||The species of genus Lucifer are epiplanktonic shrimps, widely distributed in tropical and subtropical waters; usually form a major component of the planktonic decapods. This is the first extensive survey of Lucifer assemblages in relation to hydrographical factors in the waters surrounding Taiwan. Samples were collected during two seasonal cruises of Fishery Research I in January (winter) and July (summer) of 2005 in the waters around Taiwan, and four seasonal cruises of Ocean Research III from October 2011 to December 2012 in the neritic water off southwestern Taiwan. |
Four species of the genus Lucifer were identified from the study area, which were Lucifer intermedius, L. penicillifer, L. typus, and L. hanseni. In the waters around Taiwan, L. intermedius, L. penicillifer, and L. typus contributed > 99% of the numerical total of Lucifer, with mean abundance of 111 ± 28 ind./100 m3 in winter, and 2769 ± 707 ind./100 m3 in summer. Abundance of Lucifer and hydrographic conditions showed clear seasonal changes. Lucifer abundance was highly correlated with temperature and salinity, implying a closely relation with water masses. In winter, Lucifer was present in the warm area where Kuroshio Current and Kuroshio Branch Current prevailed, while almost none was found in cold and low-salinity China Coastal Current. During summer, peak of Lucifer abundances occurred in Taiwan Strait where was dominated by warm and lower saline South China Sea Surface Current. Lucifer hanseni was relatively scarce during Fishery Research I cruises in the waters around Taiwan, but we discovered L. hanseni was abundant during Ocean Research III cruises in the neritic waters off southwestern Taiwan. L. hanseni abundance showed significantly higher at inshore stations than at offshore stations and was positively correlated with chlorophyll a concentration. Analysis of indicator species showed that L. typus and L. penicillifer could be indicator species of South China Sea Surface Current in summer, and L. typus could be an indicator species of Kuroshio Current in winter.