• 제목/요약/키워드: Island Length

검색결과 411건 처리시간 0.027초

농업용 저수지에 설치한 인공식물섬에 의한 오염물질 농도의 변화 (Changes in Pollutant Concentrations by Artificial Floating Island Installed in Reservoir for Irrigation)

  • 양홍모
    • 한국환경복원기술학회지
    • /
    • 제9권2호
    • /
    • pp.23-32
    • /
    • 2006
  • Total suspended solids (TSS), five-day biochemical oxygen demand ($BOD_5$), total nitrogen (T-N), and total phosphorous (T-P) concentrations around and under a floating island were examined from October 2002 to September 2003. The island was installed in July 2002 on the surface of an agricultural irrigation reservoir located in the southern part of the Korean Peninsula. It was composed of six polyethylene panels. Each panel was 2 m (length) ${\times}$ 1 m (width) ${\times}$ 0.02 m (thick) and had about thirty-two holes each with a diameter of eight centimeters, through which plant roots grew down into the water. Coconut fibers of nine-centimeters in height were placed on the panel, which sustained plants rhizomes and roots. Both the fibers and the panel were raped with polyethylene wire mashes. About thirty irises (Iris pseudoacorus) were planted into the fibers of each panel. The concentrations of TSS, $BOD_5$, T-N and T-P below the island during the iris-growing season averaged 9.70, 2.59, 3.61 and 0.14 mg/L, respectively and those around it averaged 9.99, 2.83, 4.07 and 0.16 mg/L, respectively. The average concentrations of TSS, $BOD_5$, T-N and T-P below it during the iris non-growing season were 8.68, 2.37, 3.25 and 0.14 mg/L, respectively and those near it were 8.76, 2.43, 3.34 and 0.15 mg/L, respectively. At a significance level of ${\alpha}$=0.05, $BOD_5$, T-N and T-P concentrations under the island during the iris-growing season were significantly low when compared with those around it except TSS. No differences in TSS, $BOD_5$, T-N and T-P concentrations between around and near it were found at a significance level of ${\alpha}$=0.05 during the iris non-growing season. The removal of $BOD_5$, T-N, and T-P during the growing season were significantly high when compared with those during the non-growing season. TSS abatement of the floating island was very low during both the growing and non-growing seasons. The island's reductions of $BOD_5$, T-N and T-P were good during the growing season, especially T-N and T-P, which have been considered as primary pollutant sources causing the water quality degradation of reservoirs. The removal of T-N and T-P was primarily attributed to the absorption of nitrogen and phosphorous by the irises during the growing season.

제주도 연안에 분포하는 창꼴뚜기(Loligo edulis)의 자원생물학적 연구 (Fisheries Biology of Swordtip Squid, Loligo edulis in Jeju Island, Korea)

  • 강현정;김영혜;이은희;이동우;장대수
    • 한국패류학회지
    • /
    • 제25권1호
    • /
    • pp.23-28
    • /
    • 2009
  • 2006년 6월부터 11월까지 매월 1회씩 제주도 귀덕, 신산, 김녕, 강정 연안에서 정치망에 의해 채집된 창꼴뚜기를 대상으로 창꼴뚜기의 생식생물학적 특성에 관하여 연구하였다. 조사기간 동안 총 759 개체의 창꼴뚜기 중에서 암컷은 429 개체, 수컷은 330 개체로 나타났다. 암컷의 경우, 조사 기간 중 미숙, 중숙, 성숙, 완숙기의 개체들이 혼재하여 출현하였으며 산란이 가능한 완숙 개체는 조사기간 중 초기인 6월을 제외하고 모든기간에 걸쳐 관찰되었고, 11월에 출현비율이 가장 높았다. 수컷도 조사기간 중 미숙, 중숙, 성숙, 완숙기의 개체들이 혼재하여 출현하됐으며 생식소의 숙도가 방정이 가능한 성숙단계이상의 개체는 전 기간에 걸쳐 관찰되었고 완숙기의 개체는 암컷과 같이 11월에 출현비율이 가장 높았다. 창꼴뚜기가 산란에 참여하는 군성숙외투장을 알아본 결과 성숙외투장은 17.1cm 로 추정되었다.

  • PDF

Two New Marine Tardigrades from Palawan Island, the Philippines

  • 창천영;노현수
    • Animal cells and systems
    • /
    • 제1권3호
    • /
    • pp.419-423
    • /
    • 1997
  • Two new marine tardigrades, florarctus kwoni n. sp. and Batillipes philippinensis n. sp. belonging to Halechiniscidae and Batillipedidae, respectively, are described on the basis of the specimens sieved from sublittoral coral sands and shell gravels of Palawan Island, the Philippines. florarctus kwoni n. sp. is characterized by the rocket-shaped aliform expansion, with the distal margin of posterior ala flattened. Batillipes philippinensis n. sp. closely resembles B. similis Schulz, 1955 and B. annulatus De Zio, 1962. However, it is clearly discernible from the former by the shape of lateral body projection between leg III and leg IV, and the relative length of cirrus E and the spine on leg IV, and from the latter by the shape of the lateral body projection and the clavar shape. This is the first report of the marine tardigrades from the Philippines.

  • PDF

Sex Reversal Pattern of Wrasse in Jeju Coastal Waters

  • Lee, Young-Don;Kim, Se-Jae
    • 한국발생생물학회:학술대회논문집
    • /
    • 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
    • /
    • pp.76-76
    • /
    • 2003
  • Eleven wrasse species inhabit the coastal waters of Jeju Island, Korea. They are the target of leisure fishing and are considered good eating. We investigated the distribution of standard length (SL) by sex of wrasse in Jeju coastal waters for Halichores poecilopterus, H. tenuispinis, Pseudolabrus japonicus, and Pteragogus flagellifera. A cross-section of the ovary showed the ovarian cavity and ovarian lamellae containing oocytes. A cross-section of the testis showed many lobules containing spermatogonia and spermatocytes. A cross-section of a gonad undergoing sex reversal showed the regression or reduction of oocytes and some spermatocytes located in the ovarian lamellae. A cross-section of a sex-reversed testis showed the primary structure of the ovary, with spermatocytes distributed in the epithelium of the lamellae, and reformed seminiferous ducts in the basement lamellae. (중략)

  • PDF

Crasiella clauseni, a New Gastrotrich Species (Macrodasyida, Planodasyidae) from Jeju Island, South Korea

  • Lee, Ji-Min;Chang, Cheon-Young
    • Animal Systematics, Evolution and Diversity
    • /
    • 제28권1호
    • /
    • pp.42-47
    • /
    • 2012
  • A new gastrotrich species of the genus Crasiella (Planodasyidae) is described from the sublittoral sandy bottom of Jeju Island, South Korea. The family Planodasyidae and the genus Crasiella are recorded for the first time from East Asia. Crasiella clauseni n. sp. differs from its congeneric species by the combination of characters: absence of cephalic sensory pits; unseparated arrangement of anterior tubes and ventrolateral tubes, comprising about 120 adhesive tubes along whole body length; 5-7 horizontal rows of adhesive tubes and a pair of TbV in the anterior part of pharyngeal region; bifid pedicles with 8-11 posterior adhesive tubes; and tube-shaped seminal receptacle and copulatory organ. This paper deals with description of the new species, and provides a key to the species of genus Crasiella.

Two New Marine Clathrids Sponges(Poecilosclerida: Microcionidae) from Jejudo Island, Korea

  • Kim, Hyung-June;Sim, Chung-Ja
    • Animal cells and systems
    • /
    • 제12권1호
    • /
    • pp.53-59
    • /
    • 2008
  • Two new marine sponges, Clathria(Clthria) gimnyeoungenesis n. sp. and Clathria(Clthria) reticularis n. sp., were collected in Jejudo Island, Korea by fishing nets in September 1994. C.(C.) gimnyeoungenesis n. sp. is closely related to C.(C.) toxipraedita Topsent, 1913 based on spicule types, but are different in the size of spicules and growth forms. Especially, the thick styles and large toxas length of this species are half of C.(C.) toxipraedita. Growth form of the new species is branched but massive encrusting in C.(C.) toxipraedita. C.(C.) reticularis n. sp. is similar to C.(C.) compressa Schmidt, 1862 based on spicule types, but are different in the size of spicules. Especially, large toxas of this new species is twice as long as C.(C.) compressa and they have large isochelae, which are absent in the latter.

First Record of Tri-spine Horseshoe Crab, Tachypleus tridentatus (Merostomata: Xiphosurida: Limulidae) from Korean Waters

  • Yang, Kea Cheong;Ko, Hyun Sook
    • Animal Systematics, Evolution and Diversity
    • /
    • 제31권1호
    • /
    • pp.42-45
    • /
    • 2015
  • A tri-spine horseshoe crab, Tachypleus tridentatus (Leach, 1819) was collected from a sandy beach of Udo Island of Jeju during the full moon tides in November 1997. Three spines on the posterior margin of the opisthosoma were characterized indicating that the specimen was T. tridentatus. This specimen was a female with the total length of 49.5 cm and prosoma width of 23.0 cm. Tachypleus tridentatus was the first record from Korean waters. A brief description and figures of the species were given. This finding indicates that Korea is included to the distribution range of the species.

New Korean Record of Setarches longimanus (PISCES: Scorpaenidae)

  • Shin, Ui Cheol;Kim, Jin-Koo;Joo, Dong-Soo
    • Fisheries and Aquatic Sciences
    • /
    • 제19권2호
    • /
    • pp.10.1-10.5
    • /
    • 2016
  • Setarches longimanus (Alcock 1894), in the family Scorpaenidae, was collected from Busan and the coastal waters of Jeju Island, Korea, in January and November 2014, respectively. Two specimens are characterized by XI, 10 dorsalfin rays; 19-21 pectoralfin rays; III, 5 anal fin rays; a second preopercular spine much shorter than the first and third; and an interorbital width 11.3 %-11.6 % of the standard length. We also analyzed 587 base pairs of the mitochondrial DNA cytochrome c oxidase subunit I sequences in order to confirm the taxonomic status of the specimen. As a result, the sequences of our specimen almost corresponded to those of Chinese S. longimanus (genetic distance, d = 0.005), but considerably differed from those of S. guentheri (d = 0.120-0.124). We propose the new Korean names "Ma-su-gam-peng-sok" for the genus Setarches, and "Bul-geun-ma-su-gam-peng" for the species S. longimanus.

A New Sponge of the Genus Haliclona (Gellius) (Haplosclerida: Chalinidae) from Gageodo Island (So-Huksando), Korea

  • Kim, Hyung-Jun;Sim, Chung-Ja
    • Animal cells and systems
    • /
    • 제8권4호
    • /
    • pp.247-250
    • /
    • 2004
  • A taxonomic study on marine sponges was conducted by SCUBA diving at Gageodo Island, Korea from August 1999 to July 2001. Among them, Haliclona (Gellius) coreana n. sp. turned out to be new to science. This new species seems to be close to H. (G.) arcoferus Vosmaer, 1885, based on the type of spicules. However, it is different in size of toxa and growth form. Toxa of the new species is half in length compared to H. (G.) arcoferus. The growth form is jar shaped in this new species, but flat in H. (G.) arcoferus.

A new species and a new record of Meghimatium Slugs (Pulmonata: Philomycidae) in Korea

  • Park, Gab-Man
    • 환경생물
    • /
    • 제39권3호
    • /
    • pp.399-405
    • /
    • 2021
  • Until now, five species (Meghimatium bilineatum, M. fruhstorferi, Limax flavus, L. marginatus, Deroceras reticulatum) in three genera of families Philomycidae and Limacidae have been reported in Korea. Philomycidae is a family of air-breathing land snails. Meghimatium hongdoensis sp. nov. is described based on its middle size (60-80 mm in body length), its body coloration (dark-red yellow), no dorsal with streaks, its genitalia, and 16rDNA sequence analysis. Specimens of this new species were collected from Hongdo island, Sinan-gun, Jeollanam-do, Korea. This species is only known from the type locality at Hongdo to date. It could be found in high-humidity sites. Meghimatium uniforme (Laidlaw 1937) was the first one reported in Korea. It was also collected from Gageodo island, Sinan-gun, Jeollanam-do, Korea. In this study, morphological characteristics including their radula and genital structures of these two species were described. Preliminary results of mitochondrial 16S rDNA sequencing and phylogenetic analyses indicated that these species belonged to the Korean clade.