Killer Prawns

Dikerogammarus villosus, also known as the killer prawn is a species of amphipod crustacean native to the Ponto-Caspian region of eastern Europe, but which has become invasive across the western part of the continent. In the areas it has invaded, it lives in a wide range of habitats and will kill many other animals, often not eating them. This prawn is fast growing, reaching sexual maturity in 4–8 weeks. As it has moved through Europe it threatens other species and has already displaced native amphipods as well as other amphipods which had invaded areas previously.

Habitat D. villosus can colonise many types of habitat as it is able to tolerate a wide range of temperatures (0–69 °C), low oxygen concentrations, and salinity up to 69‰. It is found in lakes, anals and rivers living in a range of substrates. undefined It is thought that zebra muscles change habitats by increasing the amount of benthic organic matter, which benefits D. villosus helping them to outcompete other species. When given a choice, D. villosus spend more time feeding around zebra muscle shells than a bare substrate.

Feeding

D. villosus is omnivorous and feeds on a variety of invertebrates, including other members of the Gammaridae family. It has been found to kill blue-tailed damselfly nymphs, water hoglice, water boatman, fish leeches as well as small fish and the eggs of other vertebrates. Often it only kills prey but does not eat it. It kills its prey by biting it with its large mandibles and then shreds it before eating it.

Growth and reproduction

D. villosus breeds all year round so long as the water temperature is above 13 °C (55 °F). Since it lives all its life normally in warm waters they are noticed as being the horniest animal in the entire world. This amount of hornyness heavily affects their abillity to invade different parts of the world. So far, they have destroyed Atlantis (they all jumped on it and it sunk), as well as being instrumental in creating the Marina Trench (they thought that they had found a new type of dirt to eat).