Bio 108 - Lecture 20 Flashcards Preview

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Flashcards in Bio 108 - Lecture 20 Deck (22):
1

Recent Changes of Phylogeny of Arthropoda

- Hexapods and myriapods used to be sister taxa
- Hexapods now places with crustaceans, new clade called pancrustacea

2

Tagmata of Arthropods

Head an thorax sometimes merge as cephalothorax
Head top, thorax middle, abdomen, back

3

Subphylum Trilobita

- Wiped out in end-permian
- 1 antennae
- Pair of compound eyes
- Many biramous

4

Physical Features of Subphylum Crustacea

- 2 pairs of antennae
- Biramous limbs
- Head and thorax merged to form cephalothorax
- Covered by carapace
- Mouthparts are mandibles
- Exchanges gas through gills
- Use tracheae

5

Mandibles

Single segmented moutparts for biting / chewing

6

Crustacean Life Cycle

- Only hermaphroditic species is barnacles
- Copulation sperm transfer
- Femals brood their eggs until hatch
- Most direct developers
- Most start out with sex limped nauplius larvae

7

Ecology and Importance of crustaceans

Some filter feed, scavenge, or prey on fish
Some are commensals or parasites
- Value for food
- Bottom trawling to catch them is bad

8

Hexapods Defining Features

- Insects
- 6 Legged
- Includes class Insecta
- And Class Collembola

9

Morphology of Hexapods

- Head, Thorax, Abdomen
- Mandibles enclosed by cheeks in collembola
- Mandibles not enclosed by cheeks in Insecta
- Furcula used for jumping
- Ventral projection used for osmoregulation called collophore
- Wings
- Compound eyes

10

Entognathous vs Ectognathous

Ento - Mandibles are enclosed
Ecto - Mandibles not enclosed

11

Hexapod Life Cycle 3 Main variations

1) Ametaboly: Young look exactly like adult
2) Hemimetaboly: Wings slowly develop, young are called nymphs
3) Holometaboly: Wings develop at once during pupa stage, Juveniles called larva

12

Other Characteristics of Life Cycle for Hexopods

All shed ectocuticle
In direct sperm transfer
All Prerygot insects copulate

13

Ecology and Importance of Hexopods

- All terrestiral
- Polinate flowers
- Colony-collapse disorder is a dissaster

14

Myriapoda
Myria =

= A great many
- Only have head and trunk
- All terrestrial, oldest knows fossils of terrestrial animals

15

Class Diplopoda

- Millipedes
- Two pairs of legs and two stigma
- Diplosegments because adjacent segments fuse

16

Class Chilopoda
Cheilos=

- Centepedes
- Modified legs behind mouthparts
- Poison claws used to subdue prey
= Lip

17

Chelicerata
Chel=
Cereos=

- Have chelicerae as main mouthparts
- 2 Tagmata
(Prosoma and Opisthoma)
- Cephalothorax and abdomen
= claw
= horn

18

Class Xiphosura
Xiphos=
Uros=

- Horeshoe Crabs
- Compound eyes
- Book Gills
- Long terminal spine
- Eat dead plants and animals by ingesting particles
- Larvae are planktonic
= Sword
= Tail

19

Class Arachnida

- Spiders
- Fluid feeding predators

20

Order Araneae

- Spiders
- 2 segmented chelicerae
- Spinnerets
- Gas exchange through tracheae and book lungs
- Poison glands
- Maternal care
- Suck up sperm using pedipalp

21

Order Scorpiones

- Pedipals modified as grasping pincers
- Segmented
- Poisonous sting

22

Order Acari

- Mites
- Many fluid feeders but detritivores can ingest solid particles
- Youth hatch with only 3 pairs of legs
- Youth called larvae
- Most economically important arachnids