Checklist of Reef Fishes from Taiping Island (Itu Aba Island), Spratly Islands, South China Sea

A total of 49 families and 399 species of fishes was recorded from the reef area around Taiping Island (Itu Aba Island) in the Spratlys (Nansha Islands), located at 114°21'-114°23' E, 10°22'-10°23' N. Data were collected by underwater observation, specimen identification, and photography during our survey of 19-23 April 1994. A checklist, including previous records, of 50 families and 421 species was compiled. If all midwater pelagic species are taken into account, the number of fish species occurring at Taiping Island is well over 450, a figure below that anticipated for a reef island located close to the equator and Indo-Australian diversity center. Limited reef area and recent reef degradation may be the principal causes of the disparity. Czekanowski similarities for eight regions around Taiwan and in the South China Sea show that the reef fish fauna of Taiping Island most closely resembles that of Green Island, then Orchid Island, Tungsha (Pratas Island), Hsiaoliu- chiu, southern Taiwan, Penghu, and northern Taiwan in that order. The fish fauna of the western coast of Taiwan, which has a predominantly sandy environment, is most different from that of Taiping. The results suggest that the fish fauna of Taiping Island originated by larval dispersal from the Kuroshio Current as is probably the case for southern Taiwan and its adjacent islets. However, 42 species found in this survey, of which 11 are probably undescribed, are not known from the waters around Taiwan. Most of the fish species (95.7%) at Taiping Island are widely distributed, particularly in the Indo-Pacific Region. Fewer than 20 species are restricted in their distribution

Longitudinal variation in food sources and their use by aquatic fauna along a subtropical river in Taiwan

1. River food webs rely on two major food sources: autochthonous primary production within the river and allochthonous organic matter transferred to the river. We characterised the consumer communities and assessed the food sources of dominant consumers along a subtropical mountainous river (the Lanyang River of north-eastern Taiwan) at the catchment scale from the headwater to the estuary using natural abundances of stable carbon and nitrogen isotopes. 2. The downstream transport of fine particulate organic matter (FPOM) was two orders of magnitude greater than that of coarse particulate organic matter (CPOM). Transport of both materials increased from the headwater and reached a maximum in the midstream reach. CPOM composition exhibited a gradual shift from leaves and branches in the headwater, an area characterised by high canopy cover, to algae in the midstream reaches and marsh plants in the downstream reaches. 3. Consumer communities can be classified into two regional categories: the upland category in the headwater and upstream and midstream reaches and the lowland category comprised of samples from the downstream reach and estuary. The upland category revealed a clear and gradual seasonal shift in community composition, but a seasonal shift was not apparent for the lowland category. Nutrient concentrations and water temperature were the main factors explaining longitudinal and seasonal variations. 4. The use of sources of organic matter by dominant consumers along the Lanyang River was primarily determined by their availability. Riparian C3 plants were the major food sources in the headwater, upstream reach and estuary, but the contribution of periphyton increased in the upper midstream reach where the river flows through an agricultural area. In the lower midstream and downstream reaches, the contribution of riparian C4 plants became dominant. 5. The trophic transfer of organic materials in the Lanyang River may be influenced by the fast current velocity and by sewage nutrient loading in the river, both of which have important implications for predicting how the functioning of subtropical river food webs will respond to human-related changes in land use