Sexy Snots

Thursday, May 15, 2025

Sexy Snots

Today’s special animal friend is the Cuban painted snail, Polymita picta, also known as the Cuban land snail. Several subspecies of these tree-dwelling snails are native to eastern Cuba, especially Alexander von Humboldt National Park, a very diverse ecosystem on the northeast coast of the island. Here are some photos.

Painted snails can grow up to .8” in length. Their shells have a variety of bright colors with distinctive spiral stripes. Scientists are conflicted regarding the evolutionary utility of the coloration. It might confuse predators such as birds, or it could be a factor in the selection of mates. Because of their markings, the shells are highly collectible, used in jewelry and trinkets. Habitat loss due to the expansion of tobacco plantations is also a threat.

Painted snails favor several species of native trees, where they eat lichens, moss, and fungal biofilms. Like most air-breathing land snails, painted snails are hermaphroditic. Mating occurs in the wet season, September and October. Two individuals check one other out and then exchange “love darts” or gypsobelum. These are large (relative to the animal’s size), sharp projectiles made of bone (calcium) or shell (chitin) that are expelled into the soft tissue of a potential mate while in contact. It is suggested that mucus on the darts stimulates reproductive hormones. Many species of gastropods have this facility, and research is incomplete, but let us all take a moment to *shudder*. After the stabbing phase of courtship, each snail deposits sperm with the other, and both individuals go on to lay fertilized eggs.

Painted snails are dormant in dry weather. They can seal the opening in the shell with mucus, allowing the animal inside to remain moist for long periods. Scientists believe that snails arrived in Cuba in this dormant state, clinging to tree branches carried across the sea by storms and tides.

All the subspecies of painted snails are critically endangered. Their survival depends on better education of potential purchasers of the shells in the U.S. and elsewhere. In addition, improved economic incentives for the residents of Cuba are needed. Over 23,000 shells intended for the U.S. market were seized by the Cuban customs authorities between 2012 and 2016, so it is clear that the potential profit from export of the shells outweighs the $20 fine charged by the Cuban government if a poacher is caught.