Episode 342: Giant Snails and Giant Crabs
b"Thanks to Tobey and Anbo for their suggestions this week! We're going to learn about some giant invertebrates!\\n\\nFurther reading:\\nThe Invasive Giant African Land Snail Has Been Spotted in Florida\\nA very big shell:\\n\\n\\n\\nThe giant African snail is pretty darn giant [photo from article linked above]:\\n\\n\\n\\nThe largest giant spider crab ever measured, and a person:\\n\\n\\n\\nShow transcript:\\nWelcome to Strange Animals Podcast. I\\u2019m your host, Kate Shaw.\\nThis week we\\u2019re going to learn about some giant invertebrates, suggested by Tobey and Anbo. Maybe they\\u2019re not as big as dinosaurs or whales, but they\\u2019re surprisingly big compared to most invertebrates.\\nLet\\u2019s start with Tobey\\u2019s suggestion, about a big gastropod. Gastropods include slugs and snails, and while Tobey suggested the African trumpet snail specifically, I couldn\\u2019t figure out which species of snail it is. But it did lead me to learning a lot about some really big snails.\\nThe very biggest snail known to be alive today is called the Australian trumpet snail, Syrinx aruanus. This isn\\u2019t the kind of snail you\\u2019d find in your garden, though. It\\u2019s a sea snail that lives in shallow water off the coast of northern Australia, around Papua New Guinea, and other nearby areas. It has a coiled shell that\\u2019s referred to as spindle-shaped, because the coils form a point like the spindle of a tower. It\\u2019s a pretty common shape for sea snails and you\\u2019ve undoubtedly seen this kind of seashell before if you\\u2019ve spent any time on the beach. But unless you live in the places where the Australian trumpet lives, you probably haven\\u2019t seen a seashell this size. The Australian trumpet\\u2019s shell can grow up to three feet long, or 91 cm. Not only is this a huge shell, the snail itself is really heavy. It can weigh as much as 31 lbs, or 14 kg, which is as heavy as a good-sized dog.\\nThe snail eats worms, but not just any old worms. If you remember episode 289, you might remember that Australia is home to the giant beach worm, a polychaete worm that burrows in the sand between high and low tide marks. It can grow as much as 8 feet long, or 2.4 meters, and probably longer. Well, that\\u2019s the type of worm the Australian trumpet likes to eat, along with other worms. The snail extends a proboscis into the worm\\u2019s burrow to reach the worm, but although I\\u2019ve tried to find out how it actually captures the worm in order to eat it, this seems to be a mystery. Like other gastropods, the Australian trumpet eats by scraping pieces of food into its mouth using a radula. That\\u2019s a tongue-like structure studded with tiny sharp teeth, and the Australian trumpet has a formidable radula. Some other sea snails, especially cone snails, are able to paralyze or outright kill prey by injecting it with venom via a proboscis, so it\\u2019s possible the Australian trumpet does too. The Australian trumpet is related to cone snails, although not very closely.\\nObviously, we know very little about the Australian trumpet, even though it\\u2019s not hard to find. The trouble is that its an edible snail to humans and humans also really like those big shells and will pay a lot for them. In some areas people have hunted the snail to extinction, but we don\\u2019t even know how common it is overall to know if it\\u2019s endangered or not.\\nTobey may have been referring to the giant African snail, which is probably the largest living land snail known. There are several snails that share the name \\u201cgiant African snail,\\u201d and they\\u2019re all big, but the biggest is Lissachatina fulica. It can grow more than 8 inches long, or 20 cm, and its conical shell is usually brown and white with pretty banding in some of the whorls. It looks more like the shell of a sea snail than a land snail, but the shell is incredibly tough.\\nThe giant African snail is an invasive species in many areas. Not only will it eat plants down to nothing, it will also eat stucco and concrete for the minerals they contain. It even eats sand, cardboard, certain rocks, bones,"