September 20, 2012 at 6:32am
Can't tell if it's an Apple Snail from the pic, looked more like a clam to me too. If it is an Apple Snail, it is an invasive species as noted above and should be reported.
Here's a copy of an article I did for Louisiana Sportsman in 2008 on the Apple Snails:
Most sportsmen are well aware of non-native species such as nutria, water hyacinth and giant salvinia that were introduced into Louisiana’s ecosystem and flourished. While they may have found our state to their liking, they have all come with their share of problems and have proven difficult to control. Will the apple snail be the next exotic creature to wreak havoc in Louisiana?
First located near Gretna, Louisiana in 2006, apple snails have now been additionally confirmed in the greater New Orleans areas of Terrytown and Belle Chasse. A separate population of the snails has also been identified in the Houma, Schriever and Thibodaux areas. They are large, freshwater snails that derive their name from the shape and size of their shell.
Michael Massimi is the Invasive Species Coordinator for the Barataria-Terrebonne National Estuary Program and is concerned that the apple snails could be spread to other parts of the state, including the rice farming areas of western Louisiana.
“These snails will eat virtually any submerged aquatic vegetation and rice farmers in Hawaii and southeast Asia are realizing significant crop damage from the snails,” he said.
Massimi believes that both identified populations in Louisiana were probably the result of separate incidents of snails being released into the wild. apple snails are popular amongst aquarium enthusiasts and it is believed that they were likely released once their owners tired of them or they became too big for the aquarium. “They really are fascinating creatures to observe in an aquarium, but the public needs to be aware of the devastating potential to the natural ecosystem if they are released,” said Massimi.
The snails consume enormous amounts of plant matter and are not picky eaters. They will devour almost any soft plant matter. Another concern is that they could eat their way through Louisiana’s already struggling wetlands. The snails seem to eat all of the larger plants first and then leave the areas susceptible to more turbid and muddier conditions which favor the growth of algae and such plants as hydrilla.
They are not saltwater tolerant but, the snails have the ability to seal off their shell and virtually go dormant for many months. “Though they can’t live in saltwater, they could possibly seal off and bob around for several months until the conditions become more favorable,” said Massimi.
Although they spend almost all of their time underwater, apple snails have also proven very tolerant of long periods of drought. Again, under adverse conditions such as drought or intentional water draw-downs, the snails will simply seal up and go dormant. “Farmers in Hawaii have reported that they have to completely dry their fields for 18-months in order to achieve one hundred percent kill rates on the snails.
Due to their habit of remaining almost constantly underwater, the actual snails are rarely seen. However, a sure sign that they are in an area is by spotting the large pink clusters of eggs which they lay above the water’s surface. The snails crawl out of the water at night to lay their eggs on pilings, pipes and vegetation just above the waterline. They will even lay eggs on boats that are sitting in the water.
While the primary means of the snails spreading to other areas is through intentional release, they can also be spread by eggs on boat hulls or birds that will pick them up to eat and then drop them in another location. While the egg viability in such cases has not yet been studied, Massimi has seen many egg clusters laid on barges near the Intracoastal Wateraway. “While such eggs may be susceptible to being washed away or damaged from the heat of the metal barges, we cannot discount the possibility that these eggs could be spread to other areas by transportation on these vessels,” he added.
The eggs must remain above the water to hatch and the best current control method is to simply knock or scrape egg clusters back into the water where they will die.
The Louisiana Department of Wildlife and Fisheries urges anyone that spots the egg clusters to knock them off into the water.
Massimi notes that each time a new invasive species is identified, the story gets sensationalized for a while and then fades away. “Today it’s the apple snail, but tomorrow it will be some other exotic plant, reptile or fish,” said Massimi. “The public must stay aware and report any unusual sightings so that they can be investigated at an early stage,” he added.
To report any sightings of apple snails or their eggs, call Brac Salyers at (225) 765-2641 or by e-mail at firstname.lastname@example.org.