Right and Left Handed Snails?
(PhysOrg.com) -- Snail shells can spiral to the left (sinistral) or to the right (dextral), determined by a single gene. The effect of this difference has produced a separate distinct species. The most common snails are dextral, and sinistral are rare. This is a common right spiraled dextral snail This is a rare left spiraled sinistral snail The majority of snails are dextral Mating between sinistral and dextral snails is almost impossible because their genitals are on opposite sides of their body. The mating of the large Satsuma snails, for example, takes place face-to-face. All snails have both male and female reproductive organs, but when both snails are dextral or both are sinistral, everything lines up nicely. When one is dextral and the other sinistral the genitals line up male-male and female-female. It has been determined that dextral snails came from sinistral snails, caused by a single recessive gene replacement. Dextral snails ar...