Reproduction strategies of aquarium snails + reproduction table

Hearing "snails in the aquarium" immediately sets off alarm bells for many people, and a whole list of prejudices starts rattling around in their heads. But not all aquarium snails are the same, and there are some very different reproductive strategies among these fascinating animals.

 The thunderbolt snail is a viviparous species that reproduces easily in freshwater.

Hermaphrodite aquarium snails

Of course, there are also aquarium snail species that are hermaphroditic - including such well-known species as the colorful post horn snails and their relatives, the well-known bubble snail and the animals from the species complex of the mud snail. These snails are all known for their enormous ability to multiply when fed too much. We have dealt extensively with the reasons for mass reproduction in theaquarium and how to prevent it in our blog"Snail plague in the aquarium". What these snails have in common is that they lay their clutches underwater. The eggs hatch into ready-made small snails that are viable in fresh water, and all they need to do is grow.

The viviparous thunderbolt snail gives birth to 1 ready baby snail at a time from time to time

Separately sexed snails

Not all snails are hermaphrodites, however. Among aquatic snails, there are many more separately sexed snail species than hermaphrodites. These snails can store seeds and then still lay egg balls or release larvae or young snails if kept alone, but they must have been fertilized beforehand and are not capable of self-fertilization. Here there are snails that lay their calcareous, quite firm egg balls above the water surface - the apple snails of the species Pomacea diffusa, which unfortunately, like all other snails from the genus Pomacea, are subject to a ban on distribution in the EU. From these egg balls hatch fully developed young snails, which grow up in fresh water.

However, there are also separately sexed snails that lay their eggs underwater and also do not have to go through larval stages, but grow up in freshwater. In addition to the predatory snail, these include the Bella snail, the zebra apple snail and the paradise snail, for example.

The Zebra Apple Snail lays jelly-like clutches under water from which fully developed young hatch.

Live-bearing snails

Another large complex are the separately-sexed but viviparous species, in which the eggs develop in a brood pouch in the mother snail into young snails that are not born until they are "ready". The viviparous separately sexed snails that reproduce in freshwater are diverse and rich in form. These snails include the entire genus Tylomelania from Sulawesi, all Brotia species, and the swamp cover snail and its relatives such as the piano snail (Taia naticoides) and also the new to the hobby snails of the genus Filopaludina. They all have in common that every few weeks, depending on the temperature, they give birth to a single young animal that has developed in their brood pouch. The males of the swamp cover snails can be recognized by their thickened right antennae, in the case of Tylomelania snails it is unfortunately not possible to distinguish the sexes externally.

The Piano snail is easily reproduced in fresh water.

Virgin reproduction in snails

A big exception among the viviparous snails are the Malayan Turmdeckelschnecke (Melanoides tuberculatus), the Genoppte Turmdeckelschnecke (Tarebia granifera) and the Stachel-Turmdeckelschnecke (Mieniplotia scabra, formerly Thiara winteri). They are also separately sexual, but the females are capable of juvenile production and only ever have female young. Here actually a single snail is enough to gradually populate the aquarium. After a few weeks each, they too give birth to a single live juvenile that has developed in their brood pouch. They also tend to reproduce en masse when food is abundant, we have also discussed these species extensively in our blog"Snail infestation in the aquarium".

The Indian trumpet snail is a viviparous species of snail.

Separately sexed snails that lay eggs but do not develop in freshwater

Now let's move on to the separately sexed snails, which lay eggs, but their offspring cannot develop in freshwater. Their egg cocoons hatch into tiny veliger larvae, barely visible to the naked eye, which in nature drift with the current from the stream into the sea where they develop into snails. These snails have not yet been bred in captivity because it is not known how the larvae feed. There have also been no accidental breedings. Therefore, reproduction in the aquarium is completely impossible.
This includes the well known and popular algae eating racing snails like the Orange Track, the Zebra Racing Snail and also the Anthracite Cup Snail as well as the Antlered Snail (Clithon sp.)

The cappuccino snail, devil's thorn snail, or lava snail (all site variants of Faunus ater) release live larvae that develop into finished snails in the sea. The long-nosed snail Stenomelania torulosa also follows this strategy, as does Thiara cancellata, the hairy limpet.

The Batman snail lays its eggs under water, but the larvae go through several stages in which brackish/sea water is needed.