364 
Fishery Bulletin 99(2) 
labile 3 
Results of histological examination of stage-4 and stage-5 ovaries of Lophius litulon collected between February and June. Stage-4 
ovaries are defined as those in which more than 50% of the ovigerous lamellae have yolked oocytes in females with secondary yolk 
stage oocytes with no sign of atresia, regardless of the degenerative stage of the postovulatory (POF) follicles. Stage-5 ovaries are 
defined as those in which less than 50% (or none) of the ovigerous lamellae have yolked oocytes with frequent signs of atresia. GSI = 
gonadosomatic index. 
Date 
Total length 
(mm) 
GSI 
Oocyte 
stage 7 
POF 
stage 2 
Ovigerous lamellae 
with yolked 
oocytes (%) 
Atretic 
stage 2 
Ovarian 
stage 
27 Feb 93 
594 
9.14 
sy 
1 
75.0 

4 
20 Mar 95 
634 
7.00 
sy 
1 
89.7 
— 
4 
20 Mar 95 
738 
7.50 
sy 
1 
93.0 
— 
44 
18 Mar 96 
622 
5.31 
py 
e 
30.4 
— 
5 
18 Mar 96 
639 
4.50 
py 
i 
17.6 
e 
5 
18 Mar 96 
711 
6.96 
sy 
l 
97.7 
— 
4 
18 Mar 96 
1013 
6.02 
sy 
i 
92.1 
— 
4 
17 Mar 97 
821 
6.81 
py 
e 
20.6 
— 
5 
17 Mar 97 
853 
5.76 
py 
e 
25.0 
— 
5 
26 Apr 94 
645 
8.30 
py 
i 
20.0 
e 
5 
14 Apr 95 
857 
8.60 
py 
i 
16.4 
e 
5 
23 Apr 96 
702 
6.38 
sy 
e 
92.3 
— 
4 
26 Apr 97 
868 
8.45 
py 
i 
30.8 
e 
5 
5 May 93 
626 
6.48 
sy 
e 
77.6 
— 
4 
28 May 94 
891 
7.70 
py 
i 
18.2 
e 
5 
28 May 94 
981 
9.20 
py 
i 
36.4 
e 
5 
7 May 97 
825 
3.47 
yv 
i 
0 
e, 1 
5 4 
7 Jun 97 
830 
4.20 
yv 
i 
0 
e, 1 
5 
' Most advanced oocytes are py = primary yolk stage; sy = secondary yolk stage; and yv = yolk vesicle stage. 
- Postovulatory follicles are e = early stage; 1 = late stage. 
1 Atretic oocytes are e = early stage; 1 = late stage. 
J Photographs of histological sections of stage-4 and stage-5 ovaries are shown in Figure 6 (D and E). 
Gonadosomatic and hepatosomatic index 
The mean GSI for males increased from September and 
peaked in January after which it declined (Fig. 8A). The 
mean HSI for males was highly variable between Sep- 
tember and December but gradually decreased from Jan- 
uary through July (Fig. 8B). The mean GSI for females 
increased gradually throughout the early part of the year, 
peaking sharply in May, after which it dropped rapidly 
(Fig. 8C). The mean HSI for females started to increase in 
August and peaked in December (Fig. 8D). It remained low 
between March and July. 
With testicular development, the GSI increased and 
reached a maximum when the testes were in stage 4 (Ta- 
ble 6). There were significant differences in the value of 
these indices in the stage-4 testes, compared with those in 
the other three stages (P< 0.05). The mean HSI for males 
peaked in stage- 1 testes, but there were no statistical dif- 
ferences in the value of the median HSI between the four 
stages (ANOVA, P> 0.05). 
In females, the mean GSI gradually increased and 
peaked in stage-3 ovaries (Table 7), but there were no 
statistical differences in the value of the median GSI 
between the early stage-2 and stage-5 ovaries (P>0.05). 
The mean HSI peaked in early stage-2 ovaries and then 
dropped rapidly with ovarian development. The median 
HSI during the early and late stage-2 ovaries was signifi- 
cantly higher than in stage- 1, stage-3, and stage-5 ovaries 
(P<0.05). 
Size-frequency distribution of oocytes 
The size of all the oocytes in a group gradually increased 
in tandem with ovarian development (Fig. 9). When an 
advanced group of the oocytes reached the secondary 
yolk stage, they formed an isolated batch that separated 
almost completely from adjacent groups of smaller oocytes. 
Between the tertiary yolk and mature ovary stages, only 
the oocytes in the advanced batch increased in size, and 
the remainder of the group remained smaller than 550 pm. 
This finding would suggest that L. litulon is a batch 
spawner (a conclusion which has been supported by aquar- 
ium observations — see “Discussion” section). 
Batch fecundity 
The relationship between batch fecundity (BF) and total 
length (TL), based on 15 specimens with secondary yolk 
