What is the second-largest animal phylum after Arthropoda?
Mollusca is the second-largest animal phylum after Arthropoda. It encompasses 86,600 recognized extant species ranging from microscopic sea slugs to the colossal squid.
Common questions about Mollusca
Short answers, pulled from the story.
When did the first molluscs emerge in the fossil record?
The first molluscs emerged during the Cambrian period between 541 and 485.4 million years ago. Shelled molluscs such as helcionellids appeared in the Early Cambrian period over 540 million years ago.
Which molluscs produce the best natural pearls?
The best natural pearls are produced by marine pearl oysters Pinctada margaritifera and Pinctada mertensi. These species live in the tropical and subtropical waters of the Pacific Ocean.
How many people are affected by the parasitic disease Schistosomiasis?
Schistosomiasis affects about 200 million people in 74 countries. The disease has 100 million infections occurring in Africa alone with freshwater snails serving as intermediate hosts.
What percentage of recorded extinctions since 1500 are molluscs?
About 42% of recorded extinctions since the year 1500 are of molluscs. These extinctions consist almost entirely of non-marine species.