Zoology: Animal Diversity

metazoa synapomorphies

CCD, epithelia*, collagen

what characteristic sets sponges apart from metazoa?

they have ‘epithelial like’ cells

eumetazoa synapomorphyies

at least 2 germ layers and nerves

bilateria synapomorphyies

bilateral symmetry, 3 germ layers, muscles

deuterostomia synapomorphyies

radial cleavage, archenteron to coelom, blastopore to anus

lophotrochozoa synapomorphyies

lophophore feeding structure and trochophore larva in developmental stage

ecdysozoa synapomorphy

ecdysis (moulting)

protostome characteristics

cells are spiral and determinate, mesoderm splits to form coelom, mouth develops from blastopore

deuterostome characteristics

cells are radial and indeterminate, archenteron folds to form coelom, anus develops from blastopore

population

individuals of the same species that occupy the same general area, use the same resources, and are influeced by similar environmental factors

population ecology

the study of changes in population, composition and the factors that cause these changes

density

the number of individuals per unit area or volume

dispersion

the pattern of spacing among individuals

method suitable for very large animals that form herds/flocks

count the whole population

method suitable for animals who leave visible signs such as nests, droppings, dens, etc.

count signs left by organisms

method suitable for animals that are sessile

count numbers present in random plots

method suitale for mobile animals

mark and recapture