The characteristic ground colour and banding patterns on shells of the land snail Cepaea nemoralis form a classic study system for genetics and adaptation as it varies widely between individuals. We use RNAseq analysis to identify candidate genes underlying this polymorphism. We sequenced cDNA from the foot and the mantle (the shell-producing tissue) of four individuals of two phenotypes and pr...

Leptonchoid species found in soil samples taken in lowland and mid-elevation seasonal forests at four locations in Panama were as follows: Sclerostylus karri n. gen., n. sp., Basirotyleptus saccatus n. sp., B. nemoralis, B. acus, B. penetrans, Doryllium neotropicum n. sp., D. minor, Tyleptus gymnochilus, Gerthus jamesi, Dorylaimoides micoletzkyi, and Tylencholaimellus macrophallus. The discover...

The snail Helix nemoralis in negatively geotropic creeping orients upward upon an inclined surface until the angle of the path of progression (theta) is related to the tilt of the surface (alpha) as (Delta sin theta) (Delta sin alpha) = - const.; theta is very nearly a rectilinear function of log sin alpha. The precision of orientation (P.E.(theta)) declines in proportion to increasing sin alph...