title: Are filtration rates for the rough tunicate Styela plicata independent of weight or size?
abstract: The filtration rate of the rough tunicate Styela plicata was determined as an aid for potential use as a bioremediator of algae and bacteria contamination in estuarine waters. Filtration rates were calculated hourly over a period of six hours for tunicates (16.8 to 57.8 grams) exposed to two targeted concentrations (10(5) and 10(6) cells mL(-1)) of the microalgae Nannochloropsis sp. (n = 7 per treatment) and the bacteria Escherichia coli (n = 6 per treatment). Filtration rates for individual tunicates exposed to microalgae differed as much as 3520 mL hr(-1) within an hour and 2349 mL hr(-1) with bacteria. However, the average filtration rate of tunicates exposed to microalgae at 10(5) cells mL(-1) was 3065 mL hr(-1) animal(-1)(+/- 1284 mL hr(-1) s.d.), 3252 mL hr(-1) animal(-1) (+/- 1039 mL hr(-1) s.d.) at 10(6) cells mL(-1) and 3158 mL hr(-1) animal(-1) when combined. The average filtration rate with bacteria at 10(5) cells mL(-1) was 4654 mL hr(-1) animal(-1) (+/- 810 mL hr(-1) s.d.), 2296 mL hr(-1) animal(-1) (+/- 1460 mL hr(-1) s.d.) at 10(6) cells mL(-1) and 3475 mL hr(-1) animal(-1) when combined. There was no relationship between average hourly filtration rate and whole animal weight (r(2) = 0.0001) or dry organ weight (r(2) = 0.0067) indicating that filtration rate should not be reported on a live or dry weight basis. It is suggested that averaging the filtration rate of a population of animals over time would yield a more accurate value, especially for use in modeling of bioremediation effects.
authors.affiliation: Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida 33431-0991, USA. Biofreak@Charter.net
authors.forename: Lisa D
authors.initials: LD
authors.lastname: Draughon
authors.forename: John
authors.initials: J
authors.lastname: Scarpa
authors.forename: James X
authors.initials: JX
authors.lastname: Hartmann
mesh_terms: D000818:Animals; D004926:Escherichia coli / Q000302:isolation & purification; D056890:Eukaryota / Q000302:isolation & purification; D005374:Filtration; D014561:Urochordata / Q000502:physiology*; D014871:Water Microbiology