Investigation of the alien freshwater snails in the pet shop aquarium.

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K06097
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39060:Conservation of biological resources-related
• Research Institution: Nihon University
• Principal Investigator: NAKAI Shizuko 日本大学, 生物資源科学部, 助教 (40582317)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 外来種 / アクアリウム / 貝類 / 淡水無脊椎動物 / 水草

Outline of Final Research Achievements

The current state of the contamination of the alien freshwater snails in pet shop aquarium and household aquarium were investigated throughout Japan. There are two types of aquarium-related snails: the tank cleaner and the pest snail. The tank cleaner snail is introduced to remove algae from the tank wall or to be tank mates of fishes, shrimps, and others. Many alien snails are sold as tank cleaners, but these snails are not naturally breeding in aquariums except for two species. On the other hand, the pest snail is introduced to aquariums unexpectedly and increases in population without noticing. There are several alien species in these pest snails in Japan. Transportation of aquatic plants has a strong relationship with contaminating these pest snails between aquariums.

Free Research Field

生態学

Academic Significance and Societal Importance of the Research Achievements

日本国内の河川では、複数の外来淡水貝類の移入が確認されている。しかし、それら外来貝類の国内への侵入経路は不明であることが多く、野外への移入経路の一つとして家庭のアクアリウムが疑われることがあるが、家庭のアクアリウムにおける外来淡水貝類の実態は不明な点が多い。
本研究により、家庭やペットショップのアクアリウムにおける外来貝類の飼育や混入の実態が明らかになった。一方で家庭の水槽内で容易に繁殖した実例は一部の外来種に限られ、最も多く見つかったのは外来種のサカマキガイであった。家庭のアクアリウムに外来種が生息していることが明らかになるとともに、種ごとに野外への放出リスクが異なることが示唆された。