It is not entirely surprising that some animals may change their sex in accordance with their environment or age, in order to further drive the species further. But the recent discovery made at the Smithsonian Tropical Research Institute found something rather intriguing by noticing that sex change in snails is made possible just through simple touch.
The snail in question is the Crepidula marginalis, commonly known as the slipper snail, a little sea slug that inhabits shallow shore regions or intertidal areas. Its “slipper” denomination stems from the shape of its shell, presenting a tiny little shelf-like out groove on its shell. It feeds on plankton and other similar particles found in its sea environment.
Slipper snails live in large numbers across the shallow shoreline, but can sometimes be found in just groups of three. The female snail, which is larger in size, carries two male snails on its back due to the fact that male slugs are slower than their female counterpart.
In regards to sex change, it was believed that snails switch from male to female when affected by various factors from the environment at a certain age. But by making further inquiries on the subject, the Smithsonian scientists found out that by simply touching another male, a slipper snail will undergo a complex process, turning it into a female.
The experiment consisted of two groups comprised of two male snails, put in different tanks. One group was granted permission to touch one another while the other was separated through the use of a permeable barrier that allowed pheromones and other elements to pass through it. In the second tank, no change was seen.
But in the first one, the larger male snail underwent a sex change after touching the other one. Even if the larger specimen was the first to switch to female, its smaller counterpart was also suffering the same modifications, but at a much slower rate. This happens because due to its large size, the now female snail is able to house much more eggs in comparison to a smaller version. The tinier snails remain male for a longer period of time because they consume less energy when producing sperm if compared to larger male specimens.
What is rather surprising is the fact that chemical signals were not sent at all through the barrier. This was considered to be the way through which the process of sex change is started, because the snails remain relatively stationary throughout their life, and have an extremely poor eye-sight.
Slipper snails are not the only animals that undergo this sex change in order to boost population numbers. Coral reef fish, for example, use visual, chemical and behavioral cues to signal one another when a male or female is required in the group. Nonetheless, these fish still retain the same size-related factors present in snails, with larger subjects being the first to switch to female.
Even if the study showed how sex change in snails is made possible just through simple touch, researchers now want to find the exact chemical clues that snails tell one another regarding their size and the most beneficial time to undergo said change. This will be harder to discover, due to the fact that these chemical signals are sent only through touch-based interactions. Compared to when these signals are released in the surrounding environment, researchers have to keep an exact reading on when the process is actually started so that they can remove the specimen and extract chemical samples from its skin.