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Volume 30, Issue 2
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Masuzo UÉNO1969 Volume 30 Issue 2 Pages 45-58
Published: June 28, 1969
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSThis paper deals with the fauna of the six small and shallow bodies of water in the neighbouring districts of, and at some distance from, Teheran in Iran. The fauna of those waters is composed of only the Crustacea, i. e., Cladocera, Copepoda and Ostracoda. Even the species occurring in the richest number did not exceed nine, followed by six, and varying mostly from one to three. Cyclops tatricus is the dominant species occurring in almost all the bodies of water under study, with Daphnia magna and Ceriodaphnia reticulata in less abundance. The chydorids are representatives in the summer months. The annual changes are discussed concerning the species in the biocenosis of the pool at Chahar Donghe west of Teheran. This temporary water is discussed also in its typological aspect.View full abstractDownload PDF (1632K) -
Norizumi KITAGAWA1969 Volume 30 Issue 2 Pages 59-67
Published: June 28, 1969
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSThe growth of Spaniotoma sp. A, which is the most dominant species among the Chironomidae larvae at Migataki station of the Yoshino River, was studied by the periodical observation during a year, from December 1967 to November 1968.
The instars of the larva can be distinguished by its head length, though the head length changes with seasons; generally it is small in summer (the head of the forth instar larva being 0.340.38 mm long) and larger in winter (the head of the forth instar larva being 0.400.56 mm long). And the difference of length between summer and winter gets larger with the advance of the instar.
Winter-passing larvae are thought to have hatched from eggs in the early October; they pass the first half of winter period as the third instar larva and the last half as the forth instar larva. No pupa was found in winter. Low water temperature (56°C) seems to restrain the moulting of the larva as well as the pupation.
Duration of one generation is about 30 days in summer, about 60 days in spring and about 180 days over the winter.
As shown in fig IV, the generation of Spaniotoma sp. A can be assumed to repeat five or six times in a year.View full abstractDownload PDF (985K) -
Ikuko NAKAMURA1969 Volume 30 Issue 2 Pages 68-80
Published: June 28, 1969
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESS(1) The life cycle of a calanoid copepod, Eodiaptomus japonicus, in a small pond called Araike, Nara City, was studied during the late spring months (17/V3/VI) and during the summer months (22/VII16/VIII) of 1968.
(2) At three different stations in the pond vertical plankton sampling was made at time interval of mostly 15 days.
(3) The stages of Eodiaptomus japonicus were determined by the structure of the appendages as well as the whole body. Though the life cycle consists of six nauplius stages and six copepodid stages in addition to egg stage, it is not easy to distinguish the stages of the nauplius, so they were counted together.
(4) The duration of each instar was obtained by estimation of the time interval between peaks of each stage. These time intervals in days were estimated for all stages as follows :
spring summer
Nauplius stage 4 days 12 days
Copepodid I 12
C IC IV 3
C IIC V 45 (July), 12 (August)
C V more than 4
C VI (adult) 4 (July), 2 (August)
Among the three stations, no difference was recognized.
(5) The mortality rates of the instars were determined. The rate of nauplius stage was highest, being about 80%, the rates of copepodid I, II, III, IV and V were 2030% of each.View full abstractDownload PDF (1100K) -
Matsunae TSUDA1969 Volume 30 Issue 2 Pages 81-85
Published: June 28, 1969
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSDownload PDF (579K)
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