Glossary of Terms
Abdomen- the rear half of the crayfish, posterior to the cephalothorax
Anterior- directional term indicating front end of an organism; toward the front
Aquifer- underground layer of water
Areola- the space found on the dorsal surface of the carapace between two curved grooves
Carapace- The exoskeleton of a crayfish that covers the cephalothorax portion of the body
Carina- small ridge; usually referring to raised area down the center of the rostrum
Cephalothorax- the anterior portion of the body made up of the fused cephalic and thoracic regions; anterior to the abdomen
Cervical spine- sharp point on either side of the cephalothorax
Dorsal- directional term indicating the "back" or "top" of an animal or object
Endemic- native to a particular place
Exoskeleton- the hard outer covering (skeleton) of crayfish and other arthropods; this covering is shed during molting.
Fingers- the two long appendages of a claw used for grasping or defending.
Fixed finger- non-movable finger on the claw
"in berry"- term used to describe a female crayfish carrying eggs under her abdomen
Impervious- surfaces around water bodies that do not allow percolation of rain into the soil (eg. parking lots, roads, roof tops) that cause streams to receive explosive runoff during rain events
Karst- limestone area where erosion has created sinkholes, caves, and underground streams
Lateral- directional term indicating “to the side”
Lentic- areas with non-moving water such as ponds or swamps
Macrophytes- plants large enough to be observed with the naked eye
Medial- pertaining to the middle
Mesial- directional term indicating "toward the middle or midline of the animal"
Molting- the process of shedding the exoskeleton
Obliterated- no space between the grooves that delineate the areola
Omnivore- animals that eat both plant and animal matter
Palm- the portion of the claw that is not composed of fingers
pH- measure of acidity or alkalinity of a solution
Posterior- directional term indicating rear end of an organism; toward the rear
Postorbital ridge- the ridge (raised area) directly behind the eyes
Riffle- areas of fast flow in a stream where surface of water is agitated
Riparian- area along the margin of a stream
Rostrum-the "nose" of the crayfish; the portion of the carapace that is anterior to the eyes
Setae- hair-like structures
Swimmerets- paired “feathery” appendages on the ventral side of the abdomen
Telson- center segment of the tail
Troglobitic- related to living in underground habitats
Tubercle- rounded projection or bump
Ventral- directional term indicating the "belly" or "bottom/underside" of an animal
Glossary definitions taken in part from:
Fetzner Jr. JW (1999). Key to the Astacidae website. http://iz.carnegiemnh.org/crayfish/Keys/. Accessed: 2 October 2008. Based on the original publication: Horton H. Hobbs, Jr. 1972. Biota of Freshwater Ecosystems: Identification Manual No. 9. Crayfishes (Astacidea) of North and Middle America. For the Environmental Protection Agency, Project # 18050 ELD.
