Ramshorn Snail (Planorbarius corneus) Breeding Guide

Planorbarius corneus is a hermaphroditic ramshorn that lays pinkish gelatinous egg masses underwater on plants and glass. A single individual can establish a population.

Overview

Planorbarius corneus is a coil-shaped pulmonate snail of the family Planorbidae. It carries hemoglobin that acts as an oxygen transporter, allowing it to tolerate low-oxygen water, and in poorly oxygenated water it extends a siphon above the surface to fill its lungs.

Sexing

The species is hermaphroditic and capable of self-fertilization, so a single released animal can establish a stable population. No sexing or pairing is required to obtain offspring, although only about 5 percent of self-fertilized juveniles successfully hatch.

Egg-laying / Reproduction

Eggs are deposited in pinkish gelatinous masses on aquatic plants such as Elodea and Ceratophyllum and on the aquarium glass. The cylindrical or oval clutches measure roughly 12 by 8 mm and contain about 12 to 49 eggs, occasionally up to 60. Reproduction occurs in spring and autumn at water temperatures above 15 degrees Celsius.

Juvenile Care

Eggs first begin hatching within 31 to 65 days of being laid, and not all embryos hatch at once; an additional 9 to 21 days may pass before the final embryos emerge. Juveniles graze immediately and are generalist feeders, taking whatever food is available.