Life history and ecology of the glowbelly Acropoma japonicum in the Uwa Sea, Japan

The life history and ecology of the glowbelly Acropoma japonicum a commercially important fishery resource, were investigated in the Uwa Sea, Japan. Newly settled juveniles (0*) appeared at the end of the breeding season and reached maturity in the next season, i.e. when they became yearlings (1*). The yearlings made a gametic effort comparable to that of older fish. During the breeding season, the somatic conditions were more deteriorated for males than for females. That the deterioration of male somatic conditions was not attributable to a sexual difference in energy gain from feeding suggests that the males incurred higher energetic costs of reproduction despite their relatively low gonadosomatic indices. Such an energy depletion may increase the mortality risk, resulting in female-biased sex ratios in the older age classes. Most of the 1+ fish disappeared in winter following their first breeding. For A. japonicum, the observed precocity and short life span is notable because it is a higher consumer that is generally expected to show later maturation and longer life. As likely. While fishing is one of the most influential factors, the possibility of age-specific migration toward deeper waters remains to be examined.

[1]  U. Dieckmann,et al.  Maturation trends indicative of rapid evolution preceded the collapse of northern cod , 2004, Nature.

[2]  Y. Yanagisawa,et al.  Filial cannibalism by mouthbrooding males of the cardinal fish,Apogon doederleini, in relation to their physical condition , 1996, Environmental Biology of Fishes.

[3]  中坊 徹次,et al.  Fishes of Japan : with pictorial keys to the species , 2002 .

[4]  N. Okuda.  The costs of reproduction to males and females of a paternal mouthbrooding cardinalfish Apogon notatus , 2001 .

[5]  Richard Law,et al.  Fishing, selection, and phenotypic evolution , 2000 .

[6]  T. Wada,et al.  Reproductive Relationships of the Pacific Stock of Japanese Anchovy Engraulis japonicus , 2000 .

[7]  H. J.A..  Influence of sex , body size , and reproduction on overwinter lipid depletion in brook trout , 1999 .

[8]  G. Parker,et al.  Sperm Competition in Fishes: The Evolution of Testis Size and Ejaculate Characteristics , 1997, The American Naturalist.

[9]  E. Trippel.  Age at Maturity as a Stress Indicator in Fisheries , 1995 .

[10]  R. Kirkwood,et al.  SEASONAL-VARIATION IN GROWTH, MORTALITY AND FAT STORES OF ROACH AND PERCH IN LOUGH-NEAGH, NORTHERN-IRELAND , 1995 .

[11]  D. Shapiro,et al.  Sperm Economy in a Coral Reef Fish, Thalassoma Bifasciatum , 1994 .

[12]  B. Jonsson,et al.  Energetic cost of spawning in male and female Atlantic salmon (Salmo salar L.) , 1991 .

[13]  F. Huntingford,et al.  Annual variation in energy reserves in male three-spined stickleback, Gasterosteus aculeatm L. (Pisces, Gasterosteidae) , 1989 .

[14]  P. Henderson,et al.  Size-selective overwintering mortality in the sand smelt, Atherina boyeri Risso, and its role in population regulation , 1988 .

[15]  R. Peters.  The Ecological Implications of Body Size , 1983 .

[16]  W. C. Mackay,et al.  Timing and Magnitude of Energy Deposition and Loss in the Body, Liver, and Gonads of Northern Pike (Esox lucius) , 1979 .

[17]  W. C. Mackay,et al.  Protein and Lipid Content of Gonads, Liver, and Muscle of Northern Pike (Esox lucius) in Relation to Gonad Growth , 1978 .

[18]  G. Leduc,et al.  Seasonal Changes of Fat Content in the Yellow Perch (Perca flavescens) of Two Laurentian Lakes , 1975 .

[19]  Y. Haneda.  Luminous Organs of Fish Which Emit Light Indirectly , 1950 .