• Animal cells and systems
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• v.16 no.3
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• pp.245-253
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• 2012

A genuine interstitial cyclopoid species belonging to the genus Psammophilocyclops Fryer, 1956 is recorded from the filtration basin of a water treatment plant, South Korea. The genus Psammophilocyclops is very rarely found, and only three species have been recognized as yet: P. boccaroi Fryer, 1956 from Africa, P. trispinosus Shen et Tai, 1964 and P. bispinosus Shen et Tai, 1964 from China. The present new species differs from the congeneric species by the character combination of 11-segmented antennule in female, four-segmented maxilliped with 2,1,1,2 setation, the spine formula of 3,3,3,3, and setal arrangement of 3,3,5,3 on the distal endopodal segments of legs 1-4. Descriptio and taxonomic accounts of the new species are presented with a revised generic diagnosis and a key to the species hitherto known in the genus.

• Animal Systematics, Evolution and Diversity
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• v.40 no.1
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• pp.21-34
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• 2024

Two arenicolus halacarid species, Actacarus ornatus n. sp. and A. pacificus Bartsch, 1979, are recorded from sandy intertidal sediment along the coast of South Korea. Actacarus ornatus n. sp. closely resembles A. karoensis Abé, 1990, recorded from Japan, in having chaetotaxy of the idiosoma, legs, palps of gnathosoma, and perigenital setae in both males and females. However, it differs from A. karoensis by a slightly convex tectum, the presence of a row of foveae on the mid-ventral surfaces of the anterior epimeral plate and genitoanal plate, and the absence of areolae on both the anterior and posterior dorsal plates as well as microplatelets on the membranous cuticle alongside the anterior and posterior dorsal plates. Actacarus pacificus Bartsch, 1979, which is widely distributed in the Indo-Pacific region, is characterized by separated plates, a truncated tectum, the anterior epimeral plate with four pairs of setae, the posterior epimeral plate with one dorsal and two ventral setae, and three pairs of subgenital setae in males. A comparative analysis of the morphological characteristics of A. pacificus was conducted within regional populations, including the Korean population. Moreover, a key to Actacarus species from the northwestern Pacific, including a new species, is provided. The genus Actacarus is reported for the first time from Korea.