Baseline diversity and host relationships of symbiotic caridean shrimps on the coast of northern Taiwan, southern East China Sea, prior to the establishment of a conservation area

Symbiotic caridean shrimps were collected from diverse host invertebrates in a coral reef habitat of the southern East China Sea during the summer from April to August in 2014. Regular weekly sampling was conducted by scuba diving in the zone above 25 m depth at the Wang-Hai-Xiang Bay (also called as Fan-Zai-Aou Bay) in northeastern Taiwan. This region is influenced by the China Coast Current and the Kuroshio Current. In total, 27 species of shrimp in 20 genera and 3 families were identified, being taxonomically dominated by Palaemonidae (70.4% of species) and followed by Alpheidae (22.2%) and Hippolytidae (7.4%). The shrimp species were apportioned among hosts of various groups, as follows: scleractinians (45.2%), gorgonians (16.1%), echinoids (12.9%), crinoids (9.7%), actiniarians (6.5%), alcyonarians (3.2%), hydroids (3.2%), and sponges (3.2%). Six species are reported for the first time from the waters of Taiwan: Synalpheus neomeris (de Man, 1897); Cristimenes zanzibaricus (Bruce, 1967); Manipontonia paeneglabra Bruce, 2012; Miopontonia yongei Bruce, 1985; Palaemonella spinulata Yokoya, 1936; and Thaumastocaris streptopus Kemp, 1922. Of these, C. zanzibaricus also represents a northern range extension for the species. Five species, Arete indicus Coutière, 1903; Cuapetes amymone (de Man, 1902); Jocaste lucina (Nobili, 1901); Palaemonella pottsi (Borradaile, 1915); and Pontoniopsis comanthi Borradaile, 1915, showed higher than 60% prevalence on their hosts. These results provide useful baseline information on symbiotic shrimps prior to the establishment of a conservation area at this site in 2016, and also fill in faunal distribution gaps in the coral reef region between the southern Ryukyu arc and the Coral Triangle.