Sporadic in the Mississippi drainage and adjacent Great Lakes drainage with small disjunct populations throughout this range. (Becker 1983)

It occurs as far south as the Naches and Sabine Rivers in eastern Texas (Williams 1975).

Biogeographic Regions: nearctic (Native )

endemic to a single nation

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) This species has a wide but spotty distribution. It is known from the Neches and Sabine river drainages, eastern Texas (Hubbs et al. 1991, Warren et al. 2000); Mississippi River basin from Minnesota and Wisconsin south to Texas, Mississippi (Big Black River system; Ross 2001), and Louisiana (Douglas and Jordan 2002); east to the Green and Cumberland river drainages, Kentucky (pre-1930 records, and recently rediscovered), and the Clinch-Powell river system in the upper Tennessee River drainage, Tennesse and Virginia (Etnier and Starnes 1993, Jenkins and Burkhead 1994); Lake Michigan drainage, including the Wolf River system in Wisconsin (Becker 1965, 1983), and the Menominee River drainage along the Wisconsin-upper Michigan border (Bailey et al. 2004). Ammocrypta clara likely gained access to the Wolf River system via the Wisconsin-Fox Canal (Becker 1983).

Ammocrypta clara is a small, very slender fish. Its average adult size ranges from 42-67mm (1.7-2.6in.). The word ammocrypta means "concealed in sand" and clara means "clear"-which is a reference to its clear or translucent flesh. As with almost all members of the family Percidae, the western sand darter has two dorsal fins. The first dorsal fin has 10-12 spines, and the second dorsal fin has 9-12 soft rays. The pectoral fins are fairly large and located directly behind the opercles; its pelvic fins are thoracic and located directly behind the head at the anterior end of the abdomen. Its fins range from clear to weakly pigmented along the spines and rays. Live specimens are very pallid-almost transparent. Preserved specimens are light tan or straw-colored. There is a row of twelve or more small dark saddles located down the center of the back. Along both sides of the fish are rows of 10-12 small oblong spots. The scales of the western sand darter are ctenoid. The breast and belly are completely devoid of scales; scales cover the dorsal surface from its median to the lateral line. The caudal peduncle is almost completely scaled. The caudal fin is slightly lobed (Becker 1983).

Until recently, the western sand darter was considered to be the same species as the eastern sand darter (Ammocrypta pellucida). The two species were separated based on scale counts, opercular structures and pigmentation. In contrast to the eastern form, the western sand darter has only 3-5 scale rows on the side of the body, a needlelike opercular spine and less pigmentation in the mid-dorsal and lateral blotches (Becker 1983).

For 47 western sand darters from central Wisconsin, the calculated lengths at the first three annuli were 43, 56 and 61 millimeters-almost identical to the calculated lengths for southern Wisconsin populations. The western sand darter reaches 71% of its total growth during its first year of life, and 91% during the second year. Females are generally larger and more numerous than males (Becker 1983).

Range mass: 1.5 (high) g.

Length: 6 cm

Other sand darters lack a spine on the opercle, have well-developed dark blotches along the side, or have black bands on the dorsal fins (Page and Burr 1991).

The western sand darter is found in medium to large rivers that have moderate to swift currents, primarily over extensive areas of sandy substrate. It is generally found in water that ranges from about .2-.9 meters in depth. Water preference of the western sand darter is for clear to slightly turbid water (Becker 1983).

Aquatic Biomes: benthic ; rivers and streams

Habitat Type: Freshwater

Comments: Habitat is usually clear to moderately turbid medium and large rivers; this species is most common in slight to moderate current over coarse sand or fine gravel (Douglas 1974, Becker 1983, Robison and Buchanan 1988, Etnier and Starnes 1993, Pflieger 1997). In the Clinch River, Virginia, western sand darters were captured in a large riffle-run area with substrate dominated by large gravel and small and medium rubble; small patches of sand were more than 10 meters away (Jenkins and Burkhead 1994). It has been recorded as occurring in quiet margins of drainage canals and shallow backwaters, usually where there is enough current to keep the bottom largely free of silt. In the north, this species often occurs in the mouths of tributaries to large rivers, over bottoms of shifting sand (Eddy and Underhill 1974, Phillips et al. 1982). Habitats in the southern part of the range include more often include deep, open channels of medium to large streams, moderate-sized rivers, and sparsely vegetated ditches (Douglas 1974, Robison and Buchanan 1988, Etnier and Starnes 1993, Pflieger 1997). In the upper Tennessee River system, western sand darters may move into shallow riffles to spawn (see Burkhead and Jenkins 1991). Individuals bury themselves in sandy bottoms with only the eyes and part of the head protruding.

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.

The few studies that have been performed indicate that major food items include small or immature aquatic insects such as mayflies (Ephemeroptera) and midge larvae (Diptera:Chironomidae)

(Lutterbie 1976).

Comments: Eats mainly larval aquatic insects (Page 1983).

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 21 - 80

Comments: This species is represented by a large number of distinct, extant occurrences (subpopulations) (at least several dozen).

10,000 to >1,000,000 individuals

Comments: Total adult population size is unknown but likely exceeds 10,000. This species occurs in small isolated populations and is generally uncommon; it is common in a few rivers in the northern and western parts of the range (Page and Burr 1991). The species appears to be more abundant in the northern part of the range than farther south (Williams 1975). It is locally common in Wisconsin (Becker 1983) but not abundant anywhere in Missouri (Pflieger 1997). Small populations are sporadically distributed in Arkansas, where the species is not commonly collected (Robison and Buchanan 1988). It is "exceedingly rare" in the well-collected range in Tennessee (Etnier and Starnes 1993), rare in Virginia (Jenkins and Burkhead 1994) and Illinois (Smith 1979).

Average lifespan

Status: captivity: 3 years.

Little is known about the spawning requirements or the reproductive behavior of the western sand darter. It has been suggested that spawning may occur in mid-summer, judging by increased activity then and gravid females (Lutterbie 1976). By examining the ovaries and development of breeding tubercules, Williams(1975) placed the height of the breeding season in July and early August. Williams found females with mature ova in late August. In Wisconsin, western sand darters spawn from late June through July (Lutterbie 1976).

Spawns in summer, probably from about late June to early August in Iowa and Wisconsin, and probably late May-June in the upper Tennessee River system. In Wisconsin, lives 3 years at most. See Page (1983) and Burkhead and Jenkins (1991).

Reports from various agencies around the country indicate that the western sand darter is declining in abundance. Especially hard hit have been the populations in the central part of the range for the species. It is listed as rare in Illinois, depleted in Missouri, threatened in Iowa, and extirpated in Kansas. Wisconsin has placed the western sand darter in the Lake Michigan drainage on watch status. According to Cross (1967), fluctuating water levels and increasing siltation are especially detrimental to sand darters (Becker 1983). Stream degradation related to siltation is also cited as negatively impacting western sand darter populations (Page 1983).

US Federal List: no special status

United States

Rounded National Status Rank: N3 - Vulnerable

Rounded Global Status Rank: G3 - Vulnerable

Reasons: Spotty distribution in streams from Wisconsin and Kentucky to Texas and Mississippi; has declined in several regions due to habitat degradation (e.g., siltation, impoundments); however, this cryptic species may be more common than it currently appears to be, and it is more common in the northern part of the range than in areas farther south.

Intrinsic Vulnerability: Moderately vulnerable

Environmental Specificity: Narrow. Specialist or community with key requirements common.

Global Short Term Trend: Unknown

Comments: Trend over the past 10 years is unknown. Populations tend to fluctuate. A population may appear abundant for a time and then be essentially absent (Shute, pers. comm., 1994).

Global Long Term Trend: Decline of 30-70%

Comments: Over the long term, this darter has declined in distribution and abundance (Kuehne and Barbour 1983; Hubbs, pers. comm. 1993; Burr, pers. comm. 1993), but the magnitude of the decline is uncertain. Much of the decline probably occurred decades ago. Recently the species as rated as "vulnerable" in the southern U.S. by Warren et al. (2000). In Iowa, it has been extirpated or nearly extirpated in the Cedar, Des Moines, Raccoon, and Shellrock rivers, and it persists as a widespread species only in the Mississippi River (Harlan et al. 1987). In Missouri, the species has progressively declined in collections from the upper Mississippi River since the early 1940s; it seems to be declining also in the lowlands of southeastern Missouri (Pflieger 1997). Trend in range extent in Arkansas is uncertain (Robison and Buchanan 1988). This species formerly was described as the most common darter in the Powell River, Tennessee, but now it is exceedingly rare in the well-collected Powell and upper Clinch rivers (Etnier and Starnes 1993); it is also rare, but apparently has been recovering, in the Clinch-Powell system in Virginia (Jenkins and Burkhead 1994). In Kentucky, the species has been found in 5 general locations, but in 3 of these the most recent records are earlier than 1984 (Kentucky Fish and Wildlife Information System, data through May 2005). A survey of the Big Black River system in Mississippi (the only known location for the species in that state), did not detect this species (Pezold et al. 1993).

Degree of Threat: B : Moderately threatened throughout its range, communities provide natural resources that when exploited alter the composition and structure of the community over the long-term, but are apparently recoverable

Comments: Habitat degradation is considered to be the primary cause of decline (Douglas, pers. comm. 1993; Shute, pers. comm. 1993). Habitat has been degraded and remains threatened by siltation (Smith 1979, Pflieger 1997), such as results from poor agricultural practices, and chemical spills, such as that which occurred in the Clinch River in 1967. Alteration of the Mississippi River for commercial navigation purposes, including multiple lock and dam structures, has eliminated habitat for this species (Wisconsin Department of Natural Resources 2005). Impoundments undoubtedly have destroyed much habitat in the Tennessee River drainage (Burkhead and Jenkins 1991). Extirpations associated with impoundments in Illinois and Wisconsin were reported by Smith (1979) and Becker (1983); a Wisconsin extirpation below a dam also was associated with the use of fish toxicants during a carp control program (Becker 1983). In Tennessee, "both the Powell and Clinch river habitats are jeopardized by coal-related pollution originating in Virginia, and local gravel-removal operations pose an additional threat to the Powell River population" (Etnier and Starnes 1993). Stream channelization is a potential threat. Small scattered populations are highly vulnerable to local extirpation.

Global Protection: Few to several (1-12) occurrences appropriately protected and managed

Comments: Several protected occurrences exist. In Texas, TNC owns land containing prime habitat (Sandyland).

The western sand darter has no adverse affect on the human environment.

There is little evidence that this species has a positive or negative benefit to humans. Because of its small, slender body it is not suitable as a bait fish (Becker 1983). However, the continued existence of this species will be directly influenced by humans. As has been stated elsewhere, the decline of the western sand darter has been directly linked to the degradation of aquatic habitats throughout the natural range of the sand darter-as the result of human activities. Perhaps the greatest benefit that Americans can derive from the western sand darter by its continued existence will be its contribution to the biodiversity of North America.

Stewardship Overview: The primary management consideration for this species is maintenance of good water quality and prevention of stream siltation and impoundment.

Wisconsin Department of Natural Resources (2005) identified the following priority conservation actions: (1) protect and restore appropriate habitat in the medium and large rivers of the Mississippi and Lake Michigan drainage basins; (2) control point and non-point source pollution, including use of broad riparian buffer strips, stiff pesticide regulations, upland erosion control, and modern pollution control systems; and (3) obtain more information on distribution, populations trends, and limiting factors.

Comments: In a phylogenetic analysis based on morphology, Simons (1991) concluded that Ammocrypta asprella should be included in the genus Crystallaria (generally has been regarded as a subgenus of Ammocrypta ) and that the genus Ammocrypta should be regarded as a subgenus of Etheostoma. Page and Burr (1991), Simons (1992), and Wiley (1992) adopted this change, but Etnier and Starnes (1993) and Jenkins and Burkhead (1994) retained Ammocrypta as a distinct genus and treated Crystallaria as a subgenus. Patterns of molecular variation are consistent with the recognition of Ammocrypta species as taxonomically distinct from Etheostoma (Wood and Mayden 1997, Faber and Stepien 1998, Near et al. 2000). Nelson et al. (2004) recognized Ammocrypta as the appropriate genus for this species.