JOURNAL OF PLANKTON RESEARCH | VOLUME 4 | NUMBER 2 | PAGES 189-201 | 1982
© Oxford University Press
research-article |
Laboratory-measured grazing and ingestion rates of the salp, Thalia democratica Forskal, and the doliolid, Dolioletta gegenbauri Uljanin (Tunicata, Thaliacea)
Skidaway Institute of Oceanography P.O. Box 13687, Savannah, Georgia 31406, USA
Received on August 1, 1980; accepted on May 1, 1981
Grazing and ingestion rates of laboratory-born Thalia democratica aggregates and Dolioletta gegenbauri gonozooids, phorozooids and oozooids were determined while fed Isochrysis galbana (4–5 µm diameter) alone or in combination with Peridinium trochoideum (16–18 µm diameter) at concentrations of 0.15–0.70 mm3 x 1–1. Grazing rates (ml x zooid–1 x 24 h –1) ranged from 10 to 355, and at zooid weights greater than 5 µg carbon were in order oozooid > gonozooid > aggregate. Grazing rates increased exponentially with increasing zooid weight. Weight-specific grazing rates (ml x µgC–1 x 24 h–1) were independent of the four-fold initial food concentration. Mean weight-specific grazing rates increased linearly with increasing zooid weight for the aggregates and oozooids, but gonozooid mean rates were independent of zooid weight. Aggregate and gonozooid ingestion rates (106 µm3 x zooid–1 x 24 h–1) ranged from 4 to 134 while oozooid rates ranged from 3 to 67. All ingestion rates were independent of the initial food concentration but increased linearly with increasing zooid weight at similar rates. All mean weight-specific ingestion rates (ml x µgC–1 x 24 h–1) were independent of zooid weight. The mean aggregate daily ration (µgC ingested x µg body C–1) was 59% and the mean doliolid ration was 132%. Field studies indicate that normal concentrations of D. gegenbauri in the Georgia Bight clear their resident water volume (1 m3) in about 4 months, but that highly concentrated, swarm populations which occur along thermohaline fronts clear their resident water volume in less than 1 day.
1Current address: MacLaren Plansearch Ltd., P.O.Box 13250, sta.A., St.John's, Nfld. A1B 4A5
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  T. Kiorboe The Sea Core Sampler: a simple water sampler that allows direct observations of undisturbed plankton J. Plankton Res., June 1, 2007; 29(6): 545 - 552. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Katechakis, H. Stibor, U. Sommer, and T. Hansen Feeding selectivities and food niche separation of Acartia clausi, Penilia avirostris (Crustacea) and Doliolum denticulatum (Thaliacea) in Blanes Bay (Catalan Sea, NW Mediterranean) J. Plankton Res., June 1, 2004; 26(6): 589 - 603. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D.M. Gibson and G.-A. Paffenhofer Feeding and growth rates of the doliolid, Dolioletta gegenbauri Uljanin (Tunicata, Thaliacea) J. Plankton Res., August 1, 2000; 22(8): 1485 - 1500. [Abstract] [Full Text] [PDF]
|
|