Sub Phylum Mandibulata Class Crustacea Sub Class Malacostraca Sub Class Copepoda Sub Class Branchiopoda Sub Class Cirripidea

I. Characteristics of Crustacea Biramous appendages Appendages are biramous Usually with gills Head Serial Homology : ant1, ant2, Mnd, Mx1 Mx2 Characteristic larva is the nauplius

II. Crustacean Diversity Crustaceans are grouped by the number of segments they possess in each tagma Name Region Function Comments Other names used Antennule head sensory 1st antennae Antennae head sensory 2nd antennae Mandible head crushing/grinding food items jaw Maxillae head chewing /shredding food items 1 or 2 pairs Maxilliped thorax manipulating food items 0-3 pairs Periopod thorax walking, clinging as many as 5 pairs walking legs Pleopod abdomen respiration, swim, hold offspring swimmerettes Uropod telson (last abd. segment) protection, escape tail fan Generalized biramous crustacean appendage. (Karen Osborn, UC Berkeley)

A. Class Copepoda 2nd Maxilla used for feeding

Copepoda Feeding Vortices -- Focus of intensive studies on suspension feeding -- Acute selection for food size, quality Acartia fed diatoms cultured in high and low nutrient conditions Feeding Vortices

SubClass A. Copepoda B. Branchiopoda Most Marine, some F.W. Feed on microscopic algae Most F.W., few marine “Lawn mowers of lakes”

Branchiopoda: Leptodora Bythotrephes (spiny water flea) Daphnia Cercopagis (fish hook flea)

Cladocera Reproduction Cyclic Parthenogenesis Amictic Mictic

-- morphological changes in response to predators Cyclomorphosis: -- morphological changes in response to predators -- usually involves a developmental change that is induce by chemicals released from predator The different heads of Daphnia retrocurva Phantom midge larvae are important Daphnia predators. The Daphnia spines are long enough to reduce midge larva predation

C. SubClass Malacostraca Decapoda Active lifestyle 1500 species of crabs, in every marine habitat In humid tropics adults live entirely on land

I. Characteristics of Crustacea cephalothorax Metameric segments replaced by tagma Primitively as Head and Trunk; later head, thorax, abdomen Five segments have fused to form the head; appendages are antennule, antenna, mandibles, 1st and 2nd maxilla Thorax has 6-8 segments depending on the group

The largest land land invertebrate: 1 m across and up to 4+ or 10 lbs amelia Earhart was believed to have been scavenged on by Robber Crabs, after skeletal remains of a woman dating back to the 1930s were found in crab burrows (4)

“Robber” or “coconut” crab Breathe using an organ called a Branchiostegel Lung; gills are vestigial Its large size and the quality of its meat means that the coconut crab is extensively hunted and is very rare on islands with a human population. It is considered a delicacy and an aphrodisiac, and intensive hunting has threatened the species' survival in some areas.

Yellow –extinct populations Red- current populations Mate on land but release larvae into the ocean- zoea are marine for about a month before molting to juvenile that temporarily picks up snail shell for protection Yellow –extinct populations Red- current populations comicvine.gamespot.com

Life Cycle of the Blue Crab in the Chesapeake Bay Blue crabs mate from May to October in the brackish or slightly salty waters of Chesapeake Bay. Just prior to the final molt, an immature female crab, known as a "she-crab", is cradled by a mature male. The female is escorted by the male, commonly referred to as a "doubler", for a few days before and after her molt. During the molt, the male releases the female, but remains nearby. After molting, the female turns on her back and unfolds her abdomen. The male then transfers his sperm to the female. Although the female mates only once, she may spawn several times. The sperm received is stored and used to fertilize the eggs of all future spawnings. After mating, the two crabs resume the cradle carry until the female's shell hardens. Shortly after mating, the now mature female crab, known as a sook, migrates to the saltier waters of the Bay near the ocean. The female crab lays her eggs from 2 to 9 months after mating, depending upon when the mating took place. For example, a spring mating would result in a late summer spawn, while a fall mating would result in an early summer spawn the following year. Females develop an external egg mass on the underside of their abdomen which may contain between 750,000 and 8 million eggs, depending on the size of the crab. Young sponges are orange and gradually turn to brown and then black as the sponge matures. These crabs are called "sponge crabs" and hatching of the eggs occurs in approximately 2 weeks from June through September. The newly-hatched larvae are called zoea and look nothing like an adult crab. These young crabs are microscopic in size and drift about in the water currents. It is believed that the majority of these developing larvae are transported into the ocean by an interaction of seasonal winds and bottom water circulation patterns, and eventually returned to settle on seagrass beds in the spawning area. After approximately 6 or 7 molts, the zoea changes into a post-larval form known as the megalops. The megalops has claws like a crab, but can swim and crawl on the bottom. Eventually the megalops settles and metamorphoses to the first crab stage which looks much like an adult crab, but is only 1/5 of an inch from point to point. As these young crabs develop their locomotion, they will migrate away from the high salinity waters near the mouth of the Bay up to more brackish regions. By winter, juvenile crabs can be found as far north as the Susquehanna Flats. Adult males and immature females remain in the brackish waters of the Bay and its tributaries, migrating to shallow grassbeds, shallow muddy bottoms, and/or deeper waters of mid-Bay as temperatures begin to drop in the fall. As winter approaches, most crabs will bury themselves in the mud and shallow grassbeds of the Bay. Female crabs will remain in the higher salinity waters of the lower Bay, whereas males will remain in the upper portions, migrating to deeper waters to spend the winter months. Little or no growth occurs from December to March, but when the temperature begins to rise, crabs become more active, begin feeding and searching for a mate. Crab zoea

States with major blue crab fishery Chesapeake 2010 catch 92 m lbs @ $2 / lb retail Female population estimated at 190 million Calli : beautiful Nectes: swimmer Sapid: tasty

Sartwell, Masters thesis 2009, Duke Univ.

Other Notable Crustacean Fisheries Alaskan King Crab

Other Crustacean Fisheries American Lobster Commercial fishery in Maine Alone: 40 million pounds up to 10 thousand licensed fishermen

Per capita consumption in U.S. is ~ 3-4 lbs; seafood 16.3 lbs More than 50% is farmed shrimp More than 80% is imported Farmed black tiger prawn Raised in estuarine coastal waters Brood stock is wild caught

1.1 billion pounds of shrimp in 2010 Or 3.5 lbs/person

D. Subclass Cirripidiea Acorn barnacle Gooseneck barnacle > one thousand spp

D. Subclass Cirripidiea Acorn barnacle All barnacles are marine Exclusively affixed (also on ship hulls) Live within CaCO3 shell made up of plates Head is greatly reduced Suspension feeders

Barnacle feeding mode varies with velocity of flow Active Passive Suspension Feeding

Life Cycle Eggs hatch into naplius larva Molts 6 times and turns into cypris larva Cypris larva finds place to attach Secretes cement from cement glands on the 1st antennae to attach Develop into adult

Pass through a planktonic nauplius then a cyprid stage before becoming affixed

Parasitic (Rhizocephalan) Barnacles This is the egg mass of the parasite

Rhizocephalan Infection