Age and growth of the Japanese silver-biddy, Gerres equulus, in western Kyushu, Japan

Reproductive biology of the Japanese silver-biddy, Gerres equulus, in western Kyushu, Japan

“…The mean calculated total length of G. oyena was 133.3 mm at 1 year of age for both sexes combined in the Arabian Gulf waters (El-Agamy, 1988). But a previous study on the age and growth of G. equulus in western Kyushu, Japan (Iqbal et al, 2006), found that the mean standard length of the female G. equulus was 133.1 mm at 2 years and 159.4 mm at 3 years old. According to that study, the size at 141 mm SL of a sexually mature female G. equulus, may correspond to a 2-year-old fish.…”

“…According to that study, the size at 141 mm SL of a sexually mature female G. equulus, may correspond to a 2-year-old fish. The estimated size and age at sexual maturity of a female G. equulus was relatively larger and older when compared to other species of the same genus, such as G. rappi, G. acinaces, G. filamentosus and G. oyena (Cyrus and Blaber, 1984;El-Agamy, 1988;Iqbal et al, 2006). This difference in size at sexual maturity for the female G. equulus as compared with the above mentioned species may result from differences in growth characteristics and population density (Avsar, 2001;Shimose and Tachihara, 2005).…”

“…The Japanese silver-biddy Gerres equulus (Temminck and Schlegel) is distributed from southern Korea and southern Japan, except in the Ryukyu Islands, to just north of Sado Island, Niigata, Sea of Japan, and Boso Peninsula, Chiba and the Pacific Coast of Honshu Island (Iwatsuki et al, 1999;Nakabo, 2000). This fish is one of the most common shore fish in the costal waters of southern Japan, where it supports a commercially important local fishery and is fished mainly by set gill net (Usuki, 1976;Iqbal et al, 2006). Some biological studies have been conducted on G. equulus for developing effective management measures due to its importance in the fishery.…”

“…Some biological studies have been conducted on G. equulus for developing effective management measures due to its importance in the fishery. Usuki (1976) studied its territorial behaviour, Kinoshita (1984) reported its early life history, Horinouchi and Sano (2000) examined its feeding habits, and Iqbal et al (2006) observed its age and growth using otoliths. However, until now there has been no study of the reproductive biology of this species.…”

Age and growth of Gerres oyena (Forsskal, 1775) on Okinawa Island, Japan

“…Other maximum ages for gerreids are: Parequula melbournensis , 4 years (Sarre et al., 1997) from the inner continental shelf and lower coast of Australia; and G. setifer , 3 years reported from Mangalore, India (Anantha and Joseph, 1995). Five, 3 + and 2 years for Diapterus rhombeus , from eastern Venezuela (Etchevers, 1978), Mexico (Ayala‐Perez et al., 2001) and Puerto Rican waters (Austin, 1971), respectively; recently Iqbal et al. (2006) reported 10 years for both sexes for G. equulus from western Kyushu, Japan.…”