The ecology of the American eel, Anguilla rostrata (Lesueur), in the Hudson River
American eels, Anguilla rostrata, were collected from the Hudson River between river mile 12, at the George Washington Bridge, and river mile 151 at Troy, New York. Trawling was performed at night between June 15 and August 13, 1987 and resulted in the capture of 468 eels. This sample was examined in totality and separated into brackish (260) and freshwater (208) groups. Length of specimens ranged from 68 to 660 mm with a mean of 282.8 mm. Weight ranged from 0.2 to 698.1 g with a mean of 55.7 g. The mean age determined by otolith analysis was 6.5 years. Problems associated with otolith interpretation are discussed in detail. Annual growth averaged 19.1% or 38.9 mm. Empty stomachs were found in 21.8% of specimens. Stomach contents analysis of the remaining 366 eels revealed a generalized feeding pattern with 48 different prey species. Arthropods were the major food group. They occurred in 85.3% of stomachs and constituted 48.6% of total food weight. Fishes composed 33.9% of stomach contents by weight but occurred in only 10.1% of stomachs. The isopod Cyathura polita was the single most important prey species. It was found in 44.3% of stomachs and formed 14.7% of total food weight. Gammarus was the most important genus of prey with several species occurring across the range of the study area. Observation of eels in laboratory tanks showed a number of behavioral patterns that increase feeding plasticity and reduce mortality due to predation. Behavioral observations and examination of preserved samples revealed many factors that may contribute to the eel's success.
Mattes, Kenneth Christopher, "The ecology of the American eel, Anguilla rostrata (Lesueur), in the Hudson River" (1989). ETD Collection for Fordham University. AAI9020017.