January 20, 2014 PetGuide
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  • Group: Saltwater
  • Size: Small
  • Temperament: Non-aggressive
  • Aquarium Size: Medium (30+ gal)
  • Swimming Region(s): Middle
  • Suitable Tank Mates: Clownfish, Dartfish, Gobies, Hawkfish, Puffers and Tangs
  • Difficulty Of Care: Weekly care

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Chromis are an extremely popular family of saltwater fish. They are characterized by their slim, oval shaped bodies and bright colorations. Their small size, peaceful temperament and hardy nature make them an excellent choice for most beginner saltwater aquarists. Most species only grow up to a couple of inches in length and often school in groups of 20 or more in the wild.

Chromis are an extremely popular family of saltwater fish.

Chromis originate from the Indo-Pacific Ocean.

Most species of chromis are brightly colored and come in shades of grey, silver, black, blue, green, purple and yellow.

Chromis 1Chromis are one of the easiest species of saltwater fish for the home aquarium and make excellent pets for the beginner aquarist. They are also able to tolerate a wide range of water conditions and are among some of the hardiest species of saltwater fish.

They are extremely peaceful in nature and can coexist in groups and with other non-predatory fish. They should ideally be kept in shoals of 6 or more to feel secure in the aquarium. They will establish a social hierarchy amongst the group but will do so peacefully. However, it is not recommended to keep large groups of chromis in aquariums that are less than 55 gallons in size.

This fish thrive when housed in aquariums with large open swimming spaces and lots caves and crevices to hide in. They do not feed on coral and other invertebrates and make excellent additions to reef aquariums.

Chromis will readily accept a variety of live, frozen and processed foods in the aquarium. It is advisable to feed them with a few small portions of foods throughout the day instead of one or two large meals. Algae are a significant part of this fish’s diet in the wild and it is recommended that they be fed on algae and algae based foods occasionally.

Chromis are one of the easiest species of saltwater fish for the home aquarium and make excellent pets for the beginner aquarist.

Chromis breed in groups comprised of one male and a few females. When ready to breed, a chromis male will build a nest in the aquarium substrate which will be shared by all the females in the group. Once the eggs are laid, the male will guard them and fan them with fresh water using his caudal fin. The male will also eat any unfertilized eggs to prevent them from spreading bacterial and fungal infections among the whole spawn.

Agile, Black and White, Black Axil, Reef, Lemon, Paletail, etc.

Photo credit: Kevin Bryant/Flickr; Steve Mohundro/Flickr

Other Fish

Go to Surgeonfish


  • Group: Saltwater
  • Size: Small, Medium
  • Temperament: Community
  • Aquarium Size: Very Large
  • Swimming Region(s): Mid-Range
  • Suitable Tank Mates: Other Non-Aggressive Species of Similar Size; Other Surgeonfish, Tangs, Unicornfish
  • Difficulty Of Care: Daily
Go to Moorish Idol

Moorish Idol

  • Group: Saltwater
  • Size: Medium
  • Temperament: Non-aggressive
  • Aquarium Size: Very large (200 gal)
  • Swimming Region(s): All
  • Suitable Tank Mates: Small Angelfish, Wrasse, Anthias, Basslets, and Chromis
  • Difficulty Of Care: Weekly care