BIS2C: Lecture 30: Triploblasts: Protostomes: Ecdysozoans II

Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Lecture 30:
Triploblasts:
Protostomes:
Ecdysozoans II
BIS 002C
Biodiversity & the Tree of Life
Spring 2016
Prof. Jonathan Eisen
1

Where we are going and where we have been…
2
•Previous lecture:
•29: Triploblasts: Protostomes:
Ecdysozoans I
•Current Lecture:
•30: Triploblasts: Protostomes:
Ecdysozoans II
•Next Lecture:
•31: Deuterosomes I: Echinoderms &
Hemichordates

Topics ..
3
• Arthropod Features
• Arthropod Diversity & Major Groups
• Trilobites
• Crustacea
• Myriapods
• Chelicerate
• Hexapoda
• Blood and lots of blood

Animal Diversity
4
Diploblasts
Triploblasts
Monoblasts

Triploblasts
5
Triploblasts

Protostomes
6

Ecdysozoans
7

Arthropods
8

Arthropod Key Feature: Exoskeleton
• Exoskeleton is a thickened
cuticle
• Restricts movement and gas
exchange
• Requires ecdysis
• Muscles attached to inside
• Provides support for walking
on land, prevents drying,
and provides some
protection from predators.
• Aquatic arthropods were
thus excellent candidates to
invade land.
9

Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 10

Arthropod Key Feature: Segmentation and Appendages
• Segmentation - division of the
body into repeated
independently operated
sections
• Segments have independent
muscles and pairs of jointed
appendages
• Appendages used for
locomotion, food capture, gas
exchange, copulation, and
sensory perception.
• Tagmatization = fusing of
segments
11
segments
head
thorax
abdomen
tagmata

Arthropod Key Feature: Compound Eyes
12
• Arthropods share an eye which is composed of separate light
sensing organs called ommatidia.
• Many arthropods can see into the UV.

Metazoans: Numbers of Species Per Group
13
Numbers of described species
among the major animal groups
(from Wilson, 1992).

Metazoans: Numbers of Species Per Group: Sponges
• Previous lecture:
!Bis2B
! 
14
Sponges

!Bis2B
! 
15
Mollusca
Metazoans: Numbers of Species Per Group: Molluscs

!Bis2B
! 
16
Annelida
Metazoans: Numbers of Species Per Group: Annelids

!Bis2B
! 
17
Arthropods are
everything else!
Metazoans: Numbers of Species Per Group: Arthropods

Arthropod Major Groups (Subphyla)
18
Myriapoda
(Millipedes, Centipedes)
Crustacea
(Crabs, Shrimp,
barnacles, copepods)
Hexapoda
(Insects,entognatha)
Chelicerata
(Spiders, Scorpions,
Horseshoe crabs)
Trilobites
(Extinct)

Trilobites
19
Myriapoda
Crustacea
(Crabs, Shrimp,
Hexapoda
Chelicerata
Horseshoe crabs)
Trilobites
(Extinct)

Figure 32.19 A Trilobite Fossil
20

Trilobites
• Trilobites flourished in Cambrian and
Ordovician seas; went extinct (~250 mya)
at the end of the Permian.
• Left an abundant fossil record. Used to
data samples.
• Segmented, cephalized, many with well-
developed eyes.
• Jointed legs first appeared in trilobites.
Some appendages were modified for
different functions.
21

23
Myriapoda
Crustacea
(Crabs, Shrimp,
Hexapoda
Chelicerata
Horseshoe crabs)
Trilobites
(Extinct)

Crustacea
!24Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
• Three tagmata (head, thorax, abdomen)
• Two pairs of antennae
• Dorsal carapace covers thorax & head
• Nauplius larval stage
• Appendages modified:
- Swimming
- Feeding
- Walking
- Sensory
- Breathing
- Sex and Brooding
Thorax
HeadAbdomenheadthoraxabdomen

Crustacean Diversity
• 50,000 species, diverse feeding modes and ecology
• Marine, freshwater, and terrestrial environments
• Three groups to know:
1. Copepoda 2. Cirripedia 3. Malacostraca

27
Myriapoda
Crustacea
(Crabs, Shrimp,
Hexapoda
Chelicerata
Horseshoe crabs)
Trilobites
(Extinct)

Chelicerates
• Two tagmata (cephalothorax, abdomen)
• Head has two pairs of appendages
modified into mouthparts (chelicerae)
• Four pairs of walking legs and pedipalps
• Predators, herbivores, parasites
• Arachnida is the most diverse
Araneae- Spiders Acari- Mites & Ticks
Xiphosura-
Horseshoe Crabs
Scorpiones- Scorpions

A Few Summaries for Your Enjoyment After Hours

Xiphosura- Horseshoe Crabs
• Few living species, but an extensive fossil record.
• Body morphology is largely unchanged (stasis) for 400 my.
• Common in shallow marine waters along eastern North
America and Asia

Pycnogonida- Sea ‘Spiders’
• Small marine predators with a resemblance to spiders.
• Bizarre morphology and uncertain relationships make them
enigmatic among arthropods.

Acari- Mites and Ticks
• Dominant arthropods in many ecosystems
• Few body segments, chelicerae highly modified
• Predators, herbivores, parasites
Deer Tick (Lyme’s Disease)Chigger Mite

Scorpiones- Scorpions
• Telson with a sting and venom gland
• Give birth to live young, maternal care
• Extensive fossil record
Chelicerae
Telson
Sting

Araneae- Spiders
• Two tagmata (cephalothorax,
abdomen)
• Spinnerets produce silk
• Pedipalps modified as sperm
delivery organs
Chelicerae
Spinnerets
Pedipalps

Nicky Bay - photographer
• http://www.wired.com/2013/07/weirdest-spiders-ever/
• Nicky Bay

LONG HORNED ORB WEAVER
36

MIRROR SPIDER
37

BIRD DUNG SPIDER
38

TWIG SPIDER
39

LADYBIRD MIMIC
40

EIGHT-SPOTTED CRAB SPIDER
41

NET-CASTING/OGRE-FACE SPIDER
42

TWO-TAILED SPIDER
43

WRAP-AROUND SPIDER
44

TREE STUMP ORB
WEAVER
45

HEAVY JUMPING SPIDER
46

BLACK ARMORED TRAPDOOR SPIDER
47

ANT MIMIC JUMPING SPIDER
48

49
Myriapoda
Crustacea
(Crabs, Shrimp,
Hexapoda
Chelicerata
Horseshoe crabs)
Trilobites
(Extinct)

Myriapoda- Millipedes and Centipedes
• Two major groups: Chilopoda (centipedes) and Diplopoda
(millipedes)
• All are terrestrial herbivores or predators

Chilopoda- Centipedes
• One pair of legs per segment
• First pair of appendages modified into poison claw (forcipules)
• Small to large (2mm- 30cm), often with bright warning colors
• All are predaceous
Scutigera
Scolopendra

Diplopoda- Millipedes
• Two pairs of legs per segment
• Many different body morphologies
• Some are bioluminescent and produce cyanide as defense
• All are herbivores

Giant Millipede of Peru

55
Myriapoda
Crustacea
(Crabs, Shrimp,
Hexapoda
Chelicerata
Horseshoe crabs)
Trilobites
(Extinct)

!Bis2B
! 
56
Arthropods are
everything else!
Metazoans: Numbers of Species Per Group

Hexapods
57
Hexapoda

Hexapods
58
Three orders of
insects
comprise more than
50% of described
animal species

Hexapoda- Insects
• Three tagmata (head, thorax, abdomen)
• One pair of antennae
• Three pairs of legs
• Respiration by tracheae
• Mouthparts with mandibles
• Many can FLY FLY FLY
• Many have complete metamorphosis
(Holometabolous)

Lepidoptera- butterflies and moths
• 175,000 described species
• Highly specialized and diverse lifestyles
• Important pests and pollinators, plant coevolution
• Many species sequester defensive chemicals from host plants
Monarch Viceroy

Coleoptera- beetles
• The most diverse insect lineage
• One pair of wings modified into protective coverings; elytra
• Amazing diversity in life history and ecology

Diptera- flies
• 150,000 described species, many undescribed
• One pair of wings modified into counterweights; halteres
• Great diversity in life history; herbivores, predators, parasites, etc
• Medical significance
Bot fly larva & adult
halteres

Hymenoptera- bees, wasps, ants
• 130,000 described species
• Two pairs of wings connected by hooks; hamuli
• Females with ovipositor modified into a sting
• Important pollinators in agriculture, many beneficial species
• Great diversity in lifestyles; some are social

Insect Mouthparts
Mandibles & modified mouthparts
mandible
(ancestral):
biting-
chewing
piercing-
sucking
siphoning sponging
http://www.entomology.umn.edu/cues/4015/morpology/

Mandibles & modified mouthparts
mandible
(ancestral):
biting-
chewing
piercing-
sucking
siphoning sponging
http://www.entomology.umn.edu/cues/4015/morpology/
Insect Mouthparts

Mosquito Feeding
67

Mosquito Feeding on Mouse …
68
http://www.dailymail.co.uk/sciencetech/article-2385937/What-REALLY-happens-mosquito-bites-
Scientists-capture-parasite-bites-sucks-blood-gruesome-video.html

Mosquito Feeding Video Details
• See Ed Yong blog post
• http://phenomena.nationalgeographic.com/
2013/08/06/heres-what-happens-inside-
you-when-a-mosquito-bites/
• Choumet V, Attout T, Chartier L, Khun H,
Sautereau J, Robbe-Vincent A, et al.
(2012) Visualizing Non Infectious and
Infectious Anopheles gambiae Blood
Feedings in Naive and Saliva-Immunized
Mice. PLoS ONE 7(12): e50464. http://
dx.doi.org/10.1371/journal.pone.0050464
69

Mosquito
70

Bed Bug
71

Lice
72

Vampire Moth
73

Leech
74

Tick
75

TseTse Fly
76

Clickers
Which of the following (shown on previous
slides) is not an arthropod?
A. Tsetse fly
B. Mosquito
C. Bedbug
D. Tick
E. Leech
77

Clickers
Which of the following (shown on previous
slides) is not an arthropod?
A. Tsetse fly
B. Mosquito
C. Bedbug
D. Tick
E. Leech
78

Blood Feeding - Hematophagy
• Found in many organisms
• Most of them are Protostomes
• Examples include
!Bats
!Annelids (e.g., leeches)
!Nematodes
!Arthropods
!Birds (vampire finches)
!Fish (e.g., lampreys)
79

Adaptations of Blood Feeders?
80

Adaptations of Blood Feeders?
• Piercing
• Sucking
• Anticoagulation
• Vasodilation
• Movement and hiding
81

Why Should We Care about Blood Feeding Animals?
82

Human Diseases Transmitted by Mosquitoes
• Chikungunya
• Dengue fever
• Rift Valley fever
• Yellow fever
• Zika
• Malaria
• Japanese encephalitis
• Lymphatic filariasis
• West Nile fever
83

Lots of Other Vector Borne Human Diseases
• Leishmaniasis
• Sandfly fever (phelebotomus fever)
• Crimean-Congo haemorrhagic fever
• Lyme disease
• Relapsing fever (borreliosis)
• Rickettsial diseases (spotted fever and Q fever)
• Tick-borne encephalitis
• Tularaemia
• Chagas disease (American trypanosomiasis)
• Sleeping sickness (African trypanosomiasis)
• Plague (transmitted by fleas from rats to humans)
• Rickettsiosis
• Onchocerciasis (river blindness)
• Schistosomiasis (bilharziasis)
84

• Every year there are more than 1 billion
cases and over 1 million deaths from
vector-borne diseases
85

Clicker
Which of the following is NOT involved in
circulation in plants?
• A. Xylem
• B. Phloem
• C. Tracheids
• D. Vessel elements
• E. Carpals
86

Clicker
Which of the following is NOT involved in
circulation in plants?
• A. Xylem
• B. Phloem
• C. Tracheids
• D. Vessel elements
• E. Carpals
87

In-Text Art, Ch. 35, p. 735

What to do?
• What can we do about all these arthropod borne
diseases?

Eliminate Dengue
91
http://www.eliminatedengue.com/our-research

Zika and Wolbachia
92
http://www.voanews.com/content/infected-mosquitoes-enlisted-stop-zika-dengue-wolbachia/3187811.html

Clicker
What other kind of organism did we
discuss that has Wolbachia living in it?
• A. Dinoflagellates
• B. Nematodes
• C. Coral
• D. Cnidarians
• E. Sponges
93

Clicker
What other kind of organism did we
discuss that has Wolbachia living in it?
• A. Dinoflagellates
• B. Nematodes
• C. Coral
• D. Cnidarians
• E. Sponges
94

• http://www.nytimes.com/2016/05/05/
science/zika-virus-moquitoes-
microbe.html?_r=0
95

http://www.cnn.com/videos/world/2016/01/28/zika-mutant-male-mosquitos-
mclaughlin-pkg.cnn/video/playlists/zika/

BIS2C: Lecture 30: Triploblasts: Protostomes: Ecdysozoans II

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