Crustaceans are members of an enormous category of creatures known to science as arthropods.
Arthropod is from the Greek meaning “jointed leg.”
All of the members of the family have exoskeletons and jointed limbs.
The arthropod phylum also includes insects and arachnids, or spiders to you and me.
The subphylum of crustaceans contains lobsters, crabs, shrimp, krill and even barnacles.
There are crustaceans that live on land, like woodlice and terrestrial hermit crabs, but the majority inhabit the seas, and most of those stick close to shore.
Crustaceans are also some of the oldest animals on Earth.
Evidence of their exoskeletons fills the fossil record dating all the way back to the Cambrian Period nearly five hundred and forty million years ago.
Obviously, they have been very successful creatures.
What is food to a lobster?
It’s a simple fact that animals able to eat the broadest variety of foods have the best chance at survival and crustaceans fit that bill.
The diet of lobsters and crabs consists of pretty much every animal they can catch such as fish, other crustaceans, clams, mussels and sea urchins.
They are also part of nature’s cleanup crew, scavenging the flesh of dead animals.
Crustaceans are not only opportunistic as far as what they will eat, but also when and where they eat.
Although lobsters tend to hunt at night, many crabs can be seen in daylight hours, clinging to the rocks and delicately picking their meals from the algae.
Crabs tend to inhabit both sea and land, moving back and forth to take advantage of varied habitats.
Shrimp live an entirely different lifestyle.
They are free-floating creatures that inhabit a wide range of ocean zones and their diet is free-floating as well.
They eat plankton, the great soup of nearly microscopic plants and animals that are the foundation of almost all sea life.
Barnacles also dine on plankton but their strategy is one of waiting for the food to come to them.
Barnacles cling to a solid surface and when it’s feeding time, usually at night, they extend their feathery jointed legs called cirri into the passing current and harvest their meals.
Would you date a crustacean?
The mating of crustaceans is as varied as their diets.
Lobsters fight before mating.
Lobster females, like most crustaceans, can only mate in a short period of time after they have molted their shells.
Since they are at their most vulnerable during this period of time they prefer dominant males who will offer them the best protection.
Not only must the male fight other males to earn the right to mate, but he also starts the mating process by fighting with the female to show-off his prowess.
The mating of crabs is a more delicate affair.
It requires some dancing.
When a male finds a sexually available female he engages in an elaborate dance.
He waves his claws above him, stands on the tips of his legs and moves from side to side.
When a female has accepted the male, she will respond with her own dance.
Mating with crabs can sometimes last a week.
Shrimp mate three times a year, seasonally and once again only when the female has just molted.
A female can lay as many as 25,000 eggs and she keeps them with her until they hatch, attached to hairy appendages under her tail.
Barnacles have the oddest mating behavior of all the crustaceans.
The male grows a mating appendage that is eight times the length of his and probes the area for nearby females.
Crustaceans have it tough.
Since crustaceans tend to stick to the margins between land and sea they are vulnerable to any damage that afflicts coastal areas from storms to human activity.
Pollution, loss of habitat, climate change and over-fishing all have negative impacts on crustacean habitat.
Crustaceans in great numbers also inhabit coral reefs around the world and face the same environmental threats from human impact and warming seas that the reefs face.