The Russian tortoise (Agrionemys horsfieldii), also commonly known as Horsfield's tortoise or the Central Asian tortoise, is a species of tortoise and a popular pet.1  1 Etymology.he Russian tortoise is a small tortoise species, with a size range of 13â25 cm (5â10 in). Females grow slightly larger (15â25 cm [6â10 in]) to accommodate more eggs. Males average 13â20 cm (5â8 in).