Witthames et al. : Advances in methods for determining fecundity in marine fishes 
159 
40 
30 
20 
European hake: 
Spawning 
Atlantic cod: 
Spawning 
1 
Atlantic mackerel: 
Late maturation 
European plaice: 
Spawning 
lunnq 
400 800 1200 1600 2000 
400 800 1200 1600 2000 400 800 1200 1600 2000 
Follicle diameter (pm) 
400 800 1200 1600 2000 
Figure 7 
Follicle number per g of ovary (percentage of total count) per 25-pm class interval follicle diameter found in Atlantic 
cod ( Gadus morhua), European hake ( Merluccius merluccius ), Atlantic herring ( Clupea harengus), Atlantic mackerel 
( Scomber scombrus), European plaice (Pleuronectes platessa), redfish (deep water redfish [ Sebastes mentella ] or golden 
redfish [Sebastes marinus]) used to produce the autodiametric calibrations (Table 5) by Institutes AZTI (A, stained rose 
bengal), Cefas (B, stained with periodic acid Schiff’s, except European plaice with eosin), CSIC (C, hake rose bengal, 
redfish unstained), and IMR (D, unstained). 
Table 4 
Regression coefficients used to fit relative potential fecundity (F bw ) with mean follicle diameter (Dp pm) in the following equation 
F bw = a xLn (Dp) + b using data collected from Atlantic cod (Gadus morhua), European plaice (Pleuronectes platessa), and common 
sole (Solea solea) caught in the Irish Sea during 1995. 
Species 
Coefficient 
SE 
t 
P 
Atlantic cod, n = 54 
b 
4356 
2039 
4.6 
<0.0001 
a 
-521 
317 
-1.6 
0.1068 
European plaice, n=220 
b 
1578 
318 
55.0 
<0.0001 
a 
-190 
46 
-4.1 
<0.0001 
Common sole, n=129 
b 
3257 
929 
6.8 
<0.0001 
a 
-406 
143 
-2.8 
0.0055 
