PANARTHROPODA Flashcards
Why are the arthropods so successful?
Rigid skeleton
Segmented body+jointed limbs
Image forming eyes
In which phylum do the velvet worms belong?
Onychophora
Describe the body of the onychophores?
Have worm-like body form similar to an errant polychaete
What similarities doe onychophores share with the annelids?
Soft, not articulated cuticle and body wall muscle
Multiple, paired, segmented nephridia
Motile cilia
Ciliated excretory and reproductive tract
Paired, paddle-like unjointed limbs
What similarities do onychophores share with arthropods?
Cuticle must be molted Reduced coelom Spacious hemocoel Foregut & hindgut lined with cuticle Respire with trachea/spiracle system Large brain Cleavage not spiral
Defensive slime which shoots out up to 50 cm and hardens to ensnare potential predators.
Slime papillae
What do some onychophores use to transfer sperms?
Spermatophores
In which phylum do the water bears belong?
Tardigrada
Similarities of the tardigrades with the annelids include:
Soft, generally not articulated cuticle
Paired, paddle-like unjointed limbs (lobopods)
Similarities of tardigrades with arthropods include:
Cuticle must be molted No circular muscle layer Discrete muscles attached to the cuticles Reduced coelom Spacious hemocoel but no heart Fore- and hindgut lined with cuticle Form sensory setae Cleavage not spiral
What are the unique traits that belong to the tardigrades?
Muscular pumping pharynx with stylets
Ceolom and mesoderm form via outpocketing of gut
The ability of the tardigrades to survive complete desiccation and extreme freezing multiple times.
Cryptobiosis
