• The Korean Journal of Ecology
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• v.4 no.3_4
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• pp.114-123
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• 1981

Diurnal acid fluctuations, stomatal resistance, and morphology and anatomy were investigated in leaves and stems P. oleracea L. growing under the natural environmental condition. A CAM-like pattern of acid fluctuation was exhibited not in leaves of the young purslane but in its stems. Defoliated stems showed a decreased in diurnal changes of total acidity as compared with normal stems. Excised stems stored in continuous darkness exhibited diurnal acid rhythms, and they showed light deacidifications for three days. Kranz-type arrangement was observed in leaves, but not in stems. Micrography of cross sections of stems showed cells with relatively large vaculoles and a few chloroplasts. The number of stomata was 3,275cm-2 in leaves, while the stomata could not be observed in stems. Stomatal resistance was high at night and low in daytime in leaves of the young purslane, and the range of its value was 5~40 sec.$\textrm{cm}^{-1}$. But stomatal resistance in leaves of the water-stressed plant was comparratively high in day time, and its value was 30 sec.$\textrm{cm}^{-1}$. The result of these studies showed the possibility that the stem of P.oleracea L. possesses CAM under certain stressed conditions.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.2
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• pp.112-119
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• 2012

This study investigated the diel and tidal distributions of the two mysids, Archaeomysis kokuboi and Acanthomysis nakazatoi, in relation to their growth stages in the sandy surf zone of Yongil Bay, located on the southeastern part of Korean Peninsula. Sampling was conducted with a sledge net at every two hours for almost 24 hours at three sites: water edge, water surface and sand bottom both in 1-m deep water areas. The abundance of Archaeomysis kokuboi juveniles was too low to count both in day and night samples. While there was no difference in immature A. kokuboi abundance between day and night in the bottom or water edge, that at the water surface was significantly higher at night than daytime. The abundance of A. kokuboi adults, especially of males, in the bottom was significantly higher in daytime than night and no individuals appeared to the water surface either day or night. In comparison, the abundance of Acanthomysis nakazatoi juveniles between day and night did not differ significantly at all the three sites, with the highest number being distributed in the bottom. The abundance of immatures between day and night also did not differ significantly and no individuals appeared to the water surface either day or night. The abundance of A. nakazatoi adults, especially females, in the bottom was significantly higher at night than daytime and there was no significant difference in abundance between day and night in the other sites. There was also no significant difference in abundances of the two species between ebb and flood tides, except for A. kokuboi immatures which appeared significantly more during the ebb tides at the water surface. Overall, the distribution of the two sympatric species, A. kokuboi and A. nakazatoi, was not the same in the sandy surf zone. Its difference seems to depend on their stages of growth, and the change in their abundance may be influenced more by diurnal rhythms than tidal effects. The population density of A. nakazatoi in the sandy surf zone was much higher than that of A. kokuboi, and relatively higher densities in all growth stages of the former were found in the sandy bottom ranging from juveniles to adults. These results indicate that A. nakazatoi has exceedingly better ability of sand burrowing even from the juvenile stage, and thus is an ecologically better adapted species in the sandy surf zone than another sympatric species, A. kokuboi.