Some genera of snails in this subfamily create and use love darts as part of their mating behavior. The dart sac contains one to two glands. They are also defined by missing a diverticulum.
In this subfamily, the number of haploidchromosomes present lies between 26 and 30.[2]
The name of both the subfamily and the genus Bradybaena are derived from the Greek words bradus (= slow) and baino (= walk), meaning "slow walker".
Formerly considered as a separate family, molecular phylogenetic studies from 2007 showed that bradybaenids were closely related with the Camaenidae, a family that they are now considered a subfamily of. In these studies both Bradybaenidae and Camaenidae are mutually polyphyletic, and together form a monophyletic group. This finding suggested that the distinction between the clades was based essentially on the absence (Camaenidae) or presence (Bradybaenidae) of a diverticulum, and was arbitrary. This anatomical structure was apparently lost (or was gained) in several groups in convergence and is therefore not suitable for the delimitation of natural groups.[3]
Two live individuals of Aegista tokyoensis, one retracted and one active
The following genera are recognized in the subfamily Bradybaeninae:[1]
^Barker G. M.: Gastropods on Land: Phylogeny, Diversity and Adaptive Morphology. in Barker G. M. (ed.): The biology of terrestrial molluscs. CABI Publishing, Oxon, UK, 2001, ISBN0-85199-318-4. 1-146, cited pages: 139 and 142.
^Wade C. M., Hudelot C., Davison A., Naggs F., Mordan P. B. (2007). "Molecular phylogeny of the helicoid land snails (Pulmonata: Stylommatophora: Helicoidea), with special emphasis on the Camaenidae". Journal of Molluscan Studies73(4): 411-415. doi:10.1093/mollus/eym030.
