The Extent of Occurrence (EOO) of this species has been estimated to exceed 11,100 km2.
endemic to a single nation
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (5000-20,000 square km (about 2000-8000 square miles)) This species occurs in the Saline and Honey Creek systems (Ohio River drainage) in extreme southeast Illinois and Ohio, and the Patoka (Wabash River drainage) and Ohio River drainages in southwest Indiana. In Indiana, it is found in the Patoka River system and the Black River, tributaries of the Wabash River; and in tributaries of the Ohio River from Pigeon Creek to Anderson River. In Illinois, it is present in six counties in the Saline River system and is common in Honey and Rock Creeks, tributaries of the Ohio River. It has been extirpated from a large portion of the historical range in the Saline River drainage, Illinois (Page and Mottesi, 1995) but two dozen new sites have been found there recently (Simon and Thoma, 2006). Some of the earlier sites cited by Rietz (1912) for Illinois are believed to be based on misidentifications of Orconectes stannardi and Orconectes propinquus (Simon and Thoma, 2006).
Male with hooks only on 3rd pereiopod; male first pelopod terminating in two elements and as described above; chela sparsely setose dorsally and with tubercles of opposable margins of fingers visible.
Habitat and Ecology
Habitat Type: Freshwater
Comments: This species inhabits streams with coarse substrates primarily on large rocks or woody debris; preferring high gradient streams having riffles, runs, and pools with clear water of moderate nutrient levels. Presence is strongly correlated with the presence of rock cobble or boulder habitat. Preferred stream size includes perennial headwater and intermittent streams, but also in the main channel of the Patoka River and further downstream near the confluence with the Wabash River (an extensively channelized site, characterized by riffle habitat, generally uncharacteristic of this river). The species has not been collected from areas that are heavily silted. Relative abundance is high (0.76/square meter; max 106 individuals or 0.707/square meter) in streams with cobble, rubble bottoms and low sediment loads and absent or low in heavily sedimented streams (Simon and Thoma, 2006).
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Home range probably does not exceed 100 m
Comments: Opportunistic but mostly detritivore.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 21 - 80
Comments: A survey was conducted in 1993 in Indiana and Illinois of historical sites and 28 new sites occur in suitable habitat areas. Individuals were collected at 11 sites in Indiana and ten sites in Illinois (Page and Mottesi, 1995). A 1996 survey in Illinois did not result in any additional sites (Loges, 1997). Simon and Thoma (2003) documented it in the Patoka River basin of Indiana throughout the watershed but most abundant in the upper third in the Hoosier National Forest. Simon et al. (2005) documented additional Indiana records in the Patoka River drainage in Dubois and Orange Cos. and determined it was more common there than previously thought. Simon and Thoma (2006) summarized the current distribution in Illinois as the Saline River drainage in Gallatin, Saline, Williamson, Johnson, and Pope Cos.; and a few sites in the Ohio River drainage in White Co. Page and Mottesi (1995) confirmed the species extant at all but three sites known historically from Illinois. Simon and Thoma (2006) also summarized distribution in Indiana where it is found in the extreme southwestern part of the state in th Patoka River system in Posey Co.; Ohio River tributaries from Vanderburgh Co. to Perry Co. Page and Mottesi (1995) confirmed that the Patoka River was one of the last remaining watersheds with populations in Indiana, however, which was further confirmed by Simon and Thoma (2006) who also found it in Black River systems (Wabash River drainages) and Pegeon Creek and Anderson River (Ohio River drainage) in southwestern Indiana and the Saline River and Honey Creek systems (Ohio River drainage) in southeastern Illinois. Although it was thought the species was extirpated from Bigson and Dubois Cos., Indiana, surveys by Simon and Thoma (2006) found the species still extant there as well as additional localities in the upper Patoka River on public lands (42 total sites including 27 new sites encompassing both states).
100,000 to >1,000,000 individuals
Comments: A 1993 survey collected a total of 52 individuals from eleven sites in Illinois and 94 individuals from ten sites in Indiana. This survey indicates the crayfish is common in southern Indiana. However, the present range in Illinois is much smaller than the historic range (Page and Mottesi, 1995). In a more recent survey, Loges (1997) collected a total of 301 individuals from three Indiana sites. Fewer than 100 miles of stream are believed to be inhabited in Illinois (Glen Kruse, pers. comm. 1998). Relative abundance is high (0.76/square meter; max 106 individuals or 0.707/square meter) in streams with cobble, rubble bottoms and low sediment loads and absent or low in heavily sedimented streams (Simon and Thoma, 2006).
Life History and Behavior
Ovigerous females have been recorded during April and May and first form males and females were observed during only a short reproductive season in late fall and early spring. Two ovigerous females carried 81 and 9 eggs total and five females with attached instars carried 16 to 108 individuals (Simon and Thoma, 2006).
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N3 - Vulnerable
NatureServe Conservation Status
Rounded Global Status Rank: G3 - Vulnerable
Reasons: This species has been extirpated from a large part of its historic range in Illinois, although two dozen new sites have been reported expanding the range in that state; and it has been reported from a few sites in Indiana. It can be considered abundant in its current range and is still relatively broadly distributed in parts of Indiana and Illinois.
Intrinsic Vulnerability: Unknown
Environmental Specificity: Very narrow to narrow.
Comments: This species inhabits streams with coarse substrates primarily on large rocks or woody debris; preferring high gradient streams having riffles, runs, and pools with clear water of moderate nutrient levels. Presence is strongly correlated with the presence of rock cobble or boulder habitat. Preferred stream size includes perennial headwater and intermittent streams, but also in the main channel of the Patoka River and further downstream near the confluence with the Wabash River (an extensively channelized site, characterized by riffle habitat, generally uncharacteristic of this river). The species has not been collected from areas that are heavily silted. Relative abundance is high (0.76/square meter; max 106 individuals or 0.707/square meter) in streams with cobble, rubble bottoms and low sediment loads and absent or low in heavily sedimented streams (Simon and Thoma, 2006). Simon and Morris (2008) found this species to be virtually intolerant of high concentrations of sediment contaminants in the Patoka River watershed, Indiana, occurring only on rock habitat in the absence of contaminants.
Other Considerations: Maintaining state endangered status in Illinois recommended (Page and Mottesi 1995). Ranked as a species of "Special Concern", a species that may become endangered by the American Fisheries Society, Endangered Species Committee (Taylor et al. 1996).
Global Short Term Trend: Decline of 30-50%
Comments: Population trends are stable in some areas and declining in others. Six of the 18 sites that contained the species in Indiana and Illinois in 1993 no longer have documented populations, three have declining populations, and nine have stable populations (Simon and Thoma, 2006). Considered common and stable in southern Indiana and not in need of special protection (Page and Mottesi 1995). However, the range has declined in Illinois and the Saline River drainage is seriously degraded (Page and Mottesi 1995). It is presumed currently stable in Indiana (Burr et al., 2004).
Global Long Term Trend: Decline of 30-70%
Comments: Historically, the species was considered to have been present throughout the entire Wabash River drainage and the dominant crayfish in the White River prior to the Illinoian glacier (Simon and Thoma, 2006). This species is absent from the north fork of the Saline River where historical records document its presence (Page and Mottesi 1995), which comprises about 25% of its range in Illinois.
The coal mining that occurs around streams around the middle and south forks of the Saline River seems not to be resulting in detectable impacts on the species (C. Taylor pers. comm. 2009). The remainder of the area is relatively rural and there are not considered to be any effects from urbanization. In the eastern portion of its range where its habitat coincides with a national forest, it was collected in more than 30 locations, in many different tributaries (Simon & Thoma 2006).
Degree of Threat: High
Comments: The degree of threat varies across state lines and is considered not very threatened in Indiana and moderately threatened in Illinois. Threats include reduction in overall water quality associated with strip mining, siltation, stream channelization, desiccation, and agriculture (Loges, 1997; Glen Kruse, pers. comm. 1998). Simon (2001) notes in Indiana it is primarily distributed in areas severly impaired by anthropogenic disturb ance. Simon and Thoma (2006) cite stream modification, especially channelization; increased nutrient and sediment loads; strip mining activities and their consequent influence on pH changes. They noted 8 or 11 historical sites in the Patoka River drainage no longer support the species due to coal mining, stream channel clearing, channelization, and poor water quality. The North and Middle Forks of the Saline River, Illinois are badly polluted and little aquatic life of any kind occurs in these streams (Page, 1985). The species is also potentially threatened by introduced non-native crayfish species including Orconectes virilis, Orconectes rusticus, and Orconectes menae (Loges, 1997; Simon and Thoma, 2006).
Global Protection: Several (4-12) occurrences appropriately protected and managed
Comments: New populations found during surveys conducted during 2001-2003 in the headwaters of the Patoka River drainage include numerous sites in the Hoosier National Forest, Patoka National Wildlife Refuge, and on public lands owned by the Army Corps of Engineers (Simon and Thoma, 2006). All but one occurrence in Indiana is in the Hoosier-Shawnee Ecological Assessment Area (Burr et al., 2004).
Needs: Streams with suitable water quality would benefit from the placement of rock-rubble substrates in the stream. Prevention of non-point run off by employing wooded and grassed buffer strips on stream and ditch edges will enhance habitat. Efforts to secure publica lands along the edges of the Hoosier National Forest, U.S. Fish and Wildlife Service Patoka River National Wildlife Refuge, and land owned by the Army Corps of Engineers would benefit long-term species stability (Simon and Thoma, 2006).
Relevance to Humans and Ecosystems
Comments: No known economic value.
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