Limacina retroversa

Limacina retroversa is a distinct species of swimming planktonic gastropods, belonging to a group of predatory sea snails known as sea butterflies (Thecosomata). The name Limacina retroversa describes the unique morphology of this sea snail, including its slug-like body and coiled, backwards-turning shell. They are typically found in the epipelagic zone of cold, polar waters, but can be found worldwide, in any ocean. L. retroversa are currently under threat, as their numbers are decreasing due to rising global carbon levels and other human-caused climate threats.

Etymology

The species name "retroversa" essentially means "turned backwards" in Latin, and likely refers to the way the shell of Limacina retroversa appears coiled in a reverse direction compared to most other snail species. The genus name "Limacina" comes from the Latin word "limax" which means slug or "snail-like", and refers to the general body structure of L. retroversa.

Distribution

L. retroversa have a broad distribution and can be found in oceans ranging from the North Atlantic ocean, Northwest Atlantic Ocean, European waters, the Mediterranean Sea, and Caribbean Sea. They can be found at any depth of ocean, but are most abundant in the epipelagic layer, specifically neritic rather than oceanic.

L. retroversa have a particular high biomass in polar regions as they are a cold water species. Higher numbers of L. retroversa are typically found in late winter and early spring; but have a low density in late summer and fall and tend to shift lower into the water column.