Animal Diversity Web

Ge­o­graphic Range

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

Habi­tat

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

Phys­i­cal De­scrip­tion

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).

• Other Physical Features
• bilateral symmetry

• Range mass

  1.5 (high) g

  0.05 (high) oz

Re­pro­duc­tion

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).

Lifes­pan/Longevity

• Average lifespan
  Status: captivity

  3 years

  AnAge

Be­hav­ior

One very in­ter­est­ing as­pect of this fish's be­hav­ior is its habit of bury­ing it­self in the sub­strate (Daniels 1989). Sev­eral re­searchers have in­ves­ti­gated this phe­nom­e­non in an at­tempt to ex­plain its adap­tive use­ful­ness. Williams (1975) con­cluded that the ster­ile na­ture of the sand darter's habi­tat gen­er­ally pre­cludes the pres­ence of preda­tory species. This ab­sence of preda­tors would sug­gest that the sur­vival value of the bury­ing be­hav­ior may not be due to the pro­tec­tion it pro­vides; this be­hav­ior may be more im­por­tant in en­ergy con­ser­va­tion. For a fish to main­tain its po­si­tion in the mod­er­ate to fast cur­rent of a sand rif­fle, its en­ergy ex­pen­di­ture would be con­sid­er­ably greater than if the same in­di­vid­ual lied buryed in the sand. It is thought that the lower tem­per­a­ture below the sur­face of the sand re­sults in a re­duc­tion of the meta­bolic rate (Becker 1983).

• Key Behaviors
• natatorial
• motile

Com­mu­ni­ca­tion and Per­cep­tion

• Perception Channels
• tactile
• chemical

Food Habits

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).

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

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.

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

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

Con­ser­va­tion Sta­tus

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).

• IUCN Red List [Link]

  Not Evaluated

• US Federal List

  No special status

Other Com­ments

There is un­pub­lished ev­i­dence that this fish species has been found in an ad­di­tional river-wa­ter­shed in north­ern Wis­con­sin and Michi­gan. An en­train­ment mor­tal­ity study was con­ducted for Wis­con­sin Pub­lic Ser­vice (WPS), on the Menom­i­nee River, as part of their re­li­cens­ing re­quire­ments for the Fed­eral En­ergy Reg­u­la­tory Com­mis­sion (FERC). This study took place be­tween May 1993 and April 1994. Dur­ing the sum­mer of 1993, 28 dis­creet sam­ples, col­lected on 17 dif­fer­ent sam­pling dates pro­duced 104 spec­i­mens of this species (WPS 1994). After ver­i­fi­ca­tion of the iden­ti­fi­ca­tion, sev­eral spec­i­mens were do­nated to the Uni­ver­sity of Michi­gan Mu­seum of Zo­ol­ogy. Their ac­ces­sion num­ber is 224173(Per­sonal comm).

Con­trib­u­tors

Stan­ley F. Cow­ton (au­thor), East­ern Michi­gan Uni­ver­sity, Cyn­thia Sims Parr (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

1994. Final Re­port for Fish En­train­ment and Tur­bine Mor­tal­ity Study at the Grand Rapids Hy­dro­elec­tric Pro­ject (FERC NO. 2433) on the Menom­i­nee River May 1993 through April 1994 Pre­pared for Wis­con­sin Pub­lic Ser­vice Cor­po­ra­tion(WPS) , Green Bay, Wis­con­sin. Bed­ford, New Hamp­shire: Nor­man­deau As­so­ci­ates, Inc..

Becker, G. 1983. Fishes of Wis­con­sin. 114 North Mur­ray Street, Madi­son, Wis­con­sin 53715: The Uni­ver­sity of Wis­con­sin Press.

Bond, C. 1979. Bi­ol­ogy of Fishes. West Wash­ing­ton Square, Philadel­phia, PA 19105: Saun­ders Col­lege Pub­lish­ing.

Daniels, R. 2/27/89. Sig­nif­i­cance of Bury­ing in Ammocrypta pel­lu­cida. Copeia, 1989(1): 29-34.

Lut­ter­bie, G. Au­gust 1976. The Darters (Pisces: Per­ci­dae: Etheostom­ati­nae) of Wis­con­sin. A The­sis sub­mit­ted in par­tial ful­fill­ment for the De­gree of Mas­ter of Art in Teach­ing(Bi­ol­ogy): 17-25; AP­PEN­DIX III.

Page, L. 1983. Hand­book of Darters. Nep­tune City, New Jer­sey: T.F.H. Pub­li­ca­tions.

Robins, C., R. Bai­ley, C. Bond, J. Brooker, E. Lach­ner. 1991. Com­mon and Sci­en­tific Names of Fishes from the United States and Canada. Bathesda, Mary­land: Amer­i­can Fish­eries So­ci­ety.