''Dikerogammarus haemobaphes'' is a species of

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

gammarid Gammaridae is a family of amphipods. In North America they are included among the folk taxonomic category of " scuds", and otherwise gammarids is usually used as a common name. They have a wide distribution, centered on Eurasia, and are euryha ...

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

. These gammarids are commonly known as demon shrimp, likely because they are an extremely successful

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

. Native to the Ponto Caspian basin, ''Dikerogammarus haemobaphes'' expanded their range in 1955. This expansion began in

Lake Balaton Lake Balaton () is a freshwater lake in the Transdanubian region of Hungary. It is the largest lake in Central Europe, and one of the region's foremost tourist destinations. The Zala River provides the largest inflow of water to the lake, and th ...

, Hungary and then spread into certain rivers and lakes in Austria, Belgium, Germany, Poland, Russia, Ukraine, and the United Kingdom. These crustaceans likely broadened their range due to the interconnection of waterways in Europe and the use of transportation vectors such as boats and ships.

Identification

''Dikerogammarus haemobaphes'' have a semi-transparent, white body consisting of a head,

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...

, and abdomen. Their body consists of seven segments, each with a pair of pereopods (walking legs). These shrimp are different from other

species as their peduncle, flagellum of antennae, and gnathopods have short bristles rather than long ones. Males average 16 mm in length, but can grow up to 21 mm. Females range between 7-15 mm long.

Habitat preferences

''Dikerogammarus haemobaphes'' have a wide salinity tolerance and are able to live in fresh and

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

water. They are also considered a eurythermal species, because they can tolerate a wide range of thermal temperatures. Demon shrimp feed on sediments,

detritus In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts commun ...

, unicellular and filamentous

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

, and small crustaceans. These shrimp prefer living in coarse grained cobble substrates, but can be found in all types of substrate. Demon shrimp are also commonly found in the same environment as ''

Dreissena polymorpha The zebra mussel (''Dreissena polymorpha'') is a small freshwater mussel. The species originates from the lakes of southern Russia and Ukraine, but has been accidentally Introduced species, introduced to numerous other areas and has become an inv ...

,'' or zebra muscles. It has been found that ''Dikerogammarus haemobaphes'' prefer living on top of zebra muscle shells rather than other substrate types.

Invasiveness

The invasion of ''Dikerogammarus haemobaphes'' has been shown to negatively impact their new habitat. Demon shrimp are highly successful invaders due to their rapid growth rates and early maturation. They also have a much higher

fecundity Fecundity is defined in two ways; in human demography, it is the potential for reproduction of a recorded population as opposed to a sole organism, while in population biology, it is considered similar to fertility, the natural capability to pr ...

than native gammarid species, making them able to increase their population quickly. Their wide salinity tolerance, sediment preferences, and thermal tolerance also makes them able to successfully invade foreign

ecosystems An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

. Amphipods play a major role in the energy flow within their environment due to their shredding and decomposition activities. ''Dikerogammarus'' ''haemobaphes'' has been reported to have lower

detrital Detritus (; adj. ''detrital'' ) is particles of rock derived from pre-existing rock through weathering and erosion.Essentials of Geology, 3rd Ed, Stephen Marshak, p G-7 A fragment of detritus is called a clast.Essentials of Geology, 3rd Ed, Stephen ...

processing efficiency than native

amphipod Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descr ...

shrimp, such as ''

Gammarus pulex ''Gammarus pulex'' is a species of amphipod crustacean found in fresh water across much of Europe. It is a greyish animal, growing to long. Description Adult males of ''Gammarus pulex'' may reach a total length of , while females only grow to . ...

''. Therefore, a shift in the dominant amphipod species would lead to slower decomposition rates within the environment. For these reasons, if the demon shrimp take over a particular environment, the energy flow would be altered, which will cause deleterious effects on that particular niche. Since leaf shredding provides fresh and brackish water ecosystems with carbon and organic matter, a decrease in shredding activities would cause these levels to drop. In addition to feeding on detritus, Demon shrimp also prey on native shrimp and insect species. This

cannibalistic Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species In biology, a species is the basic ...

behavior has a significant impact on community dynamics, disrupting local food chains, and altering ecosystem function. The demon shrimp’s

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutri ...

diet also proves advantageous over native gammarid species; as they have more available

food sources Food is any substance consumed by an organism for Nutrient, nutritional support. Food is usually of plant, animal, or Fungus, fungal origin, and contains essential nutrients, such as carbohydrates, fats, protein (nutrient), proteins, vitamins ...

to sustain their growth. The wide habitat breadth, carnivorous activities, high fecundity, and rapid growth of ''Dikerogammarus haemobaphes'' makes this species an extremely successful invader.

References

{{Taxonbar, from=Q3934176 Gammaridae Crustaceans described in 1841