ELEMENT STEWARDSHIP ABSTRACT

for

clubshell

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(01995

THE NATURE CONSERVANCY

1815 North Lynn Street, Arlington, Virginia 22209 (703) 841-5300

The Nature Conservancy

Element Stewardship Abstract

For PLEUROBEMA CLAVA

Common Name: CLUBSHELL

Global Rank: GI

SHELL: To 90 mm, small stream specimens considerably smaller. Elongate, triangular, distinctly wedge-shaped, the umbos placed anteriorly. No observable sexual dimorphism in shell. The majority of specimens have the umbos placed just posterior to the anterior margin; occasional examples have the umbo projecting past this margin. Individuals become increasingly more elongate with the umbos placed progressively forward with age. Anterior portion inflated, posterior portion compressed and tapering to an acute posterior margin. Shell sculptureless except for growth lines and a weak posterior ridge. Sulcus present on juvenile shell but may not persist into adult stages. Shell thickened anteriorly, posterior margin thin and fragile, even in large specimens. The beaks are sculptured with two to three microscopic, undulating ridges set obliquely to the umbo. Periostracum yellow in juveniles, becoming darker with age, with growth annuli dark and pronounced. Very old individuals may be nearly black. Shells patterned with dark green rays, particularly in juveniles. The typical pattern is of many fine rays anteriorly and one or more broad rays over the region of the sulcus. All rays are interrupted by the growth annuli creating a checkerboard pattern in many examples. Hinge plate moderately thick, the umbonal cavity shallow and wide. Left valve with two pseudolateral and pseudocardinal teeth each; right valve with one each. Teeth coarsely serrate. Nacre white, iridescent posteriorly, occasionally with a golden tinge to the teeth. Anterior adductor scar deeply set near anterior margin; posterior adductor scar at posterior end of hinge plate. Retractor muscle scars prominent.

ANIMAL: White to pale orange (unpreserved). The inner gill is somewhat larger than the outer in the male and nongravid female. In gravid females the outer is used as the brood pouch (Pennack, 1978) erroneously states that the inner gill is the brood pouch). The water tubes and placentae are lanceolate and the eggs pale in color. Incurrent opening coarsely papillose, excurrent finely papillose.

The shell has been illustrated by Call (1900, plate 62), Clench (1959) as PLEUROBEMA MYTILOIDES (figure 43.72), and by Parmalee (1967, plate 30A), Burch (1975, figure 62), and Stansbery (1976).

An individual or aggregation occurring within a stream/river separated from other individuals or aggregations by a segment of at least 0.25 mi. within which 1) no individuals have been located after several surveys by an experienced observer or 2) there is significant habitat discontinuity, such as a barrier.

Despite shell variation there should be no difficulty in identifying this species. Superficially similar species such as P. DECISUM and P. CHATTANOOGAENSE are more southern in distribution. The fragile posterior portion of the shell is usually broken away in all but the freshest specimens, but the small size and anteriorly placed umbos are usually sufficient for identification.

11. STEWARDSHIP SUMMARY

Refer to the General Freshwater Mussel ESA.

111. NATURAL HISTORY

Historically, it was distributed in the Wabash, Ohio, Kanawha, Kentucky (Danglade, 1922), Green, Monongahela, and Alleghany Rivers and their tributaries. Stansbery (1964) reported it from Mussel (now Muscle) Shoals, Alabama, in the Tennessee River and later (1976) stated that it was not found south of Florence, Alabama, or in any Tennessee River tributaries in Alabama; Mussel Shoals therefore probably represents the southern limit of P. CLAVA. Simpson (1900) lists it from the Iowa River, St. Peter's River in Minnesota, and "Nebraska"; all of these records are probably erroneous. Lapham's 1852 record for Wisconsin is also in error (fide Baker, 1928).

It has been extirpated from most of its range in this century and is now mainly or exclusively limited to the headwaters of rivers it formerly occupied. It was lost from the Ohio River prior to 1920 (Taylor and Spurlock, 1982). Stansbery and King (1983) believed it to be absent from the Muskingum River proper and Parmalee (1967) stated that it was extremely rare or extirpated from Illinois. Call (1900) listed it as common in the Wabash River. Specimens were recovered in 99 collections between 1966 and 1967 (Krumholtz et. al. 1970) and in the study of Clark (1976) of the Wabash River. Taylor (198 1, p 95) found it only in a subfossil state in Eagle Creek of the Kentucky River and concluded that it was "very rare or no longer present." Stansbery, Newman, Borror, and Stein (19 8 5) state that it had not been found living or fresh dead in the Walhonding and Mohican Rivers of the Muskingum River in Ohio in the past decade. It was not found in a recent survey of the Kanawha River proper (Taylor, 1983).

Despite the type locality of Lake Erie (apparently in error), this is a species of small to medium-sized rivers and streams. Ortmann (1919) remarked that it was "a rare shell, and never found in great numbers. It is found mostly in sand and fine gravel, and is deeply buried." Hoggarth (pers. comm.) and Watters (unpublished) have found live individuals completely buried with the posterior shell margin facing up in sand/gravel substrate in riffle/run situations in less than 1.5 feet of water. This seems to be the habitat of choice. Because it buries itself beneath the substrate, it is rarely found alive even in places where it is believed to occur in some numbers. Ecology:

Virtually nothing is known specifically for P. CLAVA. Refer to the General Freshwater Mussel ESA for more information on the general biology-ecology of mussels.

Virtually nothing is known specifically for P. CLAVA. Ortmann (1919) reported that it bred from mid-May to late July.

Based upon counts of annular growth lines, PLEUROBEMA CLAVA may reach 30+ years of age. It is not known at what ages reproductive maturity begins and ends. Because of the rarity of live material, it is not known if existing populations are reproductively active. Because of their small size, it is not known if juveniles are present in any of the populations. It must be emphasized that existing populations may be large, healthy, and reproductively active and still be in imminent danger of extinction if the host fish is not present in the range.

IV. CONDITION

The existing populations (at least in Ohio) are predominately in agricultural areas. Filter-feeders such as naiads have the potential to concentrate various runoff products such as herbicides, insecticides, and fertilizers to a toxic level. Stansbery (pers. comm.) believed that various pesticides were at least partially responsible for the overall decrease in the fauna of areas in which P. CLAVA was present.

Refer to the General Freshwater Mussel ESA.

The original range includes waterfront on such cities as Indianapolis, Toledo, Cincinnati, Columbus, Charleston, and Pittsburg. It is doubtful that the range of P. CLAVA can ever be recovered based upon the present water quality of the rivers serving these cities. Furthermore, until the host fish has been identified, it is unlikely that a successful program to conserve this species can be realistically undertaken. At this time the reasons for the extirpation of P. CLAVA from most of its range are unknown; this reduces any conservation plans to save it to mere guesswork.

Refer to the General Freshwater Mussel ESA.

Refer to the General Freshwater Mussel ESA.

The Nature Conservancy already has land on Big Darby Creek at the Commercial Point Bridge in Pickaway County, Ohio, and is considering acquisition of additional land on this creek. This species is one of several under review for that project. However, it has not been shown that Big Darby Creek supports a population of P. CLAVA at present outside of the confluence of Big and Little Darby Creeks. A survey of the entire system is planned for July-September, 1986, to determine the location of remaining populations for possible acquisition by The Nature Conservancy.

Refer to the General Freshwater Mussel ESA.

There are no known monitoring programs for this species. Refer to the General Freshwater Mussel ESA for information on monitoring of other species.

VI. RESEARCH

Michael A. Hoggarth (Ohio State University Museum of Zoology, Columbus OH 43210-1394) has conducted research on the determination of unionid host fish by glochidial identification.

Refer to the General Freshwater Mussel ESA.

VII. INFORMATION SOURCES

Baker, Frank Collins. 1928. The Freshwater Mollusca of Wisconsin: Part 11 Pelecypoda. Bulletin of the University of Wisconsin, Serial No. 1627, General Series No. 1301:47- 5 1.

Bier, Charles W. Western Pennsylvania Conservancy. 316 Fourth Avenue. Pittsburgh, PA 15222. Ph: 412-288-2777.

Burch, J. B. 1975. Freshwater unionacean clams (Mollusca:Pelecypoda) of North America. Malcological Publications, Hamburg, Michigan. 204 pp.

Call, R.E. 1900. A descriptive illustrated catalogue of the mollusca of Indiana. Annu. Rep. Indiana. Dept. Geol. Nat. Res. 24:335-535.

Clark, C. F. 1976. The freshwater naiads of the lower end of the Wabash River, Mt. Carmel, Illinois to the South. Sterkiana (61):1-14.

Clench, W. J. 1959. Mollusca. Pages 1117-60 in H. B. Ward and G. C. Whipple, Freshwater Biology (Second Edition). John Wiley and Sons, New York, New York.

Danglade, E. 1922. The Kentucky river and its mussel resources. U.S. Bureau of Fish. Doc. (934):1-8.

Hoggarth, M. A. 1985. Museum of Zoology, Ohio State University. Personal communication.

Krumholz, L. A., Bingham, R. L. and E. R. Mayer. 1970. A survey of the commercially valuable mussels of the Wabash and White Rivers of Indiana. Proc. Indiana Acad. Sci. 79:205-26.

Lapham, 1. A. 1852. Catalogue of the Mollusca of Wisconsin. Trans. Wisc. State Agric. Soc. 2:367-70.

Ortmann, A.E. 1919. Monograph of the naiades of Pennsylvania. Part 111. Systematic account of the genus and species. Memoirs of the Carnegie Museum 8(l). 385 pp.

Parmalee, Paul W. 1967. The freshwater mussels of Illinois. Popular Science Series, Vol VIII. Springfield,111. 107pp.

Permack, R. W. 1978. Freshwater Invertebrates of the United States. (Second Edition). John Wiley and Sons, New York, New York. xv + 803 pp.

Simpson, C. T. 1900. Synopsis of the naiades, or pearly freshwater mussels. Proc. U.S. Natn. Mus. 22(1205):501-1044.

Stansbery, D. H. 1976. Endangered and threatened plants and animals of Alabama. Bull. Alabama Mus. Natur. Hist. (2):42-52.

Stansbery, D. H. 1976. Ohio's endangered naiad mollusks. Amer. Malac. Unoin. Ann. Meeting. Prog.

Stansbery, D. H. Museum of Zoology, Ohio State University. Personal communication.

Stansbery, D. H. and C. C. King. 1983. Management of MusKingum River mussel (unionid mollusk) populations. Compl. Report, Comm. Fish. Res. Dev. Prog. (3 -318-R): 1-79.

Stansbery, D. H., K. E. Newman, K. G. Borror, and C. B. Stein. 1985. Literature records of bivalve mollusks of the Muskingum River System, Ohio. Ohio Biol. Surv. Tech. Rept. (8):xiv-472.

Stansbery, David H. 1964. The Mussel (Muscle) Shoals of the Tennessee River revisited. Annual Reports for 1964 of the American Malacological Union. pp. 25-28.

Taylor, R. W. Freshwater naiaides of Eagle Creek, A tributary of the Kentucky River (Unionidae). Nautilus 95(2)93-95.

Taylor, R. W., and B. D. Spurlock. 1982. The changing Ohio River naiad fauna: a comparison of early Indian middens with today. Nautilus 96(2):49-5 1.

Taylor, Ralph W. 1983. "A survey of the freshwater mussels of the Kanawha River." Prepared for Huntington District, Corps of Engineers, Huntington, VN. Contract no. DACW69-82-C0081. 62 pp.

VIII. DOCUMENT PREPARATION & MAINTENANCE

Edition Date: 1986-08-01

Edition Author: Watters, Thomas G.