Labidocera pavo Giesbrecht, 1889 and L. sinilobata Shen and Lee, 1963, belonging to the detruncata group in the genus Labidocera were collected from the southwestern coastal waters of Korea, using a Norpac net (0.2 mm mesh size). Labidocera sinilobata, known to be endemic species in estuary of Chinese rivers, is the first record in Korean waters. In Chinese waters, this species has only been briefly documented and illustrated. In the study, their morphological characteristics were fully redescribed with careful examination of the fine epidermal structure using a SEM (Scanning Electron Microscope) in addition to their illustrations and compared with species of the detruncata species-group.

Benthic harpacticoids were collected from the East Sea of Korea. Specimen were identified as members of the genus Robertgurneya Apostolov & Marinov, 1988 based on the following characteristics: the fourth segment of antennule with aesthetasc, antenna with three-segmented exopod, shape of mandible, and P1-P4 armature formula. Robertgurneya donghaensis sp. nov. is morphologically most closely related to R. simulans (Norman & Scott T., 1905) and R. similis similis (Scott A., 1896). However, R. donghaensis is characterized by the rostrum with a pointed tip, caudal rami about as board as the length of its inner edge, the first segment of the P1 endopod much longer than entire exopod, and the P5 exopod with five setae in male. The genus Robertgurneya is reported from Korean waters for the first time.

2012년 8월 1일부터 7일까지 한국 남해 연안의 목포에서 부산에 이르는 37개의 정점에서 채집된 Acartia 속 요각류의 공간 분포 양상에 대하여 분석하였다. A. erythraea는 용존산소가 2 mg L-1 이하인 반 폐쇄적인 (가막만, 마산만) 만에서 높은 출현 개체수를 보였다. A. sinjiensis는 엽록소-a 농도가 2 μg L-1 이상인 반 폐쇄적인 만에서 높은 출현 개체 수를 보였다. A. ohtsukai는 수온 26°C 이상, 염분 30 이하일 때 높은 출현 개체수를 보였다. A. hongi, A. hudsonica는 수온이 27°C 이하, 용존산소 5 mg L-1 이상인 해역에서 출현 하였다. 이러한 결과 환경요인이 여름철 남해 연안에 출현 하는 Acartia 속 요각류의 공간적 분포에 영향을 미칠 수 있음을 시사하고 있다.

Two species of the minuta-subgroup within the oncaeid copepod genus Triconia Böttger-Schnack, 1999 collected in the equatorial Pacific Ocean are newly recorded. A female T. minuta (Giesbrecht, 1893 [“1892”]) and both male and female T. umerus (Böttger-Schnack and Boxshall, 1990) from the northeast equatorial Pacific are redescribed with the comparison of its morphological details, which differs from previous studies, in terms of the larger body size, the length to width ratio of the genital double-somite, the relative length of the outer basal seta on P5, and the ornamentation of the appendages. The characters, which are used for identification, such as the length ratio of the outer subdistal and outer spine versus the distal spine on P3-P4, and the outer spine length of the middle exopodal segment on P3 and P4 are reported for the first time. Information on the variations in the endopodal spine lengths of swimming legs 2-4 is also provided for T. minuta and T. umerus, with the summary of the wide zoogeographical distribution of these two species.

Stable Isotope Analysis (SIA) of carbon and nitrogen is useful tool for the understanding functional roles of target organisms in biological interactions in the food web. Recently, mixing model based on SIA is frequently used to determine which of the potential food sources predominantly assimilated by consumers, however, application of model is often limited and difficult for non-expert users of software. In the present study, we suggest easy manual of R software and package SIAR with example data regarding selective feeding of crustaceans dominated freshwater zooplankton community. We collected SIA data from the experimental mesocosms set up at the littoral area of eutrophic Chodae Reservoir, and analyzed the dominant crustacean species main food sources among small sized particulate organic matters (POM, <50 μm), large sized POM (>50 μm), and attached POM using mixing model. From the results obtained by SIAR model, Daphnia galeata and Ostracoda mainly consumed small sized POM while Simocephalus vetulus consumed both small and large sized POM simultaneously. Copepods collected from the reservoir showed no preferences on various food items, but in the mesocosm tanks, main food sources for the copepods was attached POM rather than planktonic preys including rotifers. The results have suggested that their roles as grazers in food web of eutrophicated reservoirs are different, and S. vetulus is more efficient grazer on wide range of food items such as large colony of phytoplankton and cyanobacteria during water bloom period.

The genus Halectinosoma Vervoort, 1962 is first reported from Korean waters by the discovery of H. perforatum Itô, 1981. This species, previously recorded only from Japan, is collected from the sandy beach on the south coast of Korea, and is well distinguished from other congeners by the combination of following morphological characteristics: the elongate caudal ramus; the remarkably bilobated exopod of female P5; the small innermost seta on the distal margin of female P5 exopod; the presence of three setae on the distal exopodal segment in P4; and the presence of scale-like spinules on the ventral surfaces of urosomite. We herein provide detailed description and illustrations of this species.

Mormonilla phasma is redescribed, based on the specimens from the Northeastern Pacific. M. phasma in the study area has the following morphological characteristics; second endopodal segment of mandible partly fused to basis and a distinct three-segmented

The spatio-temporal distribution of four coexisting acartiid species in two subgenera Acartiura (Acartia hongi and A. omorii) and Odontacartia (A. erythraea and A. pacifica) was examined at seven stations in the southwestern waters of Korea, between Janua