Apistogramma regani

By Pet Zone SD Team • October 2026

Overview

Apistogramma regani is a small lower Rio Negro dwarf cichlid that matters more for who it's named after than for how often anyone keeps it. Sven Kullander described it in 1980, in the same landmark Bonner Zoologische Monographien revision of the genus that gave this site several of its other species — and he named it specifically to honor British ichthyologist Charles Tate Regan. That's a bigger connection than it might look. Cichlidae.com (Cichlid Room Companion) and Wikipedia both credit Regan himself with erecting the genus Apistogramma in 1913, and with personally describing — under the older genus name Heterogramma, later merged into Apistogramma — four species already covered on this site: borellii (1906), commbrae (1906), pleurotaenia (1909), and steindachneri (1908). Kullander's 1980 paper also placed caetei in the "Regani" species group this fish's own name anchors. Five species on this site now trace back to one taxonomist's work across more than a century.

Despite that pedigree, regani is genuinely obscure in the hobby. PlanetCatfish's own species page for it is titled, plainly, "Got a picture?" — see the FAQ below for why.

Natural Habitat

FishBase places A. regani in the lower Rio Negro basin within Brazil's Amazon drainage, in freshwater, benthopelagic habitat at 23–30°C. Cichlidae.com's own species page documents a male photographed at Ambe Igarapé, a forest stream in that same lower Negro drainage, in October 2012. Neither source states a confirmed type locality for the original 1980 description, so treat the Ambe Igarapé record as a documented collection point rather than the type locality itself. The lower Negro is classic Amazonian blackwater territory — acidic, mineral-poor, and tannin-stained — broadly consistent with the soft, slightly acidic water this site's other Rio Negro specialists need.

Tank Setup

• Tank size: No source gives a specific minimum footprint or volume for this species. Follow this site's general dwarf cichlid guidance in the tank setup guide and give a male enough floor space to hold territory from several females.
• Substrate & décor: Aquatic Republic's breeding setup uses a simple small, upturned plant pot as a spawning cave — the same low-cost approach used for several other small apistos on this site. Soft sand and driftwood or leaf litter, consistent with a blackwater forest-stream habitat, are a safe general choice.
• Water chemistry: FishBase's recorded environment gives a minimum pH of 6.5 and minimum hardness of 5 dH at 23–30°C, with upper bounds not published. Aquatic Republic's breeding-specific water is slightly more acidic, pH 6.0–6.5 at roughly 5 dH. See our water parameters guide for building soft, slightly acidic water safely, and the FAQ below for reconciling the two ranges.
• Filtration & flow: No source gives species-specific filtration guidance. Gentle flow and stable parameters are a safe default for any Rio Negro blackwater apisto — see our water quality guide.

Feeding

Aquatic Republic recommends sinking foods such as flakes and granules as a base diet, since the species feeds near the bottom, with live or frozen bloodworm or brine shrimp added to bring pairs into breeding condition. No source gives further detail specific to this species; see our general feeding guide for broader conditioning-diet strategy.

Temperament & Compatibility

Direct behavioral reporting on this species is thin. Aquarium Glaser's 2019 import notice describes its stocked specimens as "very robust and healthy animals" and notes a pronounced color-change ability — most visibly, a "zebra crossing" banding pattern that intensifies when the fish are worried or stressed. The imported variant also showed a red spot at the tail root, and the species is sometimes traded under the German name "Gelbwangen" ("yellow cheek"). None of this is a substitute for a real temperament rating, which no source currently provides; keep it with calm tankmates and avoid other Apistogramma to prevent hybridization, as with every species on this site.

Breeding

Regani is a cave spawner. FishBase describes eggs attached to the ceiling of a cave, with the female caring for both eggs and larvae. Aquatic Republic's recommended setup pairs one male with several females to encourage natural pairing, using a small upturned plant pot as the spawning cave, and tightens general water down to pH 6.0–6.5 at roughly 5 dH specifically to trigger spawning. Follow our general breeding guide for the broader conditioning-to-fry process.

Sourcing Notes

This is one of the harder species on this site to actually find. Aquarium Glaser's own 2019 stock notice for imported specimens states plainly that its supplier sells only to wholesalers, not directly to retail customers — a concrete, sourced reason the species stays scarce and poorly photographed in the hobby even though it anchors an entire taxonomic group. If you do find it offered, confirm the seller can speak to its collection locality, since so little published material exists to cross-check an identification against. See our general sourcing guide for broader guidance on verifying identification.

Final Thoughts

Regani is proof that a species doesn't need to be common, large, or brightly colored to matter. It's the fish that carries forward the name of the taxonomist who built the genus itself — and who, decades earlier, had personally described four other species that now share this site with it. If you want an established, far more available species to start with, try cacatuoides or borellii. If you're drawn to the taxonomic threads that connect this genus together, regani sits naturally alongside commbrae, pleurotaenia, caetei, and the more recently grouped Bolivian linkei.

Frequently Asked Questions

What makes Apistogramma regani historically significant beyond its own care requirements?

It closes a taxonomic loop that already runs through this site. Cichlidae.com (Cichlid Room Companion) and Wikipedia both credit British ichthyologist Charles Tate Regan with erecting the genus Apistogramma itself in 1913. Decades later, Sven Kullander named this species specifically to honor Regan in his landmark 1980 Bonner Zoologische Monographien revision of the genus — the same paper that formally described several species already on this site. What makes it unusual is that Regan wasn't just an administrative namesake: Cichlidae.com credits him as the direct original describer (under the older genus name Heterogramma, later merged into Apistogramma) of four species covered here — borellii (1906), commbrae (1906), pleurotaenia (1909), and steindachneri (1908) — plus the genus placement that put caetei in the "Regani" species group named after this very fish. Five species on this site trace back to one taxonomist's work, spanning more than a century of ichthyology.

How big does Apistogramma regani get?

Unusually for a species on this site, two independent sources actually agree. FishBase lists a maximum of 4.9cm (1.9in) standard length for males and unsexed fish, 5.0cm for females, with a maximum recorded weight of 2.29g. Aquatic Republic separately gives 49mm (1.9in) standard length — essentially the same figure. Treat it as a small, consistently-sized apisto rather than one where sources are guessing at different things.

What water parameters does Apistogramma regani need?

Sources split slightly between general tolerance and breeding-specific advice, and the two don't perfectly line up. FishBase's recorded environment gives a minimum pH of 6.5 and minimum hardness of 5 dH, at 23–30°C (73–86°F), with upper limits not published. Aquatic Republic's breeding-specific advice calls for slightly more acidic water — pH 6.0–6.5 at roughly 5 dH — to trigger spawning. The practical read: keep general water at or above FishBase's pH 6.5 floor, and be ready to nudge pH down toward 6.0 only when conditioning a pair for breeding. See our water parameters guide for building soft, slightly acidic water safely.

Is Apistogramma regani endangered?

No. Wikipedia's infobox lists it as Least Concern on the IUCN Red List, citing a 2025 assessment by R.G. Frederico — a notably current citation for a species this obscure in the hobby. That puts regani in better conservation shape than several of this site's data-deficient or formally unevaluated Rio Negro specialists, such as brevis and caetei.

Why doesn't a species this taxonomically important even have a confirmed photo on major reference sites?

Because it's genuinely rare in the hobby, not because nobody's looked. PlanetCatfish's own species page for A. regani is literally titled "Got a picture?" — a placeholder the site uses when it has no confirmed photograph on file. SeriouslyFish's Apistogramma genus page, which profiles 28 species, doesn't cover regani at all, consistent with this site's standing note that SeriouslyFish's list isn't exhaustive. Aquarium Glaser's own 2019 stock notice says the wholesaler supplying its imported specimens sells only to other wholesalers, not directly to retail stores — one concrete reason actual photographs and firsthand keeping reports stay this thin for a species that otherwise anchors an entire taxonomic group.