Lecture 25 & 26 Anthropoda Flashcards
1
Q
what are the five subphyla of anthropoda?
A
- trilobata - formerly numerous marine animals, went extinct end-Permean
- chelicerata - horseshoe crabs and arachnids
- myriapoda - mili/centipedes
- crustacea - primary aquatic
- hexapoda - insects and relatives
2
Q
what are the tagmata most common in anthropoda?
A
- cephalothorax or - head - thorax - abdomen
3
Q
what is the phylogeny of anthropods?
A
under dispute
- crustacea may be paraphyletic as hexapoda evolved from within it
- relative positions unresolved
4
Q
what is subphylum trilobita?
A
ecdysozoa - anthropoda
- well known fossil group of extinct marine anthropods
- abundant in cambrian
- 3 distinct tamgata: cephalon (head), thorax, pygidium (tail)
- sensory organs (compound eyes, flexible antennae)
- each thoracic segment had biamous (2 branched) legs and pair of gills
5
Q
what is subphylum trilobita?
A
ecdysozoa - anthropoda
- well known fossil group of extinct marine anthropods
- abundant in cambrian
- 3 distinct tamgata: cephalon (head), thorax, pygidium (tail)
- sensory organs (compound eyes, flexible antennae)
- each thoracic segment had biamous (2 branched) legs and pair of gills
6
Q
what is subphylum crustacea?
A
- crabs, lobsters, shrimp, relatives
- huge size range
- variable morphology
7
Q
what is the crustacean morphology?
A
- 3 tagmatized regions: head, thorax, abdomen, usually have cephalothorax
- cephalothorax covered by a carapace – shield that covers dorsal and lateral sides, sometimes also covers abdomen
- 2 pairs antennae
- compound eyes
- biramous limbs
8
Q
what is the crustacean morphology?
A
- 3 tagmatized regions: head, thorax, abdomen, usually have cephalothorax
- cephalothorax covered by a carapace – shield that covers dorsal and lateral sides, sometimes also covers abdomen
- 2 pairs antennae
- compound eyes
- biramous limbs
- head: segmented mandibles maxillae (appendages specialized for feeding/locomotion)
- thoracic limbs for locomotion
- abdominal limbs for many things
- exoskeleton with CaCo3
- exchange gases via cuticle or gills (modified appendages)
- few truly terrestrial crustaceans use traechea – branching tunnels from openings in the body wall – deliver O2 directly to individual cells
9
Q
what is the crustacean life cycle?
A
- variable
- most have separate sexes, reproduce sexually (except for barnacles - herm)
- parthenogenesis widespread among crustaceans
- sperm transfer via copulation (placing sperm on or in female) – via intromission or spermatophore (capsule)
- some brood eggs until they hatch
- direct (daphnia) and indirect development – more common
10
Q
what are hexapods and myriapods shared features?
A
- one pair of antennae
- mandibles for main mouthparts
- trachea (respiratory tubes)
- uniramous limbs
- pancrustacea? hexapods belong with crustaceans and myriapods are sister taxa to pancrustacea – DNA and some morphological features
11
Q
what is subphylum hexapoda?
A
- 6 legged anthropods
- class insecta
12
Q
what is hexapod morphology?
A
- consistent tagmitization: head with one antennae, thorax with 3 pairs of jointed legs, abdomen without any appendages
- multilensed compound eyes
- many have simple eyes : ocelli (eye spots) with a single lens
- segmented terminal appendages (cerci)
- primitive groups lack wings (apterygote)
- most have wings as adults (pterygota) which are a synapomorphy of the clade
13
Q
what are the two hexapod life cycles?
A
- incomplete metamorphosis: juveniles are nymphs which may share morphology and habitat of adult; wings develop
14
Q
what are the two hexapod life cycles?
A
- incomplete metamorphosis: juveniles are nymphs which may share morphology and habitat of adult; wings develop slowly over several molts
- complete metamorphosis: wings develop all at once in a special stage called a pupa; juveniles are larva and always have a different morphology and ecology than adults
- no metamorphosis in primitively wingless groups – small adults w/o genitalia
15
Q
what is the hexapod life cycle?
A
- ALL separate sexes
- collembolans and apterygote insects transfer sperm INDIRECTLY VIA SPERMATOPHORE ON SUBSTRATE
- all pterygote insects copulate
- shed all ectodermally derived cuticle during moulting
- new cuticle produced before molt is soft and wrinkled - swallows air and water to expand new skin
