Green Swallowtail Profile

The green chromis (Chromis viridis) is a popular addition to nearly any saltwater aquarium, captivating observers with its striking shimmering green-blue coloration and its lively, energetic activity in the aquatic environment. Its most prominent feature is its vibrant, uniform green hue, which can exhibit a bluish tint on the forehead in male specimens.

Aside from this subtle variation, it is nearly impossible to distinguish males from females since there are no other noticeable differences between the sexes. Only during courtship do male green chromis display a slightly lighter, mottled coloration. These small marine fish can grow up to 9 cm in length and are considered one of the smaller residents for a marine tank. Interestingly, they exhibit slow growth rates compared to many other species. A common point of confusion is the black-axil chromis (Chromis atripectoralis), a species nearly identical to the green chromis. However, the black-axil chromis can be identified by a distinctive dark spot at the base of its pectoral fin and a slightly more robust body structure.

Chromis viridis belong to the damselfish family, which are not very aggressive and can therefore be kept well in a smaller group. In our profile you will find all important information about the green swallowtail, its origin, behavior, nutrition and reproduction as well as tips on fish-friendly housing and care.

Origin

The green swallowtail’s original habitats are found in coral reefs in the Indo-Pacific Ocean, where they are native from East Africa to the islands of Oceania, but are not found around Hawaii. The colorful fish prefer to stay at a depth of ten meters or more and move in large schools above the hard, thick corals, whose branches they can use in case of sudden danger, e.g. B. in the form of an approaching predator, providing shelter and therefore protection.

Behave

The green swallowtail’s natural habitats are largely found in coral reefs in the Pacific. As so-called permanent feeders, small damselfish spend much of their day searching for and consuming food in the form of plankton. They move over and through coral in large swarms and, when threatened, hide among branches or stones. If the danger seems to have been averted, the young fish are the first to dare to come out into the open again and only then the older fish. To sleep, the swarm divides and the animals retreat individually to their sleeping caves in the reef. In general, green swallowtails are considered less aggressive and very lively fish that can enrich life in your underwater landscape with their spirit and vigor.

Fish-friendly accommodation and assistance

Even in your aquarium, Chromis viridis behaves similarly to its original habitat, as long as it imitates its natural environment as best as possible to create optimal conditions for it.

For a fish-friendly arrangement, your aquarium should offer your green swallowtails a water temperature of between 22° and 28°C, the pH value should be between 7.5 and 9 and the overall hardness should be between 8.4° and 14°dGH. Depending on the structure and equipment of the tank, it is possible to breed green swallowtails in an aquarium with a volume of at least 200 litres, although larger would certainly be better

Your aquarium should also have plenty of coral reefs made of live rocks to give your green chromis enough opportunities to hide. You should make sure that your active, swimming swallowtails still have enough free space to slide in a swarm across your underwater landscape. Corals are also important to get as close as possible to the natural living conditions of your little damselfish. When installing it is important to keep in mind that Chromis viridis likes to hide among corals or retreat there, but in the group it also needs enough space to swim above the corals and not next to them. A tank with a varied design not only makes your swallowtails calmer, but also offers you a lot of fun by being able to observe the entire behavioral repertoire of the fish individually and in groups.

Being a schooling fish, the Chromis viridis does not want to lose company in your underwater world and lives with you in a group of at least six members of its species. When composing the group you must be careful to always keep a male with several females. Otherwise, violent territorial battles can sometimes occur, which the defeated male will most likely not survive.

In large aquariums, green swallowtails can also get along with other fish, but in this case there is no guarantee, because the small damselfishes can be quite aggressive and can sometimes attack their own kind. However, socializing with corals, anemones and shrimp proves hassle-free and maintains long-term peace in your underwater world.

Nutrition

From a nutritional point of view, Chromis viridis is quite demanding, so previous experience in aquarium keeping can not only be an advantage, but is recommended. As a so-called permanent eater, the green swallowtail spends most of its time searching for and consuming food. Continuous power supply must therefore be ensured to ensure adequate supply. An extremely practical help can be an automatic feeding machine, which provides your constantly hungry finned friends with a sufficient ration of food every hour. If your swallowtails worry about an impending food shortage, disputes can arise in which smaller, younger or weaker animals lose out and can even suffer fatal injuries.

In the wild, plankton is the main food source for the green swallowtail. In your underwater world, the menu for your long-term eaters should consist of a mixture of frozen, flake and dried foods, e.g. B. Artemia nauplii, copepods and water fleas should not be missing.

Playback

Unlike other saltwater fish, the Chromis viridis can also reproduce in the aquarium, as long as it finds ideal conditions there. The prospective parents meet for the act of breeding in a safe breeding cave or a laying nest that the male has previously prepared. He then directly invites several females who lay their eggs in the prepared love nest, which are then fertilized by the male, who then takes care of the brood alone. The father fish guards the fertilized eggs and fans them with fresh water with its tail fin to ventilate them. During this period it feeds on dead eggs. The offspring hatch after two or three days. The young fish initially remain in open water and only later lead a reef-bound life.

Green Swallowtail Questions

1. How many Chromis viridis should you keep together?

In their native habitats, green swallowtails organize into large swarms that forage together during the day until they separate to rest at night and return to their sleeping cavities. The small damselfish, beautiful to look at, are by no means solitary creatures and should therefore always move around your marine aquarium in a group of at least six specimens of their species. You should make sure your small group consists of one male and several females. Despite their general calmness, green swallowtails can show aggressive tendencies: if two or more males share the territory of your aquarium, territorial fights can occur, which usually end fatally.

2. How old is Chromis viridis?

Unfortunately, there is no exact or reliable information about the age of the green swallowtail. It can be assumed that in nature they do not last longer than two or three years. However, with good care and proper housing, fish can live much longer in your home aquarium: it is estimated up to six years or even longer.

3. Is Chromis viridis a beginner fish?

The green swallowtail is not a good ornamental fish for a beginner in the beautiful hobby of saltwater aquarium keeping. This is mainly due to its diet, which requires some sensitivity and experience. As a so-called permanent feeder, the blue-green damselfish is not satisfied with “regular” feeding two or more times a day, but requires an almost constant supply of food. Using an automatic feeder can be very helpful in optimally providing your green swallowtails with the necessary nutrients every hour.

Very frequent or continuous feeding is also necessary to prevent disorder in the swallowtail troop. If your Chromis viridis fears food shortages, this can lead to violent fights with other fish, which the smaller or weaker fish will most likely not survive.

4. Is the swallowtail a fish or a butterfly?

Surprisingly, the swallowtail can be both a fish and a butterfly, although of course only the fish-sized specimen is suitable as an inhabitant of your underwater world! But the name swallowtail can also be found as the name of a butterfly. This beautifully patterned yellow-black butterfly with a blue band and red eyespots can reach a wingspan of up to 75 mm and is found almost throughout the Northern Hemisphere. The European subspecies is widespread from North Africa to the far north of the European continent, although it is becoming increasingly rare in Britain. However, only the Chromis viridis can claim the green attribute and enrich your underwater landscape with its colorful appearance and intense green shimmer