08-14-2004, 07:25 PM
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[/size][/font][#cc9966][font "Comic Sans MS"][size 2][size 1] [/size]Crayfish, also called "crawfish, crawdads, or sometimes mud-bugs", are characteristic and common inhabitants of a wide variety of environments, that include most types of running waters, shallow of lakes, ponds, sloughs, swamps, underground waters, and even wetlands where there is no open water. They are one of the most diverse aquatic groups in the world and over time seem to have adapted to nearly every nook and cranny that provides fresh water. Anyone, especially youngesters, who has ever spent any time looking in Tennessee streams, is more than likely familiar with crawdads.[/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"]
[size 2][/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"][size 2][size 1] [/size]Crayfish are members of a large group (or Phylum) known as Arthropods. Arthopods ("joint-footed" animals) include familiar animals such as insects, spiders, and crabs and lobsters that are charactized by a hard but flexible external shell called an exoskelton. Crayfish are members of the Class Crustacea, consisting of (with few exceptions) aquatic animals that breath with gills and have two pairs of antennae. They are further classified in the Order Decapoda, which includes mostly marine animals such as shrimp, crabs, and lobsters. The latin "decapod" literally translates to mean "ten-footed," referring to the five pairs of segmented legs that all decapod crustacea possess.[/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"]
[size 2][/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"][size 2][size 1] [/size]There are about 450 species of crayfish world-wide, and they inhabit every continent except for Africa and Antarctica. In southeast Asia, parts of central Europe, and in tropical regions, their space seems to be occupied by other crustaceans like shrimps and crabs. For example, Europe has an impoverished crayfish fauna of 15 species. The United States, though, with about 330 species, is the world crayfish capital. They are absent from the greater portion of the Rocky Mountain region, however, and family Astacidae (genus Pacifastacus), with exception of the upper Missouri River, is found in streams and lakes only west of the Continental Divide. The vast majority on North American crayfish (belonging to family Cambaridae) are found east of the Rocky Mountains in the United States and the South is the hands-down leader.[/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"]
[size 2][/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"][size 2][size 1] [/size]Tennessee's crayfish fauna exhibits the most extensive speciation of any state with at least 76 nominal species or subspecies and other probable manuscript forms within its political boundary. The fauna consists of two subfamilies, 6 genera, and 25 subgenera of the family Cambaridae. This diversity is due, in part, to the state's wide, east-west geologic complexity that crosses six physiographic regions with many varied ecological habitats. Also, Middle Tennessee is inhabited by a number of primitive endemic species and is thought to be and area of early speciation. For example the center of origin for [/size][/font][/#cc9966][#cc9966][font "Comic Sans MS"]
[size 2]Cambarus[/size][/font][/#cc9966][#cc9966][font "Comic Sans MS"][size 2] is considered to have existed in the area of northern Alabama northward through the limestone belt of Tennessee onto the Cumberland Plateau - most of this is in middle Tennessee. [/size][/font][/#cc9966] [font "Arial, Helvetica, adobe-helvetica, Arial Narrow"]
[size 2][/size][/font] [font "Arial, Helvetica, adobe-helvetica, Arial Narrow"][size 1] [/size][/font][#cc9966][font "Comic Sans MS"][size 2]The Tennessee Wildife Resources Agency is currently documenting distributions and status of crayfish species across the state and is building a reference collection of the various species that inhabit Tennessee's waters. [/size][/font][/#cc9966] [font "Arial, Helvetica, adobe-helvetica, Arial Narrow"]
[size 2][/size][/font]![[Image: zig_zag.gif]](http://www.homestead.com/~site/tool/Homestead/HC_Objects/Images/HCUser_Divider/Static/zig_zag.gif)
[font "Comic Sans MS"][size 2]Cambarus tenebrosus[/size][/font] ![[Image: cdubius.JPG]](http://www.homestead.com/twra4streams/files/cdubius.JPG)
[font "Comic Sans MS"][size 2]Cambarus dubius[/size][/font] ![[Image: williami.jpg]](http://www.homestead.com/twra4streams/files/williami.jpg)
[font "Arial, Helvetica, adobe-helvetica, Arial Narrow"][size 2]Cambarus williami[/size][/font]
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[/size][/font][#cc9966][font "Comic Sans MS"][size 2][size 1] [/size]Crayfish, also called "crawfish, crawdads, or sometimes mud-bugs", are characteristic and common inhabitants of a wide variety of environments, that include most types of running waters, shallow of lakes, ponds, sloughs, swamps, underground waters, and even wetlands where there is no open water. They are one of the most diverse aquatic groups in the world and over time seem to have adapted to nearly every nook and cranny that provides fresh water. Anyone, especially youngesters, who has ever spent any time looking in Tennessee streams, is more than likely familiar with crawdads.[/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"]
[size 2][/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"][size 2][size 1] [/size]Crayfish are members of a large group (or Phylum) known as Arthropods. Arthopods ("joint-footed" animals) include familiar animals such as insects, spiders, and crabs and lobsters that are charactized by a hard but flexible external shell called an exoskelton. Crayfish are members of the Class Crustacea, consisting of (with few exceptions) aquatic animals that breath with gills and have two pairs of antennae. They are further classified in the Order Decapoda, which includes mostly marine animals such as shrimp, crabs, and lobsters. The latin "decapod" literally translates to mean "ten-footed," referring to the five pairs of segmented legs that all decapod crustacea possess.[/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"]
[size 2][/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"][size 2][size 1] [/size]There are about 450 species of crayfish world-wide, and they inhabit every continent except for Africa and Antarctica. In southeast Asia, parts of central Europe, and in tropical regions, their space seems to be occupied by other crustaceans like shrimps and crabs. For example, Europe has an impoverished crayfish fauna of 15 species. The United States, though, with about 330 species, is the world crayfish capital. They are absent from the greater portion of the Rocky Mountain region, however, and family Astacidae (genus Pacifastacus), with exception of the upper Missouri River, is found in streams and lakes only west of the Continental Divide. The vast majority on North American crayfish (belonging to family Cambaridae) are found east of the Rocky Mountains in the United States and the South is the hands-down leader.[/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"]
[size 2][/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"][size 2][size 1] [/size]Tennessee's crayfish fauna exhibits the most extensive speciation of any state with at least 76 nominal species or subspecies and other probable manuscript forms within its political boundary. The fauna consists of two subfamilies, 6 genera, and 25 subgenera of the family Cambaridae. This diversity is due, in part, to the state's wide, east-west geologic complexity that crosses six physiographic regions with many varied ecological habitats. Also, Middle Tennessee is inhabited by a number of primitive endemic species and is thought to be and area of early speciation. For example the center of origin for [/size][/font][/#cc9966][#cc9966][font "Comic Sans MS"]
[size 2]Cambarus[/size][/font][/#cc9966][#cc9966][font "Comic Sans MS"][size 2] is considered to have existed in the area of northern Alabama northward through the limestone belt of Tennessee onto the Cumberland Plateau - most of this is in middle Tennessee. [/size][/font][/#cc9966] [font "Arial, Helvetica, adobe-helvetica, Arial Narrow"]
[size 2][/size][/font] [font "Arial, Helvetica, adobe-helvetica, Arial Narrow"][size 1] [/size][/font][#cc9966][font "Comic Sans MS"][size 2]The Tennessee Wildife Resources Agency is currently documenting distributions and status of crayfish species across the state and is building a reference collection of the various species that inhabit Tennessee's waters. [/size][/font][/#cc9966] [font "Arial, Helvetica, adobe-helvetica, Arial Narrow"]
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[font "Comic Sans MS"][size 2]Cambarus tenebrosus[/size][/font] [font "Comic Sans MS"][size 2]Cambarus dubius[/size][/font] [font "Arial, Helvetica, adobe-helvetica, Arial Narrow"][size 2]Cambarus williami[/size][/font][signature]