366 
Fishery Bulletin 99(2) 
Month 
Figure 8 
Monthly changes in the mean gonadosomatie index (GSI) and hepatosomatic index 
(HSI) for mature male (n=306) and female (n= 67 ) Lophius litulon in the East China 
and Yellow seas. Only specimens larger than the size at 50% sexual maturity for 
males (L 50 =362 mm) and females (L so =567 mm ) were used in our study. Vertical 
lines indicate standard error. 
Discussion 
The testicular structure of L. litulon is similar to that 
of other teleosts with unrestricted spermatogonial (Grier 
et al., 1980; Grier, 1981) or lobular type testes (Billard 
et ah, 1982; Billard, 1986). Although the process of sper- 
matogenesis conformed to that of other teleosts, it was not 
completed within the germinal cysts. Rather, spermatids 
were released into the lumina of the seminiferous t ubules 
and did not differentiate synchronously. This form of sper- 
matogenesis first described in Lepadogaster lepadogaster 
(Mattei and Mattei, 1978), and later termed “semi-cystic” 
type (Mattei et ah, 1993), has subsequently been reported 
in Neoceratiidae ( Jespersen, 1984), blennioid fishes (Lahn- 
steiner and Patzner, 1990), Ophidion sp. (Mattei et ah, 
1993), Opistognathus whitehurstii (Manni and Rasotto, 
1997), and L. setigerus (Yoneda et ah, 1998c). 
The ovarian structure of L. litulon is similar to that 
reported in other Lophiiformes such as L. piscatorius 
(Afonso-Dias and Hislop, 1996), Antennarius scaber, His- 
trio histrio, and Ogcocephalus vespertilio (Rasquin, 1958), 
L. americanus (Armstrong et ah, 1992), and L. setigerus 
(Yoneda et ah, 1998a). Most female Lophiiformes are 
thought to spawn gelatinous egg masses, within which in- 
dividual eggs float in separate chambers (Rasquin, 1958; 
Armstrong et ah, 1992; Afonso-Dias and Hislop, 1996; 
Yoneda et ah, 1998a, 1998c). In L. litulon, as in other lophii- 
form fishes (Rasquin, 1958; Armstrong et ah, 1992; Yone- 
da et ah, 1998a, 1998c), gelatinous material was secreted 
from the epithelium of both the ovigerous lamellae and 
the ovarian wall. Rasquin (1958) compared the structure 
of the ovary of H. histrio with that of the released egg 
mass and concluded that the shape of the egg mass was a 
replica of the internal surface of the ovary. This is expected 
to be the case in other fishes of the family Lophiiformes. 
Each stalk-like ovigerous lamella is thought to serve as 
a “mold,” forming a separate chamber within the gelati- 
nous egg mass. The arrangement of oocytes, with the most 
advanced oocytes at the margins of the ovigerous lamel- 
lae, may facilitate the release of mature oocytes into each 
chamber. 
Our examination of the gonadal condition of both sexes 
indicates that L. litulon spawns during the period from 
February through May. Most females with late-develop- 
ing, mature, or spawning ovaries are found in March and 
April. This finding agrees with previous reports. The peak 
of the spawning season of L. litulon occurred between Feb- 
ruary and March in inshore waters off Kyushu Island (Mi- 
to, 1963) and in March and April in the East China and 
Yellow seas (Yamada, 1986). In Sendai Bay, off the north- 
east coast of Honshu Island, Japan, the spawning season 
of L. litulon occurs between May and July (Kosaka, 1966). 
