• Animal cells and systems
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• 제2권1호
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• pp.123-131
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• 1998

The unc-29 region on the chromosome I of Caenorhabditis elegans has been mutagenized in order to obtain lethal mutations. In this screen, the uncoordinated phenotype of unc-29 (e193) mutant was used to identify any lethal mutations closely linked to the unc-29 gene, which encodes a subunit of nicotinic acetylcholine receptors. We have isolated six independent mutations (jh1 to jh6) out of approximately 5,200 ethyl methanesulfonate(EMS) treated haploids. Four of the six mutations demonstrated embryonic lethal phenotypes, while the other two showed embryonic and larval lethal phenotypes. Terminal phenotypes observed in two mutations (jh1 and jh2) indicated developmental defects specific to posterior part of embryos which appeared similar to the phenotypes observed in nob (no back end) mutants. Another mutation (jh4) resulted in an interesting phenotype of body-wall muscle degeneration at larval stage. These mutations were mapped by using three-factor crosses and deficiency mutants in this region. Here we report genetic analysis and characterization of these lethal mutations.

• International Journal of Industrial Entomology and Biomaterials
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• 제33권2호
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• pp.50-53
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• 2016

The size of head capsule is one of the most important factors for identifying developmental stage. In order to understand the developmental characteristics of the butterfly Atrophaneura alcinous, we examined fluctuations in larval head capsule size under three different temperature conditions (20, 25, and $30^{\circ}C$) and 60% humidity. As a result, larvae developed to the fifth instar at all three temperatures. The head capsule size of larvae tended to be larger at the lowest temperature and smaller at the highest temperature. The development rate showed a regular change, consistent with Dyar's rule regarding head capsule size development. Furthermore, the development of head capsule size was found to correspond to a second degree polynomial regression better than to a linear regression. On the basis of these results, it would appear to be possible to perform an accurate assessment of instar status during the development of A. alcinous.

• 한국수산과학회지
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• 제23권6호
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• pp.457-467
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• 1990

Sessile barnacle, Balanus trigonus Darwin, was collected from the intertidal rocks and the external shells of bivalve Mylius coruscus. The nauplius and cyprid larvae were cultured in a constant temperature cabinet at a temperature of $20^{\circ}C$ and a light regime of 14 h light and 10 h darkness. Larval development includes the six nauplius stages and a cyprid stage prior to settlement and metamorphosis to the young adult. Morphological characteristics including antennules, antennae and mandibles are described and illustrated. All nauplius larvae have trilobed labra typical in balanoides. The developmental time taken from newly hatched nauplius I to cyprid was $9\~13$ days and averaged 11 days.

• 한국응용곤충학회지
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• 제39권1호
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• pp.25-29
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• 2000

야외관찰과 사육실험을 통하여 과거에 한국에서 Hydropsyche KUe로 알려져 온 동양줄날도래의 미성숙단계와 성충의 관계를 밝혔다. 각 영의 유충, 유충은신처, 번데기, 번데기집, 수컷과 암컷성충을 기재하였으며, 간략한 생태에 대하여 기록하였다.

• Animal cells and systems
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• 제14권2호
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• pp.129-136
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• 2010

The introduced spider crab Pyromaia tuberculata was collected from Korea in 2005 and it was ovigerous. After hatching, larvae were reared in the laboratory at $20^{\circ}C$. The larval stage of the species consists of two zoeal and one megalopal stages. The larvae of the Korean species differ somewhat from those from New Zealand described by Webber and Wear (1981; N Z J Mar Freshwat Res. 15:331-383) and from Brazil described by Fransozo and Negreiros-Fransozo (1997; Crustaceana. 70:304-323.) in the setal presence of the antennule, the maxillule, the maxilla and the maxillipeds, and the abdomen. It is found that Fransozo and Negreiros-Fransozo have overlooked some setae on the basis of the zoeal maxillipeds and that re-examination of their larvae is needed. Also, it is found that the Inachoididae is heterogeneous based on the zoeal morphology because two distinct groups exist in the family.

• Animal cells and systems
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• 제14권4호
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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.

• The Korean Journal of Ecology
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• 제15권3호
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• pp.257-265
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• 1992

The effects of insecticide dimilin including the technical grade(tg) and wettable power(wp-25), inhibiting the synthesis of chitin in the cuticle of insect larvae, and herbicides alachlor and atrazine on the development of shrimp caridina denticulata denticulata were investigated in various concentrations. This species is abundant in the freshwater such as river and pond. The shrimp larvae were reared at dimilin solutions(tg and wp 2), alachlor solutions, and atrazin solutions. the concentrations of dimiline were 0, 1, 5, 10 and 25 ppb dimilin solutions, and those of alachlor and atrazin were 0, 1, 5, 10 and 25ppm, respectively.mortality was high at 10 ppb when the larvae were exposed to dimilin and at 25ppm in the case of alachlor and atranzine solutions. If lethal concentration is defined as a concentration in which less than 10% of larvae to the post larval stage from hatching it can be concluded that the lethal concentration of dimilin is 5ppb, and that of alachlor and atrazin is 25 ppm.

• 한국양식학회지
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• 제13권2호
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• pp.119-128
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• 2000

진주담치(Mytilus edulis), 홍합(Mytilus coruscus), 참굴(Crassostrea gigas) 및 진주조개(Pinctata fucata martensii)를 인위적인 방란 방정을 유도하여 이들의 수정란과 부유유생을 사육하여 난 발생, 유생의 성장 및 형태를 비교한 결과는 다음과 같다. 수정란의 크기는 진주담치와 홍합이 각각 65.1 ${\mu}m$, 70.3 ${\mu}m$로 비슷한 크기를 보였고, 참굴과 진주조개는 각각 52.3 ${\mu}m$, 45.3 ${\mu}m$로 비슷한 크기를 보였다. 수정란에서 D형 유생으로 되는 데 소요되는 시간은 진주담치와 참담치는 자연수온(17.0$\pm$1$^{\circ}C$)에서 각각 47시간55분, 45시간 55분이 소요되었고, 참굴과 진주조개는 수온 21.$0^{\circ}C$와 26.$0^{\circ}C$에서 각각 23시간 55분과 22시간이 소요되었다. 진주담치, 홍합, 참굴, 진주조개가 초기 D형 유생에서 부착기 유생으로 성장하는 데는 각각의 수온에서 각각 20일, 27일, 22일, 및 21일이 소요되었고 이때의 평균 각장의 크기는 각각 194.1 ${\mu}m$, 233.6 ${\mu}m$, 274.9 ${\mu}m$, 190.9 ${\mu}m$ 였다. 초기 D형 유생에서 초기 부착기 유생까지 각장(L)과 각고(H)의 상관관계는 높으며, 각장에 따른 각고/각장의 비율(H/L)은 진주담치: H/L : 0.002L+0.5334 (($R^2$ = 0.957), 홍합: H/L : 0.001L+0.603 ($R^2$ : 0.944), 참굴: H/L =0.001L+0.871 (($R^2$=0.550) 및 진주조개: H/L =0.001L+0.791 (($R^2$ = 0.700)로 나타났다

• 한국패류학회지
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• 제32권1호
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• pp.37-43
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• 2016

This study was carried out to determine the optimal water temperature for the embryonic development and laboratory culture of larvae of an intertidal mud snail, Nassarius festivus. The embryos and hatched veliger larvae of N. festivus were incubated at six different temperatures (5, 10, 15, 20, 25 and $30^{\circ}C$). Developmental time for each stage decreased as water temperature increased. The elapsed time to develop to the veliger larva at 15, 20, 25 and $30^{\circ}C$ was 559, 155, 131 and 103 hrs, respectively. At 5 and $10^{\circ}C$, embryo developed to veliger larvae but failed to hatch out of the egg capsule. In contrast, all embryos successfully hatched in the temperature range from 15 to $30^{\circ}C$. The biological minimum temperature during the embryonic development of N. festivus was estimated to be $9.5{\pm}0.4^{\circ}C$. The cumulative water temperatures for blastula, gastrula and veliger stages were calculated as $111{\pm}84$, $486{\pm}185$, $1,164{\pm}72^{\circ}C$, respectively. Temperature also affected the larval survival. Five days after hatching, more than 84% of larvae survived at all experimental temperatures. However, survival began to decrease after 6 days. It was 0% at $30^{\circ}C$. Survival of larvae incubated for 8 days was higher at 15 and $20^{\circ}C$ than other experimental temperatures. We therefore suggest that the optimal range of temperature for embryonic development and larval survival of N. festivus is $15-20^{\circ}C$.

• Animal cells and systems
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• 제13권1호
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• pp.59-69
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• 2009

This paper documents the defining morphological characteristics of the larval stages of Chionoecetes tanneri Rathbun, 1893, the grooved Tanner crab, from specimens reared in the laboratory. Chionoecetes tanneri larval stages include two zoeae and one megalopa. The first zoea is characterized by: six setae on the posterior margin of the carapace; postero-lateral spines on abdominal somites 3 and 4, extending beyond the posterior margin of adjacent somites and bearing 9-10 spinnules; 12 plumose setae and one stout distal plumose seta present on the margin of the scaphognathite of the maxilla; and one fused lateral spine and one articulated dorso-medial spine on each fork of the telson. The second zoea is characterized by: 9 setae on the postero-lateral margin of the carapace; a serrated mandible molar; a mandibular palp bud; 25-26 plumose setae on the margin of the scaphognathite of the maxilla; pereiopods with well-developed gills and buds; and four pairs of stout setae on the posterior margin of the telson. For the megalopal stage, the distinguishing characteristics include: a rostral spine equal in length to the supraorbital spine; six setae on the exopod of the uropod; and a single spine on the ischium of the second pereiopod. This study allows C. tanneri larvae to be distinguished from the larvae of known sympatric congeners. This information provides a basic taxonomic tool for researchers in fisheries management and zooplankton ecology who are addressing issues related to trophic interactions, metapopulation dynamics and ecosystem impacts in the evolving marine resource management strategies in the North Pacific, and those related to Chionoecetes species in particular.