Aquatic Sciences Meeting, Albuquerque 2001

PC01 Harmful Algal Blooms

Date: Tuesday, February 13, 2001

Location: Southwest Hall

Cancellieri, P, J, North Carolina State University, Raleigh, NC, USA, pjcancel@unity.ncsu.edu

Deamer-Melia, N, J, North Carolina State University, Raleigh, NC, USA, nora_deamer@ncsu.edu

Glasgow, H, B, North Carolina State University, Raleigh, NC, USA, howard_glasgow@ncsu.edu

Burkholder, J, M, North Carolina State University, Raleigh, NC, USA, joann_burkholder@ncsu.edu

ATTRACTION OF PFIESTERIA ZOOSPORES TO FISH MUCUS IS INFLUENCED BY THE DURATION OF PRIOR ZOOSPORE ISOLATION FROM FISH PREY.

Toxic strains of the estuarine dinoflagellates, Pfiesteria piscicida and P. shumwayae, can cause fish death and disease. Chemosensory attraction of three functional types of these two species including TOX-A (actively ichthyotoxic), TOX-B (temporarily nontoxic), and NON-IND (incapable of toxic activity), was separately evaluated as attraction to fish mucus. Attraction was measured by the number of zoospores that entered a microcapil-lary tube filled with fresh fish mucus or sterile-filtered 15-psu water. TOX-A zoospores (both species) exhibited the strongest response to fish products, TOX-B zoospores were intermediate in response and NON-IND zoospores showed low to negligible attraction. Overall, increased duration away from live fish decreased the attraction of zoospores to fish mucus. An extended-duration experiment indicated that attraction of TOX-A zoo-spores to fish mucus was lost after 48 hr, but sterile-filtered mucus remained attractive for at least 96 hr, indicating a role of bacteria in blocking or degrading the attractive signal. This study indicates the major of functional type or toxicity status in the behavioral ecology of Pfiesteria spp.

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Aquatic Sciences Meeting, Albuquerque 2001

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