Great Basin Naturalist Volume 41 Number 4 Article 7 12-31-1981 A note on the food of Callibaetis (Ephemeroptera: Baetidae) C. E. Cushing Battelle-Pacific Northwest Laboratories, Richland, Washington R. T. Rader Columbia High School, Richland, Washington Follow this and additional works at: https://scholarsarchive.byu.edu/gbn Recommended Citation Cushing, C. E. and Rader, R. T. (1981) "A note on the food of Callibaetis (Ephemeroptera: Baetidae)," Great Basin Naturalist: Vol. 41 : No. 4 , Article 7. Available at: https://scholarsarchive.byu.edu/gbn/vol41/iss4/7 This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Great Basin Naturalist by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. A NOTE ON THE FOOD OF CALLIBAETIS (EPHEMEROPTERA:BAETIDAE) C. E. Gushing' and R. T. Rader' Abstract.— CalUbaetis nymphs in Rattlesnake Springs, Hanford Reservation, Washington, feed almost exclusively on fine particulate organic matter (FPOM) collected from the stream bottom. Ward and Short and Ward The functional group concept proposed by (1979), (1981). The majority of the particles were spherical; Cummins (1973) has become increasingly hence, volumetric calculations were based on used in characterizing invertebrate fauna in the particle size diameters. streams. Inherent in categorizing aquatic or- ganisms by various functional groups, or tro- phic relationships (collectors, grazers, shred- Results and Discussion ders, etc.), is knowing the food eaten and Data for 31 nymphs from eight sites are how it is obtained. Merritt and Cummins presented in Table 1. The number of organic (1978) have simimarized a large body of in- detrital particles per nymph gut ranged from formation on trophic relationships of North 3270 to 17,600, and varied in size from 111 American aquatic insects; however, the tro- jLim to 230 jum. These particles comprised phic relationships for the genus CalUbaetis is from 95 to 100 percent of the material pres- unclear. This note provides information on ent, by number; diatoms comprised 1 to 5 the food habits and trophic relationships for percent, and insect parts, probably ingested this mayfly in Rattlesnake Springs, Washing- by chance, less than 1 percent. The calcu- ton, and supplements the Edmunds et al. lated volume of the particles per nymph (1976) note on food of this genus. ranged from 7.6 to 22.3 mm^. Rattlesnake Springs is a small permanent Stations 1 through 17 are in the spring-stream on the U.S. Department of open desert, and 27, 29, and 31 are in a steep-sided Energy's Hanford Reservation in south-cen- canyon. The unusually high number of par- tral Washington. The region is in the north- ticles in the guts of nymphs from Sta. 31 may em extension of the Great Basin. Base flow is be related to its location. It is located at the about 0.011 m^/s, and the stream flows about origin of Rattlesnake Springs in a seepage 3 km before disappearing into the desert pool with heavy growths of filamentous floor. Further physical, chemical, and biolog- green algae. ical data can be found in Cushing et al. These data indicate that CalUbaetis is pri- (1980) and Cushing and Wolf (in press). marily a collector-gatherer (sensu Cummins 1973) feeding mainly on fine particulate or- Methods ganic matter (FPOM) from the stream bot- tom. These results are in contrast to Edmunds CalUbaetis nymphs were collected with et al. who state that CalUbaetis hand nets during a sampling program to (1976), nymphs are herbivorous, feeding on diatoms characterize the invertebrate fauna of Rattle- and other algae. A rich diatom and algal flora snake Springs. Samples were preserved in 70 is present in Rattlesnake Springs (Lippert and percent ETOH until examination. Gut con- Cushing 1973); yet these forms make up less tents were analyzed by suspension, filtration, than 5 percent of the food ingested in Rattle- and microscopic examination essentially as snake Springs. The findings are, however. described by Cummins (1973), Gray and 'Ecological Sciences Department, Battelle-Pacific Northwest Laboratories, Richland, Washington 99352. 'Columbia High School, Richland, Washington 99352. 431 432 Great Basin Naturalist Vol. 41, No. 4 consistent with data on other Baetidae (Cum- Edmunds, G. P., Jr., S. L. Jensen, and L. Berner. 1976. The mayflies of North and Central America. mins 1973, Merritt and Cummins 1978). Univ. of Minnesota Press, Minneapolis. V. Gray, L. J., and J. Ward. 1979. Food habits of stream benthos at sites of differing food avail- Literature Cited ability. Amer. Midi. Nat. 102:157-167. LippERT, B. E., AND G. E. Gushing. 1973. Taxonomy of Rattlesnake Springs (ALE) algae. Pages 6.15-6.16 Cummins, K. W. 1973. Trophic relations of aquatic in- in Pacific Northwest Laboratory Annual Report sects. Ann. Rev. Ent. 18:183-206. for 1972 to the USAEC Division of Biomedical Gushing, C. E., C. D. McIntire, R. Sedell, K. W. J. and Environmental Research, Volume I Life Sci- R. G. Petersen, Cummins, G. W. Minshall, and ences, Part 2 Ecological Sciences, BNWL-1750. of phys- R. L. Vannote. 1980. Comparative study Merritt, R. W., and K. W. Cummins. 1978. An in- ical-chemical variables of streams using multi- troduction to the aquatic insects of North Ameri- variate analyses. Arch. Hydrobiol. 89:343-352. ca. Kendall/Hunt Publ. Co., Dubuque, Iowa. Gushing, C. E., and E. G. Wolf. In press. Organic R. A., V. 1981. of Short, and J. Ward. Trophic ecology energy budget of Rattlesnake Springs, Washing- three winter stoneflies (Plecoptera). Amer. Midi. ton. Amer. Midi. Nat. Nat. 105:341-347. Table 1. Detrital (FPOM) particles in Callibaetis guts taken during July 1980. Date.