Which angelfish?

This guide covers Pterophyllum scalare. Koi and black angelfish are selected forms of this species. Pterophyllum altum is a separate species requiring a separate preparation plan. Sharing an angelfish trade name does not make them interchangeable.

FishBase reports approximately 15 cm total length for scalare: a head-to-tail measurement including the caudal fin, rather than vertical height. Assess the span of the dorsal and anal fins separately for the individual and fin form. Those fins need room when choosing water depth and spaces between decorations.

Where do angelfish come from, and when were they described?

Pterophyllum scalare was described by Schultze in 1823 as Zeus scalaris. Eschmeyer’s Catalog of Fishes records the type locality as the lower Amazon River in Brazil. This identifies the origin associated with the scientific name, not the first time people ever encountered the fish or the limits of its entire range.

Its natural distribution includes the Amazon basin in Peru, Colombia and Brazil, with additional drainages in Guyana and French Guiana. Sheltered, flooded vegetation helps explain its tall, laterally compressed body. Selected aquarium color forms such as Koi and Black Angelfish have no separate wild discovery locality.

What aquarium size suits angelfish?

For an adult community, a broad aquarium such as 120 × 50 × 60 cm offers a useful planning example. Its gross volume is 360 litres, with decoration and fill level reducing usable space. This is not the only permissible dimension: it helps illustrate swimming height, routes and separate territories in one layout.

Raising juveniles and keeping an established adult pair are different plans. If starting with a group, prepare for paired fish to exclude others. Adding more angelfish solely to create a group can lead to trouble when there is insufficient adult space or no separation option.

Plants and water conditions

Angelfish suit planted tanks. Vallisneria, suitable Echinodorus and attached plants can create sheltered edges with an open central corridor. Check each plant's temperature and lighting needs. The fish should not scrape its upper and lower fins on hardscape at every turn.

25–28 °C is a useful range to assess when planning routine care of domestic scalare. Captive lines can suit stable soft to moderately hard water; ask about the actual fish's conditions. Measure pH and hardness before adding acids or minerals. A fish continually pushed sideways below the outlet is a reason to reassess flow distribution.

How should you plan pH and hardness?

FishBase lists pH 6–8 and hardness of 5–13 °dH. These compiled ranges are not one experimentally established optimum for every captive line, nor a recipe combining all extremes. Ask about the fish’s rearing water and measure pH, GH and KH in both source water and the aquarium. Use those measurements to plan soft to moderately hard water. GH helps describe mineral hardness and KH buffering; lowering pH alone does not reproduce the same water.

Within the 25–28 °C care plan, undetectable ammonia and nitrite, mature filtration and adequate oxygen matter. Use replacement water with compatible temperature and mineral content, appropriately treated for chlorine and chloramine. Breeding in very soft water does not require moving an entire community to those conditions. Treat adult maintenance and egg development as separate goals.

What fish can live with angelfish?

• Lemon tetras: a suitably sized adult group can be assessed against shared water conditions, but they may nip extended fins. Avoid pairing them with veil-fin angelfish.

• Bronze cories: an option where temperature and open floor space suit both species. They need their own group and food reaching the bottom. Entering an angelfish spawning area may lead to chasing.

• Ancistrus: confirm the actual species and adult size. Fish sold under a general pleco label do not all stay small.

• Small neon tetras, tiny rasboras and shrimp: animals that fit an adult angelfish’s mouth may become prey.

• Tiger barbs and other fin-nipping fish: a poor starting choice for long-finned angelfish.

Size and temperature are only part of the decision. Watch meals and chasing after introduction. Exclusion from food or damaged fins means the community arrangement needs to change.

How do you sex angelfish?

A prominent forehead or pointed fins does not reliably establish a male. Colour and shape are particularly weak shortcuts with juveniles. The genital papilla visible around spawning may help; observing which fish actually lays eggs provides stronger evidence.

Two fish cleaning a leaf together do not automatically establish a fertile male–female pair. Egg development and hatching also need observation. Koi markings or the depth of black pigmentation do not identify sex; the form guides discuss these appearance traps separately.

A pair is fighting: what now?

Check when it began: pairing, spawning, an addition or a layout change? Briefly driving a fish out of one patch differs from confining it to an upper corner all day. Missing meals and fresh fin damage call for safe separation planning. Medication does not solve a territory shortage.

Offer appropriately sized complete food and check every fish receives a portion. Regular water changes, filter checks and short daily observations help catch problems early. Record the pair's territory, the excluded fish and the date of changes in NeoMa to make the next adjustment better informed.

Natural habitat and reproductive biology

Pterophyllum scalare belongs to Cichlidae and is recorded from flooded, vegetated areas in the Amazon basin and neighbouring South American drainages. This does not mean filling the whole tank with plants. Provide vertical shelter around the edges and gaps wide enough for a deep-bodied fish to turn.

A pair may clean a leaf or another suitable surface and deposit adhesive eggs; both parents can participate in defence. White eggs alone do not diagnose fungus. Distinguish failed fertilisation, arrested development and subsequent microbial decay. Record development and water conditions instead of increasing medication after every failed spawn.

Newly hatched larvae and free-swimming fry have different feeding stages. Prepare suitable small first foods and mature filtration with a protected intake beforehand. A freshly filled container is not a ready fry tank. Leaving eggs with parents permits observation of natural behaviour but cannot guarantee high fry survival in a community aquarium.

Domestic scalare can be manageable for a first angelfish project when adult housing and a separation option are ready. Do not postpone adult accommodation until after buying juveniles.

Do not use one first-feeding calendar for every brood. A study of angelfish larvae found better early outcomes with protozoa and rotifers than Artemia under its tested conditions. This does not make Artemia unsuitable for every angelfish brood; mouth opening, nauplius size and actual ingestion matter. Observe capture, swallowing and growth. Experimental hatching times and pH conditions should not become universal recipes for all breeding lines.

The Koi, Altum, Bronze Corydoras and Neon Tetra guides linked above are currently drafts and may not open publicly until published.

For practical preparation and harvesting, see hatching and harvesting Artemia for fry; match nauplius size to the fry and check actual feeding.

Sources

FishBase — Pterophyllum scalare; species identity, distribution and compiled biological records

Korzelecka-Orkisz et al. (2012). Early ontogenesis of the angelfish, Pterophyllum scalare; Neotropical Ichthyology 10:567–576.

Eschmeyer’s Catalog of Fishes — Zeus scalaris / Pterophyllum scalare; authorship, type locality and current status.

This guide was written by NeoMa Aquatics. Original: https://neomaaquatics.com/en/guides/freshwater-angelfish-care