Arthropods (phylum Arthropoda) (from Greek ἀρθρον, meaning joint and πούς/ποδός, meaning foot) are the largest phylum of animals and include the insects, arachnids, crustaceans, and others. Approximately eighty percent of extant animal species are arthropods, with over a million modern species described and a fossil record reaching back to the early Cambrian. Arthropods are common throughout marine, freshwater, terrestrial, and even aerial environments, as well as including various symbiotic and parasitic forms. They range in size from microscopic plankton (~0.25 mm) up to forms several metres long.

Arthropods are characterised by the possession of a segmented body with appendages on each segment. They have a dorsal heart and a ventral nervous system. All arthropods are covered by a hard exoskeleton that is made out of chitin, a polysaccharide. Periodically, an arthropod sheds this covering when it moults. This covering makes arthropods less prone to dehydration.

Basic arthropod structure

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MarineBio Blog

You can love the ocean and seafood too…
Joni Tue, 26 Aug 2008 00:25:27 -0000
Ocean and seafood lovers unite and spread the word. There is such a thing as sustainable seafood. And organizations such as SeaWeb’s Seafood Choices Alliance and Charting Nature are here to tell you all about it. Charting Nature donated 100 copies of their informative and beautiful Seafood Guide posters. The posters are available in fish or [...]
I can’t bear the ignorance any longer. Spread the facts: SHARK FIN SOUP IS BAD
Joni Wed, 20 Aug 2008 15:10:22 -0000
Because travel is one of life’s greatest pleasures, I often watch the Travel Channel to travel vicariously when I’m not traveling myself. There’s a show that I find interesting for its glimpse into off-the-beaten-path cultures, but not so much for its main focus - the consumption of “bizarre” food. Unfortunately, a recent episode featured the [...]
My favorite recent headline: First Do More Harm
Joni Thu, 14 Aug 2008 19:43:11 -0000
Once again, I’m abandoning MarineBio’s policy of striving to remain politically neutral. What is with the Bush administration? First it’s “hey! let’s drill offshore to trick people into thinking it will lower gas prices - it won’t do any good, but my buddies in the oil industry will give me another atta boy!” Now it’s [...]
Good news and great advice about the plight of corals
Joni Wed, 06 Aug 2008 21:31:18 -0000
I just came across this quote in an interview with International Society for Reef Studies President Richard Aronson on SeaWeb and was immediately inspired to share it with you: The main thing that I would advise scientists, conservationists and the public to do is to take heart, be courageous and don’t give up on coral [...]
Tuna: A Love Story
Joni Thu, 31 Jul 2008 19:50:32 -0000
Richard Ellis’ new book Tuna: A Love Story is now in bookstores. In his latest book, Ellis focuses on the bluefin tuna - an amazing species that is being loved to death in sushi bars worldwide. We’re fans of Ellis’ The Empty Ocean, which paints a grim but accurate view of the exploitation of the ocean [...]
Why corals need urgent protection
Joni Thu, 24 Jul 2008 22:11:30 -0000
Time Magazine published this great article earlier this month. Read: You don’t have to be a marine biologist to understand the importance of corals — just ask any diver. The tiny underwater creatures are the architects of the beautiful, electric-colored coral reefs that lie in shallow tropical waters around the world. Divers swarm to them not [...]

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