Effects of Environmental Temperature on the Dynamics of Ichthyophoniasis in Juvenile Pacific Herring (Clupea pallasii)

Table 1

Clupea pallasii. Summary data for 3 Ichthyophonus experiments conducted in this study. Pacific herring in experiments 1 and 2 fasted during challenge, herring in experiment 3 fasted for 56 d prior to challenge and then fed to satiation during challenge.

	Experiment		Herring			Ichthyophonus		Temperature (°C)^a
No.	Disease state	Duration (d)	Age (d)	FL (mm)	Weight (g)	Schizonts^b per inoculation	Dose (schizontsg^−1)^c	Low	Amb	High
(1)	Diseased: 19 d after exposure	80	164	44	1.0	174	174	6.7	9.3	12.3
(2)	Infected: 1 d after exposure	127	241	70	3.6	167	46	5.6	7.9	12.4
(3)	Infected: 1 d after exposure	54	431	92 (100)^d	6.5 (9.2)^d	112	17 (12)^d	9.3	12.0	15.3

aTemperature reported is mean of temperature recordings made every 30 minutes during course of challenge.
bSchizonts are multinucleate spherical bodies from in vitro Ichthyophonus cultures, number reported is mean of three 50 μL samples.
cDose = mean number of schizonts divided by mean weight of fish.
dValues in parentheses are from group of herring that did not go through prechallenge fast in experiment  (3).