• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.6
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• pp.485-491
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• 2004

Spawning induction, egg development and larval growth of ark shell (Tegillarca granosa) (L.) were investigated. The most effective method of spawning induction was steady temperature increasing from$4^{\circ}C\;to\;28^{\circ}C$ with irradiation of sea water by UV after T. granosa was exposed to air at $4^{\circ}C$ Optimum condition for larval roaring was under the 32.4 psu and two temperature $regimes:\;28{\pm}1^{\circ}C\;and \;25{\pm}1^{\circ}C$. Fertilized eggs was demersal isolated eggs, and egg diameter was $60{\mu}$. D-shaped larvae appear about 20 hr after hatching with $94.1{\mu}$ in shell length and $86.7{\mu}$ in shell height. Ten days were required from hatching to umbo larva stage, of a mean shell length $125.2{\mu}$. On 25th day, the larva grew to $450{\mu}$ in shell length and began to settle on the bottom. Effect of temperature between $25^{\circ}C$ (control group) and $28^{\circ}C$ on larval growth was not different. Survival rate of larvae settled on the bottom was about $19{\%}$ in both temperatures conditions $(25^{\circ}C\;and\;28^{\circ}C)$.

• Molecules and Cells
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• v.39 no.11
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• pp.834-840
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• 2016

Caenorhabditis elegans (C. elegans) utilizes two different cell-cycle modes, binucleations during the L1 larval stage and endoreduplications at four larval moltings, for its postembryonic intestinal development. Previous genetic studies indicated that CDC-25.2 is specifically required for binucleations at the L1 larval stage and is repressed before endoreduplications. Furthermore, LIN-23, the C. elegans ${\beta}$-TrCP ortholog, appears to function as a repressor of CDC-25.2 to prevent excess intestinal divisions. We previously reported that intestinal hyperplasia in lin-23(e1883) mutants was effectively suppressed by the RNAi depletion of cdc-25.2. Nevertheless, LIN-23 targeting CDC-25.2 for ubiquitination as a component of E3 ubiquitin ligase has not yet been tested. In this study, LIN-23 is shown to be the major E3 ubiquitin ligase component, recognizing CDC-25.2 to repress their activities for proper transition of cell-cycle modes during the C. elegans postembryonic intestinal development. In addition, for the first time that LIN-23 physically interacts with both CDC-25.1 and CDC-25.2 and facilitates ubiquitination for timely regulation of their activities during the intestinal development.

• Mycobiology
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• v.38 no.3
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• pp.180-183
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• 2010

This study was conducted out to select a silkworm variety suitable for synnemata production of Isaria tenuipes. Four kinds of the mulberry silkworm varieties, Bombyx mori, were hybridized using a Japanese parental line and a Chinese parental line, and used to test for synemata formation in I. tenuipes. The larval period of normal silkworms was 22 hr longer than the silkworms inoculated with this fungus. Among the silkworm varieties tested, Hachojam had the shortest larval period with 23.02 days. The non-cocooning silkworm had a shorter larval period than the cocoon producing silkworms. The pupation rate of normal silkworms was about 9% higher than that of silkworms sprayed with I. tenuipes. Hachojam had the highest infection rate at 99.8%, but no significant difference was observed for the infection rate by silkworm variety. The production of synnemata was the best in JS171 $\times$ CS188 with an incidence rate of 99.3%, followed by Hachojam, and Chugangjam. The synnemata produced from Hachojam were the heaviest and showed white or milky-white in color.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.2
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• pp.134-138
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• 1999

Eggs and larval development of Chelon affinis were reared and observed in the laboratory with parent fishes obtained in the Minrak fish market Pusan on March, 1997. The spawned eggs of the species are transparent, round, separated, floated, and their diameters were varied within 0.95$\~$1.06 mm. Hatching began about 73 hours after spawning at $16.0^{\circ}C$. The newly hatched larvae were 1.72$\~$1.92 mm in total length with 19 myomeres, mouth and unopened anus, rod shape melanophores distributed in body. The larvae absorbed yolk material completely in 5 days after hatching and became postlarvae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.4
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• pp.498-506
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• 2015

We examined the feeding habits of larval Clupea pallasii using 148 specimens collected from December 2010 to April 2011 in the Nakdong River estuary, Korea. We found that larval C. pallasii [8.3-26.0 mm NL (notochord length)] are carnivorous, consuming mainly copepods, rotifers, cirripeds, and free-living flatworms (Macrostomida). Their diet also include small quantities of shrimp nauplii, tintinnids, cladocerans, and larval bivalves, among other food sources. To evaluate ontogenetic changes in dietary composition, we split larvae into four size groups: 8-12 mm, 12-16 mm, 16-20 mm, and > 20 mm NL. Rotifers were the most important prey items for the smallest group, but all other groups predominantly consumed copepods. The largest group frequently preyed on rotifers, cirripeds and flatworms, in addition to copepods. Larvae also showed bi-modal feeding, with peaks in the late afternoon and at midnight, wherein the mean number of prey per individual peaked at 1,800-1,900 h.

• Animal Systematics, Evolution and Diversity
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• v.5 no.2
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• pp.89-105
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• 1989

농게(Ura arcuata) (달랑게과, 달랑게아과) 의 유생을 부화에서부터 첫 번째 게기까지 수온 $25^{\circ}C$ , 염분농도 33.3$\textperthousand$의 해수에서 사육하고, 각 유생기이 형태적인 특징을 기술 및 도식하였다. 이 종은 5기의 zoea와 1기의 megalopa 유생을 거쳐 첫 번째 게기로 변태하였다. 제 1 zoea 유생기는 제 1 소악의 내지에 4개의 말단강모와 제 2 악각의 기절과 내지에 각각 3개의 우상강모와 0, 0, 5 강모식을 가지고 촉각은 B형이었다. 이러한 특징들은 이미 보고된 같은 과의 유생들의 특징들과 잘 일치하고 있다.

• The Korean Journal of Zoology
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• v.34 no.1
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• pp.93-102
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• 1991

Larvae of Ilyoplax dentimerosa Shen, 1932 were reared in the laboratory at $25^{\circ}C$ and 33.3%o salinity. Four zoeal stages were recognized in the lanral development, and these are described and illustrated. The first soeae of 1. dentimerosa are distinguished from other llyoplax zoeae by having minute spicules on the rostral and dorsal carapace spines, a short dorsal carapace spine about half of the carapace length, a conspicuous antennal exopodite with a subterminal sutta and acute spines on the postero-lateral border of the fourth abdominal somite.

• Animal cells and systems
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• v.11 no.1
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• pp.79-92
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• 2007

Eight zoeal stages and one decapodid of the hippolytid shrimp Latreutes acicularis Ortmann, 1890 are described from laboratory-reared material hatched from egg from ovigerous females collected from Shimoda, Japan. The presence of a minute dorsomedian protuberance on the third abdominal somite, the spinules on the dorsal margin of the fourth and fifth abdominal somites, and a pair of dorsolateral spines on the fourth and fifth abdominal somites readily distinguish the larvae of L. acicularis from those of L. anoplonyx Kemp, 1914 and L. laminirostris Ortmann, 1890, the other two known larvae of Latreutes from East Asia.

• The Korean Journal of Zoology
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• v.33 no.4
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• pp.411-427
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• 1990

The complete larval development of Enocheir japonicus De Haan reared in the laboratory is described and illustrated. E. japonicus passes through 5 zoeal stages before metamorphosis to the megalopal stage. The megalopa and crab I inStar are attained in 17 and 27 days after hatching, respectively. The culture was carried out under a photoperiod of 14 h light and 10 h dark and a constant temperature of $25^{\circ}C$. Morphological charaderistics of each larval stage of this species are compared with those of E. japonicus from Japan. Morphological features between zoea I of the Varuninae are briefly discussed.

• The Korean Journal of Malacology
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• v.32 no.1
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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 $15-20^{\circ}C$.