Drainagewide Occurrence 
of the Freshwater Jellyfish, 
Craspedacusta sowerbyi Lankester 1880, 
in the Tennessee River System 
Bruce L. Yeager 
Office of Natural Resources and Economic Development, 
Division of Services and Field Operations, 
Field Operations, Eastern Area, 
Tennessee Valley Authority, 
Norris, Tennessee 37828 
ABSTRACT . — Historical records and 42 new collections at 13 sites 
along 673 miles of the Tennessee River system are reviewed and pre- 
sented for the freshwater jellyfish, Craspedacusta sowerbyi. The exten- 
sive distribution pattern of C. sowerbyi in the Tennessee River system 
represents one of the few examples in North America of watershed 
colonization, rather than isolated occurrence of this organism. 
Although some researchers (Hargitt 1919, Schmitt 1939, Lytle 
1960) have discussed the general distribution of the freshwater jellyfish, 
Craspedacusta sowerbyi Lankester 1880, in North America, almost all 
reports are of single, isolated occurrences with no watershed or drain- 
agewide observations. Nine records of the freshwater jellyfish in the 
state of Tennessee have been published. Powers (1938) documented the 
species’ presence in east Tennessee from a bloom on Andrew Jackson 
Lake, a small private lake in Knox County. Isom and Sinclair (1962) 
published five records from Center Hill and Old Hickory reservoirs on 
the Cumberland River. One collection of medusae (Chadwick and 
Houston 1953) was recorded from the most downstream portion of the 
Tennessee River on Kentucky Reservoir. Pennington and Fletcher 
(1980) collected C. sowerbyi in the Tennessee River system, from Ken- 
tucky Reservoir in Tennessee and Guntersville Reservoir in Alabama. 
Summarizing the relatively few records of freshwater medusae from the 
southeastern United States, Lytle (1962) reported an observation from 
Wilson Reservoir, another mainstream impoundment of the Tennessee 
River in Alabama. The present report summarizes historical and new 
records in the Tennessee River system and firmly establishes the drain- 
agewide presence of the medusoid stage of Craspedacusta sowerbyi. 
Brimleyana No. 13:91-98, July 1987 
91 
