The Green Chromis (Chromis viridis) is another damselfish but don't let that scare you away from keeping these little beauties. Their colors seem to change based on the aquarium lighting levels, sometimes appearing white and sometimes blue with hues of green. The pictures on this page don't do them justice.
Green Chromis are sometimes confused with Chromis atripectoralis because the two do look very similar. However, the Chromis atripectoralis has a small black area above the pectoral fin and they are a little bigger as adults. They can usually be found in local saltwater fish stores anywhere from $5 USD to $20 USD depending on their size.

For a damselfish, Green Chromis are relatively peaceful and it is preferred to keep them in small schools (shoal) of 6 or more. They will get along with each other and should establish some sort of pecking order within the group. Once they mature and are ready to breed they may become slightly more aggressive with tank mates, but given their relatively small size, they shouldn't do much harm. Some hobbyists who keep saltwater reef tanks will sometimes witness spawning of this fish. Male Green Chromis can turn more yellow in color and will build small nests in the sand and court various females. The males then guard the eggs until they hatch a few days later.

The Blue Green Chromis is a very active fish once acclimated and should be given frequent small feedings. They will accept most saltwater fish foods including flakes, frozen, freeze dried and live foods. Give them a varied diet for best results.

Even though they are really hardy and a great fish for a saltwater beginner, Green Chromis may come down with most of the common saltwater fish diseases and using a quarantine tank is a must. Keep them in quarantine for 2 - 3 weeks before introducing them into your main tank so you can monitor for any sign of a potential outbreak.

The Blue Chromis is a member of the damselfishes and given their hardy nature they can be a good choice for a saltwater beginner. In fact, many hobbyists use them to cycle new tanks (not recommended). They need to be in small schools (shoals) of 6 or more and are a very active fish.
They are a brilliant blue color with a black outline along the bottom of the dorsal fin and around the caudal fin.

Blue Chromis should do well in most tank setups, but you don't want to keep them with overly aggressive tank mates or fish large enough to eat them. Keep them in a small school and they should do fine. You may notice a pecking order develop among the Blue Chromis school and that is normal behavior. The Blue Chromis is sometimes sold as a "dither fish" because it is out in the open so much and it makes the shy fish in your tank more at ease.

Blue Chromis eat zooplankton in the wild and will accept most types of marine fish food including frozen, freeze dried, vitamin enriched flakes and live foods. Give them a variety of foods for optimal coloration.

They seem to be fairly disease resistant but you still need to take proper pre-cautions and use a quarantine tank before introducing them into your main tank.

The Three Stripe Damselfish is readily available and often quite inexpensive compared to other saltwater fish species. They usually go for about $3 to $7 at the fish store. Online they might be even cheaper, but after you factor in shipping costs maybe not so much. They are easily confused with the Dascyllus melanurus which is more commonly known as the Four Striped Damselfish. This one has 3 vertical black stripes, the other has 4 black stripes running vertically.
Similar to many other damselfish species, these too have been used to cycle an aquarium or two. This is not an advisable practice nowadays though. It's so much easier (and better for the fish) to cycle with live rock or even some of the forumlations containing the necessary bacteria. Besides, after cycling your tank with these fish you may realize that you didn't really want to keep them (due to their aggressive nature) but you find out too late how hard these little boogers are to catch. Especially in a tank with live rock. Forget about it. You will be removing some rock to get these guys out of the tank.

As alluded to previously they can be quite aggressive. They definitely have the "little man" syndrome and will nip at much larger fish to keep them away from "their" territory. This is definitely not a community type fish. Choose tank mates wisely. Tank mates that are too big and these Three Stripe Damselfish become a nice snack. Stock them in with tank mates too little and they will pester the smaller tank mates.

Feed them a variety of foods and they should live a nice long time for you. This is definitely an interesting species in it's own right but needs to be kept in a stocking scheme that is well thought out before hand. Be ready to remove them if needed.

The Yellowtail Blue Damselfish is sometimes confused with the Azure Damselfish (Chrysiptera hemicyanea) because they do look very similar. The Chrysiptera hemicyanea has more yellow on its body than the Chrysiptera parasema, which just has the yellow on its tail. This damsel is usually better kept in groups of 3 or more because they can become very territorial if kept singly. This is probably one of the least aggressive of all the damsels, but can still be aggressive nonetheless. Try putting your arm in the tank to perform tank maintenance and you'll see what we're talking about.
The Yellowtail Damselfish is particularly hardy and many hobbyists will use them to cycle a new tank. Using them to cycle your tank is not recommended because it is very cruel to the fish. A better, more humane way to cycle your saltwater tank would be to use live rock. As always, do not keep them with fish large enough to view them as a nice snack.

Yellowtail Blue Damsel will go after most fish food including vitamin enriched flake food, frozen, freeze dried and live foods.