Reproduction and Early Life History of the Redfin Pickerel, (Esox americanus americanus).
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
Pagination or Media Count:
The reproductive strategy of the redfin pickerel Esox americanus americanus in a blackwater system in Sumpter County, South Carolina was studied using daily aging techniques derived from otolith analysis. The presence of biannual spawning, a significantly different strategy from that found in the rest of the genus, was expected. One hundred thirty-seven fish were sampled from 15 March to 27 May, 1994 using a backpack electroshocker. Once the presence of daily increments in the sagittal otoliths was confirmed p-value 0.0001, daily ages were assigned to each fish based upon the sectioned sagitta. Ages were subtracted from capture dated for each fish to yield a distribution of hatching. This distribution was unimodal, but protracted from 21 December to 7 March. Fish were divided into two groups based upon batch date, with the date of the lowest temperature of the season used to divide them. Average growth rates of these two groups, as measured by the width of otolith increments, were different p-value 0.05. Finally, daily mean temperature and daily rainfall were used to predict spawning activity through analysis of variance. Temperature and cumulative rainfall for 8 - 14 days prior to spawning were significantly correlated with spawning p-values 0.0001 and 0.0087, respectively