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Successful breeding of the giant panda (Ailuropoda melanoleuca) following artificial insemination was achieved at the Ueno Zoo in 2 consecutive years (1985 and 1986). The first cub, born in June 1985, unfortunately died 43 hours after birth from being crushed by the mother panda; the second cub, born in June 1986, has been growing in good health. Electroejaculation and artificial insemination procedures were performed after immobilization with diazepam (0.1 mg/kg) and ketamine HCL (4.0-5.0 mg/kg). Semen of the male panda was collected by electroejaculation using a rectal probe with a diameter of 2.0 cm and with eight rings as electrodes. Stimulation of the male was given with 3 V (30-40 mA) over a 5-sec period with 5-sec intervals. The female panda exhibited estrus between late February and early March in 1985 and also between middanuary and early February 1986. Increased excretion of urinary total estrogen showed coincidentally at maximum behavioral estrus, and a gradual rise of pregnanediol level was followed by artificial insemination. The gestational length for the first pregnancy was 110 days and that of the second 121 days.

Two methods were developed for the quantitative sampling of rotifers and cladocerans attached to aquatic macrophytes while separating them from plankton. We named them the "covering method" and the "picking-up method." We consider the covering method to be better for estimating the abundance of animals on plants, but it requires hard work on a boat. In contrast, the picking-up method is simple and easy to perform, but it seems to estimate animal abundance with some errors. The densities of rotifers and cladocerans on emergent and submerged plants in two Japanese lakes were estimated by the two methods, and the results were compared. The densities of most animals (e.g., the rotiferans Brachionus, Mytilina, Lepadella, and Colurella, and the cladoceran Alona) estimated by the picking-up method did not differ from those estimated by the covering method. In contrast, the densities of the rotiferans Monostyla, Euchlanis, and Trichocerca estimated by the picking-up method tended to be lower than those estimated by the covering method. These suggest that the picking-up method is suitable for estimating many densities, except for some rotiferan genera.

Lake Kitaura is a shallow lake maximum depth: 7m surrounded by low diluvial uplands and alluvial plains in the eastern Kanto region, central Japan. A northeasterly wind prevails throughout the year except in winter. The steady wind direction is suitable for the study on wind effects in relation to bottom surface sedimentation in Lake Kitaura.Grain size and chemical components of bottom surface sediments are controlled by water movements such as lake currents and wave action Inouchi et al., 1989;Kumon et al., 1993 . The dominant factors for lake water movement may average out the nature and distribution of the bottom sediments. Lake sediments can record sedimentary processes of lakes which reflect past environmental conditions. There are many controlling factors of sedimentary process; however, it is thought that Introduction wave action induced by wind is the principle controlling factor in shallow lakes Sly, 1978. Inouchi et al. 1989 showed the spatial distribution of heavy metals, total carbon and total nitrogen in Lake Kasumigaura, and explained that the distribution was due to reworking and resedimentation by wave and lake current. Inouchi et al. 1989 and Inouchi 1990 also showed the areal distribution pattern of heavy metals, total carbon, total nitrogen and the accumulation rate in Lake Biwa, and put forward a cloud model for deep lake sedimentation. Kumon et al. 1993 studied the grain size distribution of bottom surface sediments in Lake Biwa.They pointed out that the geostrophic gyre may be a primary factor controlling the distribution of bottom sediments in the off-shore zone of Lake Biwa, and advocated that the grain size distribution reflected average movements of lake currents. Chikita 1986 is an example of an earlier study discussing the river inflow effect to lake sed- Characteristics of bottom surface sediments in relation to wind and wave action in Lake Kitaura, central JapanIn order to reveal sedimentary processes in shallow lakes, we collected samples from points in Lake Kitaura-a shallow coastal lagoon in the eastern margin of the Kanto region, central Japan, and analyzed grain size distribution, TOC, TN and C/N ratio. We propose a new depositional model for shallow lakes controlled by wave action owing to wind. The distribution of sandy sediments is restricted to areas near the perimeter of the lake, and correlates with areas of low contents of TOC and TN. Alternatively, clay-rich sediments are most widely distributed, and show high concentrations of TOC and TN. The TOC /TN ratio is low, about to throughout the basin, suggesting that major organic matter originated from planktons in the lake. High TOC/TN ratios over recognized in the northern end of the lake evidently suggests the influence of tributary rivers. The bottom sediments of Lake Kitaura are characterized by a predominance of clayey sediments which cover most of the sublacustrine plain and a narrow zone of sandy sediments along the southern coastal area shallower than . m. The former sediments are transported as suspended matter rew...

We investigated seasonal changes in the density of epiphytic cladocerans Alona spp.