Since I was an undergraduate student, I have been studying Daphnia pulex (Japanese name: “Mijinko”) living in Japan. There are four non-sexually reproducing strains of D. pulex in Japan, and these four strains have different distribution ranges. “Why does the distribution range differ among the species?” To reveal this question, I went to field sampling at lake or pond and I conducted some culture experiments by focusing on growth rate and temperature tolerance. I am now developing this study a little and are studying the mechanism of intraspecific coexistence of D. pulex using not only the ecological methods but also molecular methods.In addition, in the laboratory, we are also conducting research on the classification of undescribed Daphnia species from morphological observation and genetic analysis of Daphnia. I drew sketches by dissecting Daphnia through a microscope to observe detailed morphological characters.

When I was in the first year of junior high school, I fell in love with the picture of Daphnia in the science textbook. She is so small, but she has big black eyes, internal organs and complicated structures. So, “she is living as hard as we are!” I thought. Then, I read a book about the ecology of Daphnia and looked pictorial books, and I was shocked that the organism itself, Daphnia, is well known, but the ecology is full of things that are unexpectedly unknown. When I was in junior high school, I went to a nearby paddy field to look for Daphnia, but I could not easily meet a Daphnia. When I first saw a “Daphnia” in a small swamp when I was in third grade, I was very happy and impressed! However, I think about it now, I can now understand that although that “Daphnia” was a member of Cladocera , it was a slightly different species belonging to Macrothricidae.

Since last year, it has become a really unstable world, and I think that you are forced to live with the stress. Especially, high school students may be particularly worried about the future. I also sometime get depressed, but I still love Daphnia, so my research life after entering university is really like a dream and I really enjoy it. Please don't be discouraged and do your best taking pride in what you like or interesting. And if you are interested in Daphnia and take a look at the world of Daphnia, I am so happy!