Epioblasma obliquata obliquata
|Listed||July 10, 1990|
|Description||A freshwater mussel.|
|Food||Filter-feeds organic detritus, phytoplankton, and tiny zooplankton.|
|Reproduction||Lays externally fertilized eggs, and has planktonic larvae that are parasitic on fish.|
|Threats||Habitat destruction by impoundments, pollution, and gravel mining.|
|Range||Alabama, Illinois, Indiana, Kentucky, Ohio, Tennessee|
The catspaw, also known as the purple cat's paw pearlymussel, has a medium-sized shell that is subquadrate (roughly rectangular) in outline. The outside surface has numerous distinct growth lines, fine wavy green rays, a smooth and shiny surface, and is yellowish-green, yellow, or brownish in color. The inside of the shell is a lustrous purplish to deep purple.
The specific food habits of the catspaw are unknown. Like other freshwater mussels, however, it probably filter-feeds on detritus, diatoms, phytoplankton, and zooplankton. As with other unionid bivalves, the larvae (or veligers) have a planktonic stage during which they are parasitic on species of fish. Afterwards, they settle to the bottom and adopt the sedentary, filter-feeding lifestyle of the adults.
The catspaw inhabits large rivers with a sand/gravel substrate. It occurs in water of shallow to moderate depth, with a moderate to swift current. It inhabits boulder to sand substrates.
The catspaw was once known from the Ohio, Cumberland, and Tennessee River Systems in Ohio, Illinois, Indiana, Kentucky, Tennessee, and Alabama.
The range and abundance of the catspaw are greatly reduced from former times. Most of its historical populations were lost through the conversion of extensive sections of its riverine habitat into a series of large impoundments (i.e., through the construction of dams). This greatly reduced the availability of riverine habitat, and also affected the distribution and availability of the fish hosts of the parasitic mussel larvae. The degradation of water quality is also a problem, including runoff from oil and gas exploration and production, the dredging of gravel, channel maintenance, and commercial fishing for other species of mussels. The rare catspaw is also threatened by the invasion of its habitat by an introduced alien species, the zebra mussel (Dreissena polymorpha ), which out-competes many native species of unionid bivalves. Only three populations of the catspaw survive. These are located in the middle Cumberland River in Smith County, Tennessee, and in the Green River in Warren and Butler Counties, Kentucky. However, two of these populations only have old animals, and appear to be non-reproducing.
Conservation and Recovery
Surveys are needed to determine whether any additional populations of the catspaw survive, and to monitor the known populations. The known populations must be protected from obvious threats, such as gravel mining. Unless additional reproducing populations can be found, or methods developed to maintain the three known populations or create new ones, the species will remain at great risk of extinction. Research is needed to better understand the life-history requirements of the rare catspaw, and to determine the threats to its existence so they can be alleviated.
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
U. S. Fish and Wildlife Service
330 Ridgefield Court Telephone:
Asheville, North Carolina 28806
U. S. Fish and Wildlife Service. 2000. Cat's Paw Pearlymussel (Epioblasma [= Dysnomia] obliquata obliquata ).http://endangered.fws.gov/i/f/saf15.html
U.S. Fish and Wildlife Service. 10 July 1990. "Endangered and Threatened Wildlife and Plants: Purple Cat's Paw Pearlymussel Determined To Be An Endangered Species." Federal Register 55:132.
"Catspaw." Beacham's Guide to the Endangered Species of North America. . Encyclopedia.com. (November 14, 2018). https://www.encyclopedia.com/environment/science-magazines/catspaw
"Catspaw." Beacham's Guide to the Endangered Species of North America. . Retrieved November 14, 2018 from Encyclopedia.com: https://www.encyclopedia.com/environment/science-magazines/catspaw
Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).
Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.
Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:
Modern Language Association
The Chicago Manual of Style
American Psychological Association
- Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
- In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.