Transcript Biol 1031 Lab 8 Slides

Lab 8:
Animals II: Non-molting and
Molting Protostomes
Phylum Mollusca - Mollusks
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Non-molting
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unsegmented
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muscular foot (may be highly modified)
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mantle – membrane present in all; in most,
secretes and maintains one or two calcerous valves
(shells)
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most have a radula (rasping tongue with chitinous
teeth)
Phylum Mollusca - Mollusks
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diverse group, over 100,000 living species (2nd
ranking in number among animal phyla)
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of 7 classes, 4 classes covered in lab:
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Polyplacophora (chitons)
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Gastropoda (gastropods) – snails, slugs, and
nudibranchs (sea slugs)
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Bivalvia (bivalves) – scallops, oysters, clams, etc.
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Cephalopoda (cephalopods) – octopuses, squid,
cuttlefish, etc.
Phylum Mollusca - Mollusks
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Video: The Shape of Life: Episode 6 – Survival
Game (Molluscs)
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body plan
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radula
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octopus camouflage
Task A-1:
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Phylum Mollusca
examine the preserved specimens in the mollusk box
and on display, note the following:
• Polyplacophora – chiton (display only):
• gills
• mantle
• foot
Task A-1:
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Phylum Mollusca
examine the preserved specimens in the mollusk box
and on display, note the following:
• Gastropoda – snail and slug:
• coiled valve (snail) or no valve (slug)
• broad, flat foot
Task A-1:
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Phylum Mollusca
examine the preserved specimens, note the following:
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Bivalvia – clam:
Task A-1:
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Phylum Mollusca
examine the preserved specimens, note the following:
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Cephalopoda – squid:
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muscular foot with tentacles (with suction
discs)
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thick mantle but no external shell (true for
most cephalopods)
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excurrent siphon (for jet propulsion)
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large eyes
Phylum Nematoda – roundworms
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molting (ecdysis) – periodic shedding of protective
cuticle so that organism can grow or change
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pseudocoelomate
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complete digestive system
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dioecious
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longitudinal muscles for movement
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many are free-living, but many are parasites
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very common in soil
Task B-1:
Phylum Nematoda
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examine the preserved specimens in the Nematoda
box
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prepare and examine a slide with live vinegar eels;
note their movement, powered by longitudinal
muscles
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examine Ascaris cross section slide; note structures
from figure 8-3
Phylum Arthropoda – arthropods
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“joint-foot” – jointed appendages
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segmented – often with some fusing and distinctive
regions (details later); very distinct cephalization
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exoskeleton containing chitin; used for protection,
and for muscle attachments
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molting (ecdysis) – shedding of exoskeleton for
growth; new exoskeleton later hardens
Phylum Arthropoda – arthropods
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very diverse group and successful group
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over 1 million named species, by far the most
species of any phylum (in fact, 2/3 of ALL
named species)
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estimates are as high as 30 million living species
unnamed
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most of the species (well over half) are insects
Phylum Arthropoda – arthropods
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focus on both subphyla and classes for tests
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4 subphyla, 6 selected classes to cover
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Subphylum Cheliceriformes
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Subphylum Myriapoda
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Subphylum Crustacea
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Subphylum Hexapoda
Subphylum Cheliceriformes
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body plan: cephalothorax and abdomen
on cephalothorax, starting at anterior end:
• paired chelicerae
• paired pedipalps
• 4 pairs of legs
• selected classes:
• Merostomata – horseshoe crab
• Arachnida – spiders, scorpions, mites, ticks, etc.
Subphylum Myriapoda
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Body plan: head and multisegmented trunk
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on head:
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one pair of antennae
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paired mandibles
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Legs on trunk (either one or two per segment,
depending on class)
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appendages are uniramous (unbranched)
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most have tracheal respiratory system
Subphylum Myriapoda
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Diplopoda (millipedes)
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two pairs of legs per
trunk segment
Chilopoda (centipedes)
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one pair of legs per
trunk segment
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poison claws on trunk
segment nearest the
head
Subphylum Crustacea
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One class (also called Crustacea)
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barnacles, crayfish, crabs, lobsters, shrimp, etc.
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on cephalothorax, starting at anterior end:
• two pairs of antennae
(unique feature)
• paired mandibles
(jaws)
• most then have 5 pairs
of chelate appendages
(pincher-like)
swimmerets
Subphylum Crustacea
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appendages are biramous (two-branched;
another unique feature)
Subphylum Hexapoda
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Hexapoda – “six feet”
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One class to worry about: Insecta
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Body plan: head, thorax, and abdomen
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On head: one pair of antennae
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On head: paired mandibles
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On thorax: three pairs of legs
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On thorax: often two pairs of wings
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appendages are uniramous (unbranched)
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most have tracheal respiratory system
Task B-2:
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Phylum Arthropoda
arthropod box and displays:
• for all, note segmentation, head, exoskeleton, and
paired jointed appendages
• items to note for each animal class (use Fig. 8-4
as a guide for structures):
• Merostomata – horseshoe crab
• large cephalothorax (from dorsal and ventral
views)
• chelicerae, pedipalps, and legs
• book gills
• telson
Task B-2:
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Phylum Arthropoda
arthropod box:
• Arachnida – garden spider
• chelicerae with fangs
• pedipalps (used by males in mating)
• 4 pairs of legs
• unsegmented abdomen with spinnerets for
making silk
Task B-2:
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Phylum Arthropoda
arthropod box:
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Crustacea
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barnacle – shell and holdfast
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blue crab – chelate appendages, mouth and
feeding appendages, cephalothorax, abdomen
(tucked under cephalothorax)
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crayfish – chelate appendages, mouth and
feeding appendages, cephalothorax, gills,
abdomen with swimmerets (note biramous
nature)
Task B-2:
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Phylum Arthropoda
arthropod box:
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Diplopoda – millipede
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head with mandibles, short antennae
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multisegmented trunk
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two legs per segment (key to identification)
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look for evidence that each “segment” is
actually a fusion of two segments
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look for spiracles
Task 3:
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Arthropods (Phylum Arthropoda)
arthropod box:
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Chilopoda – centipede
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head with mandibles, short antennae
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multisegmented trunk
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one legs per segment (key to identification)
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poison claws derived from first leg pair
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look for spiracles
Task B-2:
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Phylum Arthropoda
arthropod box:
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Insecta – grasshopper and walking stick
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head with antennae, mandibles, and compound
eyes
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thorax with three pairs of legs (note
uniramous appearance of appendages) and
two pairs of wings (grasshopper)
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segmented abdomen
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spiracles on sides
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in grasshopper, note the large tympanum
(eardrum) on first segment
Task B-2:
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Phylum Arthropoda
arthropod slides:
• tick, body louse, and water flea (Daphnia)
• for each, try to identify the class based on
external features
TODAY YOU WILL TAKE AN
EXIT QUIZ !!!