First Record of Cordylophora lacustris Allman from Kansas

Abstract

Cordylophora lacustris Allman, a unique colonial hydroid coelenterate usually abundant in brackish waters, was collected from Melvern Lake, Osage County, Kansas, on 14 September and 3 October 1980. Those collections constitute a first record for Kansas. Since Cordylophora lacustris Allman is abundant in brackish waters and has been collected only occasionally from fresh waters, it has been assumed that this unique colonial hydroid coelenterate is a brackish-water animal in the process of evolving into a fresh-water form (Carpenter, 1928; Wesenberg-Lund, 1939). Reports of infrequent collections of C. lacustris from fresh waters in the Western Hemisphere have been made, but many of those earlier collections are only doubtfully non-brackish (Clarke, 1878; Bibbens, 1892; Nutting, 1901; Hargitt, 1908; Gaggero, 1923 and 1935). However, Davis (1957) cited records of the collection of this organism prior to 1957 from Benson Creek, Kentucky, Gatun Locks in Panama, Fairmount Reservoir in Pennsylvania, the Schuylkill River in Kentucky, the Illinois and Mississippi Rivers in Illinois, the Arkansas River at Little Rock and the Red River at Shreveport, Louisiana, along with his collection from the mouth of the Chagrin Harbor, Ohio, as coming from incontestable fresh waters. I agree that all of those bodies of water are classified as fresh, but I do not agree that all have a low salt content. Both the Arkansas and Red Rivers are bedded in soils of high salt content, and they have tributaries that actually course over exposed salt deposits. One tributary of the Arkansas River, the Salt Fork of the Arkansas River, crosses the Great Salt Plains in Alfalfa County, Oklahoma, and is impounded to form the Great Salt Plains Lake near Cherokee. Ransom (1968) collected C. lacustris 21 times in a total of 1232 Ekman dredge hauls from the Cimarron arm of Keystone Reservoir near Tulsa, Oklahoma. The Arkansas River forms the other main arm of the reservoir. Specific conductance in Keystone Reservoir at the time of the collections ranged from 1700 to 12,000 /mhos/cm and was due mostly to a high sodium chloride concentration. Hutchinson (1967) stated that although the data are This content downloaded from 157.55.39.178 on Fri, 05 Aug 2016 05:21:43 UTC All use subject to http://about.jstor.org/terms 226 TRANSACTIONS OF THE KANSAS ACADEMY OF SCIENCES incomplete C. lacustris generally has been found in inland waters of relatively high salt content. I see no reason to question his statement in 1980. Pennak (1953) reported C. lacustris occurred in brackish inlets and estuaries from New Jersey to the Gulf of the St. Lawrence and that it has been collected in inland rivers in Illinois, Arkansas and Louisiana, probably the same collections as those reported by Davis (1957). Isom and Sinclair (1962) reported collections of C. lacustris from the Tennessee, Cumberland and Duck Rivers from 1955 through 1962. There is a published record of an earlier collection than the one from Keystone Reservoir in Oklahoma and that was from a flume near Tulsa (Blair, 1964). I collected a large number of specimens of C. lacustris from Melvern Lake, Osage County, Kansas, on 14 September 1980, and on 3 October 1980. Since those dates, I have observed the organism many times at the same location. The present find is the first record of this species in Kansas. Specimens were taken from depths ranging from 2 to 10 meters and they were attached to sumerged roots removed by a boat anchor and to Potamogeton stems. The collected specimens are in my personal collection and representatives have been delivered to The Kansas State Biological Survey, University of Kansas. Melvern Lake is without question a clear, fresh body of water. The salt content is very low, with a conductivity ranging between 150 and 400 /gmhos/cm. A Secchi disc reading on 3 October 1980, was more than 110 cm at the collecting site. The 1980 C. lacustris collections from Melvern Lake were unquestionably fresh-water specimens.