs. Two pandas, two bronze and two albino is not a group of six. It is three pairs, and the fish behave like it.

What the genus guide says

Pretty much any community fish that won't eat or attack them. A 10-gallon aquarium may be suitable for dwarf species; 20 gallons or more for most other varieties.

What the species page says, for the most searched one

Unsuitable for the general community aquarium. Many popular aquarium fish will also find it an ideal snack.
They are not talking past each other. Aquarium Co-Op has a page for this exact species and it names neon tetras, chili rasboras, celestial pearl danios, otocinclus, betta fish, snails and adult dwarf shrimp as tank mates, and that danio is one of the few pairings on this site where nothing has to be reconciled: its published rows sit entirely inside this record on both water rows, 6.6 to 7.5 inside 6.5 to 7.8 and 73 to 76 inside 72 to 82. Seriously Fish, on its page for the same fish, calls it unsuitable for the general community aquarium and names angelfish, gouramis and larger catfish as fish that will find it a snack. The two lists are consistent if you read the second as the boundary of the first: small, slow, peaceful company is a community, and it is not the community most people already have.
02

Six of one species, on a floor that forgives

Two requirements were the load bearing part of this record because the first two sources both gave them, and one of the two has since stopped being unanimous: the group, and the substrate the group has to work over.

Smooth sand or gravel

Aquarium Co-Op is specific: smooth sand or gravel is preferred, because of the barbels these fish feed with. They root through the substrate and the substrate is what they root with their face into. Sharp gravel is the one setup decision that is hard to undo later, because it is under everything else in the tank.

Seriously Fish adds the behavior that explains it. Corydoras paleatus is described as enjoying rooting about in sandy substrate, and Corydoras habrosus as forming aggregations close to submerged vegetation or solid structures. The floor is not decor for this genus, it is the feeding surface, and the plants above it are the cover the group holds to.

Cory catfish are not cleaners

Aquarium Co-Op states it directly: cory catfish are not primarily algae eaters, so you will need to specifically feed them. This is the most common misconception attached to any bottom dwelling fish in the hobby, and it is the reason corydoras are sold as a solution to a problem they do not solve.

What they do is forage. Seriously Fish calls C. aeneus and C. habrosus foraging omnivores and C. paleatus an opportunistic omnivore that will take virtually anything offered. Offered is the operative word: food has to reach the floor, and it has to still be food when it gets there.

03

The genus numbers, then the real ones

The water below is what Aquarium Co-Op states for corydoras as a group. The table after it is what Seriously Fish states species by species, and the gap between the two is the point of this section.

Temperature, genus
72–82°F

Stated as depending on species: peppered and julii prefer cooler, sterbai tolerate higher. No single corydoras is recorded across this whole span.

64 °F70778490 °F
pH, genus
6.5–7.8

Aquarium Co-Op, for the group. Species by species Seriously Fish records anywhere from 5.5 to 8.0, which is a wider tolerance than the summary suggests.

4.05.57.08.510.0
Hardness, across the six
18–268ppm

No source states a figure for the genus. This is the span across the six species below, converted where the source states degrees rather than ppm.

075150225300 ppm
Types of corydoras, as Seriously Fish states them, species page by species page
Field Pygmy Salt and pepper Panda Peppered Sterba's Bronze
Species C. pygmaeus C. habrosus C. panda C. paleatus C. sterbai C. aeneus
Adult size 3 cm30 to 35 mm5 cm7 cm6.5 cm65 to 75 mm
Tank, as stated 45 by 30 by 30 cm base 60 by 30 cm 45 by 30 by 30 cm 24 by 15 by 12 in 45 by 30 by 30 cm base 80 by 30 cm
Temperature 72 to 79 °F68 to 79 °F72 to 77 °F72 to 78 °F75 to 82 °F70 to 81 °F
pH 6.4 to 7.45.5 to 7.56.0 to 7.46.0 to 7.06.0 to 7.66.0 to 8.0
Hardness 2 to 15 °H36 to 179 ppm1 to 12 °Hup to 12 °H1 to 15 °H36 to 268 ppm
Group 6, better 10+4 to 6, better 10+at least 6in groupsat least 64 to 6
Lifespan not recordednot recordednot recordednot recordednot recordednot recorded

The units are mixed because the sources are mixed: some pages state hardness in ppm and some in degrees. One degree of general hardness is about 17.9 ppm, so 12 °H is roughly 214 ppm. Nothing in this table has been converted into a tidier figure than the source published, and no lifespan appears on any of the six species pages. One arrived from outside them, and it is in the next table down.

Read the temperature row across and the mixed community problem appears on its own. Panda tops out at 77 °F and sterbai starts at 75. Seriously Fish adds that a panda kept warmer than its range long term will likely have its lifespan reduced considerably, so those two species share a two degree window and no more. A single species per tank is not a purist position here; it is the only way to hold one temperature that every fish in the group is recorded for.

The genus, across the four sources that publish figures for it
Field Seriously Fish Aquarium Co-Op Aqueon Aquarium Source
Minimum tank per species10 gal dwarf, 20+ most 30 gal best for most10 gal bare minimum, 20 advised
Group size shoaling, no number6+ of one species 5 or more4, 5, preferably 6+
Temperature per species, 72 to 8272 to 82 °F 74 to 80 °F, captive bred70 to 80 °F
pH, captive bred per species, 5.5 to 8.06.5 to 7.8 7.0 to 8.07.0 to 7.8
pH, wild caught not splitnot split 5.5 to 7.05.5 to 7.0
Alkalinity not statednot stated 3 to 10 dKH captive, under 3 wild3 to 10 dKH
Lifespan not statednot stated not stated5 to 7 wild, over 20 captive
Species in the genus not countedmore than 160 not countedmore than 165 named

Plants are cover, not decoration

Aquarium Co-Op is direct about it: cory cats love plants, nibble the leaves and use the cover to hide in. For a fish that spends its day on the floor of a lit glass box, plants are the difference between being out and being exposed, and a bare planted tank produces a group you never see.

This is the same distinction the pea puffer record draws, where a source attaches dense planting to a stocking figure rather than to the look of the tank. The aquarium plants silo holds what we have verified about the plants themselves; nothing in it is recorded as a corydoras requirement, because no source states one.

Captive bred or wild caught, which almost nobody asks

Two of these four sources do something the other two do not: they give one set of water figures for a captive bred cory catfish and a different set for a wild caught one. They did it independently and they landed in nearly the same place.

  • pH. Aqueon gives 7.0 to 8.0 for captive bred and 5.5 to 7.0 for wild caught. Aquarium Source gives 7.0 to 7.8 and 5.5 to 7.0. The two bands touch at 7.0 and share nothing else.
  • Alkalinity. Aqueon gives 3 to 10 dKH, about 54 to 180 ppm, for captive bred, and below 3 dKH for wild caught. Aquarium Source gives 3 to 10 dKH without splitting it.
  • What it means in a shop. Almost every cory catfish sold in a chain store is captive bred, and the water it wants is the harder, more alkaline one. A wild caught fish put in that water is being kept at the wrong end of its own range.
  • What this record does with it. The recorded pH stays 6.5 to 7.8, which is the genus figure Aquarium Co-Op publishes, because that is the only figure two of our sources can be read as agreeing on. The split is printed rather than folded in.

The corydoras lifespan, from one source

This field was blank on this record until now, and the note said so. Aquarium Source states 5 to 7 years in the wild and more than 20 years in captivity under ideal conditions. Neither Seriously Fish across six species pages, nor Aquarium Co-Op, nor Aqueon states a lifespan at all.

So it is one source, and it is recorded as one source. Over twenty years is a long commitment for a fish bought as a clean up crew, which is the other thing this record has to say about that idea. Seriously Fish gives the only related figure: a panda cory kept above its range long term will likely have its lifespan reduced considerably.

Aquarium Co-Op puts the genus at more than 160 species with several hundred more awaiting classification; Aquarium Source says more than 165 named. Nobody is wrong, and it is a good illustration of why a record per species is the only honest unit here.

04

The full record

Care record, as verified
FieldRecordedWhere it comes from
Minimum tank10 to 20 gal

Aquarium Co-Op: a 10 gallon may suit dwarf species, 20 gallons or more for most other varieties. Seriously Fish asks for a base of 80 by 30 cm for the bronze cory long term, which is larger than either.

Aqueon disagrees upward: a 30 gallon aquarium is best for most species, with the dwarf corys hastatus, habrosus and pygmaeus as the exception. Aquarium Source calls 10 gallons the bare minimum and advises 20 with a school of five or more.

Temperature72 to 82 °F

Aquarium Co-Op, stated as depending on species. Per species Seriously Fish records 72 to 77 °F for the panda and 75 to 82 °F for sterbai, so the span belongs to the genus and to no single fish in it.

pH6.5 to 7.8

Aquarium Co-Op, for the genus. Species by species Seriously Fish records from 5.5 to 8.0 across the six in the table. Aqueon and Aquarium Source both split the figure by origin, independently and to nearly the same numbers: 7.0 to 8.0 and 7.0 to 7.8 for captive bred against 5.5 to 7.0 for wild caught. The recorded band is the genus figure, and the split is printed rather than folded in.

Hardness18 to 268 ppm

Ours: the span across the six species pages, converting degrees at about 17.9 ppm per degree. Aquarium Co-Op states no hardness figure for the genus. Aqueon gives alkalinity 3 to 10 dKH, 54 to 180 ppm, for captive bred and below 3 dKH for wild caught; Aquarium Source gives 3 to 10 dKH without splitting it.

Adult size1 to 3 in

Aquarium Co-Op, for the fish in the trade. Seriously Fish records 30 to 35 mm for Corydoras habrosus and 65 to 75 mm for Corydoras aeneus.

DietSinking, not an algae eater

Aquarium Co-Op states they are not primarily algae eaters and must be fed specifically. Seriously Fish calls them foraging omnivores across the species pages.

Water columnBottom

Both sources, with one exception on the record: Seriously Fish places Corydoras pygmaeus in the middle levels of the tank while still calling it primarily benthic.

LifespanOver 20 years, captive

Aquarium Source, the only source we hold that states one: 5 to 7 years in the wild and more than 20 years in captivity under ideal conditions. Not stated on the Seriously Fish genus or species pages, nor by Aquarium Co-Op, nor by Aqueon.

Growth rateJuveniles look like small adults in about a month

The pygmy corydoras page from Aquarium Co-Op is the only source of five with a time attached: the splotches combine into the lateral stripe in a month or so, such that the juveniles look just like miniature adults and are hard to tell from their parents. That is a figure for one species on a record that covers the genus, so it is carried as the one datum that exists rather than as a rate for every Corydoras here.

Seriously Fish, Aqueon, Aquarium Source and the general Aquarium Co-Op guide state no growth figure at all.

The same nine fields for every animal on this site are in the A to Z index.

Where our sources disagree

The genus guide and the species page for the most searched member of the genus give opposite advice about community tanks. Both are printed, because the difference between them is which corydoras you bought.

Aquarium Co-Op, for the genus

Pretty much any community fish that won't eat or attack them. A group of six corydoras or more, all of the same species, is highly suggested.

Seriously Fish, for Corydoras pygmaeus

Unsuitable for the general community aquarium. Many popular aquarium fish will also find it an ideal snack.

What we record: both hold, and the caveat is the whole sentence. At three inches a bronze cory is company for most community fish; at three centimeters a pygmy corydoras is food for several of them, including angelfish and gouramis by name.

We record the genus as bottom dwelling community fish and mark the dwarfs as a separate stocking decision.

05

The floor, and the one that leaves it

Corydoras are the floor crew of the freshwater hobby, and one of the six above does not read the job description. Seriously Fish places C. pygmaeus in the middle levels of the tank while still calling it primarily benthic; Aquarium Co-Op describes the same fish hovering midwater by flapping its fins and perching on anubias leaves and driftwood branches. Two sources, one unusual fish. Corydoras habrosus, the other dwarf, is recorded as spending more time close to the substrate than other small species. Both are sold as the same thing and they use different water.

Surface · nothing here, which is why a surface fish above them costs nothingFree
Mid water · the pygmy, per its own page, and only the pygmyPartly
Bottom · where the genus lives and feeds, with its barbelsOccupied
Substrate · smooth sand or gravel, stated rather than suggestedCondition

This is the practical reason corydoras appear in so many stocking plans: they take the layer almost nothing else wants, and they take it in a group. Add a mid water school and a surface fish and the tank is fully stocked without any two species arguing over the same water. The pygmy is the exception that will share the middle with your tetras instead.

06

Feeding a fish that eats off the floor

Aquarium Co-Op names live blackworms, frozen bloodworms and Hikari Vibra Bites, and adds Repashy gel foods, sinking wafers and other sinking community foods. Seriously Fish asks for a good quality sinking pellet or tablet as the staple on the C. panda and C. sterbai pages, supplemented with live and frozen foods such as Daphnia, Artemia and bloodworm.

Sinking is the whole requirement

Everything on both lists sinks. That is not a coincidence, it is the constraint: a fish that feeds on the substrate cannot compete for flake that never gets there, and in a community tank the mid water fish will take it first. If your corydoras are thin in a tank you feed generously, the food is being intercepted rather than rationed.

What to feed pygmy corydoras

Smaller versions of the same thing. Seriously Fish is explicit that food for C. pygmaeus must be small enough for its tiny mouth, and asks for small live and frozen foods such as sifted Daphnia or Artemia nauplii. A sinking wafer sized for a three inch bronze cory is not food for a three centimeter fish, it is furniture.

What a starter kit leaves out

Three things this record asks for that a tank with gravel in the box does not include.

  • Smooth sand, or smooth gravelfor the barbels
  • Sinking food, sized to the specieswafers, or crushed
  • Five more of the same speciessix is the group

Every item our records ask for is gathered on the tank setup topic.

Nothing here is a paid link. It is the shortfall between what this record asks for and what a boxed kit contains.

How this record was compiled

By

Verified

Sources

Seriously Fish, Aquarium Co-Op, Aquarium Co-Op, pygmy corydoras, Aqueon and Aquarium Source

Conflicts

Printed above rather than resolved quietly

Not recorded

Lifespan, a hardness figure for the genus, shrimp fry, and the emerald green cory, which has no species page behind it in this record

They are not cleaners. Aquarium Co-Op says it in as many words: you will need to specifically feed them.

01 Not algae eatersStated outright. Buying them to solve algae is buying the wrong fish.
02 Foraging omnivoresSeriously Fish, across the species pages. Sinking dried food plus live and frozen.
03 Food has to landIn a community tank the middle layer eats first. Feed after lights out if it does.
07

Company, and the size that decides it

Aquarium Co-Op sets the rule for the genus, pretty much any community fish that will not eat or attack them, and names one exception outright: goldfish. Seriously Fish sets a harder condition for the dwarfs, and both are on the record below.

{name:Ember tetra}A mid water school in a different layer, and Aquarium Co-Op lists corydoras on its tank mate list from the other side. Both records agree on 72 to 82 °F.Clears
Harlequin rasboraPeaceful, mid water, similar size. Fits the stated rule for the larger species without qualification.Clears
OtocinclusShares the floor without competing for the same food, and is on the Aquarium Co-Op list for nano communities.Clears
{name:Betta}Named as a tank mate on the Aquarium Co-Op pygmy corydoras page. Our betta record prints two sources disagreeing about community tanks at all, so this is a pairing with a source behind it and a caveat above it.Risky
Angelfish, gouramis, larger catfishNamed on the C. pygmaeus page as fish that will find it an ideal snack. For the three inch species this is a different question; for the dwarfs it is settled.Never, for dwarfs
Adult dwarf shrimpNamed on the Aquarium Co-Op pygmy corydoras page, along with neon tetras, chili rasboras, celestial pearl danios and snails. Stated for the pygmy; not stated either way for the larger species.Clears, for the pygmy
GoldfishThe one pairing Aquarium Co-Op warns against by name.Never
A second corydoras speciesNot a danger, a dilution. Six of one species is the stated group; two species of three is two groups of three.Never as a group

Will corydoras eat shrimp?

Adult dwarf shrimp are named as tank mates, for one species out of the genus.
Half of it is on the record. Aquarium Co-Op names adult dwarf shrimp among the tank mates for the pygmy corydoras. Nothing we hold says the same for the three inch species, and nothing we hold says anything at all about shrimp fry, which live on the substrate a foraging omnivore works over. So: adults with a pygmy, stated. Anything else, open.
08

What goes wrong, in order of frequency

01

A group of six, made of three species

Two pandas, two albinos and two bronze looks like six corydoras and is not one. Aquarium Co-Op specifies all of the same species; the shoaling behavior people buy these fish for is what the mixed tank loses.

02

Sharp gravel

Smooth sand or gravel is the stated preference and the barbels are the reason. This is the hardest thing in the tank to change later, because everything else sits on top of it.

03

One temperature for a mixed shelf

A tank at 80 °F suits sterbai and sits three degrees above the top of the panda range, where Seriously Fish warns the lifespan is likely to be reduced considerably. The species table above is the fix, and it is the reason this record refuses to publish one number.

04

Bought as a catfish cleaning crew

Corys are not primarily algae eaters and they do not clear uneaten food you never gave them. A tank that stays dirty with corydoras in it had a feeding problem, not a staffing problem.

05

Dyed and short bodied fish

Seriously Fish records that artificially dyed specimens and mutated short bodied strains of C. aeneus are in the trade. Both are choices made at the fish's expense, and neither is a variety.

09

Questions about corydoras catfish care

What is the pygmy corydoras size?

Around 1.2 inches, or 3 cm, as a maximum standard length on the Seriously Fish species page. Aquarium Co-Op puts it at a grand total of 1 inch, or 2.5 cm, and the difference is what is being measured: standard length stops at the base of the tail. Either way it is the smallest of the six species in the table above and roughly a third the length of a bronze cory.

What is the pygmy corydoras tank size?

Ten gallons, and Seriously Fish and Aquarium Co-Op land there for different reasons. Aqueon exempts the dwarf corys from its 30 gallon figure, so it does not contradict this one. Seriously Fish states 18 by 12 by 12 inches, which is 45 by 30 by 30 cm or 42.5 liters. Aquarium Co-Op asks for a 10 gallon or larger specifically so that you can keep a bigger school of at least 8 to 12 pygmies. A standard 10 gallon is 20 by 10 inches, so it clears the stated length and is 2 inches narrow front to back.

How many corydoras should I keep together?

Six or more, all of the same species, per the Aquarium Co-Op genus guide. Seriously Fish states at least four to six on the bronze and salt and pepper pages, at least six for panda and sterbai, and at least six but preferably ten or more for the pygmy. The Aquarium Co-Op page for the pygmy goes further again and asks for 8 to 12, noting they are shy in smaller groups. This record carries six of one species as the genus minimum and ten as the dwarf one.

Do corydoras catfish eat algae?

No. Aquarium Co-Op states that they are not primarily algae eaters and that you will need to specifically feed them. They forage on the substrate, which is not the same job as grazing glass.

What to feed pygmy corydoras?

Food small enough for a tiny mouth, which is how Seriously Fish puts it, plus small live and frozen foods such as sifted Daphnia or Artemia nauplii. The sinking wafers and tablets that suit the larger species need crushing for this one.

Is an albino corydoras a separate species?

No. Seriously Fish records albino as a selectively bred strain of Corydoras aeneus, alongside long finned strains. So an albino corydoras carries the bronze cory numbers: 65 to 75 mm, a base of 80 by 30 cm for long term care, and 70 to 81 °F.

What temperature do panda corydoras need?

72 to 77 °F, per Seriously Fish, which is cooler than most of the genus. The same page warns that a panda kept warmer than its range long term will likely have its lifespan reduced considerably, so this is the species that decides the thermostat in a mixed tank.

What are the small corydoras species?

Two of the six above: C. pygmaeus at 3 cm and Corydoras habrosus, the salt and pepper cory, at 30 to 35 mm. Both ask for ten or more rather than six, and the pygmy is the one Seriously Fish calls unsuitable for a general community aquarium.

Will corydoras eat shrimp?

Not recorded. Not one of our four sources states a position on shrimp with this genus. What both state is that these are foraging omnivores taking small live food off the substrate, and the substrate is where shrimp fry are, so we leave the question open rather than answer it from a forum.

How long do corydoras live?

Not recorded. None of the six species pages we used states a lifespan, and neither does the genus guide. The one lifespan statement we do have is a warning rather than a figure: a panda kept too warm has its own reduced.

Do corydoras need sand?

Smooth sand or gravel, per Aquarium Co-Op, and the reason is the barbels they feed with. The page notes that wild corydoras live over sharp substrate; the recommendation for an aquarium is still smooth.

Can corydoras live alone?

Every source we hold gives a minimum group, and none of them is one. Nothing we read states what happens to a single corydoras, so this record says what the sources say: buy six of one species, and if you have one now, the fix is five more of the same.

Which corydoras is best for a beginner?

Aquarium Co-Op names the bronze, albino, panda, emerald green and pygmy cory as the most popular varieties in the pet trade rather than ranking them for difficulty. On the numbers, the bronze cory has the widest recorded tolerance of the six, 6.0 to 8.0 pH and 70 to 81 °F, and it also asks for the largest tank at a base of 80 by 30 cm.

What is the corydoras lifespan?

One of our five sources states one. Aquarium Source gives 5 to 7 years in the wild and more than 20 years in captivity under ideal conditions. Seriously Fish gives no lifespan on any of the six species pages we read, and neither Aquarium Co-Op nor Aqueon states one for the genus.

Treat it as a single source rather than a consensus, and treat the captive figure as the reason to take the group size seriously: a fish that can outlive a dog is not a starter animal you replace.

What are the best corydoras tank mates?

Aquarium Co-Op describes cory catfish as suiting most peaceful community fish, and the constraint this record adds is not temperament, it is temperature. Panda tops out at 77 °F and sterbai starts at 75, so the genus itself is harder to mix than the community it joins.

The refusals we hold are on the tank mates topic, and the one that matters here is the shrimp question below. Our kuhli loach record shares the floor and the gentle flow requirement, which makes it the closest thing to a compatible bottom dweller in this build.

Are cory cats and cory catfish the same fish?

Yes. Cory cats, cory catfish, corys and corydoras all name the same genus of South American catfish, and our sources use the terms interchangeably: Aqueon writes cory cats, Aquarium Co-Op writes cory catfish, Seriously Fish uses the scientific binomial for each species and nothing else.

The name that matters is the second one. A group of six corydoras is only a group if all six are the same species, and the shop label is where that goes wrong.

Do corydoras catfish need a 30 gallon tank?

Our sources disagree, and this is the widest disagreement on the record. Aqueon says a 30 gallon aquarium is best for most species and names the dwarf corys, hastatus, habrosus and pygmaeus, as the exception. Aquarium Co-Op says 10 gallons may suit dwarf species and 20 or more for most other varieties. Aquarium Source calls 10 gallons the bare minimum and advises 20 with a school of five or more.

What this record carries is 10 to 20 gallons, which is the span of the two sources that split it by species. The stocking calculator uses 10 as the floor for the dwarf species this build holds, and Aqueon's 30 is on the table above rather than averaged away.

Are corydoras paleatus and corydoras sterbai interchangeable?

Not on temperature. Corydoras paleatus, the peppered cory, is recorded at 72 to 78 °F and Corydoras sterbai at 75 to 82 °F. They overlap by three degrees, and Aquarium Co-Op describes the same split from the other direction: peppered and julii prefer cooler temperatures while sterbai tolerate higher ones.

10

Eggs, and how far our sources go

Corydoras spawn readily enough that people who did not plan to breed them end up with fry, which is why this section exists at all. Aquarium Co-Op describes it for the pygmy: females deposit single sticky eggs on java moss or plant roots, the eggs hatch in two to five days depending on temperature, and the fry need microscopic foods at first, vinegar eels, infusoria or golden pearls.

Seriously Fish adds one number from a different species page: for the peppered cory, a breeding group should hold at least two males to every female. It is the only sex ratio any of our pages states, so it is the only one this record repeats.

Read that list again, because it is the whole difficulty. Adult corys will take a sinking wafer on day one; their fry will not take anything you can see. A tank with java moss in it can produce eggs without any intervention, and the same tank produces nothing that survives unless the smallest food in the house is smaller than a wafer crumb.

What we have not recorded: the other five species. Their Seriously Fish pages were read for the care fields in the table above, not for their spawning notes, so this record does not summarise breeding for the bronze, the panda, the peppered, sterbai or the salt and pepper cory. Nor does anything we hold state how many eggs a female lays, how long the adults keep spawning, or what triggers it. Those are real questions and this page is not the answer to them yet.

What is stated, for the pygmy

Where the eggs go
Single sticky eggs on java moss or plant roots
Hatching
Two to five days, depending on temperature
First food
Microscopic: vinegar eels, infusoria, golden pearls
Sex ratio
For the peppered cory, Seriously Fish asks for at least two males to every female
Not stated
Egg count, spawning trigger, and whether the adults eat the eggs

The plants are doing two jobs here. Aquarium Co-Op has the same fish perching on anubias leaves and driftwood branches during the day and laying on java moss when it spawns, so a planted tank is both the setting and the spawning site. Nothing in this record asks for a bare bottom breeding tank, because nothing in our sources does.

11

The names, and how unreliable they are

This genus is a naming problem as much as a fish. Seriously Fish records that for Corydoras aeneus alone, several synonyms are currently treated as valid taxa, that the classification of fish from other localities appears far from certain, and that names such as C. schultzei and C. venezuelanus have been misapplied to aquarium strains despite being invalid synonyms. The bronze cory in a shop tank may not be the species on the label.

Which is why the trade names matter more here than on any other record. Albino corydoras is a bred strain of C. aeneus. Emerald green cory, which Aquarium Co-Op lists among the most popular varieties, is commonly the fish other sources place outside Corydoras altogether, and we have not read a species page for it, so it is not in the table above.

None of this changes a tank. It changes what you can conclude from a name on a bag: if the label says the species, read the table; if the label says a color, read the bronze row.

Telling a pygmy from a hastatus

The one identification problem worth knowing is between the two smallest corys in the trade, because they are sold interchangeably and are not the same fish. Seriously Fish states the difference plainly: C. pygmaeus carries a dark stripe running the entire length of the lateral line, while C. hastatus has a dark diamond shaped spot at the caudal peduncle, which is the narrow part before the tail, and lacks body markings. A stripe down the body is a pygmy; a diamond at the tail with a plain body is not.

What this record is built from

Genus figures
Aquarium Co-Op, corydoras catfish care guide
Species figures
Six Seriously Fish species pages, each linked in the table
Not used
Forum threads, shop listings, and any page that gives one temperature for the whole genus
Left open
Shrimp compatibility, lifespan, and the emerald green cory, which has no species page in this record

Six species is not the genus. Aquarium Co-Op counts the varieties in the trade in the dozens, and the table above covers the ones people actually search for. When another record is written it goes in the table, and the hardness row at the top will move with it.

Sheets in this set
Top

Counting which records get read

This site has no advertising and nothing to sell you. The one thing it would like to measure is which records people actually read, because that decides which one gets written next. Saying no changes nothing about what you can read here.

What it collects