100 Aquarium Facts & Statistics You Should Know

Here are the aquarium facts worth knowing in 2026: the opening group comes from FishyHub's US marketplace data, and the rest cover freshwater fish, reef life, invertebrates, plants and care. FishyHub reports its statistics as tiers and directions rather than raw figures, so every marketplace fact below is a comparison you can quote, not a number.

Key Findings

• FishyHub data shows freshwater livestock holds the larger share of US listings, with marine livestock a substantial second.
• FishyHub marketplace activity shows rising listings in every US livestock category with a trend signal.
• FishyHub data shows tetras, discus, goldfish, plecos, shrimp, clownfish, tangs and LPS, SPS and polyp corals all have very high US supply.
• FishyHub data shows halfmoon plakat bettas draw very high buyer interest in the US, and giant halfmoon plakat demand clearly outpaces supply.
• FishyHub data shows arowanas, flowerhorns, tangs, seahorses and LPS hard corals sit in the US collector / premium price tier.
• FishyHub search data shows bettas, discus, guppies, plecos, shrimp and tetras in the very high search tier.

Marketplace Facts from FishyHub's US Data

1. Freshwater livestock holds the larger share of FishyHub's US listings.
2. Marine livestock is the smaller share of US listings, but a substantial one.
3. Every US livestock category with a FishyHub trend signal shows rising listings.
4. Tetras have very high supply in the US and entry-level prices.
5. Discus have very high US supply and sit in the upper mid-range price tier.
6. American cichlids have very high US supply and mid-range prices.
7. Goldfish have very high US supply and a very wide price spread.
8. Plecos have very high US supply and a very wide price spread.
9. Catfish have very high US supply and entry-level prices.
10. Freshwater shrimp have very high US supply and entry-level prices.
11. Guppy listings sit in the entry-level tier with a narrow price spread.
12. Halfmoon plakat bettas draw very high buyer interest from US users.
13. Demand for giant halfmoon plakat bettas clearly outpaces US supply.
14. Halfmoon bettas sit in the upper mid-range, above the betta category as a whole.
15. Crowntail bettas sit in the US entry-level price tier.
16. Flowerhorns sit in the collector tier with a very wide price spread.
17. Arowanas have limited US supply and collector-tier prices.
18. Silver arowanas sit in the upper mid-range, below black and Jardini arowanas.
19. Oscars are listed in the entry-level tier, though they grow into big fish.
20. Clownfish have very high US supply and a very wide price spread.
21. Tangs and surgeonfish have very high US supply and collector-tier prices.
22. Wrasses, gobies and butterflyfish all have very high US supply.
23. LPS, SPS and polyp corals all have very high US supply.
24. LPS hard corals sit in the collector tier; SPS and soft corals in the upper mid-range.
25. Seahorses sit in the US collector / premium tier.
26. Marine invertebrates as a group are collector-tier, but marine snails are entry-level.
27. Tridacna clams have high US supply and upper mid-range prices.
28. Bettas, discus, guppies, plecos, shrimp and tetras are in FishyHub's very high search tier.
29. Axolotls, isopods, frogs and jellyfish are in FishyHub's high search tier.
30. "Other Animals" sits in the very high tier of FishyHub Feed videos.

Freshwater Fish Facts

1. Bettas are labyrinth fish and can gulp air from the surface.
2. Male bettas are kept apart because rival males fight.
3. Plakat bettas are short-finned, closer to the original fighting fish.
4. Guppies are livebearers: females give birth to free-swimming young.
5. Mollies, platies and swordtails are livebearers too.
6. Female livebearers can store sperm and drop repeated broods from a single mating.
7. Neon tetras get their glow from light-reflecting cells called iridophores.
8. Tetras and rasboras feel safest in schools, which is why they are sold in groups.
9. Corydoras catfish dart to the surface now and then to gulp air.
10. Plecos are armoured catfish with sucker mouths built for grazing.
11. Some plecos rasp driftwood as part of their diet.
12. Discus parents feed their fry on a mucus secreted from their skin.
13. Freshwater angelfish are Amazonian cichlids, unrelated to marine angelfish.
14. Many Lake Malawi cichlids are mouthbrooders.
15. Oscars learn to recognise their keepers and often beg at the glass.
16. Goldfish were domesticated from wild carp in China over many centuries.
17. Fancy goldfish prefer cooler water than most tropical fish.
18. Koi are pond fish and outgrow almost any home aquarium.
19. Arowanas are surface-feeding jumpers that need a tight-fitting lid.
20. The Asian arowana is protected under US endangered species law.
21. Snakeheads are restricted under US federal wildlife law.
22. Bichirs are an ancient lineage with a primitive lung.
23. Flowerhorns are a man-made hybrid cichlid with no wild population.
24. Pufferfish teeth keep growing, so they need snails or other hard foods.
25. Annual killifish lay eggs that survive their pools drying out.
26. Hatchetfish can leap from the water, so their tanks need lids.

Marine and Reef Facts

1. Clownfish start life male, and the dominant fish in a pair becomes female.
2. Many clownfish in the hobby are captive-bred rather than wild-caught.
3. Clownfish do not need an anemone to thrive in an aquarium.
4. Designer clownfish morphs explain much of the price gap within the category.
5. Tangs are grazers and need plenty of algae in their diet.
6. Tangs carry a sharp spine near the tail, the scalpel behind the name "surgeonfish".
7. Many wrasses bury themselves in sand to sleep.
8. Mandarin dragonets feed mainly on tiny live copepods.
9. Male seahorses carry the eggs and give birth.
10. Dwarf angelfish suit reef tanks better than large angelfish, but may nip corals.
11. Lionfish have venomous spines and need careful handling.
12. Corals are animals that host photosynthetic algae in their tissue.
13. SPS corals generally need stronger light and steadier water than soft corals.
14. LPS corals have large fleshy polyps and often accept meaty foods.
15. Fragging lets hobbyists grow new coral colonies from cuttings.
16. Tridacna clams rely on light, much as many corals do.
17. Live rock provides biological filtration in a reef tank.
18. Marine tanks need stable salinity, best checked with a refractometer.
19. Cleaner shrimp pick parasites and dead skin off fish.

Shrimp, Snails, Plants and Other Animals

1. Neocaridina shrimp come in many colour lines from a single species.
2. Caridina shrimp need softer, more carefully managed water than Neocaridina.
3. Amano shrimp larvae need brackish water, so they rarely breed in home tanks.
4. Nerite snails lay eggs in freshwater, but the eggs do not hatch there.
5. Assassin snails hunt and eat other snails.
6. Aquatic plants absorb nitrate and compete with algae.
7. Java fern and Anubias grow on wood or rock rather than in the substrate.
8. Floating plants shade the tank and soak up excess nutrients.
9. Carpeting plants usually need bright light and added carbon dioxide.
10. Axolotls are salamanders that keep their larval gills for life.
11. Axolotls need cool water, unlike tropical fish.
12. Isopods are popular clean-up crews for bioactive terrariums.
13. Crayfish will eat plants and catch slow-moving fish.

Care, Buying and Shipping Facts

1. A new tank needs cycling so bacteria can process fish waste.
2. Ammonia and nitrite are toxic to fish; nitrate is far less harmful.
3. Tap water needs a dechlorinator before it touches fish.
4. Many US water utilities use chloramine, which needs a conditioner rated for it.
5. Most tropical fish in US homes need a heater for much of the year.
6. Regular partial water changes beat occasional big ones.
7. Overfeeding is a common cause of poor water quality.
8. Quarantining new fish helps keep disease out of an established tank.
9. Live fish ship overnight in insulated boxes, often with heat or cold packs.
10. FishyHub groups US delivery into zones such as Midwest & Central and West Coast & Mountain West.
11. Alaska, Hawaii and the territories usually cost more to ship live fish to.
12. FishyHub is a marketplace: livestock is sold by independent merchants.

Methodology

The marketplace facts come from FishyHub marketplace activity in the United States over the period from October 2024 to October 2026: active listings, listed prices and price spread, wishlists, likes and "my tank" saves, new listings over time, the freshwater and marine share of listings, search terms and Feed video categories. They are reported as tiers and directions, not figures. The US marketplace is new, so US order history is not used, and buyer-interest detail is mainly available for bettas. Search terms combine the US and Singapore markets.

The remaining facts are general hobby knowledge, not FishyHub findings. FishyHub does not measure how many Americans keep fish, what they spend, or activity by state.

Frequently Asked Questions

What is the most interesting aquarium fact?

Many people are surprised that clownfish all start life as males, and that the dominant fish in a pair turns female.

Are there statistics on the US aquarium hobby?

FishyHub publishes its US marketplace statistics as tiers and directions, such as which species have very high supply or are rising, rather than as raw figures.

What aquarium fish are easiest for beginners?

Guppies, platies, danios, rasboras, corydoras and Neocaridina shrimp are hardy, widely listed and sit in FishyHub's US entry-level price tier.

Which aquarium animals are the most expensive?

On FishyHub in the US, the collector tier includes arowanas, flowerhorns, tangs, seahorses, marine angelfish and LPS hard corals.

How to Cite This Page

Source: FishyHub, "100 Aquarium Facts & Statistics You Should Know" (2026), https://fishyhub.com/us/blogs/blog-detail/100-aquarium-facts-statistics-you-should-know