The Order Decapoda is one of the most well-known of the class Malacostraca. It contains shrimp, lobsters, crabs, and crayfish. The name Decapoda actually means “ten feet.” They have a hard exoskeleton and usually have fairly large claws. They have 6 maxillipeds, which separates them from the other orders. The Order is comprised of around 14,000 species and is fairly diverse. The subtaxa of this group is frequently rearranged thus there is a vast amount of literature on classification (Brusca 527).
The habitat is just about as diverse as the group itself. They can be found in all aquatic environments. This includes muddy areas, sea bottoms, beaches, and corals. They can be found burrowing, errant, or even sedentary in the benthic zone (Brusca 527).
The Decapods have multiple eating habits. They can be predators, herbivores, filter feeders, or sometimes scavengers. The predators will dine on fish, worms, mollusks, and most meat they can get their claws on. The filter feeders will rustle up the sediment and grab what organic material they can to feed on. (“Decapoda diet”).
Mating in Decapods is a pretty straight-forward affair. Females release a pheromone to attract males and alert them that they are about to molt. Males compete to attract the female, and once they have won her over protect her until she is ready, then directly deposits the sperm. The decapods are direct developers and only grow in size once they are born. The parents usually abandon the young except in rare cases where there is parental care (Decapoda Behavior and Reproduction).
The ecological importance of the Decapods is not fully understood. What is understood is that Decapods exist in several different trophic levels. This means that they play an important role in the circulation of energy within their ecosystems since they dine on such a wide variety of organisms. More research, however, will provide a better understanding of the Decapods’ role. (Wenner)
The Decapods really play a vital role in the economy. For example, Decapods produce $542 million of the $674 million made by fishermen in the Gulf of Mexico. Shrimp alone made up 60% of the profits. (Gulf of Mexico 114). That is the fishermen alone. That’s not even including the supermarkets profits or the restaurants. The amount of possible jobs created from the sale of Decapods worldwide is a bit staggering, considering the popularity of the order.
This species is known by the common name “Giant Tiger Prawn.” It is eaten worldwide and is very highly valued. According to the Food and Agriculture association, it generated a value of $3.6 billion in 2009. It is also is becoming a problem in the Gulf of Mexico as an invasive species (Houston Chronicle). Due to its large size, it is very competitive and experts are concerned that the native species may have a problem keeping up.
This lobster, known as the American Lobster, is found along the Atlantic coast and the various Red Lobsters around America. For good reason though, it holds the record for heaviest crustacean. The heaviest one was 44 lbs (BBC News). It comes in a variety of colors and sizes, the longest being over 3ft.
This is commonly known as the Red Swamp Crayfish (or Crawfish). It is very common along the gulf coast in freshwater such as marshes, ditches, ponds, etc. They can survive on and cross dry land to make it to wetter areas, however. They are, like most Decapods, edible, and are eaten very often around the world.
I have an interest in this Order for
several reasons. When I was out in my yard as a kid, crawfish were the toughest
things I could find (the results of many battles). Getting older I realized how
delicious all of the Decapods were, and how tough some of them are to eat. Then,
as I was asked an invertebrate to choose, delicious crawfish popped in my head.
I’m really glad it did, as I enjoyed learning and writing about them, although
I was hungry the majority of the time.
Brusca, Richard, and Gary Brusca. Invertebrates (Second Edition). Massachusetts: Sinaur
Associates. 2003. Print.
“Decapoda.” FloridaNature.org, n.p., n.d., Web. 15 April 2012
"Giant shrimp raises big concern as it invades the Gulf". Houston Chronicle. Web. 16 April 2012
“Gulf of Mexico” http://www.st.nmfs.noaa.gov, n.p., n.d., Web. 16 April 2012
“Shrimps Crabs and Lobsters: Decapoda Behavior and Reproduction.” animals.jrank.org, n.p.,
n.d., Web. 16 April 2012
“Shrimps Crabs and Lobsters: Decapoda diet.” animals.jrank.org, n.p., n.d., Web. 16 April 2012
Wenner, E. “Decapod Crustaceans” http://nerrs.noaa.gov , n.p., n.d., Web. 15 April 2012
(All photos used are royalty free and copyright free)