Host species for the glochidia of the freshwater unionid mussel Sinanodonta sp. from Lake Biwako were identified by determining whether the glochidia infected 18 fish taxa in autumn. The fishes were kept in tanks for 11–16 days after glochidial infection, and the numbers of glochidia and metamorphosed juveniles detached from the hosts were counted. All adults of the mussel which used for the experiments were identified by Sinanodonta calipygos from the form of shells and season of released glochidia. Living juveniles of S. calipygos detached from Candidia temminckii, Oryzias sp., Acanthogobius flavimanus, Gymnogobius urotaenia, Trichogaster trichopterus, Rhinogobius similis and Rhinogobius sp. Therefore, these fishes were identified as suitable host species for the glochidia of S. calipygos. Some native fishes that inhabit Lake Biwako (e.g., Gymnogobius urotaenia and Rhinogobius sp.) are considered to be useful local hosts.
The karyotypes of three species of the genus Semisulcospira at Lake Biwa and the Uji river, Japan were reexamined. The observed diploid chromosome number was as follows: Semisulcospira reiniana, 2n=36 (28M+6SM+2ST); S. nakasekoae, 2n=22 (18M+2SM+2T); S. morii, 2n=32 (20M+10SM+2T). The number of chromosomes in S. niponica group ranged from 2n=18 to 32, but no case of 2n=30 has been reported. The number of chromosomes in S. libertina group was 2n=36 with a variation of karyotypes.
上述の種のほか，コガタツマミガイ“M.” subulaやヒモイカリナマコツマミガイ“M. lactea”がMucronalia属として扱われることがある。しかしながら，前者は殻口外唇が湾曲せず，カシパンヤドリニナ属Hypermastusに含めるのが妥当である。後者は，殻形態，寄生生態および予察的な分子系統解析（髙野，未発表）により，セトモノガイ属Melanellaの一種であると考えられた。しかしながら，Eulima lactea A. Adams in Sowerby II, 1854が同じMelanellaに所属すると考えられるため，ヒモイカリナマコツマミガイに対するlactea A. Adams, 1864は主観新参ホモニムとなる。そこで，ヒモイカリナマコツマミガイに対する代替名としてMelanella tanabensisを提唱した。東アフリカのザンジバル諸島産で，同じくヒモイカリナマコに内部寄生する“Mucronalia” variabilisもセトモノガイ属に含めるのが妥当と考えられ，本論文で属位を変更した（Melanella variabilis n. comb.）。
The glochidia of the freshwater pearl mussel Margaritifera laevis infect the host fish, the Masu Salmon Oncorhynchus masou masou. The salinity tolerance of these glochidia was investigated in a laboratory experiment in 2016. Masu Salmon infected with glochidia in early May were reared in fresh water from early May to 7 June, then in artificial seawater (salinity: 0–35 psu) from 7 to 10 June (for 72 hours), then again in freshwater from 10 to 30 June. Live juveniles detached from the host fish were observed on 30 June. These results suggest that glochidia of the freshwater pearl mussel exhibit temporary salinity tolerance while on the host fish.