48
J .S. Christiansen et al.
::c lOB
•
D
...
D
•
r.. 10 7
!9
q,o
~ OJ D •
Q. 10 6
II
l")
0
0
8
rlfl.i\ 0
5 10 5
~
B"cP •
....
f:
= 10 4
Q.
....
J.:
= 10 3
0
';
•
I: 10 2
•
I 0 Pelagic I
r.. q,o
• Demersal
....
~
10 '
~
0
500
1000
1500
2000
Body length (mm)
Fig. 4. Scatter plots showing maternal outputs and body lengths of pelagic and demersal
spawning fish species (boreal and polar combined). Note the logarithmic scale for maternal
output
However, when the maternal output between modes of oviposition, i.e.
pelagic vs demersal spawners, is compared (Fig. 4), pelagic spawners have
a significantly higher maternal output than substrate spawning species (p <
0.001, t-test), albeit only fish smaller than about 300 mm in body length
contribute to this difference (for fish larger than 300 mm in body lengthp =
0.897).
Table 2. Analysis of variance for the effects of body length and zoogeography (boreal or
polar) on reproductive parameters. F-values and significance levels (P) are given. ns = not
significant
Reproductive
Body length
BoreallPolar
parameters
F
p
F
P
Pelagic spawners
Egg diameter
14.75
0.0006
60.48
0.0001
Fecundity
17.44
0.0003
35.51
0.0001
Maternal output
61.93
0.0001
0.05
ns
Demersal spawners
Egg diameter
16.09
0.0002
0.11
ns
Fecundity
46.46
0.0001
2.75
ns
Maternal output
91.96
0.0001
l.ll
ns