• Animal Systematics, Evolution and Diversity
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• 제38권4호
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• pp.157-161
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• 2022

Parartotrogus minutus n. sp. is described as a parasite of the brittle star Ophiuroglypha kinbergi (Ljungman) from the intertidal zone on the Yellow Sea coast of Korea. The new species is characterized by a combination of morphological features that the body is small, less than 0.5 mm long, the caudal ramus is 1.73 times longer than wide, leg 3 bears three-segmented rami, and the exopod of leg 5 is armed with two setae. The new species is the third known species in the genus, following P. richardi Scott T. and Scott, A., 1893 known from European waters and P. arcticus Scott T., 1901 known from both North Atlantic and North Pacific.

• Animal Systematics, Evolution and Diversity
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• 제38권4호
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• pp.205-213
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• 2022

A new free-living marine nematode, Chaetonema longicorpus sp. nov., was discovered in a subtidal benthic habitat around the Uljin nuclear power plant in the East Sea. Chaetonema longicorpus sp. nov. differs from other Chaetonema species in its very long body length, relatively long cephalic setae, long and narrow buccal cavity, bottle-shaped amphideal fovea, short spicules, only one pre-cloacal seta instead of a pre-cloacal supplement, and conspicuous ventral swelling at the middle of the tail. Herein, we provide a taxonomic description and illustrations of this new species using differential interference contrast microscopy. Furthermore, an illustrated pictorial key to all valid species, including the new species and comparative tables on the biogeographical and morphological characteristics of the genus Chaetonema, are provided.

• Animal Systematics, Evolution and Diversity
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• 제38권4호
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• pp.274-278
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• 2022

One marine ciliate, Diophrys quadrinucleata Zhang et al., 2020 was newly recorded from South Korea in this study. We provided morphological diagnosis and images of the Korean D. quadrinucleata population. We determined the small subunit ribosomal DNA (SSU rDNA) and cytochrome oxidase subunit I (CO1) sequence data of D. quadrinucleata, and then the sequences were compared with other Diophrys species. Intra-specific variation between the Korean and type (Chinese) populations was identical in the SSU rDNA, while the inter-specific variations between seven Diophrys species were 0.3-3.8% in the SSU rDNA and 12.6-18.2% in the CO1. In this study, we obtained 18S and CO1 data from species with identified morphology. As the importance of securing 18S and CO1 based on morphology increases in current studies, this study will contribute to ciliate studies.

• Animal Systematics, Evolution and Diversity
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• 제38권4호
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• pp.283-286
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• 2022

Bathynellacea is a stygobitic group that is commonly associated with subterranean habitats. Allobathynella Morimoto and Miura, 1957, which is a genus of parabathynellid Bathynellacea, has the widest range of distribution and is rich in species from the Korean peninsula among Korean Bathynellacea genera. The material of Allobathynella yecheonensis Park and Cho, 2016, was found in the type locality of interstitial groundwater in the Nakdonggang River in South Korea. In this study, we determined the sequences of the mitochondrial cytochrome c oxidase subunit 1 (CO1) and nuclear 18S ribosomal DNA of A. yecheonensis and compared them with those of A. hongcheonensis, A. wonjuensis, and A. danyangensis. In addition, we provided photographs of A. yecheonensis and diagnosis including a note on morphological observations.

• Animal Systematics, Evolution and Diversity
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• 제37권3호
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• pp.219-224
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• 2021

A hesionid species, Leocratides kimuraorum Jimi, Tanaka and Kajihara, 2017 is newly reported from the sublittoral zones (100 m depth) of the Korean coasts. This species is characterized by lateral antennae as long as the palps, peristomial membrane without papillose, peristomial dorsolateral tubercles with two round marginal lobes, and pharyngeal with terminal papillae. The intra-specific genetic distance among the cytochrome c oxidase subunit I(COI) sequences of L. kimuraorum specimens from Japan (type locality) and Korea (this study) was in the range of 0.002-0.005. The inter-specific genetic distance between L. kimuraorum and other hesionid species were 0.166-0.307. The present study is the first record of Leocratides species in Korean fauna. This paper also provides a morphological description and photographs of L. kimuraorum, with partial sequences of the mitochondrial COI based on Korean specimens.

• Animal Systematics, Evolution and Diversity
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• 제37권3호
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• pp.225-228
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• 2021

Eleven Gonioctena species have been recorded in the Korean Peninsula. Most species in the genus have very similar coloration and morphology. The male genitalia is generally used as the only reliable diagnostic character differentiating closely related species, but it is still difficult to identify females to species accurately. Here, we determined the COI barcodes of two Gonioctena species described from Korea and give morphological descriptions. The interspecific genetic divergence (Kimura 2-parameter) among the Gonioctena ranged from 0.073 to 0.138 and averaged 0.108. The pairwise genetic distance between the two Korean species(0.102) is similar to the average interspecific divergence. We predict that these analyses will help to resolve taxonomic issues and find cryptic species.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제26권4호
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• pp.333-342
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• 2022

In this paper, we perform a direct comparison study of real experimental data for domain rearrangement and the Cahn-Hilliard (CH) equation on the dynamics of morphological evolution. To validate a mathematical model for physical phenomena, we take initial conditions from experimental images by using an image segmentation technique. The image segmentation algorithm is based on the Mumford-Shah functional and the Allen-Cahn (AC) equation. The segmented phase-field profile is similar to the solution of the CH equation, that is, it has hyperbolic tangent profile across interfacial transition region. We use unconditionally stable schemes to solve the governing equations. As a test problem, we take domain rearrangement of lipid bilayers. Numerical results demonstrate that comparison of the evolutions with experimental data is a good benchmark test for validating a mathematical model.

• Animal Systematics, Evolution and Diversity
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• 제22권1호
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• pp.23-27
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• 2006

Subsocial woodroaches of Cryptocercus occur in high mountainous forests in temperate regions and they live in a family in complicated galleries of rotten logs. A prominent feature of the geographical distribution of Cryptocercus is the wide disjunction between the eastern and western species in North America, and between West China and Northeast Asia. Recently, five species of the genus were added from Asian areas and two of them are distributed in Northeast Asian areas. We examined morpho-anatomical structures of male genitalia in Manchurian and Korean Cryptocercus, focusing on male genital hooks and subgenital plates.

• Animal Systematics, Evolution and Diversity
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• 제22권1호
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• pp.105-108
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• 2006

Some sea urchins were collected from the subtidal rocky bottom along the coastal line in Jeju Island by SCUBA diving in April 2005 and identified on the basis of their morphological characteristics. Among them, Asthenosoma ijimai Yochiwara, 1897 was newly recorded from Korea and redescribed based on the specimen collected at 20m deep in southern breakwater of Seogwipo harbor. The order Echinothurioida including family Echinothuriidae and genus Asthenosoma was firstly recorded in Korea. Seventeen species of echinoids are reported to be distributed in Jeju Island of Korea.

• Animal Systematics, Evolution and Diversity
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• 제22권2호
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• pp.209-215
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• 2006

Two rare ciliates from soil under the oak tree and mosses in the top of mountain in Korea were identified as Gonostomum algicola Gellert, 1942 and G. gonostomoida (Hemberger, 1985), respectively. There is little information on their morphological features, therefore their detailed redescriptions are needed. The description was based on the observation of living and protargol impregnated specimens, and biometric analysis. Their diagnostic characteristics are as follows. Gonostomum algicola; $88-113\times30-40{\mu}m$ in vivo, colourless cortical granules, 20-31 adoral membranelles, two fronto-terminal cirri, five fronto-ventral cirri, no mid-ventral cirri, two transverse cirri, two to three micronuceli. Gonostomum gonostomoida; $60-121\times21-40{\mu}m$ in vivo, no cortical granules, 27-34 adoral membranelles, no fronto-terminal cirri, two fronto-ventral cirral rows with each row bearing three cirri, midventral cirral row with 11-14 cirri, two to three transverse cirri, one to six micronuceli. So far, total three species within the genus Gonostomum have been recorded from Korea by the present study.