Butterfly rainbowfish - Pseudomugil signifer

With many different population occurrences, the pretty butterfly rainbowfish originally comes from the East Australian coast and, like its relatives from the family of Pseudomugilidae, belongs to the blue-eyes - because that is indeed what it has: beautiful shining blue eyes! In addition, Pseudomugil signifer convinces with a butterfly-like appearance, which rightly gave it its name. This very popular aquarium fish is not so common in the trade and meets especially the nerve of passionate blue-eye fans, who can not get enough of them. But also in the community aquarium the small Australians represent genuine eye-catchers, which look so "completely" somewhat fluttery and "differently".

Their basic color is shimmering silvery to golden yellow. Especially their very large and blue eyes are immediately noticeable. The males can be distinguished purely externally very well from the females, because above all they form reshaped pectoral fins, with which they row quasi "over the head", which has brought them among other things the nickname "butterfly of the aquaristics". These are black and yellow colored. Their bipartite dorsal fin is extended strongly and pointedly in the front part and almost reminds of a flag. The anal and second dorsal fins are also extended like sails. Their scientific species name Ps. "signifer" means "signal-bearing" - and this hits the nail absolutely on the head. The caudal fin is triangle-shaped, transparent yellow with black shading on the outer edges, which are fringed with white. Especially during the mating season, the males intensively intensify their colors. The females, on the other hand, tend to stay somewhat behind in color. The blue-eyes grow to about 4-7 cm in size and live for about 2.5 years.

The breeding of the wonderful butterfly rainbowfish is also possible in the aquarium, but without active intervention rather difficult. Pseudomugil signifer are adhesive spawners, but also strong spawn predators. Therefore, it is advisable to introduce them separately in pairs or in harems in a spawning aquarium. In preparation, the fish can be put into spawning mood with large and cool acidic and soft water changes with simultaneous strong frost and live feeding, especially black mosquito larvae are well suited. As spawning substrate fine feathery plants, but also Java moss or simply a spawning mop made of wool are accepted. The males court their beloved violently and flap their fins up and down. Above all they become very aggressive and territorial towards their rivals - in contrast to other blue-eyes they even bite each other's fins. If the chosen lady has enough of the fin spectacle, she leads the male to her preferred spawning substrate. Both stand next to each other and release both egg and sperm while trembling. The small, hard and translucent eggs attach themselves firmly to the spawning substrate by means of adhesive filaments. On average, they lay about 10 eggs daily, preferably in the morning hours.

Although Pseudomugil signifer can already be kept in aquariums from 60 liters, the keeping of these schooling fish is recommended from at least 10 animals with excess females rather from an edge length of 80, rather 100 cm, so that the animals can live out their pronounced social structure. Butterfly Rainbowfish tolerate water values with a total hardness (GH) between 5-20 °dGH, a pH of 5. 5-8.3 and temperatures of 25-28 °C. Especially with regard to the behavior of the sometimes territorial males, the aquarium should have a very good infrastructure in the form of stones, roots and sometimes dense plant stands, which provide visual protection and territorial markings, but also retreat possibilities for annoyed or defeated fish. Despite all this, they still need enough swimming space and, as they know it from their habitat, at least a superficial current and good water hygiene. If the aquarium is not too brightly lit and offers a few darker corners in places, for example by  Floating plants this promotes the well-being and the feeling of security of these impressive animals.

Butterfly Rainbowfish can be socialized, but keeping them purely as a species would be more advisable. Peace loving and rather larger fish that can cope with the same water parameters can be socialized with them. Keep in mind that a school of Pseudomugil sinifer will dominate in the community aquarium. Bottom dwelling species like Loricariids or Corydoras can also serve as by-fish. Dwarf crayfish and crayfish would be inadvisable, however, as they may pinch the fins of the pretty blue-eyes. Larger shrimps like for example Amano shrimps are usually rather unbothered.

Pseudomugil signifer is a carnivore in the aquarium and can be easily fed with small live and frozen food, such as mosquito larvae, daphnia, but also artemia. However, they can also be switched to small commercial dry food, granulated food and flake food.

Our food recommendation: The professional NatureHolic Nanofeed is a staple food for all small aquarium fish. This mini fish food and rearing food is a fine soft granulate which, thanks to its softness, resembles the consistency of tiny crustaceans and insect larvae and protects the delicate mouths of nanofish and fish fry from micro-injuries.

Our plant recommendation: For planting, use NatureHolic InVitros. These are free of snails, planarians and other unwanted co-inhabitants. Also free of algae spores, bacteria and fungi.

Expert Tip: We recommend when keeping fish the NatureHolic 3 Phase Liquid. The care set offers the best all-round protection for your animals. It ensures optimal conditions for successful breeding and keeping.