caa a22 4500 606227008 CHVBK 20210128101156.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s10641-015-0382-8 doi (NATIONALLICENCE)springer-10.1007/s10641-015-0382-8 Reproductive biology and spawning aggregation fishing of the white-streaked grouper, Epinephelus ongus , associated with seasonal and lunar cycles [Elektronische Daten] [Itaru Ohta, Akihiko Ebisawa] The reproductive biology of the white-streaked grouper Epinephelus ongus, which forms spawning aggregations in the Yaeyama Islands, Okinawa, was examined by gonadal histology and oocyte development analysis. Gonadal histology showed that the spawning season was determined from April to July, but there are two spawning periods associated with the specific lunar cycle, during the week after the last quarter moon in two consecutive months. The pattern of oocyte development indicated that individual females spawned more than once, but fecundity may be determinate within a single spawning period. Fecundity was correlated to body size and ranged from several hundred thousand to a million eggs. Detailed catch data analysis showed that the catches during the two spawning months accounted for about 40% of the annual landings and the fluctuation of the catch data corresponded well to some reproductive activities related to spawning aggregation. The two stepwise increases and the peaks of the catches coincided with the occurrence of matured individuals and the onset of spawning at the last quarter moon, respectively. These findings suggest that the spawning of E. ongus was concentrated within a few days just after the last quarter moon and that aggregation fishing was also concentrated in the critical reproductive periods. Springer Science+Business Media Dordrecht, 2015 Reproduction nationallicence Lunar periodicity nationallicence Seasonality nationallicence Oocyte development nationallicence Spawning aggregation nationallicence Aggregation fishing nationallicence Ohta Itaru Okinawa Prefectural Fisheries Research and Extension Center, Kyan 1528, 901-0354, Itoman, Okinawa, Japan aut Ebisawa Akihiko Okinawa Prefectural Fisheries Research and Extension Center, Kyan 1528, 901-0354, Itoman, Okinawa, Japan aut Environmental Biology of Fishes Springer Netherlands 98/6(2015-06-01), 1555-1570 0378-1909 98:6<1555 2015 98 10641 https://doi.org/10.1007/s10641-015-0382-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10641-015-0382-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ohta Itaru Okinawa Prefectural Fisheries Research and Extension Center, Kyan 1528, 901-0354, Itoman, Okinawa, Japan aut NATIONALLICENCE 700 1- Ebisawa Akihiko Okinawa Prefectural Fisheries Research and Extension Center, Kyan 1528, 901-0354, Itoman, Okinawa, Japan aut NATIONALLICENCE 773 0- Environmental Biology of Fishes Springer Netherlands 98/6(2015-06-01), 1555-1570 0378-1909 98:6<1555 2015 98 10641