• Title/Summary/Keyword: Decapoda larva

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Seasonal Fluctuation of Zooplankton Community in Asan Bay, Korea (아산만 동물플랑크톤 군집의 계절변화)

  • CHOI Keun-Hyung;PARk Chul
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.26 no.5
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    • pp.424-437
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    • 1993
  • About three fourths of total variability of zooplankton in Asan Bay was associated with season and the difference between inner bay and outer bay was relatively small. However, the differences in percent compositions of major taxa at inner bay and outer bay increased gradually with time, suggesting the change of ecosystem in this bay due to the human exploitation such as reclamation. Seasons of maximum abundances were different among the taxa but consistent for each taxon throughout the three survey years. Calanus sinicus and Acartia bifilosa showed maximum abundance in spring. Sagitta crassa, Paracalanus parvus, A. pacifica, Tortanus spinicaudatus, Corycaeus affinis and Decapoda larva were most abundant in summer. Labidocera euchaeta and Bivalve larva appeared most abundantly in fall. But in winter no taxon showed maximum. In general, low abundance with many species in fall, low abundance and few taxa in winter, increase in both number of taxa and abundance in spring, and high abundance and many taxa in summer were observed. A hypothesis for the observed patterns was suggested although more evidences were needed to support this.

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First Zoea of Sesarmops intermedius (De Haan, 1835) (Crustacea: Decapoda: Brachyura: Sesarmidae)

  • Lee, Hwa Ja
    • Fisheries and Aquatic Sciences
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    • v.18 no.3
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    • pp.321-324
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    • 2015
  • The first zoeal characters of Sesarmops intermedius (De Haan, 1835) [=Sesarma (Sesarma) intermedium], belonging to the family Sesarmidae, are described and illustrated in detail based on laboratory-hatched material from a female collected from Gangjeung, Seogwipo, Jeju Island. Morphological comparison is performed based on previous descriptions of Sesarma (Sesarma) intermedium from Japan and three other species in the Sesarmidae. The first zoea of Sesarmops intermedius can be readily distinguished from those of the three species Chiromantes haematocheir [=Sesarma (Holometopus) haematocheir], Chiromantes dehaani [=Sesarma (Holometopus) dehaani], and Parasesarma pictum [=Sesarma (Parasesarma) pictum] by the presence of two setae on the exopod of the antenna, fine setae on the inner and outer margin of the forked spine of the telson, and three aesthetascs and one simple seta on the antennule.

Distribution of Zooplankton in Asan Bay, Korea with Comments on Vertical Migration (아산만 동물플랑크톤 분포와 수직이동)

  • PARK Chul;CHOI Keun-Hyung;MOON Chang-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.24 no.6
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    • pp.472-482
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    • 1991
  • Seasonal distributions of zooplankton were investigated in Asan Bay, Korea. Labidocera euchaeta, Sagitta crassa, Calanus sinicus, Acartia omorii were dominant taxa throughout the year with seasonally varying percent compositions. Bivalve veliger larva (fall), Decapoda larva (spring and summer), and Paracalanus Parvus, Evadne tergestina (summer) were also dominated during contain period. The patterns of time dependent vertical distributions of one major taxon, A. omorii, showed seasonal differences, i.e., it showed the trends of normal vertical migration in winter and reversed vertical migration in spring. At surface layer day time abundances were equal or less than night time abundances in general.

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Early zoeal stages of edible crab Erimacrus isenbeckii (Brandt, 1848) (Crustacea: Decapoda: Brachyura: Cheiragonidae) and a comparison with other cheiragonid zoeae

  • Lee, Chu;Ko, Hyun-Sook
    • Animal cells and systems
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    • v.14 no.4
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    • pp.323-331
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    • 2010
  • Ovigerous crabs of Erimacrus isenbeckii were collected from the northeastern coast of South Korea and their larvae were reared in the laboratory. Two zoeal stages were described and illustrated in detail. The first zoeal characteristics between the present material and Sasaki and Mihara's (1993: J Crust Biol. 13:511 522) were different especially in the setations of the endopods of the maxillipeds. The zoea of Erimacrus isenbeckii strongly resembled those of two Telmessus species in the Cheiragonidae, but the former could be distinguished from the latter by having spinulate carapace spines, a lateral process on the abdominal somite 3, and longer lateral spines on the telson fork.

Larval development of Scyra acutifrons (Crustacea: Decapoda: Epialtidae) with a key from the northern Pacific

  • Oh, Seong-Mi;Ko, Hyun-Sook
    • Animal cells and systems
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    • v.14 no.4
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    • pp.333-341
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    • 2010
  • The larvae of Scyra acutifrons are described and illustrated for the first time. The larval stage consists of two zoeal and a megalopal stages. The zoea of S. acutifrons is compared with those of other known species of the Epialtidae from the northern Pacific. The zoea of Scyra acutifrons can be easily distinguished from that of S. compressipes by having a longer rostral carapace spine and an endopod of maxillule with three setae. It is found that the genus Scyra (Pisinae) shows a great similarity to Pisoides bidentatus (Pisinae) and the genus Pugettia (Epialtinae) in the family Epialtidae; especially, S. acutidens coincides well with two Pugettia species (Pugettia incisa and P. gracilis) in the characteristics of the zoeal mouthpart appendages. To facilitate the study of plankton-collected material, a provisional key to the known zoeae of the Epialtidae from the northern Pacific is provided.

Complete Larval Development of Hemigrapsus sanguineus(Decapoda, Brachyura, Grapsidae) Reared in Laboratory (무늬발개 Hemigrapsus sanguineus(게 아목, 바위게 과)의 유생발생)

  • Hwang, Sang-Gu;Lee, Chu;Kim, Chang-Hyun
    • Animal Systematics, Evolution and Diversity
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    • v.9 no.2
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    • pp.69-86
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    • 1993
  • The larval stages of Hemigrapsus sanguineus were reared in the laboratory and described with illustrative figures. Five zoeal and one megalopal stages were found in the complete larval development. At 25^{\circ}C.$, the megalopa and the first crab instar were attained in 18 and 31 days after hatching, respectively. The first zoeal larva of H. sanguineus showed the characteristics ~ h i c h coincide with those of the same genus by bearing lateral spines on carapace, B-types of telson and antenna, 1 +5 setae on the endopod of maxillule, and 2 + 2 setae on the endopod of maxilla. Morphological features of H. sanguineus larvae were compared to the previous descriptions of larvae of the same genus and morphological differences among them were discussed.

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