Lecture 10 - Ecdysozoa Flashcards
What is Ecdysozoa? (4 traits)
Multilayered cuticle, cuticle is molted, molting regulated by ecdysone in arthropods and possibly other ecdysozoans, multilayered cuticle molting during growth is a synapomorphy of ecdysozoa
Ecdysozoa in Tree
In group 2 of protostomes
Ecdysozoa phyla
Arthropoda, onychophora, tardigrada, nematoda, nematomorpha, priapulida, kinorhyncha, loricifera
What is a roundworm? (Phylum Nematoda) find 7
Nematoda, unsegmented, roundworm, pseudocoelom, no appendages, no organs for gas exchange or nutrient circulation, a single species can be both hermaphroditic or male, most live in soil, eat small organisms and detritus, some are parasites, only longitudinal muscles no circular muscles
What is a water bear (Phylum Tardigrada) 8 traits
Tardigrada, segmented, lobopodal legs, can survive for decades without food in the “tun” state, herbivores and carnivores, sexual reproduction and parthenogenesis, is marine freshwater and terrestrial
What is a velvet worm (Phylum Onchyphora) 7 traits
Onychophora, segmented, lobopodal legs on trunk, three pairs of head appendages incl antennae jaws and slime papillae, all terrestrial, carnivorous, slime papillae and sharp head and jews to capture and puncture cuticle of prey
What is an arthropod (Phylum arthropoda) 8 traits
Arthropoda, jointed legs and head appendages, segments arranged into tagmata, hard exoskeleton, ladder-like CNS, mostly sexual reproduction, terrestrial arthropods -internal fertilization, aquatic arthropods- external fertilization
What are the lineages of arthropoda (4)
Chelicerata, myriapoda, crustacea, hexapoda
Chelicerata (lineage of Arthropoda) animals
Ticks, mites, spiders, scorpions, daddy longlegs, sea spiders, horsehsoe crabs
Chelicerata (lineage of arthropoda) 5 traits
ticks and mites are parasites everyone else are predators, sea spiders and horseshoe crabs are marine everyone else is terrestrial, chelicerae are appendages near the mouth homologous to appendages of other arthropods, two tagmata which are cephalothorax and abdomen, scorpions are ovoviparous and have prolonged prenatal care which is unusual for arthropods
Myriapoda (lineage of arthropoda) organisms
Centipedes and millipedes
Myriapoda (lineage of arthropoda) traits 6
Two tagmata which are head and trunk, all are terrestrial, one pair of legs per trunk segment in centipedes, centipedes are predacious, two pairs of legs per segment in millipedes, millipedes are detritivores
Crustacea (lineage of arthropoda) 5 traits
Primarily aquatic, some crabs are terrestrial, some isopods are terrestrial, three tagmata which are head thorax and abdomen, biramous appendages two branches which are expodite that is an outer branch including an epipodite (gill) and endopodite which is an inner branch that has legs pulps and flagella
Hexapoda (lineage of arthropoda) traits
insects and their relatives, three tagmata including head thorax and abdomen, three pairs of legs on thorax, most have two pairs of wings on thorax
Arthropod phylogeny
Hexapoda is resed within crustacea, hexapoda + crustacea = pancrustacea, crustacea is paraphyletic
