Marine Arthropods

1. Marine Arthropods

2. Invertebrates • Arthropods • Characteristics of Phylum: • About 1 million species known, mostly marine • Most marine species are in a group of arthropods called crustaceans • About 75% of all animals on earth are arthropods • Chitin exoskeleton- hard, but light and moderately flexible • Since the skeleton is external, an arthropod must shed the shell to be able to grow – this process is called molting. There is a soft new shell underneath. • Jointed appendages • Many divided into sections called head, thorax and abdomen • Specialized segmentation- segments combined for specific functions • Specialized eye & sensory organs- wide angle of vision

3. Invertebrates • Arthropods • Characteristics of phylum: • Specialized respiratory structures, gills, used for gas exchange • Some are filter feeders, some scavengers, others carnivores

4. Invertebrates • Types of Marine Arthropods: • Crustaceans • 68,000 species • 2 pairs antennae • Gills for respiration • Head and thorax fused into a single unit called a cephalothorax; entire external body is called the carapace • Large array of appendages specialized for different functions; ex: pinchers on crabs, swimmerettes on the underside of shrimp hold developing eggs, etc. • Types of crustaceans – copepods, barnacles, amphipods, isopods, crabs, shrimp, lobsters, etc.

5. Characteristics of Crustacea External a. Appendages 2 prs of antennae: 1st homologous to antennae of insects & myriapods, 2nd homologous to chelicerae 3rd pair of head appendages are mandibles Biramous - terminal segment with endopod and exopod b. Tagmata Head and trunk (often divided into thorax and abdomen) A carapace may cover dorsal and lateral surfaces c. Exoskeleton chitin may be calcified in larger species

6. Characteristics of Crustacea Feeding and Digestion a. Nearly all are suspension filter-feeders b. Larger species predator/scavengers c. Appendages specialized for cutting, tearing, collecting d. Foregut enlarged into cardiac and pyloric stomach e. Midgut bears two digestive glands (hepatopancreas) comprised of highly branched, blind canals secrete enzymes absorb nutrients store glycogen and fat

7. Gas Exchange, Circulation, and Excretion a. Respiration All Crustaceans have gills May be within thoracic cavity or on appendages b. Circulatory System Heart --> dorsal vessel --> sinuses --> gills -->pericardial sinus --> ostia in heart Respiratory proteins (hemocyanin) in blood of larger species c. Excretion Excretory organs near antennae (antennal glands) or maxillae (maxillary glands)

8. Nervous and Sensory Structures a. CNS is typical for arthropods: dorsal brain, paired ventral nerve cord, ganglia b. Eyes of two types median simple eye (naupliar - from naupliuslarvae) compound eyes - ommatidia (25 to 14,000) c. Prioprioceptors and statocysts in soft tissues between segments single pair at base of 1st antennae d. Sensory hairs for mechano- and chemoreception

9. Phylum Arthropoda • Class Crustacea • Subclass Malacostraca • Order Decapoda • Order Amphipoda • Order Isopoda • Subclass Branchiopoda • Subclass Ostracoda • Subclass Copepoda • Subclass Cirripedia

10. Subclass Malacostraca • "Soft Shell" • Over half (>22,000 spp.) of Crustacea • Typically 14 segments: 8 thorax, 6 abdomen • First 1-3 thoracic are forward - maxillipeds • Abdominal appendages called pleopods • 1st pair often used in mating • 6th pair is turned backward for swimming (uropods)

11. Guess which crustcean we’re talking about first???? http://www.youtube.com/watch?v=4rT5fYMfEUc That’s right! SHRIMP!

12. Subclass Malacostraca: Order Decapoda("Ten Legs") 10,000 species - crabs, shrimp, lobster, crayfish Commercially and ecologically important Mostly marine, crayfish common freshwater, some intertidal crabs are "semi-terrestrial" 3 prsmaxillipeds, 5 prs legs (1st pr often chelate) Gills in branchial chamber enclosed by carapace Carry eggs on pleopods (swimmerets) beneath body

13. photo

14. Shrimp

15. Brine shrimp Who knows an interesting fact about these?

16. Ever heard of “Sea Monkeys”?

17. SEA MONKEYS!!!!

18. No, really…….

19. Sea Monkey Video http://www.youtube.com/watch?v=Vc85AjH3zWA

20. How do they do that????? http://www.seamonkeysrule.info/amazingfacts.htm

21. Pistol Shrimp 500 species All pistol shrimp have one (Or sometimes two) oversized claw that create a cavitation bubble as it snaps shut. This bubble, very briefly reaches temperatures approaching that of the sun, about 4700 degrees Celsius. A loud "popping" noise is created as well. Despite being less than an inch long, the creatures can emit an astonishing 218 decibels  -  louder than a gunshot.

22. BBC Pistol Shrimp http://www.youtube.com/watch?v=XC6I8iPiHT8 Goby and shrimp http://www.youtube.com/watch?v=FEslHsv-HF4

23. Peppermint shrimp

24. Shrimp life cycle

25. Shrimp eggs Shrimp eggs are tiny, almost invisible particles released deep in Gulf waters to float in the water column, providing food for zooplankton and incidental nutrition primarily for filter feeders ranging from rays and sharks to mollusks.

26. Nauplius Larva and Protozoea Larva Larvae develop from floating fertilized eggs, growing and molting through many of each of these stages over a two- or three-week period. They cannot swim or control their movements. They feed on nanoplankton, zooplankton and phytoplankton (green algae, copepods and diatoms) as well as suspended detritus, while small fishes and filter feeders consume some of them.

27. Mysis Larva Maturing larvae in the mysis stage are carried towards shore by flood tides and wind-driven currents, continuing to feed on zooplankton and phytoplankton. A shrimp larva at this life stage is large enough in size for some juvenile fish to see and hunt. Its niche is more noticeable and it is more aware of its environment. Mysis larvae seem to respond to light by moving away from it — that is down in the water column to avoid predators – although they do not yet have swimming appendages.

28. Postlarva Currents and incoming tides carry the maturing crustacean into brackish (mixture of salt and fresh water) estuarine waters. Over a 4-6 week period, the individuals begin to look like shrimp and to forage or graze like shrimp, clinging to the bottom most of the time. They develop swimming and walking legs.

29. Juveniles Small juveniles prefer shallow salty water along the edges of marshes, where plants provide both cover and detritus, and where microorganisms thrive in the soft bottom. Small juvenile shrimp are food for juvenile fishes also living in the estuary such as southern flounder, spotted seatrout, red drum, inshore lizard fish, Atlantic croaker and pinfish.

30. Adult Move back to the sea. Out in the Gulf once more, the adult shrimp continues to grow in size on the sea’s bottom as an opportunistic omnivore, and its niche at this stage is primarily as food for many. It lives in deep water, 60-500 feet below the sea’s surface. when there is a sharp increase in the water column’s temperature the females will spawn, producing thousands of eggs to begin the cycle again.

31. Shrimp anatomy

33. Shrimp or Crayfish observation Uropod- The sixth and last pair of abdominal appendages of lobsters and related crustaceans, forming part of the tail fan. Telson- the terminal segment of the body of an arthropod Rostrum- the often spinelike anterior median prolongation of the carapace of a crustacean Pleopod- an abdominal limb of a crustacean Maxillipeds- any of the crustacean appendages that comprise the first pair or first three pairs situated next behind the maxillae Carapace- a bony or chitinous case or shield covering the back or part of the back of an animal Antennae-

35. Crayfish

36. Crayfish life cycle

37. How are lobster and crayfish different http://animals.howstuffworks.com/marine-life/crayfish-info.htm

38. Decapod video 3 min http://www.youtube.com/watch?v=0_HGZESgbjs

39. Lobster

40. B 52’s Rock Lobster!!!!! http://www.youtube.com/watch?v=Oh5J33KAaqw

41. Lobsters are carnivores (meat-eaters). Most lobsters are nocturnal (most active at night). They are predators that eat crabs, clams, worms, snails, mussels, flounder, and other lobsters Many animals eat lobsters, including fish (especially cod), octopi, other lobsters, and people. Lobsters continue to grow throughout their lives. The biggest lobster caught weighed over 44 pounds (20 kg). Lobsters may live to be 100 years old

42. Largest Lobster The largest American lobster was caught off of Nova Scotia, and weighed 44 pounds, 6 ounces and was 3 feet, 6 inches long. 1977

45. Lobster facts Lobsters and other crustaceans inhabit all the world’s major oceans. Although lobsters can be found worldwide, different types of lobster choose different areas in which to live. Many lobsters live in shallow water in the coastal areas around islands. One group of lobsters, called deep-sea lobsters, lives in the cold, deep sea.

46. On its antennae, legs, carapace, and tail, a lobster has tiny, hairlike receptors that can detect specific chemical molecules in the environment, which help the lobster to identify and locate food. The lobster crawls over the bottom of the sea, eating dead and living fish, starfish, clams, and other animals and seaweed. It grinds its food with six pairs of jaws. The food is then further ground and mixed with digestive juices in the stomach, which contains toothlike grinding organs.

47. Much of the information a lobster gets about its surroundings is gathered by millions of tiny hairlike sensors on its antennae, mouthparts, legs, and shell. Some of these sensors “sniff” chemicals that help lobsters locate and taste food. Others warn lobsters of predators or alert them to potential mates.A lobster also has special organs located at the base of its antennules, as the shorter pair of antennae are called. These organs are pits that are lined with tiny bristles. As a lobster moves, particles that are floating within the pits bend the tiny bristles in different directions. Signals that are sent from these bristles through the lobster’s nervous system help the lobster determine its position in its surroundings and keep its balance.

48. molting The lobster molts, or sheds its shell, frequently while young, less frequently as it grows. After molting it is helpless against predators and must hide until the new shell hardens. If it loses a claw or a leg, the lobster grows a new one. To molt, the lobster shrinks the muscles and other tissues in its limbs by releasing fluid out of the tissues. This lets the lobster withdraw its appendages from the surrounding shell. Once the shell cracks, the lobster is able to withdraw its entire body from its old shell. After it is out of its shell, the lobster takes in water to swell its body to a larger size. The new soft shell can withstand the pressure from the lobster’s swollen body without cracking. It takes several weeks for the new shell to harden around the swollen lobster. Once the new shell is hard, the lobster pushes the excess water out from its body. It now has a new, roomier shell to grow into.

49. A typical American lobster is 12 inches (30 cm) long and weighs about 2 pounds (0.9 kg). Some grow to more than 3 feet (90 cm) long and weigh more than 40 pounds (18 kg). Spiny lobsters are about the same size as American lobsters. Lobsters can live as long as 100 years

50. Types of lobster There are two kinds of lobsters, and these are commonly referred to as "clawed" lobsters and "spiny" lobsters, or rock lobsters. Clawed lobsters include the American lobster, a well-known marine species. Clawed lobsters are generally found in cold waters. Spiny lobsters do not have claws, but instead have long, strong antennae. These lobsters are generally found in warm water.