Larval feeding of northern anchovy, Engraulis mordax, on dinoflagellates: implications for year-class strength
Huntley, M. (1989). Larval feeding of northern anchovy, Engraulis mordax, on dinoflagellates: implications for year-class strength, in: Ros, J.D. (Ed.) Topics in Marine Biology: Proceedings of the 22nd European Marine Biology Symposium, Barcelona, Spain, August 1987. Scientia Marina (Barcelona), 53(2-3): pp. 239-245 In: Ros, J.D. (Ed.) (1989). Topics in marine biology: Proceedings of the 22nd European Marine Biology Symposium, Barcelona, Spain, August 1987. European Marine Biology Symposia, 22. Scientia Marina (Barcelona), 53(2-3). 145-754 pp., more In: European Marine Biology Symposia., more |
| Abstract | A series of experiments have been conducted to test the hypothesis that blooms of dinoflagellates ("red tides") may adversely affect year-class strength of northern anchovy, particulary if the red tide occurs during the anchovy spawning season. Experiments were conducted to determine the effects of a variety of dinoflagellate species on the feeding, growth and survival of first-feeding larval anchovy, Engraulis mordax. The dinoflagellate species tested were Gyrodinium dorsum, G. resplendens, Gonyaulax grindleyi, G. polyedra, Protogonyaulax catenella and Gymnodinium splendens. All species occur in southern Califomia waters. Growth experiments were conducted at 16-17°C using dinoflagellate concentrations > 1,000 µg C liter-1. Larvae were reared for a period of 9 days. Highest growth rates were obtained on Gymnodinium splendens. Lowest growth rates and survival- no different than on filtered seawater -were obtained on Gonyaulax grindleyi. Survival ranged from almost 90% on Gymnodinium splendens to < 10% on Gonyaulax polyedra and G. grindleyi. Feeding experiments yielded results which are consistent with results of the growth experiments. Fully half the species we investigated appear to have deleterious effects on feeding, growth and survival of larval anchovy. It is concluded that, in years when anchovy are spawned during blooms of Gonyaulax polyedra or Protogonyaulax catenella, poor year-classes may result. |
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