Phytoplankton Ingestion by the Fingernail Clam, Sphaerium Transversum (Say), in Pool 19, Mississippi River

Abstract

In Pool 19 of the Mississippi River, the fingernail clam, Sphaerium transversum, appears to feed non—selectively on phytoplankton, although green algae were in higher percentages in guts than in plankton samples. Diatoms were of paramount importance in clam guts and water samples during most sampling periods, especially from December to April when mean monthly water temperatures were less than 4 degrees C. Ingestion by clams was heaviest in spring, early summer, and fall. Clams appeared to stop ingesting when water temperatures fell to about 2—4 degrees C. In February and March, 80—90% of the clams had ceased ingesting. Ingestion did not cease simultaneously in all clams. Throughout the year some contained little or no phytoplankton. Much of the phytoplankton in the gut near the anus appeared completely undigested. Phytoplankton diversity (d) in clam guts and in water was high in July and August and low in February and March. A maximum of 33 phytoplankton genera occurred in clams in August; 38 genera were present in water samples in July and August. Concentrations of over 50,000 plankters/ml (primarily Stephanodiscus hantzschii) occurred in March 1968; minimum concentrations occurred in July.

Growth and Survival of Juvenile Freshwater Mussel, Chamberlainia hainesiana (Lea, 1856), at Three Densities in the Natural Reservoir and River Environments, Thailand

“…This greater phytoplankton abundance resulted in higher growth rates of cultured freshwater pearl mussels in the reservoir than in the river. The observed high percentages of Chlorophyta phytoplankton in both the reservoir and the river are in accordance with a study of rainbow mussels by Liberty et al () and other studies of freshwater mussels (Gale and Lowe ; Huca et al ; Binhe ; Paterson ; Kovitvadhi et al ).…”

The functional role of burrowing bivalves in freshwater ecosystems

“…Unionidae, Sphaeriidae Filtering rates vary with water temperature Gale & Lowe (1971); Hinz & Scheil (1972); Benjamin & Burky (1978); Hornbach et al (1984a), Paterson (1984); Burky et al (1985); Vanderploeg et al (1995) Unionidae, Sphaeriidae, Filtering rates vary with Winter (1978); Hornbach et al (1984a); Lauritsen (1985), (1986);…”

“…Corbiculidae particle concentration Way (1989); Way et al (1990); Tankersley & Dimock (1993); Englund & Heino (1996) Unionidae Bivalves are size selective in the particles they retain Paterson (1984); Jorgensen et al (1984); Way (1989); Tankersley & Dimock (1993); Vanderploeg et al (1995) Unionidae, Corbiculidae Bivalves select particles by type Bisbee (1984); Leff et al (1990) Unionidae, Corbiculidae Bivalves do not select particles by type Gale & Lowe (1971); Paterson (1984); Lauritsen (1986); Way et al (1990); Boltovskoy et al (1995); Parker et al (1998) Unionidae, Corbiculidae Variation in gill size and cirral structure is related to ®ltering ability Way (1989); Tankersley & Dimock (1993); Silverman et al (1995), (1997) Filter-feeding: evidence for resource limitation Unionidae, Corbiculidae Filter-feeding controlled phytoplankton abundance Cohen et al (1984); Phelps (1994); Welker & ...…”

Possible Effect of Lock and Dam 19 on Phytoplankton Communities of the Upper Mississippi River

“…This fl ow may be the only way for water to move from above to below the dam at low river water levels and may have had signifi cant effects on abundances of algae immediately below the dam. In addition, local planktivorous fauna including Hypophthalmichthys molitrix (Valenciennes in Cuvier and Valenciennes) (Silver Carp), H. nobilis (Richardson) (Bighead Carp), Polyodon spathula (Waldbaum) (Paddlefi sh) (Coker 1923, Lazzaro et al 1992, bivalves (Gale and Lowe 1971, Raidow and Hamilton 2001, Welker and Walz 1998, and other river invertebrates (Lamberti andMoore 1984, Madenjian 1995) known to congregate along the power plant, lock wall, and river bottom in this area (R.V. Anderson, unpubl.…”