Sub Phylum Mandibulata Class Crustacea Sub Class Malacostraca

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

I. Characteristics of Crustacea Biramous appendages • Appendages are biramous • Usually with gills • Head Serial Homology : ant 1, ant 2, Mnd, Mx 1 Mx 2 • 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 Antennule head sensory 1 st antennae Antennae head sensory 2 nd antennae Mandible head crushing/grinding food items Maxillae head chewing /shredding food items Maxilliped thorax manipulating food items Periopod thorax walking, clinging as many as 5 pairs Pleopod abdomen respiration, swim, hold offspring Uropod telson (last abd. segment) protection, escape Other names used jaw 1 or 2 pairs 0 -3 pairs walking legs swimmerettes tail fan Generalized biramous crustacean appendage. (Karen Osborn, UC Berkeley)

A. Class Copepoda 2 nd Maxilla used for feeding

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

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

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

Cladocera Reproduction Cyclic Parthenogenesis Amictic Mictic

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. Sub. Class 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, 1 st and 2 nd maxilla • Thorax has 6 -8 segments depending on the group

The largest land invertebrate: 1 m across and up to 4+ or 10 lbs

“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.

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 Crab zoea

States with major blue crab fishery Chesapeake 2010 catch 92 m lbs @ $2 / lb retail Female population estimated at 190 million

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

Shrimp Imports to U. S. in $1000 U. S. $ (2, 205 lbs) 5, 000 4, 500, 000 4, 000 3, 500, 000 3, 000 2, 500, 000 2, 000 1, 500, 000 1, 000 500, 000 0 1984 1994 2004 2014 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 > one thousand spp Gooseneck barnacle

D. Subclass Cirripidiea Acorn barnacle All barnacles are marine Exclusively affixed (also on ship hulls) Live within Ca. CO 3 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 1 st 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