EEB266H1 Lecture Notes - Lecture 4: Rotifer, Parthenogenesis, Mollusca
28 Apr 2016
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Eutelic growth: fixed number of cells because the fertilized embryo undergoes a fixed number of splittings. Syneytial epidermis: tissue which cell membranes are absent one flat function. Size is 0. 1 1. o mm in length (neophonra) A few marine but mostly freshwater and limnoterrestrial: within the water of mosses and soil. Corona: mouth is ventrally located and terminal end is sensory and adhesive: ciliated organ that moves metachorically (one beats immediately before one neighbor and immediately after). Mastax: muscular pharynx with skeletal elements: these skeletal elements are called trophi (chitinous jaw). Parthenogenetic most of the time, with phases of sexual reproduction. Males are extremely rare; dwarfs, aberrant, short lived and parasitic. Mictic eggs: meiosis: females (diploid) under environmental stressors produce haploid eggs that become males which then copulate on the female by hyperdermic insemination. Amicitic eggs: parthenogenesis: females typically undergo asexual reproduction. Some external brooders and some viviparous species (avoid consuming offspring). Seasonal changes in body shape amongst genetic clones.
