Research groups such as Osaka Prefecture University have conducted field surveys aimed at identifying the cause of the decline in the number of wild Japanese rye butterflies, which are considered to be endangered species in the national natural monument.As a result, two species of protozoans that parasitize the gastrointestinal tract are widespread in the Japanese rye butterfly, and the infection rate is particularly severe in the summer, which is the breeding and brooding season, which is one of the factors for the decrease in the population. It became clear that it may have become.In addition, genetic analysis revealed that one of the protozoans is a new species.
The population of Japanese grouse was about 1980 in the 3000s, but now it has decreased to less than 2000.In particular, the low growth rate of chicks after hatching is an issue, but the details of the cause are unknown.
本研究では、日本アルプスの山岳において889検体（雛72検体含む）の便を採取し調査した。原虫の陽性率は、2006年と2007年では41.7％と57.5％、2016年と2017年では34.3％と38.5％で、感染率は孵化後の育成期である7～8月にかけて上昇し、特に雛で重度に感染していた。
Two types of protozoans were detected, and as a result of genetic analysis, both were unreported species in the world.One of them was named E. raichoi, which means derived from Japanese grouse, as a new species.
Protozoans are usually vulnerable to cold and do not infect at low temperatures.However, the protozoan parasitizing the Japanese grouse can be infected even at low temperatures and can survive for a long time in cold regions.It is possible that protozoans that accidentally parasitized grouse from chickens and turkeys evolved with grouse and adapted to cold regions.
Based on the results of this research, which identified two species of protozoans that parasitize grouse at the genetic level, it is expected that active measures against protozoans will contribute to increasing the population of grouse.
