Marmorkrebs (Procambarus Fallax F. Virginalis)

Marmorkrebs, Marbled Crayfish, Self-cloning Marbled Crayfish

Distribution

Unfortunately, the origins of this species are not known. It is only known that the first specimens were available for sale in Germany in 1990. Everything suggests that they came from the USA, but there they were most likely artificially introduced into the environment. Currently, populations of these crayfish have appeared in Europe (Germany, the Netherlands, Italy), Japan and Madagascar. This is a very invasive species and poses a significant problem in these countries, to the extent that special programs have been developed to remove them from ecosystems.

Appearance

The color of the body and shell is beige with a dark brown, marble pattern. The limbs of this crayfish often have a blue, red or orange shade. In addition, it is characterized by small claws and a flat telson. Undoubtedly, this crayfish stands out from other species in that its representatives are only females (no males), and reproduction occurs parthenogenetically (without fertilization).

Disposition

This is one of the calmer species, slightly territorial, with which we can easily keep fast and agile fish and shrimps. We avoid bottom species and predatory fish - especially cichlids, for which crayfish will be a delicious snack. The marble crayfish gnaw on plants and hunt for snails that we do not want. It likes to undermine decorations under which it hides. In a larger group, you can notice a established hierarchy, and the population is controlled by the crayfish themselves (if there are too many, they will eat each other). It is a resistant and durable species, but it is sensitive to the lack of dissolved oxygen in the water. Then it may try to get out of the tank or will constantly stay closer to the water surface. Frightened crayfish deftly jump backwards to quite long distances, assisted by their tail and front claws.

Aquarium

The most important criterion for crayfish is the surface of the tank bottom - the larger, the better. The second important thing is to provide them with an adequate number of hiding places - especially when kept with other animals. We use stones, rocks, caves, pvc pipes, wooden (e.g. bamboo), ceramic, coconut husk shells, roots and sticks etc. to build them. Here you should take into account the size of the animals - so that they do not get stuck. Appropriately chosen colours of equipment allows to highlight and intensify the colour of the inhabitants. Thirdly, for these crustaceans, highly oxygenated water is essential for life. Crayfish have gills and do not breathe atmospheric air. Yes, they can stay on dry land, but only as long as their gills are moist. The crayfish will try to escape from an aquarium lacking oxygen (a tight cover of the tank is essential). Crayfish prefer to stay in turbid waters, but that does not mean that the water has to be dirty. These animals are sensitive to the presence of ammonia and nitrites. Therefore, effective filtering and systematic partial water changes are required. The lighting should not be too intense, preferably diffused. When choosing the substrate, we use those with delicate, rounded edges. From time to time, we put dry oak, beech or almond leaves and dried alder cones on the bottom of the tank (essential ingredients of crayfish diet).

Reproduction

This crayfish, because it does not have male individuals, reproduces differently than the others. The female matures (maturity is achieved after reaching a size of 3-5 cm), lays eggs (red in colour), which however are not fertilized by spermatozoa. This type of reproduction is called parthenogenesis or virgin birth. Egg incubation takes 22-42 days (depending on the water temperature), and hatching reaches 100%. The breeding season for this species falls in winter, and the number of eggs laid in one season is 300-400 pieces.

Food

These crayfish are mainly herbivores, but they also gladly consume mixtures of plant and animal food. The form of food - dry or frozen - does not play a big role, it is important that it sinks to the bottom. The composition of the food has a significant impact on the colouring of these crayfish. If we use colouring foods, rich in a specific pigment, this is the colour they will get over time. This species willingly eats snails, and their diet should be enriched with alder cones, oak, beech or almond leaves - ingredients contained in these products reduce the risk of shell ulcers (so-called rust spot) appearing on crayfish. These products should be brown, dry and clean, and they should be scalded with boiling water before serving. A variety of food guarantees peace in the aquarium and the suppression of hunting instincts.