Arthropoda diversity

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1 Arthropoda diversity -Subphylum Trilobitomorpha no living representatives (only fossil record) - Subphylum Chelicerata - Subphylum Mandibulata Horseshoe crab Sea spiders Crustacea

2 Class Crustacea. ~ species, divided in 6 major subclasses. SubClass Malacostraca. SubClass Branchiopoda. SubClass Ostracoda. SubClass Copepoda. SubClass Pentastomida. SubClass Cirripedia

3 Malacostraca diversity. Includes 5 Orders: 1) Isopoda pillbugs, woolice Deep sea giant isopods

4 Malacostraca diversity. Includes 5 Orders: 2) Amphipoda sand fleas

5 Malacostraca diversity. Includes 5 Orders: 3) Euphausiacea euphausiids (krill)

6 Malacostraca diversity Why is krill so important in the oceanic food web? The annual production of krill biomass in Antarctic waters is around 99 million metric tons per year!! Primary diet of seals, penguins, and whales in the Southern Ocean.

7 Malacostraca diversity. Includes 5 Orders: 4) Stomopoda stomopod shrimps

8 Malacostraca diversity. Includes 5 Orders: 5) Decapoda crabs, lobsters, shrimp, hermit crabs

9 Malacostraca. In addition to 2 pairs of antennae, the malacostracan head bears 3 pairs of small appendages: - Mandibles (crush food) - 1 st maxillae - 2 nd maxillae (manipulate food and generate water currents)

10 Malacostraca. The next 8 segments of the cephalothorax bear (in sequence): - 3 pairs of maxillipedes (for food manipulation) - 5 pairs of walking legs (pereopods) (may have claws on the first 3)

11 Malacostraca. Each of the 6 abdominal segments bears a pair of appendages as well - 5 pairs of pleopods (for swimming and generating respiratory currents) - The last (flat) pair are the uropods, which with the telson form the tail.

12 Malacostraca In lobsters, the eggs are placed in pleopods (they aerate the eggs with their movement)

13 Malacostraca Eggs Pleopods

14 Class Crustacea. SubClass Malacostraca. SubClass Branchiopoda. SubClass Ostracoda. SubClass Copepoda. SubClass Pentastomida. SubClass Cirripedia

15 Subclass Copepoda species, most are marine and major component of zooplankton (limited locomotory capacity mercy of currents).. Small (less than 1-2mm long)

16 Subclass Copepoda. Copepods are among the most abundant animals on Earth!! and, among the most important herbivorous of the ocean!. They are at the base of the oceanic food web. Major food source for primary carnivorous, including commercial fish

17 Copepoda

18 Class Crustacea. SubClass Malacostraca. SubClass Branchiopoda. SubClass Ostracoda. SubClass Copepoda. SubClass Pentastomida (internal parasites, e.g. snakes). SubClass Cirripedia

19 Subclass Cirripedia. Cirripedes, commonly known as barnacles. 3 defining characteristics: 1) Highly modified for attachment to hard substrates (including other animal s surface)

20 Subclass Cirripedia 2) Thoracic appendages modified as filtering cirri 3) No abdomen

21 Subclass Cirripedia. Parasitic barnacles Skin of the host

22 Class Crustacea. SubClass Malacostraca. SubClass Branchiopoda. SubClass Ostracoda. SubClass Copepoda. SubClass Pentastomida. SubClass Cirripedia

23 Phylum Chaetognatha. Free-living, torpedo shaped, marine carnivorous. Common name - Arrow Worms.. Only few centimeters long. Transparent.. i.e. lack specialized respiratory and excretory systems

24 Phylum Chaetognatha. Cilia are sensitive to vibration, enabling chaetognaths to detect the presence and location of copepods and fish larvae (primary preys)

25 Phylum Chaetognatha. Feeding behaviour is impressive. Motionless, sinking slowly until it detect the prey.

26 Phylum Chaetognatha Then, it darts forward and strikes the prey with 2 rows of long, curved, stiff spines adjacent to the mouth. This manoeuvre takes 1/15 of a second.

27 Phylum Chaetognatha Two rows of short teeth aid in holding the prey during ingestion. Toxins may exit from vestibular pits.

28 Phylum Chaetognatha One pair of small eyes. Each composed by 5 ocelli (not image forming; detect changes in light intensity). Each ocelli can be oriented in different directions wide visual field.

29 Phylum Chaetognatha The arrow worms bear one or 2 pairs of lateral fins (to stabilize) and a terminal caudal fin (forward thrust).

30 Phylum Chaetognatha. Planktonic organisms cannot swim against currents. Show diurnal vertical migration

31 The Lophophorates (includes 3 phyla) and Entoprocts

32 General characteristics. First 3 phyla have in common one major anatomical feature the lophophore It is a body region around the mouth characterized by a circular or U-shaped ridge, with either one or two rows of ciliated hollow tentacles

33 General characteristics In all species, the lophophore functions as a food-collecting organ and a surface for gas exchange.

34 General characteristics All members are sessils or sedentary suspension-feeders. No lophophorate species have distinct head

35 Phylum Phoronida. 12 marine species, that live in permanent chitinous tubes implanted in muddy or sandy substrate or attached to solid surfaces In AVATAR!!!

36 Phylum Phoronida. A giant nerve fiber permits the animal to withdraw rapidly to its tube upon provocation. About 12 cm long. No appendages except for the anterior lophophore. (removed from its tube)

37 Phylum Phoronida. Lophophore form a U-shape

38 Phylum Brachiopoda. External appearance is quite unlike phoronids. Superficially resemble bivalves, with a body covered by a pair of external calcified shells species (but over 30,000 species appear in fossil record)

39 Phylum Brachiopoda. Brachiopod lophophore resembles that of phoronids, except that it is drawn out into 2 arms

40 Phylum Brachiopoda. Most live permanently attached to the substrate, by means of a stalk - called pedicle. It may increase the rate of food capture and gas exchange.. Shells are composed by a protein matrix with calcium carbonate or calcium phosphate.

41 Phylum Bryozoa. Besides some pelagic Antarctic exceptions, bryozoans live attached to macroalgae, rocks, wood, sea turtle shells and a variety of hard and softs substrates.

42 Phylum Bryozoa. One entire individual (cystid and polypide) is termed a zooid. Funiculus cable that form connections between individual colony members. Connected to the digestive system. May provide direct transfer of nutrients among adjacent zooids.

43 Phylum Bryozoa

44 Phylum Bryozoa. All are colonial, that is, every individual reproduces itself asexually to form a group of genetically identical individuals (with up to 2 million zooids in a single colony)

45 Phylum Echinodermata

46 Phylum Echinodermata. Echinoderms and Hemichordates (next chapter) form the sister groups (closest living relatives) of Chordates.. Includes:

47 Phylum Echinodermata Sea lilies

48 Phylum Echinodermata Feather stars

49 Phylum Echinodermata Brittle stars

50 Phylum Echinodermata Sea stars

51 Phylum Echinodermata Sand dollars

52 Phylum Echinodermata Sea urchins

53 Phylum Echinodermata Heart urchins

54 Phylum Echinodermata Sea cucumbers

55 Phylum Echinodermata The major unifying characteristic of Echinodermata is the presence of what is known as the water vascular system.

56 Phylum Echinodermata. This system consists of a series of fluid-filled canals. These canals lead to tubular structures called podia, or tube feet.

57 Phylum Echinodermata. This system is linked to the outside seawater through a sieve plat called madreporite, which leads down by a stone canal (stone because it has spicules or plates of CaCO3), to the ring canal (around the esophagus)

58 Phylum Echinodermata. Subphylum Crinozoa. Class Crinoidea sea lilies and feather stars. Subphylum Asterozoa. Class Stelloroidea. Suclass Ophiuroidea the brittle stars. Suclass Asteroidea sea stars. Subphylum Echinozoa. Class Echinoidea sea urchins, heart urchins, sand dollars. Class Holothuroidea the sea cucumbers

59 Defining characteristics: Class Crinoidea The main part of the body is supported above the substrate either by a long stalk or by a series of grasping claws (cirri) Stalked crinoids (sea lilies,100 species) Nonstalked, motile crinoids (feather stars, 600 species)

60 Class Crinoidea Nonstalked, motile crinoids (feather stars, 600 species)

61 Class Crinoidea. Are the sea lilies permanently attached to the substrate by a stalk?

62 Class Crinoidea. Two rows of tubular pinnules extend from each arm

63 Class Crinoidea. In the present days, the most diverse assemble of this group is found in the Great Barrier Reef, Australia.. All crinoids are suspension feeders.

64 Class Stelleroidea. Class contains brittle stars (ophiuroids) and sea stars (asteroids)

65 Subclass Asteroidea. Asteroids are predators on large invertebrates, including sponges, gastropods, polychaetes, bivalves, other echinoderms, and even small fish.

66 Phylum Echinodermata. Subphylum Crinozoa. Class Crinoidea. Subphylum Asterozoa. Class Stelloroidea. Suclass Ophiuroidea. Suclass Asteroidea. Subphylum Echinozoa. Class Echinoidea sea urchins, heart urchins, sand dollars. Class Holothuroidea the sea cucumbers

67 Class Echinoidea. Echinoids can be regular (almost perfect, spherical symmetry, e.g. all sea urchins) or irregular (various degrees of bilateral symmetry associated with burrowing lifestyle) Irregular Regular

68 Class Holothuroidea species of sea cucumbers. Also lack arms.. A typical holothurian maybe regarded as flexible echinoid. Morphological modifications reflect adaptation for a different lifestyle.

69 Class Holothuroidea Many species respond to a variety of physical and environmental factors by expelling internal organs (intestines, respiratory trees, gonads ) true evisceration. all lost body parts are eventually reformed great regenerative capabilities (common in echinoderms)

70 Class Holothuroidea. In some, this process is limited to the expulsion of sticky and/or toxic structures Cuvierian tubules. (these structures are attached to the left respiratory tree and serve to discourage and entangle potential predators).

71 The Nonvertebrate Chordates. Phylum Chordata. Subphylum Urochordata (= Tunicata). Class Ascidiacea. Class Larvacea (= Apendicularia) 90% of invertebrate chordates. Class Thaliacea. Subphylum Cephalochordata. Subphylum Vertebrata

72 Class Ascidiacea ( a a little bag )

73 Class Ascidiacea ( a a little bag ). 90% of all urochordate species. Found in all oceans. Commonly know as sea squirts. Live attached to solid substrate (aquaculture cages circulation) reducing water

74 Class Ascidiacea ( a a little bag ). With few exceptions, adults are sessile. The body is bag-like and covered by a secretion of the epidermal cells This secreted protective test, is also called tunic ( tunicates = urochordates)

75 The Nonvertebrate Chordates. Phylum Chordata. Subphylum Urochordata. Class Ascidiacea. Class Larvacea. Class Thaliacea. Subphylum Cephalochordata. Subphylum Vertebrata

76 Class Thaliacea. Mostly free-living planktonic individuals

77 Class Thaliacea. Transparency helps to avoid detection of predators and potential prey

78 Class Thaliacea. Thaliaceans include the commonly known: 1) Pyrosomes (may attain 8 to 10m)

79 Class Thaliacea 2) Salps

80 Class Thaliacea 2) Salps

81 Class Thaliacea 3) doliolids

82 Class Thaliacea. Generally they close the buccal aperture, contract the circular muscles (deforming the test), and internal volume forces water out of the atrial siphon - The animal is then jet-propelled forward.

83 . The most primitive, the pyrosoms, seem like colonial ascidians Class Thaliacea Water is discharged through a common exit

84 Class Thaliacea Phronima sedentaria: A common pelagic carnivorous amphipod. It uses thaliaceans has barrels which they pilot, eat and use as brooding chambers,

85 Class Thaliacea Similarities?

86 The Nonvertebrate Chordates. Phylum Chordata. Subphylum Urochordata. Class Ascidiacea. Class Larvacea. Class Thaliacea. Subphylum Cephalochordata. Subphylum Vertebrata

ADVANCED INVERTEBRATES HAVE COMPLEX BODIES AND INTERNAL SYSTEMS

ADVANCED INVERTEBRATES HAVE COMPLEX BODIES AND INTERNAL SYSTEMS Arthropoda Most successful phylum on Earth Exoskeleton chitin Striated muscle Articulation Crayfish, lobsters, shrimp, crabs Echinodermata