Apistogramma caetei

By Pet Zone SD Team • October 2026

Overview

Apistogramma caetei is a small, Amazon-mouth dwarf cichlid from Pará, Brazil, whose own identity in the hobby has been genuinely unsettled for decades. Sven Kullander formally described it in 1980, in the same landmark Bonner Zoologische Monographien revision that gave this site several of its other species. But on the Apistogramma.com forum, longtime moderator and Cichlidae.com (Cichlid Room Companion) curator Mike Wise has cautioned that an informally traded "Red Cheeks" form has long been confused with it — so much so that he considers most pre-1995 hobby information published under the name "A. caetei" likely describes that other fish instead. See the FAQ below for what that means if you're buying one today.

Caetei also carries a taxonomic distinction shared with three other species already on this site: Cichlidae.com places it in the genus's "Regani" species group, alongside commbrae and pleurotaenia — both personally described decades earlier by the British ichthyologist Charles Tate Regan — and the Bolivian linkei, added to the group more recently. The group (and its own namesake species, A. regani) was named to honor Regan.

Natural Habitat

Caetei's type locality is an igarapé (forest stream) near Bragança, in the Brazilian state of Pará, and its documented range covers the Rio Caeté, Rio Guamá, and Rio Apeú — small drainages near the mouth of the Amazon, rather than the deep interior basin many other species on this site call home. PlanetCatfish lists its broader distribution as spanning the Amazon, Lower Amazon, and Tocantins basins. Fishipedia describes the natural water as humus-rich, with a temperature range of 23–30°C and pH 5.5–7 — warmer and closer to neutral than the extreme blackwater many Rio Negro-basin apistos require, which tracks with the Apistogramma.com forum's description of this general area's water as "close to neutral and moderately hard."

Tank Setup

• Tank size: ThinkFish recommends a minimum footprint of 60cm (about 24in); Fishipedia instead gives a minimum volume of 80 liters (about 21 US gallons). Either way, give a species or community tank enough floor space for a male and multiple females to establish separate territories. See our tank setup guide for general dwarf cichlid sizing.
• Substrate & décor: Both ThinkFish and Fishipedia call for a sandy substrate with caves — Fishipedia specifically suggests piles of rocks to form them, while PlanetCatfish's breeding setup uses a simple small, upturned plant pot as a spawning cave.
• Lighting & plants: ThinkFish recommends a little vegetation alongside the sand-and-cave layout; neither source calls for anything unusual on lighting.
• Filtration & flow: Fishipedia recommends keeping nitrates under 25 mg/L with 20–30% monthly water changes and notes the species is sensitive to sudden parameter swings, so a gentle, stable filter setup and a dechlorinator on tap water are worth prioritizing over raw flow rate.
• Water chemistry: General care sits around pH 5.5–7.0 and 1–6 dGH per ThinkFish and Fishipedia, with temperature 73–86°F (23–30°C). For breeding specifically, PlanetCatfish tightens that to pH 6.0–6.5 and roughly 5 dGH. See our water parameters guide for building soft, slightly acidic water safely.

Feeding

All three main sources agree caetei isn't a fussy eater. PlanetCatfish and ThinkFish both recommend sinking flakes or granules as a base diet, with live or frozen bloodworm and brine shrimp for conditioning ahead of a spawn. Fishipedia describes it as omnivorous with a leaning toward carnivory, and specifically recommends feeding only what clears in two to three minutes to avoid fouling the water. See our general feeding guide for broader conditioning-diet strategy.

Temperament & Compatibility

Sources split somewhat on how easygoing caetei really is. ThinkFish calls it peaceful overall, territorial only once breeding, with a straightforward keeping difficulty. Fishipedia takes a more cautious line, describing it as capable of aggression toward conspecifics and similarly shaped fish, prone to hiding around larger tankmates, and sensitive enough to parameter swings that it rates overall husbandry as difficult and better suited to experienced keepers. Splitting the difference is reasonable: keep it with calm, appropriately sized community fish, avoid other Apistogramma to prevent hybridization as with every species on this site, and don't treat it as a casual beginner buy just because some sources frame it that way.

Breeding

Caetei is a cave spawner, kept most successfully as one male with several females. PlanetCatfish describes the female as the primary guardian of the brood, while Fishipedia reports both parents sharing in spawn protection — a split that's plausible, since parental division of labor varies across Apistogramma broods generally and these may simply be different pairs or populations. Fishipedia gives ideal breeding conditions as roughly 27°C (81°F) and pH 6.5, close to PlanetCatfish's own breeding-water recommendation of pH 6.0–6.5.

One detail worth flagging for breeders: Mike Wise, discussing a caetei-type fish on the Apistogramma.com forum, reported that spawns raised around 75°F (24°C) skewed toward more males than females — the reverse of the usual Apistogramma pattern, where warmer water tends to favor males. He described this reversed tendency as typical of "caetei-like" fish specifically. It's a forum observation rather than a controlled study, and it came up in the same identification-confusion discussion covered in the FAQ below, so treat it as a useful heads-up rather than a guarantee. Follow our general breeding guide for the broader conditioning-to-fry process.

Sourcing Notes

Caetei is only occasionally available per ThinkFish, and the identification confusion covered above makes sourcing it more complicated than most species on this site. If a seller's stock traces back further than the mid-1990s, or they can't speak to its collection history, there's a real chance you're actually looking at the informally traded "Red Cheeks"/"Rotwangen" form rather than the formally described species — which isn't necessarily a problem for a hobbyist just wanting an attractive, manageable apisto, but matters a great deal if you're trying to keep a documented bloodline or breed toward conservation-minded recordkeeping. Ask where and when the line was established, and see our general sourcing guide for broader guidance on verifying identification.

Final Thoughts

Caetei is a reminder that a valid scientific name doesn't always settle what's actually swimming in a given tank. Forty-five years after its formal description, a respected reference-site moderator still cautions that most of what the hobby has called "A. caetei" for decades may be a different, informally identified fish — and the species sources even disagree on basic things like adult size and keeping difficulty. It's also a quiet taxonomic link on this site: caetei, commbrae, and pleurotaenia all sit in the same Regani species group, named for the same 1900s-era taxonomist whose own papers described two of them directly. If you want a far more settled, widely available species to start with instead, try cacatuoides or borellii. If taxonomic rabbit holes and identification puzzles are what draw you to this site, caetei sits well alongside commbrae and alacrina.

Frequently Asked Questions

Is the Apistogramma caetei sold in the hobby actually this species?

Not necessarily, and not always historically. On the Apistogramma.com forum, longtime moderator and Cichlidae.com (Cichlid Room Companion) curator Mike Wise has cautioned that a separate, informally traded fish — nicknamed "Red Cheeks" or "Rotwangen" and sometimes labeled A. cf. caetei pending firmer identification — has long been confused with the formally described species. His stated view: most information published about "A. caetei" before 1995 likely describes this other, informally identified form rather than the fish Kullander formally described in 1980. The practical upshot for buyers is the same identification caution this site repeats across its rarer species: a scientific name on a store tag is not a guarantee of an accurate one, especially for anything described or popularized before DNA-assisted identification became routine.

How big does Apistogramma caetei get?

Sources genuinely disagree, even accounting for measurement method. PlanetCatfish gives about 36mm (1.4in) standard length — a conservative, type-specimen-based figure. ThinkFish instead lists roughly 5cm typical and up to 6cm (2.4in) total length, and the French aquarium reference Fishipedia splits the difference at 4cm average, 5cm maximum. Standard length excludes the tail fin and total length includes it, which explains part of the gap, but not all of it — ThinkFish's maximum alone is nearly double PlanetCatfish's figure. Treat the smaller, type-specimen-sourced number as the safer planning baseline, and don't be surprised if your own fish lands somewhere in between.

What is the Apistogramma "Regani" species group, and why does caetei belong to it?

Cichlidae.com (Cichlid Room Companion) places caetei in the genus's "Regani" species group — one of the handful of recognized complexes Kullander established in his landmark 1980 revision. The group takes its name from Apistogramma regani, a species Kullander described in that same paper specifically to honor British ichthyologist Charles Tate Regan. The connection runs deeper on this site than it might elsewhere: Regan himself personally described two of this site's other species decades earlier — commbrae in 1906 and pleurotaenia in 1909, both originally as Heterogramma — and Cichlidae.com places both of those in the very same Regani group caetei now shares with them. So three species on this site trace back to one taxonomist's name, across a 74-year span of ichthyology.

Is Apistogramma caetei endangered?

No — current sources agree it's Least Concern. Fishipedia states an IUCN category of Least Concern directly, and PlanetCatfish cites a 2018 IUCN assessment reaching the same conclusion. Cichlidae.com's own species page still reads "not evaluated by the IUCN Red List," but that page was last updated in November 2007, over a decade before the 2018 assessment existed — so it's an outdated page, not a conflicting current one. Taken together, caetei appears to be in better conservation shape than several of the data-deficient or unevaluated Rio Negro specialists elsewhere on this site.

Why would a caetei spawn produce mostly males?

Mike Wise, discussing a caetei-type fish on the Apistogramma.com forum, reported that breeding at around 75°F (24°C) tended to skew a spawn toward more males than females — the opposite of the pattern seen in most other Apistogramma, where warmer water typically produces more males and cooler water more females. He noted this reversed tendency as typical of "caetei-like" fish specifically, not the genus generally. It's a forum report rather than a controlled study, and it came up while discussing the same informally identified "Red Cheeks" form covered in the identification question above — so treat it as a useful breeder's heads-up rather than a settled rule, and expect some variation between your own spawns.