7143

• UCREFRP Catalog Number: 7143
• Author: Inskip, P. D.
• Title: Habitat Suitability Index Models
• USFW Year: 1982.
• USFW - Doc Type: Northern Pike.
• Copyright Material: NO

' Growth and survival rates of northern pike fry depend on temperature.
Survival is poor at temperatures less than 5.8° C (Lillelund 1966). Growth
rate is positively related to temperature for pike fry held at constant tem-
peratures between 7.5° C and 25.6° C, but mortality of 1-day old yolk sac fry
increases significantly at temperatures greater than 20.8° C; thus, the rate
of net biomass gain is highest at 20.8° C (Hokanson et al. 1973). The rate is
high for temperatures from 18.0 to 25.6° C.
Northern pike are spring spawners, and early
ence a progressively warmer average temperature.
tures increases within the embryo and fry stages
al. 1973). The optimal temperature for growth a
from about 21° C shortly after hatching to 26° C
et al. 1973).
developmental stages experi-
Tolerance of high tempera-
(Lillelund 1966; Hokanson et
nd survival of fry increases
after 1 or 2 weeks (Hokanson
Juvenile. Young of the year and yearling northern pike fed ad libitum
grew in weight most rapidly at 19° C; maximum growth in length occurred at
21° C (Casselman 1978). Growth rate increased sharply at temperatures greater
than 10° C but was positive (about 4°0 of the maximum) even at 3 to 4° C. No
growth occurred above 28° C. The growth rate- of yearling northern pike held
in small Missouri ponds (average depth = 1.0 m) approached zero during a 3 to
5 week period in midsummer when water temperatures exceeded 27° C (Weithman
and Anderson 1977).
Dissolved oxygen concentrations below 7 ppm (77% saturation) resulted in
reduced growth rates of juvenile northern pike at a temperature of 18.6° C and
a flow rate of 0.24 ml/sec (Adelman and Smith 1970b). The decline in growth
rate was gradual down to concentrations of 3 to 4 ppm (33 to 44% saturation)
and sharp at levels below 3 ppm.
Young of the year northern pike (12 to 38 g) showed signs of stress when
held for 20 to 24 hours at dissolved oxygen concentrations less than 6 ppm
(temperature 21 to 22° C) (Petit 1973). Feeding ceased at concentrations of
2 ppm, and none of the test fish survived more than 20 hours at 1 ppm._ Test
fish held at 1 ppm until they appeared close to death recovered within 24
hours when transferred to water with a dissolved oxygen concentration of
6 ppm.
Adults. Temperature requirements of adult and juvenile northern pike
appear to be similar. Maximum growth in length of age 2 and 3 northern pike
in an Ontario lake occurred at approximately 20° C; fish of similar age reared
in the lab grew best at approximately 21° C (Casselman 1978).
Northern pike in Lake Windermere (England), where water temperatures
rarely exceed 21° C (Macau 1970), grew faster in warm than in cold years
(Frost and Kipling 1967). Surface water temperature, indexed as the cumulative
number of degree-days over 14° C, accounted for 86% of the variation in weight
of 4-year old pike, for 16 year-classes. Comparison of scale patterns for
northern pike from Waskesiu Lake in northern Saskatchewan with those for pike
from several shallow Michigan lakes (Williams 1955) suggests that high summer
temperatures may interrupt the growth of northern pike in more southern
regions.
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