Animals III Flashcards
(44 cards)
1
Q
Ecdysozoan
A
-worm-like and legged invertebrates
-animals that molt (exdysis)
-monophyletic
precambrian
-oldest known land animals (scorpions f/ Silurian 437 mya)
2
Q
ecdysozoan epidermis
A
- secretes proteinaceous 3-layered cuticle that can be reinforced with chitin or CaCO3
- thin cuticles can pass gases, mineral, water, and food in parasitic forms
- thick cuticles reinforced with chitin make up exoskeleton of arthropods
- strong, waterproof provides support for muscle attachment
3
Q
pros and cons of chitinized cuticle
A
Pros
- protects organs
- prevents water loss
- supports organs and effects locomotion
- specialized appendaes
Cons -can't grow, so have to shed -molting is energetically expensive -newly molted animals are unprotected evolutionary constraint on size
4
Q
Ecdysozoan gps
A
Basal
- priapulids
- kinorhynchs
- loriciferans
evolved
- horsehair worms
- nematodes
- tardigrades
- onchophorans
- arthropods
5
Q
basal ecdysozoans
A
- worm like
- wingless
- thin cuticles
- direct development from egg to adult
6
Q
priapulids
A
- penis worm
- unsegmented animals with 3-part body (probiscus, trunk, and tail)
- live in mud and feed on slow invertebrates
- major predator in cambrian
7
Q
kinorhynchs
A
- mud dragons
- live in marine sands and muds
- basically microscopic
- bodies divided into 13 segments, each with separate cuticular plate
8
Q
loriciferans
A
- less than 1 mm
- divided into head, neck, thorax, abdomen
- covered by 6 plates
- mini versions found in cambrian
9
Q
nematoda
- feeding
- size
- segments
- coelom
- sex
A
- wormlike
- phylogenetic position is disputed
- 25,000 spp (prob 1 mil)
- free living or parasitic
- most microscopic–> biggest is 9mm
- unsegmented
- pseudocoelomate
- dioecious and parthenogenetic
- many plant, animal , and human parasites
- some extremophiles
10
Q
Nematode ecosystems
A
- represent 90% of all life forms on ocean floor and 80% of individual animals on the planate
- parasitic and saprotrophic
- some used as bio control agents against beetle grubs or other pests
11
Q
caenorhabditis elegans
A
important in genetic research
- Eutelic = has fixed number of somatic cells as adult
- genome is completely sequenced
- all cell lineages and every neuron mapped
12
Q
Nematode parasites
A
- Ascariasis = human intestinal parasitic disease from feces
- Filariasis = carried by mosquitos
- Dirofilaria immitus causes heartworm in dogs and cats
- Trichinosis = from eating raw pork –> common in undeveloped areas
- Enterobius vermicularis = pinworm –> most common human parasitic disease in developed countries –> from poop (often symptomless)
- Dracunculiasis (guinea worm disease)–> in copepods and water
13
Q
Onychophora and Tardigrades
A
- related to arthropods (have legs; not jointed)
- like arthropods, lost the coelom body cavity and instead have hemocoel for bathing organs
14
Q
Onychophora
A
- velvet worms
- segmented, but no jointed appendages
- cuticles with chitin
- tropical/temperate
- squirt slime to subdue prey
- live in social groups
- elaborate behaviors
15
Q
Tardigrada
A
- water bears
- microscopic
- found worldwide
- 4-layered cuticle
- extremely hardy
- cryptobiosis resting state (suspended animation)
- super weird genome
16
Q
Arthropods
A
Most divers group –> over 1 mil spp
- jointed legs
- versatile, protective exoskeleton
- segmentation
- tracheal gas exchange system (hex and myria) or book lungs (chelci)
- oldest land animals (437 mya) –> same time as vascular plants
- ightly developed sensory organs
- complex behaviors
- monophyletic and ancient
- biggest froup of animals (80% of all described)
- thick, chitin or CaCO3 exoskeleton
- successful terrestrially
17
Q
Arthropod gps
A
trilobitomorpha chelicerata myriopods crustaceans hexapods
18
Q
phylogeny of arthropods
A
- undisputed monophyly
- Chelci = first diverging branch
- then myriopods
- then crustaceans
- then hexapods
19
Q
tagmosis
A
fusion of segments into functional units (tagmata)
20
Q
Tracheal gas exchange system
A
- hexapods and myriapods (both terrestrial)
- no circulatory system, so centralized vertebrate gas exchange system wouldn’t work
- chitin-ringed trachea connect directly to air through openings (spiracles)
- trachea branches into smaller and smaller tubes (tracheoles) that eventually terminate on plasma membrane of every cell in animal body
- 428 mya
21
Q
Book lungs
A
- Chelicerates
- stacks of plates of blood-filled tissues surrounded by air spaces in a ventral cavity
- Prob evolved from book gills that’re similar in structure, but are external and work in water
22
Q
Compound eyes of Arthropods
A
- insects, crustceans, millipedes
- eye has units called ommatidia
- each ommatidium is innervated by one axon and provides the brain with one picture element
- brain forms image from independant picture elements
- of ommatidia in eye depends on insect
- spiders don’t have this
23
Q
Trilobitomorpha
A
- 3 lobed (haid, thorax, tail)
- calcified exoskeleton
- Cambrian explosian
- fully extinct aft Permian
- successful for over 250 my
24
Q
Chelicerata
A
- 2 tagmata: chephalothorax and abdomen
- no antennae
- no mandibles
- 6 pairs of appendages: chelicerae, pedipalps, and 4 pairs of walking legs
Pyncogonids = sea spiders (marine) -Merastomata = horseshoe crabs (living fossils) Arachnids = spiders, scorpions, harvestment, mites, ticks
25
Special scorpion
fossil found that may have lived on land and water
- used book lungs
- might be oldes terrestrial animal
26
Spiders
- chelicerae are hollow poisonous fangs
- make silk proteins in silk glands and spinnerets to produce silk threads (used to be to protect eggs; now for webs)
- more basal ones make messier webs
27
Mandibulates
- myriapods, crusaceans, hexapods
- synapomorphies are chewing mouthparts and antennae
Myriapods = 2 tagmata with mouthparts and antennae on head with many pairs of legs
Crustaceans = 3 tagmata with segments in each bearing appendages
Hexapods = 3 tagmata, but no appendages in abdomen
28
Myriapods
- many legs
- 9+ legs
- antennae
- mouthparts made of 3 modified appendages
- terrestrial
- tracheal system
Diplopoda: 2 pairs of legs per segment; eat decayig plants
Chilopods: 1 pair of legs per segment; carnivores
29
Crustacea
- highly specialized appendages
- only arthropod with 2 pairs of antennae
- CaCO3 and chitin exoskeleton
- 2-3 body segments
- 3 or more pairs of legs
- abdominal appendages
- mostly marine
30
Types of crustaceans
- monophyletic?
- how old?
```
Branchiopoda (brine shrimp, fairy shrimp)
Remipedia (blind animals in caves)
Cephalocardia (horseshoe shrimp)
Maxilopoda (barnacles, copepods)
ostracoda (bivalve like shell)
Malacostraca (everything else)
```
maybe not monophyletic
cambrian
31
Malacostracan decapods
- crabs, lobster, crayfish, shrimp
- one of the mmost important animal groups commercially
- 15,000 species, half of which are crabs
- many appendages: mouthparts, claws, legs, swimming
- mostly scavengers
32
Hexapoda
- biggest group of arthropods
- insecta and entognatha
- over 1 mil
- mostly terrestrial insects
- 6 legs; 3 tagmata
- insects are only flying invertebrates (first flight 300 mya)
33
Entognatha
- basal hexapods
- internal mouthparts
- no wings
- all hemimetabolous
- not closely related
- external fertilization
34
entognatha examples
springtails/ collembola = diverse animals in soil --> no tracheal system --> have specialized tail-like appendage for flicking animals away
Protura (maybe) = small, soil de=welling, no eyes or wings or antennae--> very basal
Diplura = bristletails --> paired cerci on posterior --> no eyes, long antennae, bead-like segments --> biting for predation
35
Insects
-fossils from devonian
-one antennae pair
earliest insects were wingless, but now most have 2 pairs of wings
-wing extensions of cuticle
-modified mouthparts
-3 pairs of legs
-tracheal system
-holo- or hemi- metabolous
-3 tagmata
-internal fertilization
36
Insect flight
- only invertebrates to have it
- oldest flying insects 300 mya
- helped with insect success
- enabled dispersal
- evolved only once in insects
37
2 flight mechanisms
Direct: wing muscles directly at wing base (dragonflies and mayflies)
Indirect: wingfolding synapomorphy for neoptera--> wing muscles attach to thorax and deform it, causing wings to move
38
Insect diversity
-half of desacribed species are insects
```
Big 4:
Coleoptea
Diptera
Hymenoptera
Lepidoptera
```
Estimated 5-7 mil spp
39
Hemiptera
sucking outhparts
hemimetabolous
aphids, leaf hopper, cicadas
40
orthoptera
bigh hind legs
hemimetabolous
stridulation
grasshoppers, crickets, katydids
41
coleoptera
beetles
most species of any animal gp
elytra = shield-like forewings
-holometaolous
42
hymenoptera
```
holometabolous
eusocial behaviour
haplodiploid
ants, wasps, bees
some venomous
```
43
lepidoptera
butterflies and moths
| holometabolous
44
diptera
- hind wings modified into halters
- halters control balance, guidance and stability during flight
- holometabolous
- flies and mosquitos
