• Animal Systematics, Evolution and Diversity
• /
• v.37 no.3
• /
• pp.242-248
• /
• 2021

Lobohalacarus weberi (Romijn and Viets, 1924) is added to the halacarid fauna of Korea as the third member of freshwater halacarid species. Both the genus and species are newly recorded from Korea. Halacarid mites were collected from two hillside wells and a streamside hyporheic zone in the southeastern region of South Korea. Lobohalacarus weberi is characterized by a well-developed frontal spine-like process, seven dorsal setae, the fourth segment of palp with a short distal and three long proximal setae, and tibiae of legs II to IV with two, one, two pectinate setae, respectively. A few minor individual variabilities were observed in the number of perigenital seta and genital acetabula, the setal armature on genua of legs, and the shape of spinule row on lateral claws.

• Animal Systematics, Evolution and Diversity
• /
• v.33 no.1
• /
• pp.45-50
• /
• 2017

A halacarid species of Scaptognathus teuriensis $Ab{\acute{e}}$ is recorded from Korea on the basis of the specimens collected from littoral sandy sediments at Dokdo Island, the easternmost island off Uleung Island of South Korea. Korean specimens coincide well with the key characters in the original description for types from Hokkaido, Japan, such as male genitoanal plate comprising only pars sclerosum, bipartite female genitoanal plate with six perigenital setae, rounded posterior margin of anterior dorsal plate, second and fifth dorsal setae both positioned at membranous cuticle, leg chaetotaxy of bipectinate setae on tibiae I-IV of 4-2-2-2, and tarsi of all legs armed with paired large lateral claws with accessary teeth and small median claw. Redescription based on Korean specimens and scanning electron microscope photomicrographs are provided herein. This is the first record of the genus from Korea.

• Animal Systematics, Evolution and Diversity
• /
• v.37 no.1
• /
• pp.19-25
• /
• 2021

Soldanellonyx monardi Walter, 1919, a halacarid species is newly recorded from South Korea, as the second member for the freshwater halacarid mites in Korea after S. chappuisi Walter, 1917 reported from Gossi-gul Cave, a limestone cave at Yeongwol in 1968. It was collected from three wells in the southeastern part of Korean peninsula this year. Korean specimens are well accorded with S. monardi s. str. in having telofemur I less than 1.5 times longer than wide, two spiniform setae on the ventral side of tibia I, relatively longer anterior dorsal plate (slightly longer than its width and about half the length of posterior dorsal plate), and the posterior epimeral plates lacking a dorsal seta. Based on the Korean specimens, a brief table for the morphological differences between adult females and deutonymphs are provided, which shows a tendency of rather consistent increment according to growth in the number of spiniform dorsal setae on telofemora and genua of legs I and II, the number of perigenital setae, and the number of genital acetabula. In this paper, detailed redescription and a brief table for the morphological differences between adult females and deutonymphs of S. monardi are provided.

• Animal Systematics, Evolution and Diversity
• /
• v.35 no.2
• /
• pp.49-56
• /
• 2019

A new marine halacarid species of the genus Agauopsis Viets, 1927 (Acari: Halacaridae) is recorded from Jeju Island, Korea. Agauopsis tetrasetosa n. sp. belongs to the microrhyncha group in sharing one ventral and three ventromedial spines on tibia of leg I, of which two ventromedial ones are adjacent to each other, with its 20 congeneric members. Agauopsis tetrasetosa n. sp. is most similar to A. miliaris Bartsch, 2005 and A. similis Bartsch, 1979 in sharing the similar chaetotaxy of legs I-IV, positions of the second and fourth dorsal setae, and non 'H'- or 'M'-shaped costae on anterior dorsal plate. However, the new species is distinguished from them by four pairs of perigenital setae in female, the relatively anterior location of gland pores on posterior dorsal plate, and three ventral spines on the tibia of leg II. We describe the new species herein, with detailed illustrations under a differential interference contrast microscope. We also make some brief comments on the affinities between the congeneric species of the microrhyncha group and the new species, based on a tabular key to species of the group.

• Animal Systematics, Evolution and Diversity
• /
• v.39 no.4
• /
• pp.289-294
• /
• 2023

We discovered a halacarid mite species, Isobactrus tuberculatus Abé, 1996, inhabiting marine plastic debris on the coast of Jeju Island, Korea. The key characteristics of these Korean specimens were consistent with those in the original description of specimens from Hokkaido, Japan, including the presence of tuberculate membranous cuticles between the anterior and posterior dorsal plates, fusion of the posterior epimeral plates I and II, tibia II with a bipectinate seta, tibiae III and IV each with five setae, and a pair of subgenital setae in females. However, two small morphological differences were noted: the distance between the anterior and posterior dorsal plates was shorter than that in Japanese specimens, and the location of dorsal seta-2 was closer to the anterior dorsal plate in Korean specimens. We herein provide detailed illustrations of I. tuberculatus, based on the Korean specimens, with a brief taxonomic comment on the similarities among allied congeneric species. The genus Isobactrus is first reported in Korea.

• Animal Systematics, Evolution and Diversity
• /
• v.36 no.2
• /
• pp.167-174
• /
• 2020

A halacarid species of the genus Copidognathus is newly reported from Korea: C. daguilarensis Bartsch, 1997, which was described from Hong Kong. It is redescribed herein with detailed illustrations. Korean specimens coincide well with the original description, however, they showed two minor morphological discrepancies from it: quite shorter second palpal segment than the fourth and a modified dorsal seta on the second palpal segment. Korean specimens were rather smaller than the type specimens from Hong Kong, however, they did not show significant differences in the length to width ratios of important body parts. The number of perigenital setae was more variable in the Korean males, ranged 24-29 setae, versus 25-26 in Hong Kong's. Copidognathus daguilarensis is reported for the first time outside the type locality, and joins as the second member of the gibbus group in the northwest Pacific.

• Animal Systematics, Evolution and Diversity
• /
• v.36 no.2
• /
• pp.175-181
• /
• 2020

An arenicolous halacarid, Scaptognathus magnus Abé is first recorded from Korea, which was collected from littoral coarse sandy bottom around Simnibawi Rock off Gangreung in the east coast of South Korea. The remarkable characteristics of this species are large body with idiosoma more than 470 ㎛ long, nearly trapezoidal anterior dorsal plate, and a unique chaetotaxy of bipectinate setae 5-3-3-3 on tibiae I-IV. The characteristics of Korean specimens coincide well with the original description from Hokkaido, Japan, except for the number of parambulacral setae on tarsus III and the weak median claws. Detailed illustrations and scanning electron microscope photographs based on Korean specimens are provided.

• Animal Systematics, Evolution and Diversity
• /
• v.19 no.1
• /
• pp.95-102
• /
• 2003

A new species of Halacaridae, Copidognathus koreanus is recorded from the Korean coast mostly among intertidal coralline algae. The present new species comes close with C.auroroe Newell, C.curtus (Hall), C.richardi (Trouessart) and C.unolaskensis Newell. Morphological similarities and dissimilarities among them are discussed. This is the first report on the marine halacarid mite from Korea.