Xarifiid copepods (Copepoda: Cyclopoidea: Xarifiidae) parasitic in the coral Psammocora digitata Milne Edwards & Haime 1851 from Taiwan

Abstract

Four species of xarifiid copepods, including three new species and one new distribution and host record, are discussed based on specimens obtained from a widely distributed scleractinian coral, Psammocora digitata Milne Edwards & Haime, 1851, collected from Taiwan: Xarifia conreptasp. nov., X. gracilissp. nov., X. lata sp. nov., and X. diminutaHumes & Ho, 1967. Xarifia conreptasp. nov. is distinguished from its congeners by the morphology of the endopods and exopods of legs, the genital segment, maxilliped, and maxillule; X. gracilissp. nov. is diagnosed by the morphology of the leg endopods and the region dorsal to the fifth legs; and X. latasp. nov. by its shorter body length, the terminal armature of endopods and exopods, and the morphology of the maxilliped. The specimens of X. diminuta are similar to those in the original description, except for the undeveloped endopods of legs 3 and 4. Including the three new species, five species of xarifiids are now known to use P. digitata as host, raising to 18 the number of species symbiotic copepod recorded from Psammocora.

Xarifiid Copepods (Copepoda: Cyclopoida: Xarifiidae) Parasitic in the Coral Psammocora columna Dana, 1846 from Taiwan

“…We selected certain external features of Xarifia that are useful for the determination of species. Eleven features are shown in Table 2 and a useful key is provided as follows: Key to females of eight species of Xarifia parasitic in Psammocora corals (modified from [12]).…”

“…Coral fragments were placed in plastic bags underwater and transported to the laboratory. We adopted the standard methods from previous studies to collect copepod specimens [4,6,12]. Briefly, coral samples in sea water were placed in a 500 mL beaker and enough 95% ethyl alcohol was added to make an approximately 5% solution, which was left to sit for at least 4-6 h. Then, coral fragments were removed and the liquid with any sediment was poured through a fine net (approximately 100 µm mesh size).…”

“…According to the previous studies carried out from 1967 to 2010 [4,[6][7][8][9][10], 15 species of parasitic copepods have been discovered from a widely distributed scleractinian genus, Psammocora Dana, 1846 [11] throughout the Indo-West Pacific, including three highly modified cyclopoids: Xarifia diminuta Humes and Ho, 1967 [6], Xarifia formosa Humes, 1985 [4], Xarifia imitans Humes, 1985 [4]. Recently, Cheng and Lin reported three new species of Xarifia, Xarifia conrepta Cheng and Lin 2021 [12], Xarifia gracilis Cheng and Lin 2021 [12], and Xarifia lata Cheng and Lin 2021 [12], parasitic in Psammocora digitata Milne Edwards and Haime 1851 [13] from Taiwan. Thus, among 92 Xarifia species recorded up to date, six of them have been discovered in Psammocora corals.…”