Vertebral formula in red-crowned crane (Grus japonensis) and hooded crane (Grus monacha)

Red-crowned cranes (Grus japonensis) are distributed separately in the east Eurasian Continent (continental population) and in Hokkaido, Japan (island population). The island population is sedentary in eastern Hokkaido and has increased from a very small number of cranes to over 1,300, thus giving rise to the problem of poor genetic diversity. While, Hooded cranes (Grus monacha), which migrate from the east Eurasian Continent and winter mainly in Izumi, Kagoshima Prefecture, Japan, are about eight-time larger than the island population of Red-crowned cranes. We collected whole bodies of these two species, found dead or moribund in eastern Hokkaido and in Izumi, and observed skeletons with focus on vertebral formula. Numbers of cervical vertebrae (Cs), thoracic vertebrae (Ts), vertebrae composing the synsacrum (Sa) and free coccygeal vertebrae (free Cos) in 22 Red-crowned cranes were 17 or 18, 9–11, 13 or 14 and 7 or 8, respectively. Total number of vertebrae was 47, 48 or 49, and the vertebral formula was divided into three types including 9 sub-types. Numbers of Cs, Ts, vertebrae composing the Sa and free Cos in 25 Hooded cranes were 17 or 18, 9 or 10, 12–14 and 6–8, respectively. Total number of vertebrae was 46, 47, 48 or 49, and the vertebral formula was divided into four types including 14 sub-types. Our findings clearly showed various numerical vertebral patterns in both crane species; however, these variations in the vertebral formula may be unrelated to the genetic diversity.

Physical body parameters of red-crowned cranes Grus japonensis by sex and life stage in eastern Hokkaido, Japan

Red-crowned (or Japanese) cranes Grus japonensis are native to eastern Hokkaido, Japan--the island population, and mainland Asia--the continental population that migrates from breeding grounds along the Amur River Basin to winter in east China and the Korean Peninsula. The island population was reduced to about 50-60 birds in early part of the 20th century. Since 1950s, the population has increased to more than 1,300 as a consequence of human-provided food in winter, resulted in change of their habitats and food resource. From the carcasses of 284 wild cranes from the island population, collected in Hokkaido since 1976 until 2010, we measured six physical parameters (body weight and lengths of body, wing, tarsus, tail and exposed culmen) and divided into groups by sex and three developmental stages (juvenile, yearling and adult). All parameters of males were larger than those of females at the same stage. Total body length of females tends to grow up earlier than males, in contrast to body weight. Obvious time trends were not observed in these all parameters during 34 years for these six categories measured, except total length of male juveniles, which showed a significant increasing trend. These results provide the first extensive data on body size and mass in the wild red-crowned cranes.

Intestinal undifferentiated carcinoma in a red-crowned crane (Grus japonensis)

A 33-year-old red-crowned crane (Grus japonensis) had a diffuse intestinal thickening from the duodenum to colon. Microscopically, neoplastic cells were arranged in sheets and occasionally nests or cords without gland or squamous differentiation. Metastatic tumor cells were found in the lungs, heart, kidneys and adrenal glands. Immunohistochemically, the neoplastic cells were strongly positive for pan-cytokeratin and cytokeratin 8 and 18 and only partly positive for E-cadherin antibodies. Immunostaining for CD3 was positive in normal lymphocytes, and NSE was also positive in normal nerve fibers. But, the neoplastic cells were not immunoreactive to CD3 and NSE. Based on the histological features and the epithelial characteristics in the immunohistochemical stain, the present case was diagnosed as undifferentiated carcinoma originating from the intestine. Interestingly, the neoplastic cells showed a unique growth pattern; they never invaded the submucosa or muscularis throughout the intestine, whereas they spread lymphogenously or hematogenously to other organs.

Changes of mercury contamination in red-crowned cranes, Grus japonensis, in East Hokkaido, Japan

Red-crowned cranes (Grus japonensis) are native to eastern Hokkaido (island population), in contrast to the mainland, which migrates between the Amur River basin and eastern China-Korea peninsula. During the 1990s we found that Red-crowned cranes in Hokkaido were highly contaminated with mercury: however, the source was unknown. We investigated the time trend of mercury contamination in Red-crowned cranes. Total mercury levels in the livers and kidneys from cranes dead in the 2000s were lower than those dead in the 1990s. Feather is a major pathway of mercury excretion for many bird species and is used as an indicator of blood mercury level during feather growth. As internal organs from the specimens collected before 1988 were not available, we analyzed the flight feather shavings from stuffed Red-crowned cranes dead in 1959-1987 and found that the mercury level of feathers from cranes dead in the 1960s and 1970s was not more than those from the cranes dead in the 2000s. These results suggest that mercury contamination in Red-crowned cranes in Hokkaido decreased temporally during the 1990s-2000s. This indicates the possible occurrence of some mercury pollution in Red-crowned cranes' habitat in this region in the 1990s or before.

Telescience testbed experiments of intracellular recordings in the Xenopus oocyte

The feasibility of intracellular recordings under constraints for experimental conditions in outer space were tested at a telescience testbed of the National Space Development Agency of Japan. We attempted to study the dose-response relationship of adenosine-induced potential changes in the Xenopus oocyte. The testbed simulated the distance from a ground control room to oocytes in an orbital laboratory; signals were delayed and compressed from one "station" to other. A microelectrode was inserted into the oocyte using remote control on the manipulator and on the xyz-planes of the platform with stereoscopic pictures observed through a head mounted display. When the transfer rate of the visual signals was decreased from 1.5 Mbps to 128 Kbps, insertion of the electrode became almost impossible because of reduced picture quality. Once the electrode was inserted, however, dose-dependent adenosine responses could be observed with little trouble.

Aquatic animal research in space station and its issues--focus on support technology on nitrate toxicity

We studied the effects of accumulated nitrate in water on the spawning, hatching and development of medaka using a simple nitrifying filter and a combined filter having both nitrifying and denitrifying capabilities. A nitrate concentration of 100 mg NO3(-)-N/L was clearly of lethal toxicity to fish when they were exposed to nitrate in both adult and the growing phases. A nitrate concentration of 75 mg NO3(-)-N/L reduced the fertilization rate, delayed the hatching time and reduced the hatching rate of the eggs laid by adults and decreased the growth rate of juveniles. In addition, nitrate accumulations as low as 50 mg NO3(-)-N/L remarkably retarded spawning and lowered the number of eggs laid by fish exposed in the juvenile phase. The effects on the reproduction system may be initiated by a low concentration, approximately 30 mg NO3(-)-N/L.

Application of nitrifying and denitrifying processes to waste management of aquatic life support in space

Since a biological filter with nitrifying bacteria was firstly applied to aquatic animal experiments in IML-2 mission, the reactor system has been further studied to combine both nitrifying and denitrifying reactions under aerobic environment allowing an efficient removal of inorganic nitrogen from animal wastes. The isolated denitrifying bacteria had an activity under aerobic condition with rice straw providing a metabolic carbon source for the reaction. The advantage of the aerobic biological filter having both nitrifying and denitrifying activities may allow to reduce the size of the life support system and also for its manageability. The paper reports characteristics of the biological filter systems used for the IML-2 mission and the improved combined filter system having both nitrifying and denitrifying activities, and discuss its application to space experiments.

Population dynamics of nitrifying bacteria in an aquatic ecosystem

In a space environment such as Space Shuttle or Space Station, animal experiments with aquatic species in a closed system pose a crucial problem in maintaining their water quality for a long term. In nature, ammonia as an animal wastes is converted by nitrifying bacteria to nitrite or nitrate compounds, which usually become nitrogen sources for plants. Thus an application of the biological reactor with such bacteria attached on some filters has been suggested and experimentally studied for efficient waste managements of ammonia. Although some successful results were reported (Kozu et al. 1995, Nagaoka et al. 1998, Nakamura et al. 1997, 1998) in the space applications, purely empirical approaches have so far been taken to develop a biological filter having a stable nitrifying activity. In this study, we constructed a mathematical model to deal with the dynamics of the ammonia nitrifying processes in a biological reactor. The model describes population dynamics of the ammonia-oxidizing bacteria and the nitrite-oxidizing bacteria cultivated on the same filter. We estimated parameters involved in the model using the experimental data. The result shows that these estimated parameters could be applied to general cases and that the two bacteria are in a symbiotic relationship; they can better perform when both coexist, as has been empirically recognized. Based on the model analysis, we discuss how to prepare a high performance biological filter.

Isolation and properties of the Capnocytophaga ochracea bacteriocin

A bacteriocin from a subgingival plaque isolate of Capnocytophaga ochracea was purified and characterized. It was isolated from cell extract and had a molecular weight of 100,000. Streptococcus sanguis, Streptococcus mitis, Streptococcus mutans and Propionibacterium acnes were susceptible to the bacteriocin.