Taxonomic Rank
Parazoa
no true tissues
-Porifoera (sponges) only
Eumetazoa
true tissues
Radial symmetry
symmetrical from the top
Bilaterial symmetry
Symmetrical from front.. left and right the same.
Mesoderm
-one of the three primary germ layers in the very early embryo. ectoderm (outside layer) and endoderm (inside layer), with the mesoderm as the middle layer between them..
Forms into smooth muscle (in gut), red blood cells, skeletal muscle cells, and cardiac muscle
Acoelomate
no body cavities - gut, epidermis and various tissues, no cavity. epidermis, gut in middle.
Pseudoceolomates
No mesoderm
coelomate
protostomes or deuterostomes..
A coelomate animal is basically a set of concentric tubes, with a gap between the gut and the outer tubes.
Protostomes and deuterostomes
Major difference is embryotic development..
Prot - embryo forms dent on one side, blastopore, which deepens to become archenteron - first phase of growth of gut..
mouth develops from blastopore, anus develops later
Deut - original dent becomes anus, while gut tunnels through to make another opening, forming the mouth.
coelom
fluid filled cavity formed within mesoderm of some animals.
Protostomes
mollusca, annelids (segmented worms), anthropoda (crustaceans, insects, spiders), platyhelminthes, nematodes (roundworms)
Deuterostomes
echinoderms (starfish, sea urchins), chordata (vertebrates)
Biodiversity values of invertebrates
ecdyzoa
anthropods and nematods (round worms)
keying out phylum
Organize animals based on selected distinguishing characteristics
Dichotomous key – two characteristics (or group of characteristics) per decision
Tabular key – several options at once
Can be difficult to use – depend on knowing terminology, right geographic region, etc.
Results need to be confirmed by other sources
Characteristics for classification
Distinguishing characteristics
Monoecious
2 sex cells in 1 organism
Dioecious
1 sex cell in 1 organism
Taxonomy important because..
- shows different animal relations (how affect humans, benefits may provide)
Phylum porifera - structural characteristics
Pinacocyte
flat cells found on the outermost layer of a sponge. They can expand and contract to slightly alter the size of the sponge, and can also produce collagen.
Choanocyte