356 
Abstract— The reproductive cycle, sex- 
ual maturity, fecundity, and seasonal 
distribution of the anglerfish Lophius 
litulon were studied from a total of 
989 specimens collected in the East 
China and Yellow seas between March 
1991 and July 1997. Males and females 
reached 50% sexual maturity at 362 mm 
TL (age 5.4) and at 567 mm TL (age 6.2), 
respectively. The histology of the gonads 
showing seasonal changes in both the 
gonadosomatic index (GSI) and hepa- 
tosomatic index (HSI) are described. 
Mean GSI of females increases rapidly 
with ovarian development, whereas 
mean HSI decreases from the middle 
of vitellogenesis until the ovaries have 
fully matured. Segregation of oocytes 
by size within the ovary suggests that 
L. litulon spawns in batches, which was 
confirmed by observation of a captive 
specimen. Batch fecundity (BF) in 15 
females with secondary yolk stage ova- 
ries was related to total length (TL, 
mm) by the equation BF = (-1.64 x 10 6 ) 
+ 3688.13 TL (546<TL<846). In Septem- 
ber, most specimens of both sexes were 
collected in the Yellow Sea. Between 
November and January their distribu- 
tion extended from the Yellow Sea into 
the East China Sea. During the spawn- 
ing season (February to May), sexually 
immature individuals were collected 
throughout the East China and Yellow 
seas, whereas sexually mature individ- 
uals were caught only in the East China 
Sea and the coastal waters off Kyushu 
Island, Japan. The spawning grounds 
of L. litulon extend widely from waters 
of the East China Sea to inshore waters 
of Kyushu. 
Manuscript accepted 4 October 2000. 
Fish. Bull. 99:356-370 (2001). 
Reproductive cycle, fecundity, and seasonal 
distribution of the anglerfish Lophius litulon 
in the East China and Yellow seas 
Michio Yoneda 
Laboratory of Marine Biology 
Faculty of Agriculture, Kyushu University 
Hakozaki, Fukuoka 812-8581, Japan 
E-mail address: yoneda_m@agr.kyushu-u.ac ip 
Muneharu Tokimura 
Hitoshi Fujita 
Seikai National Fisheries Research Institute 
Kokubu, Nagasaki 850-0951, Japan 
Naohiko Takeshita 
Koji Takeshita 
Department of Applied Aquabiology 
National Fisheries University 
Nagata-Honmachi, Shimonoseki 759-6533, Japan 
Michiya Matsuyama 
Shuhei Matsuura 
Laboratory of Marine Biology 
Faculty of Agriculture, Kyushu University 
Hakozaki, Fukuoka 812-8581 Japan 
The anglerfish Lophius litulon (Jordan) 
is distributed throughout Japanese 
waters, in the Gulf of Po-Hai and the 
East China and Yellow seas (Caruso, 
1983; Yamada, 1986; Yoneda et ah, 
1997). In Japan, this species and a 
second anglerfish, Lophiomus setigerus 
(Vahl), are consumed as food, and their 
livers are considered a delicacy. Both 
species are caught throughout their 
range by Japanese, Chinese, and Korean 
trawl fisheries, primarily during winter 
months when these fish command a 
high market price. The catch of ang- 
lerfish is very small compared to that 
of other commercially important spe- 
cies in Japan. Anecdotal evidence from 
fishermen suggests that catches have 
declined in recent years, although no 
official landings are reported. The shal- 
low East China and Yellow seas are 
subject to intense fishing pressure and 
large anglerfish, especially L. litulon , 
have become particularly scarce. 
In spite of their commercial impor- 
tance, little biological information is avail- 
able on L. litulon and L. setigerus. Kosaka 
(1966) described age, growth, spawning 
season, and feeding habits of L. litulon 
in Sendai Bay, off the northeast coast of 
Honshu Island, Japan; Yamada ( 1986 ) re- 
ported the spawning season and size at 
maturity for L. litulon and the spawning 
season for L. setigerus in the East China 
and Yellow seas. Recently we reported 
the reproductive biology of L. setigerus 
(Yoneda et ah, 1998a, 1998c) and age and 
growth of L. litulon (Yoneda et al., 1997) 
and L. setigerus (Yoneda et ah, 1998b). 
According to Yamada (1986) and To- 
kimura, 1 the distribution of L. litulon 
1 Tokimura, M. 1992. Distribution of pri- 
mary bottom-fishes in the East China 
and Yellow Seas during the winter of 
1991. Seikai Block Sokouo Chosa Kenkyu 
Kaiho. 3:15-39 [In Japanese.] Seikai Na- 
tional Fisheries Research Institute, Ko- 
kubu, Nagasaki 850-0951, Japan. 
