BIOL 312 Lecture Notes - Lecture 5: Entognatha, Protura, Springtail

• School: University of Victoria
• Department: Biology
• Course: BIOL 312
• Professor: Steve Perlman

Document Summary

Lecture 5 arthropods, hexapods, basal insects, flight, paper on hexapod phylogeny. Chelicerata (arachnids): no antennae or mandibles, tagmata: cephalothorax and abdomen, 6 pairs of appendages: chelicerae (often claw-life, used for feeding), pedipalps (modified e. g. feeding, sensing, defence, reproduction, locomotion), 4 pairs of walking legs. Myriapoda (milli- and centipedes): many pairs of appendages, tagmata: head (single pair on antennae, mandibles, maxillae and labia) and trunk. Crusta(cid:272)ea (cid:894)lo(cid:271)sters, (cid:272)ra(cid:455)fish, (cid:449)ater fleas, daph(cid:374)ia, (cid:271)ar(cid:374)a(cid:272)les, sea li(cid:272)e(cid:895): (cid:862)i(cid:374)se(cid:272)ts of the sea(cid:863), e(cid:374)or(cid:373)ous variation in body form, no uniting features not monophyletic because insects are nested within crustaceans. Haxapoda (insects and their relatives): tagmata: head, thorax, abdomen, head one pair of antennae, mandibular mouthparts, 3 pairs of legs. Reduction in walking legs to 6 (3- segmentory locomotory) Non-insect hexapods: entognatha internalized mouthparts, mandibles and maxillae inside head capsule (oral folds enclosing the mandibles). Collembola (springtails): most abundant hexapod up to 250,000,000 individuals/sq. acre. Ventral tube (collophore) on first abdominal sefment for excretion, water transport, adhesion.