Fróðskaparrit - 01.01.2002, Síða 117

MYXIDWM GADI (GEORGEVITCH, 1916) og MYXIDIUM OVIFORME (PARISI, 1912)
í GALLBLØÐRUNl Á TOSKl (GADUS MORHUA L.)
115
the Faroese Museum of Natural History,
Tórshavn. The procedure for the species
identification is according to Lom and
Dýkova (1992), and the size measurements
are compared to MacKenzie and Kalavati
(1995).
Calculations
Defmition of prevalence of infection in this
study is defined by Margolis etal. (1982) as
fish examined devided by fish sampled.
The condition factor is calculated as
Weight (g) X 100 / length (cm). The condi-
tion factor is a measure of the state the fish
is in. In Højgaard (1998), the condition fac-
tor is significantly higher in fish infected
with Lemaeocera branchialis than in unin-
fected fish. If a fish is negatively affected
by an infection, the infecting parasite loos-
es value as a biological indicator.
The average measures of the polar cap-
sules and the spores are given with Stan-
dard errors at 68% confidence limits.
Fig. 1. Map ofthe Faroe Islands with 200 and 500 m
depth curves, showing the geographical position of the
stations.
Results
Condition factor
Since a pathogenic parasite would be un-
suited as a biological indicator I decided to
test pathogenity indirectly by comparing
the condition factor of uninfected fish with
the condition factor of the infected físh. It is
clear from Table 5 that the parasites have no
Table 4. Size measures ofthe spores and the polar capsules in pm .
Myxidium oviforme Myxidium gadi
The spore Polar capsule The spore Polar capsulc
My own Length Width Length Width Lcngth width Length width
12.75 8.40 3.85 3.35 13.05 5.90 3.45 2.50
S. E. +/- 0.977 +/- 0.68 +/- 0.67 +/- 0.67 +/- 0.94 +/- 0.72 +/- 0.60 +/- 0.69
MacKenzie and
Kalavati (1995) 14.86 8.93 4.85 14.00 6.35 3.90 3.23
S. E. +/-1.45 +/- 0.38 +/- 0.72 +/- 0.95 +/- 0.73 +/- 0.42 +/- 0.54