Angelfish are one of the most popular ornamental fish amongst aquarium enthusiasts. Their variety of colors and unique body shape are very appealing to the eye, and their long lifespan has made them one of the more desirable fish in aquariums.
Test your angelfish knowledge with these fun facts.
1. They Aren’t All Angels
Based on their name, you may think that angelfish are generally very peaceful, but this is not always the case.
Angelfish can be territorial during breeding and can show aggression to other fish if they feel threatened.
Angelfish in aquariums that are too small may become aggressive toward tank mates. But in a properly sized and maintained tank they’re usually peaceful—at least outside of breeding times.
2. Not All Angelfish Live in the Same Water
Whether you keep freshwater tanks or saltwater tanks, there is an angelfish species that may be a suitable option for your aquarium.
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Saltwater angelfish live in tropical coral reefs across the Atlantic, Pacific, and Indian oceans. They tend to have a more oval body shape.
Because their native environments are so different, freshwater and saltwater angelfish have unique care needs.
3. They Come in Many Different Colors and Patterns
Angelfish show off a wide variety of colors and patterns. Wild freshwater angelfish are typically silver with black vertical stripes, but selective breeding has led to many new looks over time.
Angelfish Colors
Freshwater angelfish come in white, silver, gold, and black colors. You can also find genetically modified GloFish that swim under specific lights, like the GloFish LED White & Blue Light Stick.
Saltwater angelfish tend to be very brightly colored and can have a variety of blue, green, yellow, and even orange markings.
Angelfish Patterns
Common pattern types among freshwater angelfish include:
Saltwater angelfish also show off lots of variety. Some have vertical or horizontal stripes, others have markings on their heads or backs, and some display mostly solid colors.
4. They Communicate with Body Language
Angelfish use body language to express themselves—especially when it comes to mating, territory, or social hierarchy.
Male angelfish might shake or expand their fins to attract a mate, or if they feel threatened, appear larger to the threat.
When two angelfish face off and “lock lips,” it often looks like kissing, but it’s actually a display of aggression. For females, this lip-locking may be more about testing a male fish’s strength.
Juvenile angelfish sometimes swim erratically so that they appear less like prey.
5. They Can Live for Over a Decade
Fish lifespans vary by species, but most angelfish can live for over a decade. Freshwater angelfish, on average, can live eight to 12 years, and saltwater angelfish can live five to 15 years.
With proper care, you can help your angelfish live a long, happy life. Saltwater and freshwater angelfish require different care. In general, the preferred parameters for saltwater and freshwater angelfish are:
| Temperature | 72–80 F | 75–84 F |
|---|---|---|
| pH | Alkaline, 8.1–8.4 | Neutral to slightly acidic 6–7.5 |
| Hardness | Hard 8–12 dKH | Moderate 3–8 dKH |
| Tank Size | Minimum 55 gallons for dwarf species
Minimum 125 gallons for large species, but may even need over 250 gallons depending on species |
Minimum 20 gallons for one angelfish
Ideally 55 gallons minimum for multiples Horizontal tank preferred |
| Salinity | 1.020–1.025 specific gravity | N/A |
6. Triangle-Shaped Bodies Help Them Hide
Through evolution, wild angelfish have developed uniquely shaped bodies to help them survive. Their compressed bodies make it easy to slip through plants and narrow spaces to avoid predators.
The coloring and patterns of angelfish can also help them blend into their natural environment. Freshwater angelfish benefit from this because their habitats are usually dense with vegetation. Saltwater angelfish can better blend in with coral reefs with their bright colors and can hide in smaller spaces when needed.
7. Angelfish Practice Parental Care
Freshwater angelfish and even some species of saltwater angelfish form monogamous pairs. Monogamy (having only one mate) is rare amongst fish, so this can be an interesting behavior to watch.
Pairing together plays an important role in protecting angelfish eggs and fry. When two angelfish work together, one can defend the territory while the other hunts for food.
Along with protecting their eggs, angelfish will fan their eggs with their fins. The fanning process allows the eggs to receive more oxygen while also helping to remove debris and fungi.
8. They’re Not Always Peaceful Tank Mates
When choosing tank mates for your angelfish, keep in mind they can show signs of aggression.
Here are a few tips for choosing the right tank mates:
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Skip long-finned fish like bettas, fancy goldfish, and fancy guppies, because angelfish may nip at their fins.
Potential Freshwater Angelfish Tank Mates
Depending on the size of your tank, some compatible tank mates for freshwater angelfish are:
Potential Saltwater Angelfish Tank Mates
Most saltwater angelfish aren’t reef-safe, but planktivores such as genicanthus angelfish usually are. They feed on plankton, so they’re less likely to nip at coral.
Dwarf saltwater angelfish can generally be housed with larger species of angelfish, but be cautious if trying to house multiple large species of angelfish.
Depending on the size of your tank, some compatible saltwater angelfish tank mates are:
9. Their Colors Change with Age—and Mood
Some saltwater fish will undergo major color changes as they grow.
Many juveniles start out dark blue before developing their bright, vivid colors in adulthood—a camouflage strategy that helps them avoid predators early in life.
Freshwater angelfish also change colors but in short bursts, usually as a nervous system response or while interacting with other fish. Prolonged color changes, however, can be an indication of disease.
10. Some Angelfish Can Change Gender
Some angelfish that are born females can change into males under certain circumstances—and some can even change back to females! While this is rare in freshwater angelfish, it has been seen in saltwater angelfish such as rusty angelfish and blackspot angelfish.
Typically, hormonal and physical changes will occur in larger females if a dominant male disappears or dies. If another large male shows up, the angelfish may revert to female.
Overall, angelfish have many unique traits and surprising facts you can share with your guests. With proper research, you may be able to find an angelfish that will fit in your current tank.
