THE SNAIL’S LOVE DART
When we talk about competition for mates, we often think of behaviors involving tense fights or flamboyant displays of traits that signal quality. However, sometimes the competition continues even after mating, as the sperm must outcompete sperm from other mates.
In land snails of the families Helicidae and Ariophantidae, this post-copulatory competition involves the injection of a calcium-based “love dart”. These snails are simultaneous hermaphrodites, so during mating, both partners can act as male and female, leading to …
FEEDING ON SLIME
Velvet worms are among the most extraordinary animals on earth! With a very simple body structure, these ancient animals have been living on our planet for nearly 500 million years. Despite their name, they are not actually worms. They are not insects either, but look like caterpillars, and belong to their own phylum called Onycophora.
Onycophorans have a remarkable technique for hunting. To capture their prey, velvet worms eject a sticky, adhesive slime from their oral papillae, which are located close to their mouth. The sticky slime immobilizes the prey so that the velvet worm can then casually approach it.
In a study of feeding behavior conducted in Costa Rica in 2019, researchers documented for the first time a form of parental feeding in velvet worms...