Invasive Species: The Rosy Wolf Snail

Invasive Species: The Rosy Wolf Snail
Euglandia rosea, or the Rosy Wolf Snail is an invasive terrestrial snail characterized by its oval shaped, pink, translucent shell and long thin body. It is usually around 7 centimeters in length, 6 centimeters in height and 2 centimeters in width. They are hermaphroditic and “lay approximately 25-40 eggs per year.” (Chhun) This snail is best known for its taste for the flesh of other snail and mollusc species, and has even been known to engage in cannibalistic behavior. This snail possess a set elongated lips that resemble tentacles called “oral lappets” which are used to track prey through the taste of the slime trails left behind by other snails. Wolf Snails do not distinguish between their own species

Their preferred habitat is within “hardwood forest, roadsides and gardens.” (Barker) This species was deliberately introduced to Hawaii in 1995, in hopes that they would help to control the population of the invasive Giant African Land Snail. By 1958 12,000 snails had been harvested to be introduced to various islands around the Pacific Rim and in the Indian Ocean under a similar pretense.(Auffenberg) Unfortunately there are no studies to support that this method had any effect on the Giant African Land Snail population what so ever. Instead, with no known predators, the Wolf Snail ran rampant and is credited with contributing to the extinction of various endemic tree and land snails, particularly in French Polynesia, Hawaii and Mauritius. (Cowie) This snail is known to have contributed the extinction of almost 50 percent of the endemics snail species in the Hawaiian Islands. Mauritius, in the Indian Ocean, has lost 24 of their 106 native snail species.

The main defense that has been employed against the effects of these snails is to simply try to re-establish the populations of the native snails in their own environments. This method has been employed in Hawaii, where they have built enclosures where the endangered snail populations can breed in peace and be protected from attacks by the Wolf Snail. One example of this ‘exclosure’ is the University of Hawaii’s Rare Snail Conservatory. They’ve partnered with a New Zealand company, known as XCluder, that “specializes in pest proof fencing,” to create a habitat that is safe from preadators such as the Wolf Snail. These ‘exclosures’ are comprised of a 4 foot tall wall with a buried portion, a curved hood, wire bristles and electric fencing.(Intelesense) There are also test involving toxic bait made from Pomenca snails in order to cut down on the Wolf Snail’s population. (Chhun) Within French Polynesia, legislation has been passed that deems this snail a “noxious species” and has forbidden any transport of this species between islands. Unfortunately there has yet to be a truly reliable way to prevent the spread of this species within a single island. The main