● Publications
8. Hasegawa R., Murakami L., Aruga N., Sato N., Nakamura S. & Koizumi I.「Host specificity of the parasitic copepod Salmincola markewitschi in an aquarium」Japanese Journal of Fish Pathology in press
7. Hasegawa R. & Koizumi I. 「Consistent negative correlations between parasite infection and host body condition across seasons suggest potential harmful impacts of Salmincola markewitschi on wild white-spotted charr Salvelinus leucomaenis」Zoological Science 41(2). 2024. doi.org/10.2108/zs230028
6. Hasegawa R. & Koizumi I. 「Parasites either reduce or increase host vulnerability to fishing: a case study of a parasitic copepod and its salmonid host」The Science of Nature 110: 10. 2023. doi: 10.1007/s00114-023-01836-x English Press release is here
5. Hasegawa R., Katahira H. & Koizumi I. 「Salmincola markewitschi (Copepoda: Lernaeopodidae) or S. carpionis ? A taxonomic confusion due to high morphological variations and a requirement for revising their taxonomic status」Folia Parasitologica 69: 025. 2022. doi: 10.14411/fp.2022.025
4. Hasegawa R., & Nitta M.「Rediscovery of Lernaeenicus ramosus Kirtisinghe, 1956 (Copepoda: Pennellidae) parasitizing the type host, comet grouper Epinephelus morrhua (Perciformes: Serranidae) from the Japanese coast, with a note on its underdeveloped head」Biogeography 24: 25-31. 2022. https://doi.org/10.11358/biogeo.24.25
3. Hasegawa R., Ayer C. G., Umatani Y., Miura K., Ukumura M., Katahira H. & Koizumi I. 「Potential negative effects and heterogeneous distribution of a parasitic copepod Salmincola edwardsii (Copepoda: Lernaeopodidae) on Southern Asian Dolly Varden Salvelinus curilus in Hokkaido, Japan」Parasitology International 87. 102529. 2023. https://doi.org/10.1016/j.parint.2021.102529
2. Hasegawa R., & Koizumi I. 「Relative importance of host dependent vs. physical environmental characteristics affecting the distribution of an ectoparasitic copepod infecting to the mouth cavity of stream salmonid」 Ecological Research 36: 1015-1027. 2021. https://doi.org/10.1111/1440-1703.12262
1. Hasegawa R., Yamada H., Ishihara C., Wada S.「Personality differences in white-spotted char fry evident habitats」Japanese Journal of Ichthyology 67 (1): 11-24. 2020．In Japanese with English Abstract
Under review:
・Hasegawa R. & Koizumi I.「Does mouth-infecting parasite alter the foraging ecology of host fish? A test by parasitic copepod Salmincola markewitschi and white-spotted charr Salvelinus leucomaenis」(submitted on 2024/2/20)
・Hasegawa R., Sugimoto Y. & Koizumi I.「A new locality record of the ectoparasitic copepod Salmincola californiensis in Japan: a potential relic population with high vulnerability to extinction」（submitted on 2024/5/24）
・Hasegawa R., Otsuki Y., Uemura Y., Furusawa C., Naka M., Kanno Y., Koizumi I.「Positive feedback between parasite infection and poor host body condition reduces host survival in the wild」(Resubmitted on 2024/6/17)
・Hasegawa R., Uemura Y., Yamashita Y., Inoshita M. & Koizumi I.「Highly threatened status for the relict populations of ectoparasitic copepod Salmincola californiensis in Japan」(submitted on 2024/7/17)
● Awards
7. Mar. 2022. Best English Presentation Award (Animal population section). The 69th Annual Meeting of the Ecological Society of Japan (See 16 below)
6. Oct. 2021. Best oral presentation award for students. The 67th Joint Annual Meeting of Northern Branches of the Japanese Society of Parasitology and the Japan Society of Medical Entomology and Zoology (See 13 below)
5. July. 2021. JASSO Repayment Exemption for Students with Particularly Outstanding Results (All exemption)
4. Mar. 2021. Best poster presentation award. The 68th Annual Meeting of the Ecological Society of Japan (See 8 below)
3. Feb. 2021. Excellent oral presentation award for master students. Master's thesis presentation in 2020.
2. Nov. 2020. Best poster presentation award. The 36th Annual Meeting of the Society of Population Ecology (See 6 below)
1. Nov. 2019. Excellent oral presentation award for students. Annual Meeting of the Hokkaido Branch of Ecological Society of Japan 2019. (See 2 below)
● Grants
7. JSPS Overseas Research Fellow（April 2024~）
「Priority effects in parasite community assembly and its consequences on host fitness and ecosystem functioning」
6. JSPS Postdoctoral Fellow (PD) (declined due to acceptance of 7)
「Resolving priority effects in parasite community assembly from host immunological aspects」
5. The research grant from Yanmar Environmental Sustainability Support Association (April 2023~ Mar. 2024)
JPY ¥300,000
「Temperature-dependent effects of Salmincola edwardsii on body condition of southern Asian Dolly Varden」
4. Grant-in-Aid for Scientific Research of Lake Akkeshi and Bekanbeushi Wetland（April. 2022~Mar. 2023）
JPY ¥150,000
「Current population status of highly threatened ectoparasite Salmincola californiensis」
3. JSPS Research Fellow DC2（April. 2022~Mar. 2024）
JPY ¥1,700,000
「Priority effects in parasite community assembly and its consequences on host fitness」
2. Hokkaido University ambitious fellowship for Ph. D. student Ministry of Culture, Science and Technology（April 2021~Mar. 2022）JPY ¥360,000
1. Grant support for overseas meeting presentation by Environmental Science Alumni (1st term, 2021) JPY ¥100,000
● Presentation at conference
◯: Presenter
Under line: Hasegawa
23. ◯Uemura Y., Otsuki Y., Hasegawa R., Naka M., Koizumi I.「Mechanisms of spatial segregation under highly asymmetric competition in juvenile charr: a field experiment」『The 10th International Charr Symposium』P9, Nikko, Japan. June 2023. Oral, English. Peer reviewed.
22. ◯Hasegawa R., Uemura Y., Miura K., Koizumi I.「Coinfection patterns of three ectoparasites on congeneric stream salmonids and its impacts on host fishes」『The 10th International Charr Symposium』P2, Nikko, Japan. June 2023. Oral, English. Peer reviewed.
21. ◯Uemura Y., Otsuki Y., Hasegawa R., Naka M., Koizumi I.「Mechanisms of spatial segregation under highly asymmetric competition in juvenile salmonids: a field experiment」『The 70th Annual Meeting of the Ecological Society of Japan』A03-03, Sendai, Japan (Online). Mar. 2023. Oral, English.
20. ◯Hasegawa R., Uemura Y., Miura K., Koizumi I.「Elucidating the coinfection patterns of three species of parasites infecting stream salmonid: effects on host condition and geographic distribution」『The 70th Annual Meeting of the Ecological Society of Japan』P2-019, Sendai, Japan (Online). Mar. 2023. Poster, Japanese.
19. ◯Uemura Y., Otsuki Y., Hasegawa R., Koizumi I.「Parapatric distribution allowed by temperature-dependent competition: a field assessment in two congeneric fishes.」『The 13th International Congress of Ecology (INTECOL2022)』329, Geneva, Swizerland (Online). August 2022. Poster, English. Peer reviewed.
18. ◯Hasegawa R., Otsuki Y., Uemura Y., Furusawa C., Naka M., Koizumi I.「Positive feedback of parasite infection and reduced host condition: a test by mark-recapture of stream salmonid and parasitic copepod」『The 15th International Congress of Parasitology (ICOPA2022)』ID113, Copenhagen, Denmark. Aug. 2022. Oral, English. Peer reviewed.
17. ◯Uemura Y., Otsuki Y., Hasegawa R., Naka M., Koizumi I. 「Do population density and individual body condition predict the habitat quality of stream salmonids?」『The 69th Annual Meeting of the Ecological Society of Japan (ESJ69)』Fukuoka, Japan (Online), P3-324, Mar. 2022. Poster, Japanese.
16. ◯Hasegawa R. & Koizumi, I「Do impacts and infection levels of parasite change across seasons? A test in stream salmonid and parasitic copepod system 」『The 69th Annual Meeting of the Ecological Society of Japan (ESJ69)』B03-04, Fukuoka, Japan (Online). Mar. 2022. Oral, English. Best English Presentation Award.
15. ◯Uemura Y., Otsuki Y., Hasegawa R., Naka M., Koizumi I. 「Temperature-dependent competition in stream salmonids: a field assessment considering biotic interactions and abiotic factors.」『The 45th Annual Meeting of Gyorui Keito Kenkyu-kai』Sapporo, Japan (Online). Dec. 2021. Oral, Japanese.
14. ◯Hasegawa R. & Koizumi I.「Are parasitized fish not vulnerable to fishing ? impacts of the mouth infecting copepods on host fish, white-spotted charr」『The 45th Annual Meeting of Gyorui Keito Kenkyu-kai』Sapporo, Japan (Online). Dec. 2021. Oral, Japanese.
13. ◯Hasegawa R. & Koizumi I.「Are parasitized fish not vulnerable to fishing ? impacts of the mouth infecting copepods on host fish, white-spotted charr」『The 67th Joint Annual Meeting of Northern Branches of the Japanese Society of Parasitology and the Japan Society of Medical Entomology and Zoology』Asahikawa, Japan (Online). Oct. 2021. Oral, Japanese. Best Oral Presentation Award.
12. ◯Uemura Y., Otsuki Y., Hasegawa R., Koizumi I. 「Habitat assessment for stream charrs: a field test focusing on the population density and individual body condition」『The 55th Annual Meeting of the Ichthyological Society of Japan』 68, Online. Sep. 2021. Poster, Japanese.
11. ◯Hasegawa R. & Koizumi I.「Are parasitized fish not vulnerable to fishing ? impacts of the mouth infecting copepods on host fish, white-spotted charr」『The 55th Annual Meeting of the Ichthyological Society of Japan』69, Online. Sep. 2021. Poster, Japanese.
10. ◯Uemura Y. , Otsuki Y., Hasegawa R., Koizumi I.「Condition-specific competition in native charrs: a field test considering abiotic factors and biotic interactions」『The 2021 Ecological and Evolutionary Ethology of Fishes Biennial Conference (EEEF2021)』Day1-005, Berkeley, USA(Online). July 2021. Oral, English. Peer reviewed.
9. ◯Uemura Y. , Otsuki Y., Hasegawa R., Koizumi I.「Temperature-dependent competition in stream salmonids: a field test considering biotic interactions and abiotic factors」『The 68th Annual Meeting of the Ecological Society of Japan (ESJ68)』G03-07, Okayama (Online). Mar. 2021. Oral, English.
8. ◯Hasegawa R., Otsuki Y., Uemura Y., Furusawa C., Naka M., Koizumi I.「Disentangling the causal relationship between parasite infection and low host condition」『The 68th Annual Meeting of the Ecological Society of Japan (ESJ68)』P1-015, Okayama, Japan (Online), Mar. 2021. Poster, Japanese. Best Poster Presentation Award.
7. ◯Uemura Y., Otsuki Y., Hasegawa R., Koizumi I.「Condition-dependent competition in stream salmonids: a field test considering biotic interactions and abiotic factors.」『Annual Meeting of the Hokkaido Branch of Ecological Society of Japan 2020』Sapporo, Japan (Online). Dec. 2020. Oral, Japanese.
6. ◯Hasegawa R., Otsuki Y., Furusawa C., Uemura Y., Naka M., Koizumi I.「Do parasite infections cause new parasite infections?: a mark-recapture approach focusing on white-spotted charr and their parasitic copepods Salmincola carpionis」『The 36th Annual Meeting of the Society of Population Ecology』PP017, Sendai, Japan (Online). Nov. 2020. Poster, Japanese. Best Poster Presentation Award.
5. ◯Hasegawa R. & Koizumi I.「Factors affecting the abundance of parasitic copepods that attach to the mouth cavity of salmonids」『The 67th Annual Meeting of the Ecological Society of Japan (ESJ67)』P1-PA-023, Nagoya, Japan. Mar. 2020. Poster, Japanese. Canceled due to covid-19
4. ◯Murakami L., Hasegawa R., Otsuki Y., Koizumi I., Kajihara H.,「Prevalence of parasitic copepods in the pools and shallows」『The 67th Annual Meeting of the Ecological Society of Japan (ESJ67)』P1-PA-023, Nagoya, Japan. Mar. 2020. Poster, Japanese. Canceled due to covid-19
3. ◯Hasegawa R. & Koizumi I.「Heterogeneous distribution and effects on the host of parasitic copepod Salmincola carpionis infecting on white-spotted charr」『The 44th Annual Meeeting of Gyorui Keito Kenkyu-kai』Sapporo, Japan. Dec. 2019. Oral, Japanese.
2. ◯Hasegawa R. & Koizumi I.「Heterogeneous distribution and effects on the host of parasitic copepod infecting on white-spotted charr」『Annual Meeting of the Hokkaido Branch of Ecological Society of Japan 2019』Tomakomai, Japan. Nov. 2019. Oral, Japanese. Excellent Oral Presentation Award for students.
1. ◯Hasegawa R., Yamada H., Morimura H., Ishihara Y., Wada S.「Personality differences between habitats in juvenile white-spotted charr: focusing on the effects of dams」『The 66th Annual Meeting of the Ecological Society of Japan (ESJ66)』P1-093, Kobe, Japan. Mar. 2019, Poster, Japanese.
● Seminar and workshop
8. ◯Hasegawa R. 「Ecological study of the lernaeopodid copepod of the genus Salmincola -Geographic distribution and causality between host body condition and infections」『CIGENE seminar series, Norwegian University of Life Sciences (NMBU)』Oslo, Norway (Online), Nov. 2022 (Oral). Invited speaker.
7. ◯Hasegawa R.「Ecology of Salmincola sp. infecting on white-spotted charr in wild streams」『The 91th Annual Meeting of the Japanese Society of Parasitology, "The 36th free-meeting of Ecology and Epidemiology"』Obihiro, Japan. May. 2022. Oral, Japanese. Invited speaker.
6. ◯Hasegawa R.「Ecological study of the lernaeopodid copepod of the genus Salmincola -Geographic distribution and causality between host body condition and infections」『Seminar at Evolutionary Biology Group, University of Bergen』 Bergen, Norway (Online). April 2022 (Oral).
5. ◯Hasegawa R.「Disentangling the causal relationship between parasite infection and low host condition」『ISM seminar - Statistical model for ecological data』Tachikawa, Japan. Jan. 2022. Oral, Japanese.
4. ◯Hasegawa R.「Ecology of Salmincola sp. infecting on white-spotted charr in wild streams」『The 85th Annual Meeting of the Japanese Society of Limnology (workshop by Limnology of youth, E-kai)』Tokyo(Online). Sep. 2021. Oral, Japanese.
3. ◯Hasegawa R.「Determinants of basin-wide distribution and effects on hosts of parasitic copepods infecting white-spotted charr」『The 13th Annual Meeting of Salmon Science Society, Night session』Sapporo, Japan (Online). Dec. 2020. Oral, Japanese. Invited speaker.
2. ◯Hasegawa R. & Koizumi I.「Heterogeneous distribution and effects on the host of parasitic copepod infecting on white-spotted charr」『The 1st Meeting of Master Course Research Seminar- learning statistical analysis with R』Sapporo, Japan. Jan. 2020. Oral, Japanese.
1. ◯Hasegawa R. & Koizumi I.「Host-patasite relationship between Salmincola carpionis and wild white-spotted char」『 Nord University Lunch time Seminar』 Bode, Norway. Sep. 2019. Oral, English.
● Outreach
6. Sep. 2023. Exhibition of parasites infecting salmonid fishes@Sapporo Salmon museum, Sapporo
5. July 2023. Sapporo culture night "Observation on fish parasites"@ Nishioka park, Sapporo
4. Oct. 2022-. Introductions for parasites infecting salmonid fish@Sapporo Salmon museum, Sapporo
3. July 2019. Environmental Education for elementary school students @ Makomanai, Sapporo
2. 2017-2018. Volunteer at Hokkaido University Museum (Management of fish collections)
1. 2016-2024 WEB-sakana-zukan staff
● Reviewer experience
・Japanese Journal of Ichthyology
・Molecular Biology Report
・Transactions of the American Fisheries Society
・Crustacean Research