Embryonic Development and Effect of Water Temperature on Hatching of Lophius Litulon

Most Lophiiformes including Lophius species are considered to spawn egg masses called an “egg veil” or “egg ribbon” composed of numerous mucoid chambers. However, Lophius eggs have been rarely collected in the field and thus little is known about their biological features. Here we examined the embryonic development of Lophius litulon and also the effects of water temperature on the embryonic development of eggs from egg veils collected in the field. Embryonic development was observed from the late cleavage stage to hatching. Low rates of mortality and deformity of embryos and early larvae were observed at 13–21°C. The estimated appropriate water temperature range closely approximated the range of temperatures (12–20°C) at which egg veils of L . litulon have been found in the field. Embryonic development accelerated with increased water temperatures. These results will enable estimation of the origin of and passive movement of egg veils and subsequently larvae and will help to reveal the spatiotemporal distribution of the spawning and nursery grounds of L . litulon .