• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.29-29
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• 2003

In order to establish effective procedures for chromosome manipulation in Haliotis gigantea and H. discus, which are of enormous aquacultural potential, temperature-dependent measures of mitotic intervals ($\tau$$_{0}$) were determined. Mitotic intervals ($\tau$$_{0}$) in these abalone were determined by averaging the duration of the first and third embryonic divisions over a range of temperatures from 8 to 26$^{\circ}C$. The relationships of each mitotic interval at two cell ($\tau$$_{I}$), four cell ($\tau$$_{II}$ ), eight cell ($\tau$$_{III}$), sixteen cell ($\tau$$_{IV}$ ) and $\tau$$_{0}$, to temperature (T in $^{\circ}C$) in H. gigantea were log $\tau$$_{I}$ : 176.1-28.3T, log $\tau$$_{II}$ : 199.5-12.4T, log $\tau$$_{III}$ = 236.2-12.2T, log $\tau$$_{IV}$ = 269.3-14.lT and log $\tau$$_{0}$ : 83.1-32.8, respectively. The relationships of each mitotic interval at $\tau$$_{I}$, $\tau$$_{II}$ , $\tau$$_{III}$, $\tau$$_{IV}$ and $\tau$$_{0}$, to temperature in H. discus were log $\tau$$_{I}$ = 104.9-13.8T, log $\tau$$_{II}$ : 138.3-10.5T, $\tau$$_{III}$ : 172.4-10.2T, log $\tau$$_{IV}$ : 211.3-12.2T and log $\tau$$_{0}$=85.6-33.3T, respectively. There were strong, negative correlations between mitotic interval and water temperatures for all ten temperatures in these two species (H. gigantea: Y = -138.75 logX + 341.25, $R^2$ = 0.97; H. discus: Y = -112.33 logX + 255.22, $R^2$ = 0.98, where Y is mitotic interval and X is temperature).d X is temperature).rature).

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.85-88
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• 2001

Temperature-related cleavage rates and mitotic intervals (${\tau}_o$) in the far eastern catfish Silurus asotus were studied by averaging the duration of the second and third embryonic divisions to establish effective procedures for chromosome manipulations. At higher temperatures eggs developed faster and underwent more asynchronous development. Mitotic intervals for far eastern catfish were $21.5{\pm}1.4$ min at $22^{\circ}C$, $18.5{\pm}1.2$ min at $24^{\circ}C$, and $14.0{\pm}2.1$ min at $26^{\circ}C$. There was a strong negative correlation between ${\tau}_o$ and water temperature (Y=-1.85X+21.9, $R^2=0.9868$, where Y is ${\tau}_o$ and X is temperature).

• Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.278-283
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• 2010

Black plaice, Pleuronectes obscurus (Herzenstein), were collected and fertilized to observe egg development, temperature-related cleavage rates, and mitotic intervals (${\tau}_0$). Fertilized egg was demersal, adhesive, and did not contain oil globules. After 1.75 h, the blastodisc formed, and hatching took place 121 h after fertilization at $14^{\circ}C$. The hatched larvae were $3.5{\pm}0.16\;mm$ in total length. At higher temperatures, eggs developed faster and underwent further identical developmental processes. Additionally, ${\tau}_0$ and water temperature were strongly negatively correlated at all temperatures (Y=-2.6981X+98.767, $R^2$=0.9831, where Y is ${\tau}_0$, and X is temperature) for black plaice.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.429-433
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• 2011

Eggs of Korean rose bitterling Rhodeus uyekii were collected and fertilized to observe temperature-related cleavage rates and mitotic intervals (${\tau}_0$). As the water temperature was increased, the slope of first cleavage frequency with elapsed time after fertilization increased, and approximately 30% of fertilized eggs reached first cleavage frequency at every 15 min. At higher temperatures, eggs developed faster and underwent further identical developmental processes. There were strong, negative correlations between ${\tau}_0$ and water temperatures at all temperatures studied (Y = -1.225X + 70.05, $r^2=0.988$, where Y is ${\tau}_0$ and X is temperature).

• Development and Reproduction
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• v.16 no.4
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• pp.321-327
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• 2012

Korean bullhead (Pseudobagrus fulvidraco) was collected from the Kum River areas of Kangkyung-eup, Nonsan city, Chungcheongnam-do, Korea, from April to June, 2012 and was fertilized in order to observe egg development and temperature-related cleavage rates and mitotic intervals (${\tau}_0$). The fertilized eggs were separative, demersal and light yellowish with $1.5{\pm}0.06mm$ in diameter, and did not contain oil globules. The first cleavage stages were 90 min, 80 min, 60 min and 50 min at $21^{\circ}C$, $24^{\circ}C$, $27^{\circ}C$ and $30^{\circ}C$, respectively. At higher temperatures, eggs developed faster and underwent further identical development. For Korean bullhead, ${\tau}_0$ were $33.4{\pm}2.08$ min at $21^{\circ}C$, $31.5{\pm}3.06$ min at $24^{\circ}C$, $28.1{\pm}2.11$ min at $27^{\circ}C$ and $26.4{\pm}3.35$ min at $30^{\circ}C$. There were strong negative correlations between the $\tau_0$ and water temperatures at all points studied (Y=-1.13X+58.15, $R^2$=0.98, n=30, where Y is ${\tau}_0$ and X is temperature). The results obtained in this work will be helpful for chromosome manipulation by use of cleavage frequency data and ${\tau}_0$ data in Korean bullhead.

• Development and Reproduction
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• v.22 no.1
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• pp.111-117
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• 2018

The objective of this study was to determine the mitotic intervals (${\tau}_0$) of two consecutive cell divisions and synchronous embryonic cleavage in grass puffer, Takifugu niphobles at different water temperatures (18, 20, 22, and $24^{\circ}C$). The color of the fertilized egg was light yellowish. The egg type was demersal and unadhesive. Egg weight was $0.09{\pm}0.002mg$. The sizes of unfertilized eggs were smaller than fertilized eggs in major axis and minor axis at $20^{\circ}C$ (p<0.05). The size of the fertilized egg of $18^{\circ}C$ water temperature group at the blastodisc stage was the smallest (p<0.05), but no significant differences were observed in the other water temperatures group except $18^{\circ}C$ water temperature group (p>0.05). The first cleavage stages at 18, 20, 22, and $24^{\circ}C$ were at 75, 90, 105, and 120 mins, respectively. As water temperature was increased, embryonic development and formation time of the first cleavage furrow were accelerated. There were negative correlation between ${\tau}_0$ and water temperature for grass puffer (Y=-1.225X+70.05, $R^2=0.988$, n=10, where Y was ${\tau}_0$ and X was temperature). This study confirmed that successful hatching of grass puffer was related to water temperature. Chromosome manipulation will be helpful for this species using cleavage frequency and ${\tau}_0$.