Crustacea By: Zackery Zwicker, Benjamin O’Toole, Katey Murphy, Katie Gallant

Evolutionary origin Cephalocarida Attempts have been made to construct a single hypothetical crustacean ancestor. Such an organism would have to possess: “elongated body, two pairs of appendages in front of the mouth, a pair of mandibles behind the mouth, and numerous trunk segments with appendages that form a continuous series of similar structure” Cephalocarida is proposed as having a body plan from which all crustacean features could emerge Cephalocarida

The earliest crustacean fossils are ostrocods. There is evidence from the Burgess shales that many crustacean features had already evolved during the Cambrian Period (542 million to 488.3 million years ago) Ostrocod fossil

Anatomy Haemocoel: The body cavity in which blood flows Sensory Organs: Compound eyes, statocysts (fluid filled cysts that sense direction of gravity), tactile hairs that respond to pressure or touch Respiration: Diffusion or gills Central nervous system: Brain and ventral nerve cord

Reproduction Crustacea produce from eggs which have been fertilized by sperm Most of the species are dioecious, there is a male and a female. Most species brood their eggs, meaning they have many eggs that hatch at the same time.

Habitat Crustacea live in: Many crustaceans are nocturnal Oceans Fresh water Land Many crustaceans are nocturnal They spend their days hidden in a burrow, buried in the sand or sleeping in a crevice. The habitats of crustacea vary due to the many species in the class. They can live in the ocean, in fresh water and some even live on land. Many crustaceans are nocturnal and spend their days hidden in a burrow, buried in the sand or sleeping in a crevice. Most crustaceans are carnivores or scavengers, some are herbivores and detritivores and few classify as parasites that are hardly recognizable as crustaceans. A crustaceans diet varies, some species eat plants while some eat fish and other feed from the bottom of the ocean or fresh water environment on anything they can find. Just as their diets vary, the way they feed varies as well. Suspension feeders feed on plankton, bacteria, and detritus. Predators feed on worms, snails, fishes and crustaceans. Some species interestingly have calcareous teeth in their stomach. Barnacles and anemone crabs use fine hairs on their appendages to filter food while most of the larger crustaceans are scavengers. The cleaner shrimp feeds on the mucus and parasites covering the skin and gills of fish. In some species of crustacea, cannibalism can occur at high densities, or when individuals have just moulted and are vulnerable for attack.   Crustaceans are key factors in marine and freshwater food webs. The majority of zooplankton in freshwater is composed of cladocerans and copepods, and in the oceans copepods, who are the major consumers of phytoplankton. There are more than 40,000 different species of crustaceans. Some 4,000 of these species occur in freshwater and nearly 200 species are found in the North American Great Lakes.

Diet carnivores or scavengers some are herbivores and detritivores few classify as parasites eat plants while some eat fish and other feed from the bottom of the ocean

Species of Crustacea There are many species of Crustacea known, 67000, many of these are used for human consumption Species Crustaceans have a very large diversity of over 67,000 species and more than 10 million tons of crustaceans are produced in fishery farms per year for human consumption   1. Barnacles thrive only in salt water. Barnacles can grow up to 15 mm making them a very small crustacean, however, they can produce up to 10,000 eggs at a time. Barnacles are sessile "meaning they are stationary" after their free living larvae stage and often live on rocks and ship hulls. Barnacles do not have an abdomen and have a reduced head. Barnacles do not have a large pair of claws for feeding like lobsters and crabs so instead they use cirri, a thorax appandage, to filter feed zooplankton, simply by holding their cirri in a water current. 2.Sand Hoppers are known for their famous hopping movements. Sand hoppers Can hop several inches into the air by standing on its legs then extending its abdomen out from its body. Sand hoppers usually do not live very long for crustaceans, only up to 21 months for males. The Sand hopper's mating pattern happens only during its nightly migration down the beach. Sand hoppers belong to the Order amphipoda, which can be marine or freshwater. Many Amphipoda are compressed laterally (flattened from side to side). Sand hoppers are an important food source for fish and shore birds 3. lobsters belong to the family Nephropidaeand are very similar to crabs and shrimp for they both come from the same order "decapoda". Lobsters can be found in all oceans however the atlantic lobster is native to the atlantic ocean. The atlantic lobster can grow up to 61 cm and weigh as much as 4.1 kg, making it the heaviest crustacean in the world. Atlantic Lobsters live in cold shallow waters and often burrow under rocks to hide from predators as well as possess an exoskeleton for protection. These clawed lobsters also have enlarged pincers (chelae). One cool characteristics about lobsters is they become more fertile as they grow older. Lobsters also have 5 pairs of legs and their eyes are mounted on stalks. Lobsters generally move slowly along the ocean floor however can reach speeds of 5 m/s when swimming! 4. Anartic Krill belong to the order Euphausiacea, also plainly known as shrimps without pincers. Krill are biolumicescent, meaning they can produce light even at night time. Anartic krill can reach lengths of 6 cm however weigh only as much as 2 grams. Anartic krill are the most abundant species on the planet in terms of biomass despite their small mass of 2 grams. ANartic Krill can be found in densities as high as 30,000 specimens per cubic metre. Also despite their small size anartic krill can live up to 6 years! Because of their large densities anartic krill are prey to many aquatic animals, and some as large as a baleen whale!

Semibalanus balanoides (Acorn Barnacle) Grow up to 15 mm Can produce up to 10,000 eggs Sessile No abdomen Feed using Cirri

Talitrus saltator (Sand Hopper) Compressed laterally “Beach Fleas” 8.2-6.5 mm long Known for hopping patterns

Homarus americanus (Atlantic Lobster) 20-61 cm .45-4.1 kg Lives in cold shallow water Same Order as crabs Culinary Delicacy

Euphausia superba (Antarctic Krill) Grows to 6 cm in length Weigh up to 2 grams Most abundant species Bioluminescent

Bibliography http://www.reefed.edu.au/home/explorer/animals/marine_invertebrates/crustaceans http://www.britannica.com/EBchecked/topic/144848/crustacean/33813/Evolution-and-paleontology http://whyevolutionistrue.files.wordpress.com/2010/03/cephalocarida.jpg http://www.nhm.ac.uk/resources-rx/images/1017/silurian-silicified-ostracod-fossil_71605_1.jpg