Cercopagis pengoi | |
---|---|
Cercopagis pengoi (above, total length 10 mm) and Bythotrephes longimanus (below) | |
Scientific classification | |
Kingdom: | |
Phylum: | |
Subphylum: | |
Class: | |
Order: | |
Family: | |
Genus: | |
Species: | C. pengoi |
Binomial name | |
Cercopagis pengoi (Ostroumov, 1891) [1] | |
Synonyms | |
|
Cercopagis pengoi, or the fishhook waterflea, is a species of planktonic cladoceran crustaceans that is native in the brackish fringes of the Black Sea and the Caspian Sea. [2] In recent decades it has spread as an invasive species to some freshwater waterways and reservoirs of Eastern Europe and to the brackish Baltic Sea. Further it was introduced in ballast water to the Great Lakes of North America and a number of adjacent lakes, and has become a pest classified among the 100 worst invasive species of the world. [2]
Cercopagis pengoi is a predatory cladoceran and thus a competitor to other planktivorous invertebrates and smaller fishes. On the other hand, it has provided a new food source for planktivorous fishes. It is also a nuisance to fisheries as it tends to clog nets and fishing gear. [3]
The length of Cercopagis pengoi body is 1–3 mm, but with the tail included they range from 6–13 mm. [4] The size varies with location, the largest are found in the Baltic Sea (average body size 2.0 mm) and smallest in Lake Ontario (average size 1.4 mm). [5] The English name refers to the three pairs of barbs and a characteristic loop at the end of the tail. [4]
Cercopagis pengoi is eurythermal and euryhaline, being able to tolerate a wide range of temperature and salinity. [5] It is a pelagic species, found in a higher abundance further from the shore and from the bottom. [5] It is a generalist feeder which preys on various species in both micro- and mesozooplankton (i.e. cladocerans, copepods, rotifers). [6] The size of prey ranges from its own body size to seventeen times smaller. [5] Prey is captured using thoracopods I, then retained by thoracopods II-IV, and crushed by its cuticle by mandibles, finally C. pengoi sucks the prey body contents. [7]
Fishhook waterfleas reproduce asexually during the summer, which produces a quick rise in population. [4] When conditions are inhospitable, C. pengoi will undergo sexual reproduction, producing resting eggs that can over-winter and repopulate the lake quickly in the spring. Resting eggs can withstand desiccation (extreme dryness), freeze-drying, and ingestion by fish. [4]
Cercopagis pengoi was brought to the American Great Lakes in ship ballast water from the Black Sea. It has been documented in Lake Ontario (1998), Lake Erie (2002), Lake Huron (2002), Lake Michigan (1999), and the Finger Lakes of New York (Canandaigua, Cayuga, Keuka, Cross, Otisco, Owasco, and Seneca lakes. [4] The species is transported in the live wells, bait water, and ropes of recreational fishing and boating. [8] C. pengoi’s wide tolerance levels and ability to reproduce both sexually and asexually makes it a very successful invader. Asexual reproduction allows for rapid population growth, and then resting eggs which are produced sexually can stick to boats and fishing gear and dispersed into new bodies of water. [9]
In the Baltic and in the Great Lakes, planktivorous fish and mysids are reported to prey on C. pengoi, implying that it has become a new food source. [10] C. pengoi directly competes with native zooplanktivores like alewife and rainbow smelt. Furthermore, C. pengoi have a long spine which deters planktivorous fish from consuming them. [4] These factors cause disruption in the lower trophic levels of the Great Lakes food web which can eventually trickle up the food chain to cause problems with fish stock through a trophic cascade.
There is no known method of eradication or control for invasive Cercopagis pengoi. [5] Containing the spread to new areas is the only form of management. Stricter ballast water regulations and awareness would prevent the spread. [5] The C. pengoi invasion of the Great Lakes occurred after the United States passed a regulation requiring ships exchange freshwater ballast water with ocean water to kill off potential invaders. [11] This means that either the resting eggs remain viable even after boats switch out their ballast water in the ocean or the required ballast water regulations are not being followed.
Locally C. pengoi spread can be limited by only releasing bait or bait water into the water body where the bait was originally collected. Boat owners should wash their boats and equipment with high pressure and hot water (above 40 °C) to limit the spread of adult C. pengoi. Alternatively boats and equipment should be allowed to dry for at least five days before moving to another body of water. [8]
Daphnia is a genus of small planktonic crustaceans, 0.2–5.0 mm (0.01–0.20 in) in length. Daphnia are members of the order Cladocera, and are one of the several small aquatic crustaceans commonly called water fleas because their saltatory (Wiktionary) swimming style resembles the movements of fleas. Daphnia spp. live in various aquatic environments ranging from acidic swamps to freshwater lakes and ponds.
The northern pike is a species of carnivorous fish of the genus Esox. They are typical of brackish and fresh waters of the Northern Hemisphere. They are known simply as a pike in Britain, Ireland, and most of Eastern Europe, Canada and the United States.
The Eurasian ruffe, also known as ruffe or pope, is a freshwater fish found in temperate regions of Europe and northern Asia. It has been introduced into the Great Lakes of North America, reportedly with unfortunate results, as it is invasive and is reproducing faster than other species. Its common names are ambiguous – "ruffe" may refer to any local member of its genus Gymnocephalus, which as a whole is native to Eurasia.
The common dace is a species of freshwater and brackish water ray-finned fish from the family Cyprinidae which is native to Europe but which has been introduced to other parts of the world. It is a quarry species for coarse anglers.
The round goby is a fish. Defined as a euryhaline bottom-dwelling goby of the family Gobiidae, it is native to central Eurasia, including the Black Sea and the Caspian Sea. Round gobies have established large non-native populations in the Baltic Sea, several major Eurasian rivers, and the North American Great Lakes.
The quagga mussel is a species of freshwater mussel, an aquatic bivalve mollusk in the family Dreissenidae. It has an average lifespan of 3 to 5 years.
Mnemiopsis leidyi, the warty comb jelly or sea walnut, is a species of tentaculate ctenophore. It is native to western Atlantic coastal waters, but has become established as an invasive species in European and western Asian regions. Three species have been named in the genus Mnemiopsis, but they are now believed to be different ecological forms of a single species M. leidyi by most zoologists.
The New Zealand mud snail is a species of very small freshwater snail with a gill and an operculum. This aquatic gastropod mollusk is in the family Tateidae.
The European perch, also known as the common perch, redfin perch, big-scaled redfin, English perch, Eurasian perch, Eurasian river perch, Hatch or in Anglophone parts of Europe, simply the perch, is a predatory species of the freshwater perch native to Europe and northern Asia. The species is a popular quarry for anglers, and has been widely introduced beyond its native area, into Australia, New Zealand, and South Africa. They have caused substantial damage to native fish populations in Australia and have been proclaimed a noxious species in New South Wales.
The bloody-red mysid, Hemimysis anomala, is a shrimp-like crustacean in the Mysida order, native to the Ponto-Caspian region, which has been spreading across Europe since the 1950s. In 2006, it was discovered to have invaded the North American Great Lakes.
The American gizzard shad, also known as the mud shad, is a member of the herring family of fish, and is native to large swaths of fresh and brackish waters of the United States of America. The adult has a deep body, with a silvery-green coloration above fading to plain silver below. The gizzard shad commonly resides in freshwater lakes, reservoirs, rivers, and streams, but can reside in brackish waters, as it does on the Atlantic coast of the United States. Their range is across most of the continental United States, although they typically go no further north than New York and no further west than New Mexico. They are large parts of many of the ecosystems they inhabit, and can drive changes in phyto- and zooplankton, thereby indirectly affecting other planktivorous fishes. The gizzard shad has been widely used as a food source for game fish, with varied success in management and effectiveness.
Bythotrephes longimanus, or the spiny water flea, is a planktonic crustacean less than 15 millimetres (0.6 in) long. It is native to fresh waters of Northern Europe and Asia, but has been accidentally introduced and widely distributed in the Great Lakes area of North America since the 1980s. Bythotrephes is typified by a long abdominal spine with several barbs which protect it from predators.
The Cladocera are an order of small crustaceans commonly called water fleas. Over 650 species have been recognised so far, with many more undescribed. They first appeared before the Permian period, and have since invaded most freshwater habitats. Some have also adapted to a life in the ocean, the only members of Branchiopoda to do so, even if several anostracans live in hypersaline lakes. Most are 0.2–6.0 mm (0.01–0.24 in) long, with a down-turned head with a single median compound eye, and a carapace covering the apparently unsegmented thorax and abdomen. Most species show cyclical parthenogenesis, where asexual reproduction is occasionally supplemented by sexual reproduction, which produces resting eggs that allow the species to survive harsh conditions and disperse to distant habitats.
Ballast water discharges by ships can have a negative impact on the marine environment. The discharge of ballast water and sediments by ships is governed globally under the Ballast Water Management Convention, since its entry into force in September 2017. It is also controlled through national regulations, which may be separate from the Convention, such as in the United States.
Cyclops bicuspidatus is a planktonic species of copepod found throughout the world, except Australia, and characteristic of the Great Lakes of North America. It is a deep water species found throughout the year with peak abundance occurring in May or June. Males grow up to 0.8–1.0 millimetre (0.031–0.039 in) long, while females are larger at 0.9–1.6 mm (0.035–0.063 in).
Daphnia magna is a small planktonic crustacean that belongs to the subclass Phyllopoda. It inhabits a variety of freshwater environments, ranging from acidic swamps to rivers made of snow runoff, and is broadly distributed throughout the Northern Hemisphere and South Africa.
The spottail shiner or spottail minnow is a small- to medium-sized freshwater minnow. It can be found as far north as Canada and as far south as the Chattahoochee River in Georgia. These shiners live in lakes, rivers, and creeks. They occupy the rocky or sandy shorelines and bottoms of the water. One of the defining features of a spottail shiner is the black spot found at the base of the caudal fin. These shiners generally spawn from late June through July.
The National Invasive Species Act (NISA) is a United States federal law intended to prevent invasive species from entering inland waters through ballast water carried by ships. NISA reauthorized and amended a previous measure, the Non-indigenous Aquatic Nuisance Prevention and Control Act of 1990 (NANPCA).
Daphnia lumholtzi is a species of small, invasive water fleas that originates in the tropical and subtropical lakes of Africa, Asia, and Australia. As an invasive species, Daphnia lumholtzi disrupts aquatic habitats by spreading throughout the warmer waters of lakes and reservoirs.
The dispersal of invasive species by ballast water refers to the unintentional introduction of invasive species to new habitats via the ballast water carried by commercial shipping vessels. Ballast water spreads an estimated 7000 living species to new habitats across the globe. These species can affect the ecological balance of their new regions by outcompeting native species or otherwise impacting native ecosystems.