Description
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus |
|---|---|---|---|---|---|
| Animalia | Crustacea | Malacostraca | Decapoda | Cambaridae | Faxonius |
Synonyms
Invasion History
Chesapeake Bay Status
| First Record | Population | Range | Introduction | Residency | Source Region | Native Region | Vectors |
|---|---|---|---|---|---|---|---|
| 1976 | Established | Expanding | Introduced | Regular Resident | North America | North America | Fisheries(Discarded Bait) |
History of Spread
Faxonius rusticus (Rusty Crayfish) is native to the Ohio drainage in OH, IA, and KY but has been introduced to at least 15 states, Ontario , and New Brunswick (Taylor et al. 1996; Taylor and Redmer 1996). Introductions are concentrated in the Northeast and Midwest, but 2 populations are known from NM (Hobbs and Jass 1988; Taylor et al. 1996). F. rusticus has been widely introduced with bait, and probably also as a an aquarium release, from the release of laboratory animals, and by other means. Its range has rapidly expanded due to a mixture of natural dispersal, aggressive displacement of other species, and human introductions (Hobbs and Jass 1988; Hobbs et al. 1989).
Within the Missisippi-Ohio basin, F. rusticus has drastically expanded its range. Range expansions of this species were reported in OH as early as 1926 (Hobbs et al. 1989). It was first recorded from IL in 1973, and is now widespread in the Illinois River system in the northern part of the state (Taylor and Redmer 1996). In the Ohio Basin, it expanded into the Kanwaha River and tributaries in southwestern WV by 1978 in the southwestern part of the state (Jezerinac et al. 1995). In WI, it was not recorded in 1932, but it became widespread by the 1960's. F. rusticus is scattered throughout Mississippi tributaries in the western part of the state, in a highly disjunct distribution. Elsewhere in the Mississippi drainage, F. rusticus has invaded streams in TN, MO, IA, and MN (Hobbs and Jass 1988).
In the Great Lakes basin, F. rusticus became widespread by the 1960's. It is found in many of the streams on the southwest (WI) shore of Lake Superior (Hobbs and Jass 1988). It was first recorded in Lake-of-the-Woods Ontario in 1964, and on the northwest shore of Lake Superior in 1985, and is now widespread on the northwest shore of the lake (Momot 1992; Momot 1996). By 1988, F. rusticus was established on the Bruce Peninsula between Lakes Erie and Ontario (Corey 1988). The distribution of this crayfish in the Great Lakes region, as mapped by Hobbs and Jass (1988) is spotty and suggests that dispersal to inland lakes and streams by bait and other means has been more important than movement through the open waters of the Great Lakes.
In Atlantic drainages, the distribution of F. rusticus has also been spotty. These records are listed below from north to south:
Kennebec and Androscoggin River Drainages - 1952-59, Great Pond, North Pond, Long Pond, Kennebec-Somerset Counties ME; Flying Pond, Kennebec county (Crocker 1979).
Connecticut River Drainage - 1952-1959, Wells River (Orange County) VT, North Thetford (Orange County) VT; North Walpole (Cheshire County) NH; 1972 Stony brook, South Hadley (Hampshire county) MA (Crocker 1979). Smith (1997) notes that the species has been found in 5 new locations, mostly in the Connecticut River system, but its abundance is low, and it is spreading slowly.
Hudson River Drainage - 1968, In an artifical pond, Schenectady County NY (Crocker 1979). It is also present in Titicus River, Westchester County NY, and in Fairfield County CT (Mills et al. 1997).
Delaware River - By 1988, northwest NJ (Hobbs and Jass 1988).
Susquehanna River - 1976, Dauphin County PA, north of Harrisburg (United States National Museum of Natural History collections). According to the collector's notes, O. rusticus was found through much of the river south to the Fall Line (in the vicinity of Conowingo Dam MD). However, this crayfish has not yet been collected in MD Based on experiences elsewhere, O. rusticus is expected to invade the lower Susquehanna and other Chesapeake tributaries, eventually (Norden 1995). In 2007, O. rusticus was found by MD Department of Natural Resources (MDNR) personnel in Conowingo Creek, Cecil County, a Susquehanna tributary about 10 km above Conowingo Dam, and about 15 km above tidewater. From 2016 through 2012, F. rusticus spread to Upper Bay drainages, including the Gunpowder and Patapsco Rivers (Pelton 2007; Kilian 2010; USGS Nonindigenous Aquatic Species Database 2017)
Potomac River- In June 2007, F. rusticus was found in the Monocacy River, Frederick County MD, by MDNR personnel (Kilian 2010). It has spread into the tidal region of the Potomac drainage, reaching Mattawoman Creek, Mallows Bay, and Nanjemoy Creek in Charles County, between 2006 and 2011 (USGS Nonindigenous Aquatic Species Database 2017).
Eastern Shore tributaries- Faxonius rusticus has now colonized many drainages on the Eastern Shore of the Bay, including the tidal Little Blackwater River, and branches of the Pocomoke, Nanticoke, Choptank, and Chester Rivers, and freshwater tributaries of Chincoteague Bay, in 2006-2012 (USGS Nonindigenous Aquatic Species Database 2017). the rapid spread of this crayfish among Bay tributaries suggest an ability to disperse through brackish water.
History References - Corey 1988; Crocker 1979; Hobbs and Jass 1988; Hobbs et al. 1989; Jezerinac et al. 1995; Mills et al. 1997; Momot 1992; Momot 1996; Norden 1995; Smith 1997; Taylor et al. 1996; Taylor and Redmer 1996; Killian 2010; United States National Museum of Natural History collections; USGS Nonindigenous Aquatic Species Database 201
Invasion Comments
Major Study areas Invaded- Established in the Great Lakes basin, but not included in Mills et al. (1993).
Ecology
Environmental Tolerances
| For Survival | For Reproduction | |||
|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | |
| Temperature (ºC) | 0.0 | 39.0 | 4.0 | |
| Salinity (‰) | 0.0 | 10.0 | 0.0 | |
| Oxygen | well-oxygenated | |||
| pH | ||||
| Salinity Range | fresh-oligo |
Age and Growth
| Male | Female | |
|---|---|---|
| Minimum Adult Size (mm) | 14.0 | 13.9 |
| Typical Adult Size (mm) | 32.0 | 29.7 |
| Maximum Adult Size (mm) | 49.0 | 44.5 |
| Maximum Longevity (yrs) | 4.0 | 4.0 |
| Typical Longevity (yrs | 2.5 | 2.5 |
Reproduction
| Start | Peak | End | |
|---|---|---|---|
| Reproductive Season | |||
| Typical Number of Young Per Reproductive Event |
|||
| Sexuality Mode(s) | |||
| Mode(s) of Asexual Reproduction |
|||
| Fertilization Type(s) | |||
| More than One Reproduction Event per Year |
|||
| Reproductive Startegy | |||
| Egg/Seed Form |
Impacts
Economic Impacts in Chesapeake Bay
Faxonius rusticus (Rusty Crayfish) has not yet been reported from tidal waters of Chesapeake Bay, so its economic impacts in the region are only potential. Based on experiences in the midwestern United States, its invasion could have wide-ranging ecological implications, some of which could have economic impacts, particularly on fisheries.
Economic Impacts Outside of Chesapeake Bay
In the Great Lakes region and upper Mississippi valley, invasions of Faxonius rusticus (Rusty Crayfish) have resulted in replacement of native species with an aggressive invader which is a more efficient predator and herbivore, and better at avoiding predators than native species (Garvey et al. 1993; Lodge et al. 1994; Lodge et al. 1998).
Fisheries - About the only positive economic benefit of Faxonius rusticus results from its sale as bait or as a laboratory animal (Gunderson 1995). Its ability to destroy macrophyte beds probably has the largest negative impact on fisheries and hunting by removing refuges for fishes and invertebrates, by increasing currents and erosion, and by removing food for waterfowl (Gunderson 1995). There are some anecdotal observations that F. rusticus invasions might decrease abundances of some fishes, either by removal of submerged vegetation [Esox lucius (Northern Pike); Lepomis macrochirus (Bluegill); Micropterus salmoides (Largemouth Bass)] or prehaps by being less available to predators [Micropterus salmoides (Largemouth Bass)] (Gunderson 1995).
Aesthetics - Dense populations of Faxonius rusticus in WI lakes have discouraged swimming some locations by pinching people's toes (Gunderson 1995).
Because of the widespread ecological impacts of F. rusticus, WI and MN have passed legislation prohibiting the sale of live crayfish (Gunderson 1995).
References - Garvey et al. 1993; Gunderson 1995; Lodge et al. 1994; Lodge et al. 1998
Ecological Impacts on Chesapeake Native Species
Faxonius rusticus (Rusty Crayfish) has been collected in the Susquehanna River in PA, and has reached tidal waters in MD. Because the crayfish are relatively convenient for field and experimental work, ecological impacts of F. rusticus' invasions have been well studied in the midwestern United States. These impacts are likely to occur to some degree if and when this crayfish colonizes tidal fresh-oligohaline waters and adjacent nontidal waters around Chesapeake Bay.
Competition - Invasions of river systems and lakes by Faxonius rusticus (Rusty Crayfish) are often associated with decline or disappearance of native crayfish species. In OH, F. rusticus has replaced Orconectes sanborni in central and west-central OH (Butler and Stein 1985). In northern IL, northern WI, the northwest shore of Lake Superior, Ontario, and in eastern Ontario, F. rusticus has largely replaced Orconectes propinquus (introduced in WI, native in IL and Ontario) and F. virilis (native in all regions) (Capelli 1982; Corey 1988; Momot 1996; Taylor and Redmer 1996). Burrowing crayfish of the genera Cambarus and Procambarus are not mentioned as having been displaced by F. rusticus invasions (Capelli 1982; Hobbs et al. 1989).
The most widespread native crayfishes in the Chesapeake Bay region, Orconectes limosus, and Cambarus bartoni , have already apparently been partially replaced by an invasion of F. virilis (Schwartz et al. 1963). O. limosus is considered to be imperiled in WV and MD (Jezerinac et al. 1995; Norden 1995; Schwartz et al. 1963). These species can be considered likely to be affected by an invasion of F. rusticus. Competitive interactions with F. limosus and C. bartoni have not been evaluated, but the apparent displacement of F. limosus and C. bartoni by F. virilis (Schwartz et al. 1963) suggests that these species are vulnerable. Average chela length in WV specimens of F. limosus was much smaller (23 mm males, 16 mm females), compared to WV O. rusticus (28 mm males, 21 mm females) (Jezerinac et al. 1995), suggesting that F. limosus might be especially vulnerable to F. rusticus, based on an apparent relationship between chela size and aggressive encounters (Garvey and Stein 1993). Chela sizes were roughly equal in C. bartoni (29 mm males, 24 mm females) and F. rusticus.
Species replacements by F. rusticus appear to involve a diversity of mechanisms, including aggressive behavioral competition for resources, earlier recruitment than many competitors, higher fecundity, faster juvenile growth, interference with mating, wider habitat preferences, differential vulnerability to predators, etc. (Butler and Stein 1985; Corey 1988; Hazlett et al. 1992; Hobbs et al. 1989). Shelters are a critical resouce for crayfishes for protection from fishes and other predators, especially by day. O. rusticus has larger chelae (claws) than its competitors, O. propinquus and F. virilis, at similar body sizes, giving F. rusticus an advantage in confrontations over shelters and other resources (Garvey and Stein 1993). In laboratory and field studies, F. rusticus tended to dominate O. propinquus and O. virilis, resulting in reduced movement and foraging by the latter species (Garvey et al. 1994; Hazlett et al. 1992). Faxonius. rusticus tended to mate inappropriately with O. sanborni, decreasing reproductive output of both species, but favoring F. rusticus because of its superior reproductive characteristics (Butler and Stein 1985). F. rusticus tends to be less vulnerable to fish predators than its competitors, because of its more rapid growth, and its lesser tendency to leave shelters by day, either because of inherent behavior, or displacement by aggression (Butler and Stein 1985; Garvey et al. 1994; Hill and Lodge 1994; Mather and Stein 1993).
Habitat Change - Faxonius rusticus, as an omnivore, has the ability to alter foodwebs through its effects on foodwebs in lakes and streams. It feeds extensively on macrophytes and on periphyton, and can greatly reduce submerged vegetation, but it can also indirectly favor the growth of periphyton by predation on snails and other macroinvertebrates (Charlebois and Lamberti 1996; Lodge et al. 1994). These effects have been demonstrated in experimental ponds, lake-enclosure-exclosure experiments, and whole lake experiments (Lodge et al. 1994; Lodge et al. 1998). Other crayfishes are also omnivorous, and can have similar foodweb effects (e.g., F. virilis, Hanson and Chambers 1995). However, replacement of other crayfish by O. rusticus may alter foodwebs because F. rusticus, with its larger adult size, more rapid growth, higher mass-specific ingestion rates of snails, and lower vulnerability to fish predation, may have a quantitatively greater impact (Lodge et al. 1994). By controlling types of plant communities, F. rusticus has the potential to affect food supplies and the structural environment for fishes and invertebrates, including refuges, sediment stability, current speed, erosion, etc. (Gunderson 1995).
Predation - Faxonius rusticus is an omnivore, and eats a wide variety of animal prey (Hobbs and Jass 1988). Its predation on snails has been studied in particular detail. In enclosure-exclosure experiments, densities of F. rusticus affected abundance, species composition, and species richness of snails. Of 11 snail species, F. rusticus preferred Physella sp. and Helisoma anceps. Other macroinvertebrates were not significantly effected by F. rusticus density (Lodge et al. 1994). Snail abundance was also related to F. rusticus density on a regional basis within lakes, and in comparisons among 21 lakes (Lodge et al. 1998). Other crayfish also consume mollusks, but replacement of other species by F. rusticus may result increased rates of predation due to F. rusticus' higher metabolic rate and and competitive life history characteristics (Lodge et al. 1994). In enclosure-exclosure experiments in a stream where snails were rare, F. rusticus abundance resulted in reduced invertebrate (mainly insect larvae), through direct predation, as well as through consumption of periphyton (Charlebois and Lamberti 1996).
Herbivory - Faxonius rusticus has long been known to affect lakes by consumption, and often elimination of beds of submerged vegetation (Hobbs et al. 1989). In enclosure-exclosure experiments, plant biomass was about 9X higher in enclosure treatments, and 12 species were present, compared to 3 species in enclosure treatments. Effects of herbivory did not differ greatly among species (Lodge et al. 1994). In a stream, F. rusticus was found to be a major consumer of periphyton (largely Cladophora), but did not affect periphyton biomass, apparently because of its removal of grazing microinvertebrates, and because foraging crayfish remove debris and detritus from the periphyton, exposing algae to increased light. In enclosures with high densities of F. rusticus, chlorophyll content of periphyton was higher (Charlebois and Lamberti 1996).
Since the health and abundance of submerged aquatic vegetation is considered an index of health of the Chesapeake Bay ecosystem, arrival of a known major herbivore such as F. rusticus is a cause of concern.
Food/Prey - Because Faxonius rusticus is better at avoiding fish predation than several other crayfish species, its invasion might lower the availability of food to predatory fishes (Mather and Stein 1993). The species tested in experimental predation studies were introduced in the Chesapeake Bay region, but effects on native fish predators are likely also.
References - Butler and Stein 1985; Capelli 1982; Charlebois and Lamberti 1996; Corey 1988; Garvey and Stein 1993; Garvey et al. 1994; Gunderson 1995; Hanson and Chambers 1995; Hazlett et al. 1992; Hill and Lodge 1994; Hobbs and Jass 1988; Hobbs et al. 1989; Jezerinac et al. 1995; Lodge et al. 1994; Lodge et al. 1998; Mather and Stein 1993; Momot 1996; Norden 1995; Schwartz et al. 1963; Taylor and Redmer 1996; United States Museum of Natural History collections
Ecological Impacts on Other Chesapeake Non-Native Species
Faxonius s rusticus (Rusty Crayfish) has been collected in the Susquehanna River in PA, and is a recent invader in tidal Chesapeake waters (Norden 1996; United States Museum of Natural History collections). It is known to interact with a number of species which have been introduced in the Chesapeake Bay region.
Competition - Faxonius virilis, native to much of midwestern United States, is introduced in the Chesapeake Bay drainage (Jezerinac et al. 1995; Schwartz et al. 1963). Faxonius rusticus has replaced it or reduced it to low abundances in many parts of the Great Lakes basin (Capelli 1982; Corey 1988; Momot 1996; Taylor and Redmer 1996). Consequently, F. rusticus is expected to eventually replace F. virilis in the Susquehanna drainage (Norden 1995). The burrowing crayfish Procambarus clarkii (established, and apparently locally common) and P. zonangulus (anpther recent invader, an escapee from Eastern Shore crayfish ponds) may be less likely to be affected by F. rusticus because of differences in habitat preference (Cappelii 1982; Hobbs and Jass 1988). Mechanisms of competition between O. rusticus and other crayfishes are discussed in 'Impacts on Residents/Comments'.
Habitat Change - Effects of F. rusticus on submerged aquatic vegetation and periphyton have the potential to affect a wide range of introduced as well as native species, through effects on foodwebs and habitat structure (Lodge et al. 1994). Species likely to be affected include snails (e.g. Bithynia tentaculata, Bellanya chinensis, Viviparus georgianus), and fishes (e.g. Carassius auratus, Lepomis spp.).
Predation - In WI lake studies, snails were the invertebrate group most strongly affected by F. rusticus' predation (Lodge et al. 1994). The introduced snail Bithynia tentaculata was frequently eaten by Faxonius virilis in laboratory experiments (Hamilton 1979) and is a likely prey for F. rusticus. Since this species appears to have more impact as a predator than other Faxoniusspp., its invasion could reduce populations of B. tentaculata and other, less common introduced snails.
Herbivory - Faxonius rusticus has long been known to affect lakes by consumption, and often elimination of beds of submerged vegetation (Hobbs et al. 1989). It consumed a wide range of native submerged macrophytes with little discrimination ( Lodge et al. 1994), so it can be expected to feed on introduced species such as Myriophyllum spicatum, Hydrilla verticillata, and others. However, its wide range of ecological impacts on native species means that it should never be released for biological control of M. spicatum or other exotic plants (Gunderson 1995).
Food/Prey - In experimental studies, Orconectes rusticus is better at avoiding predation by Micropterus dolomieu and M. salmoides (Smallmouth and Largemouth Bass) than several other crayfish species, so its invasion might lower the availability of food to this and other predatory fishes which have been introduced in Chesapeake Bay (Garvey et al. 1994; Mather and Stein 1993). It should be noted that F. rusticus has population growth characteristics which might enable it develop a higher population, perhaps offsetting the effects of its elusive behavior on fish predators.
References - Cappelii 1982; Corey 1988; Garvey et al. 1994; Gunderson 1995; Hamilton 1979; Hobbs et al. 1989; Hobbs and Jass 1988; Jezerinac et al. 1995; Lodge et al. 1994; Mather and Stein 1993; Momot 1996; Norden 1995; Schwartz et al. 1963; Taylor and Redmer 1996; United States Museum of Natural History collections