Application of heavy-ion-beam irradiation to breeding large rotifer

Abstract

In larviculture facilities, rotifers are generally used as an initial food source, while a proper size of live feeds to connect rotifer and Artemia associated with fish larval growth is needed. The improper management of feed size and density induces mass mortality and abnormal development of fish larvae. To improve the survival and growth of target larvae, this study applied carbon and argon heavy-ion-beam irradiation in mutation breeding to select rotifer mutants with larger lorica sizes. The optimal irradiation conditions of heavy-ion beam were determined with lethality, reproductivity, mutant frequency, and morphometric characteristics. Among 56 large mutants, TYC78, TYC176, and TYA41 also showed active population growth. In conclusion, (1) heavy-ion-beam irradiation was defined as an efficient tool for mutagenesis of rotifers and (2) the aforementioned 3 lines that have larger lorica length and active population growth may be used as a countermeasure of live feed size gap during fish larviculcure.

Screening for High-Growth Mutants in Sporophytes of <i>Undaria pinnatifida</i> Using Heavy-Ion Beam Irradiation

“…For instance, using the heavy-ion beam of the RIKEN RI-Beam Factory, commercial varieties of 35 lines of terrestrial plants and 2 lines of sake yeast have been derived (Abe et al 2015, Abe 2021. High-growth or large-organ mutants were obtained by ion-beam irradiation, including Japanese toad lily with large flowers (Nakano et al 2010), Artemisia annua L. with heavy leave (Inthima et al 2014), high-yielding rice with long grains (Morita et al 2019), Arabidopsis thaliana with large flower and seeds (Nhat et al 2021), and large rotifers (Tsuneizumi et al 2021). Niwa et al (2009) obtained color mutants of Neopyropia yezoensis f. narawaensis by irradiating C-ions in macroalgae.…”