Things You May Not Know About Different Types Of Mollusks
There are around an astonishing 85,000 recognized types of mollusks living in freshwater, marine and terrestrial habitats. They are extremely diverse in their size, behavior, habitat and anatomical structure. Two universal characteristics that all mollusks portray are their mantle that has a significant size cavity that they use for excrement and breathing and their identical structures that they all have making up their nervous system. Below is a look at just a few of the main mollusks you may or may not be familiar with.
Blue-ringed Octopus – Found in the Pacific Ocean, these types of mollusks may be small but they are one of the most venomous animals in the world. They are quite easily recognized by their yellowish colored skin and black and blue rings. This species hunts crab and shrimp and will bite an attacker if provoked, including humans. They paralyze their prey with their venom and then they tear off pieces to eat. As of today, there is no anti-venom available.
Giant Clam – These mollusks are gigantic, measuring four feet across, weighing more than 400 pounds and they can live for over 100 years. The clam's mantle has brown symbiotic algae that photosynthesizes the sunlight and aids in nourishing the clam. Algae provide these clams with a primary source of nutrition. These types of mollusks have become endangered due to mussel-catching vessels and the high demand for their meat.
North Pacific Giant Octopus – This species can live in shallow or deep water in North Pacific coastal waters. They feed on crabs, shrimp, clams, scallops and fish. These mollusks have short lives of less than five years and they can lay 100,000 eggs. The hatchlings are the same size as a single rice grain but only a few actually survive to adulthood.
Squids
These types of mollusks have a head, mantle, eight arms and two long tentacles. Their mantle encloses their body mass with a fin for swimming on each side. They have the ability to change colors to match their surroundings, essentially camouflaging and making themselves invisible to predators. Although most squids are less than 24 inches long, the Giant Squid can reach up to 43 feet long. A New Zealand vessel in February of 2007 caught a Colossal Squid that weighted 1090 pounds.
Cuttlefish
Cuttlefish are believed to be the most intelligent known invertebrates. They have an internal shell, W-shaped pupils, two tentacles and eight arms. They feed on crabs, shrimp, octopus, worms, fish and other cuttlefish. Although they may not be able to see color, they can see the polarization of light. Scientists have proven that their eyes are completely developed prior to being born and they can observe things around them while they are still in the egg.
Slugs
Slugs are any types of mollusks that do not have a shell. Although there are terrestrial and marine slugs, the most common referred to are land slugs. Their bodies are made up primarily of water and they need to generate a type of protective mucus in order to survive. One type of mucus is water and thing while the other type is sticky and thick, some of which is mildly poisonous.
Snails
There are land snails, freshwater snails and sea snails found in deserts, ditches and depths of the sea. They are primarily herbivores but there are a few species that are predatory carnivores and omnivores. These mollusks have thousands of tiny tooth-like structures on their radula that they use for ripping their food apart. These are the most common types of mollusks that are found as pets.