Bladder Snail (Physella acuta) Breeding Guide

Physella acuta is a simultaneous hermaphrodite that self-fertilizes and lays 50 to 100 eggs per week in gelatinous sacs underwater, making it an extremely prolific breeder.

Overview

Physella acuta is a small pulmonate snail of the family Physidae with a distinctive sinistral, or left-coiling, shell up to about 16 mm long. It is considered the world's most cosmopolitan freshwater gastropod and typically enters aquariums inadvertently with ornamental plants.

Sexing

The species is a simultaneous hermaphrodite, with both male and female reproductive organs functioning at the same time. It is self-compatible: natural populations reproduce mainly by outcrossing, with self-fertilization rates between 10 and 30 percent, so a single snail can found a population.

Conditioning

Sexually mature adults breed year-round when food and warmth are available. Outcrossing maturity is reached after about 5 to 7 weeks, while self-fertilization maturity comes at around 14 weeks.

Egg-laying / Reproduction

Adults lay 50 to 100 eggs per week, deposited in elongate gelatinous sacs attached underwater to rocks, mud or other snail shells. The eggs hatch after 15 to 20 days, and continuous laying makes the species extremely prolific in a closed aquarium.

Juvenile Care

Juveniles hatch directly from the gelatinous sacs and graze immediately on detritus and biofilm, requiring no special care. Under laboratory conditions individuals typically live 22 to 30 weeks.