• 제목/요약/키워드: urochordates

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Systematic Relationships of the Urochordates Based on Partial 18S rDNA Sequences

  • Won, Hye-Won;Rho, Boon-Jo;Song, Jun-Im
    • Animal cells and systems
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    • 제3권4호
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    • pp.359-363
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    • 1999
  • Urochordates, the most primitive group in phylum Chordata, are mostly sessile as adults although some are free living. Presently, the ancestral stock of urochordates as weir as chordates has been the focus of interest and two conflicting hypotheses have been presented. A free swimming ancestor is one and a sessile, filter feeding ancestor is the other. To clarify the phylogenetic relationships within the urochordates, 22 urochordates and five others as outgroups were used. And we applied neighbor joining, maximum likelihood, and maximum parsimony methods to partial 18S rDNA sequences. The inferred phylogeny in all analyses indicates that order Aplousobranchia of class Ascidiacea appears to be the most ancestral group among urochordates. But it is not clear for the low bootstrap value. The remaining two orders of ascidians, Phlebobranchia and Stolidobranchia, form monophyletic groups respectively, which are well supported by high bootstrap values. These two orders are closer to classes of Thaliacea and Appendicularia than to the Aplousobranchia. While class Appendicularia is strongly supported by the monophyletic group, the phylogenetic position of class Thaliacea is unclear in this study.

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그물코쥐치의 먹이습성의 일별 변화: 낮은 잡식성, 밤은 육식성 (Diel Changes in the Diet of Rudarius ercodes: A Diurnal Omnivore and Nocturnal Carnivore)

  • 곽석남;허성회;최창근
    • 한국어류학회지
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    • 제18권3호
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    • pp.178-183
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    • 2006
  • 진동만 잘피밭에 서식하는 그물코쥐치의 먹이습성의 일별변화를 조사하였다. 출현한 그물코쥐치는 1.6~4.3 cm SL의 범위였으며, 주요 먹이생물은 단각류에 속하는 옆새우류, 잘피, 갯지렁이류, 그리고 미삭동물이었다. 그물코쥐치의 먹이습성의 일별변화는 뚜렷하였다. 낮에는 잘피와 옆새우류를 주로 먹은 잡식성을, 밤에는 옆새우류, 갯지렁이류, 그리고 미삭동물을 주로 먹는 육식성을 나타내었다. 이와 같은 결과는 낮보다는 밤에 이들 먹이생물의 활동이 활발하여 그물코쥐치가 섭이하기가 용이하였던 것으로 판단된다. 또한 그물코쥐치의 섭이활동은 저조보다는 고조에 활발하였다.

Feeding Habits of Rudarius ercodes in a Zostera marina Bed

  • Kwak Seok Nam;Huh Sung-Hoi
    • Fisheries and Aquatic Sciences
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    • 제7권1호
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    • pp.46-50
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    • 2004
  • Feeding habits of Rudarius ercodes collected from a Zostera marina bed in Jindong Bay, Korea were studied. R. ercodes was a omnivore which consumed mainly gammarid amphipods, polychaetes and eelgrass (z. marina). Its diets also included a small amount of copepods, urochordates and caprellid amphipods. R. ercodes showed ontogenetic changes in feeding habits. Small individuals less than 2cm SL fed mainly on copepods, however, gammarid amphipods and polychaetes were heavily selected with increasing fish size. The consumption of eelgrass by R. ercodes was $10-20\%$ all size classes. The dietary breadth of R. ercodes were varied with fish size

해양 생물다양성 정보시스템 개발 -한국 해양생물 종 목록 수립을 중심으로- (Development of the Korea Marine Biodiversity Information System -Focus on the Establishment of the Korea Maine Species Inventory-)

  • 박수영;김성대;이윤호;배세진;박흥식;김충곤
    • Ocean and Polar Research
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    • 제29권3호
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    • pp.273-282
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    • 2007
  • For an efficient management and utilization of marine biodiversity information, we made an attempt to develop the Korea Marine Biodiversity Information System (KoMBIS), building a species name inventory of Korea marine organisms. The inventory includes 17 organism groups: phytoplankton, zooplankton, algae and halophyte, sponges, cnidarians, rotifers, nematodes, bryozoans, brachiopods, molluscs, echiurans, annelids, arthropods, echinoderms, urochordates and fish. The species names were collected from 37 different references and reviewed for validity by taxonomists, which resulted in 9,798 valid names in addition to 1,845 synonyms. The Korea marine species inventory is the first one of this kind, for previous Korean species name inventories were mostly composed of terrestrial and freshwater organisms. KoMBIS, the information system developed, contains not only the species name but also information on morphological and ecological characteristics such as distribution, DNA barcode, and references. This system is convenient for the inputting of new data and servicing users through the internet, so that management and utilization of the biodiversity information is more efficient. Linking the DNA barcode data with species information provides an objective measure for identification of a species, which accommodates the recommendation of Consortium for the Barcode of Life, and makes the Korea marine biodiversity information compatible with international databases. Considering the frequent exchange of marine organisms internationally via ballast water and such issues as climate change, this information system will be useful in many areas of marine biodiversity.