Ji-Hun Song

Nebalia Pseudotroncosoi N. SP. (Malacostraca: Leptostraca), from South Korea, with a Peculiar Sexual Dimorphism

A new crustacean, Nebalia pseudotroncosoi n. sp. (Malacostraca: Leptostraca), occurs along the southern coasts of Korea. The specimens were collected by light traps in harbors where the bottom consisted of fine sand with some algal mats. The new taxon is distinguished from all other known species of Nebalia by the following characteristics: a rectangular compound eye with two to three small distal lobes; an antennular flagellum that is clearly shorter than the peduncle, with up to 10 articles; the fourth article of the antennular peduncle has only two distal thick setae; the antennular scale is nearly oval with a length that is 1.8 times the width; the second article of the mandibular palp has three distally plumose setae; pleonites 3 to 7 have rounded denticles along their posterior dorsal margins; and the protopod of pleopod 4 lacks serration along the posterior margin. We discuss sexual dimorphism in the genus Nebalia and propose the necessity of describing male traits when reporting new species. We also provide partial sequences of the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene from the new species that can be used as a molecular diagnostic characteristic.

A New Species of Leptostraca, Nebalia koreana (Malacostraca: Phyllocarida), from South Korea

ABSTRACT Herein, we report a new species of leptostracan, Nebalia koreana (Malacostraca) collected from the southern and eastern coasts of the Korean peninsula. All the specimens of this species were collected by means of light traps from harbors where the bottoms are sandy and with algal mats. The new species differs from all other known Nebalia in the following characters: the carapace is relatively small, and covers the lateral sides of pleonite 2 and partially the lateral sides of pleonite 3; the fourth article of the antennule has up to five short distal spines; pleonites 3 to 7 have rounded denticles along the posterior dorsal borders; the epipod of thoracopod 7 bears 5 to 6 plumose setae along the posterior margin, which are lacking on the remaining thoracopods; and the protopod of pleopod 4 lacks serration along the posterior border. Only two species of Nebalia have been reported from the tropical or subtropical seas of Asia. Therefore, the new species is the first species of Nebalia found in the temperate zone of Asia. Additionally, type localities and world distribution of the genus Nebalia are provided in this paper.

A new species of Nebalia (Malacostraca: Phyllocarida: Leptostraca) from South Korea, with a key to the species of Nebalia Leach, 1814

Nebalia dolsandoensis sp. nov. (Malacostraca: Phyllocarida: Leptostraca), is described from specimens taken from light traps in harbours with organic-rich muddy sand and seaweeds along the south coast of Korea. The new species is characterized based on the following unique combination of characteristics: an antennular flagellum with up to only nine articles in the mature female; the fourth article of the antennule has up to four distal spine-like setae; pleonites 3–7 have rounded denticles along the posterior dorsal margins; the protopod of pleopod 4 has an even posterior margin; the uropods are distinctly short, about 0.6 times as long as pleonite 7 and the anal somite combined; the anal plates have a noticeably broad lateral ‘shoulder’. In addition, a key to the species of the genus Nebalia Leach, 1814 and partial sequences of the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene from the new species are provided.

Two new species, Caenanthura koreana sp. nov. and Apanthura koreaensis sp. nov. (Crustacea: Isopoda: Anthuridae) from South Korea

Two new species of anthuroid isopods, Caenanthura koreana sp. nov. and Apanthura koreaensis sp. nov. are described from the southern and western coasts of the Korean Peninsula. A key to the species and the type locality of Caenanthura are provided. Additionally, we determined the partial sequences of the mitochondrial cytochrome c oxidase subunit 1 (CO1) from two new species.

Freshwater Invertebrates of Jindo Island in Korea

We surveyed the freshwater invertebrates of Jindo Island twice on July and September 2016, as part of a joint faunal survey conducted to commemorate the 30th anniversary of the Korean Society of Systematic Zoology. Aquatic insects were not included in this study. We found 38 freshwater species from seven phyla: Porifera, Platyhelminthes, Nematomorpha, Mollusca, Annelida, Arthropoda, and Bryozoa. Twenty-one of the 38 species (55.3%) represented the first record of their respective species on Jindo Island. Among these species, a freshwater shrimp-parasitic isopod, Tachaea n. sp., was identified as a new species.

First Record of Cleantioides planicauda (Crustacea: Isopoda: Holognathidae) from South Korea

Cleantioides planicauda (Benedict, 1899) has previously been recorded in China and Japan. In the present study, to our knowledge, we report for the first time the occurrence of this species in South Korea. Here, we provide detailed descriptions and illustrations of the diagnostic characteristics of C. planicauda. Further, for the first time, we determined the partial sequence of mitochondrial cytochrome c oxidase subunit 1 (CO1) gene of C. planicauda for molecular characteristic. Additionally, we provide a key to the Korean species and distribution of the genus Cleantioides. As a result of this study, four species of the genus Cleantioides, including C. planicauda, have now been recorded in South Korea.

First records of Gnathia Leach, 1814 and Tachaea Schioedte & Meinert, 1879 from South Korea, with descriptions of two new species (Isopoda, Cymothoida, Cymothooidea)

Abstract Two new species of cymothoid isopods, Gnathiakoreanasp. n. and Tachaeakoreaensissp. n., are described from South Korea. The genera Gnathia Leach, 1814 and Tachaea Schioedte & Meinert, 1879 are recorded for the first time in South Korea. Gnathiakoreanasp. n. is distinguished from its congeners by having the smooth dorsal surface of the pereon, the strongly ridged unornamented paraocular ornamentation, the strong bifid mediofrontal process, and the serrated superior frontolateral process. Tachaeakoreaensissp. n. is distinguished from its congeners by having the expanded propodus with serrated inferior margins in pereopods 1–3, the propodus with serrated inferodistal margins in pereopods 4–7, one seta on the apical lobe of the maxilla, and ten robust setae on the posterior margin of the pleotelson.

First Record of Paranebalia longipes (Crustacea: Phyllocarida: Leptostraca) from South Korea

Paranebalia longipes (Willemoes-Suhm, 1875) is cosmopolitan and has been usually found in the algal and sponge debris on the sandy mud substrates. This species can be clearly distinguished from other species of Paranebalia by the presence of serration on posterior margin of pleopods, the number of articles on antennule and antenna, and number of teeth on flange of antennule fourth article. The genus Paranebalia is new to Korea. In this paper, we provide detail descriptions of the diagnostic characteristics and illustrations of the P. longipes. Additionally, type locality and world distribution of the genus Paranebalia are provided.