zoo prime

Total number of animal species

1.5 million

Number of freshwater fish species

15,000

Number of total fish species

32,000

Estimated number of invertebrates

30 million

Body plan determined by

constraints imposed by ancestral body plan
demands and requirements of current lifestyle

General example of shared ancestry

mammalian guts
thylacine vs dog dentition (same function, convergent evolution, but noticeably different; thylacine is marsupial and dog is mammal)

panda constrained by body plan

Pandas have carnivore

metamerism

repeated

5 levels of organisational complexity

protoplasmic
cellular
cell

protoplasmic complexity

all function contained within single cell
eukaryote or prokaryote

cellular

level complexity

cell tissue level complexity

cells aggregate into specialised tissues or layers

tissue

organ level complexity

organ system

level complexity

4 types of symmetry

asymmetry
spherical symmetry (probably in water)
radial symmetry
bilateral symmetry (probably has locomotion)

two types of early cellular cleavage

radial cleavage

two types of early cellular development

regulative

man who proposed hierarchical classification system

Carl Linnaeus

number of animal phyla

35
each is monophyletic (all animals within a phyla evolved from a common ancestor)

when life evolved on earth

4 billion years ago
appearance of atmospheric oxygen + photosynthesis (which added more O2) made multicellular life possible

when animals evolved

600 million years ago

evidence that all life is related

same genetic code used by all life (RNA and DNA)

unicellular eukaryotes

aka protozoa
30 clades, 64,000 species
small size and varied breeding systems
found everywhere with water

eukaryotic cell characteristics

specialised organelles
nucleus with DNA and chromosomes
mitochondria
golgi apparatus
plastids for photosyntehsis
vacuoles for osmoregulation and storage
allows for greater size and metabolic efficiency and makes multicellularity possible

3 types of eukaryotic cell locomotion

pseudopodia, cilia or flagella

3 eukaryotic cell body forms

ciliate, flagellate, and ameba

implications of locomotor organelles

respiration, feeding, and size

number of times multicellularity evolved

25 times

metazoa

any multicellular animal

choanoflagellates

form circular colonies in water
flagella and cilia sucks water into body
closely related to animals

phylum porifera

sponges
four classes
5,000 species
mostly marine, shallow to deep sea
many commensal (grow on other things)
spicules and chemicals to deter predation
no circulatory system; need water to flow through them, so only grow tall and thin shape (so that there's enough inner surface area compared to volume)
cells differentiated for various functions (but only 4 cell types)
radial symmetry or none
skeleton made of collagen, calcareous filaments or spicules (which double as predator defense)
no digestive system; food captured by choanocytes and eat by phagocytosis
no nervous system, although electrical signalling in glass sponges
sponges DO have circulatory structure, but constrained by rates of metabolism and waste product produced (so more commonly found in cold water; lower metabolism so lower waste)
reproduce by fragmentation and budding
monoecious

3 types of sponge structure

asconoid \= small, cylindrical water flow
syconoid \= medium, pouches on inside that add surface area
leuconoid \= large, highest inner surface area to suck water through

sponge main hole name

osculum

small sponge pore name

ostia

monoecious

male and female sex cells in one individual

phylum cnidaria

simple polyp (tree shape) or medusoid (jellyfish shape) body form
often form colonial organisms
includes corals, jellyfish, sea anemones, and hydrozoans
all are active predators
first animals that can move
only predator of jellyfish is the Mola mola (aka sunfish)
have tissue

phylum cnidaria, class hydrozoa

solitary or colonial
polyp structure
hydras, man

phylum cnidaria, class scyphozoa

includes typical medusoid jellyfish
lots of nematocysts
have gastric pouches (gut throughout the whole body) means no need for circulatory system to disperse nutrients
mouth \= manubreum, frilly thing that wraps around prey and pulls prey in

phylum cnidaria, class cubozoa

box jellyfish
well formed eyes and other sense organs

phylum cnidaria, class anthozoa

corals and anemones
individual polyps or large colonies

endoderm vs ectoderm vs mesoderm formation

endoderm \= forms gut, liver
ectoderm \= forms skin, eyes, external tissues
mesoderm \= muscles and circulatory system

acoelomate vs pseudocoelomate vs coelomate

acoelomate \= no circulatory system; materials slosh around, move through diffusion
pseudocoelomate \= mesoderm next to ectoderm, no mesoderm around gut
coelomate \= cavity inside mesoderm; mesoderm wrapped around gut \= rapid transport of material from gut. coelom evolved thrice, once in mollusca, once in arthropoda, and once in deuterostome (chordates ish)

protostomia vs deuterostomia

protostomia \= spiral mosaic cleavage, blastopore forms mouth, diverse group of animals with varied body plans
deuterostomia \= determinate regulative cleavage, blastopore forms anus, internal skeleton in echinoderms and chordates

phylum platyhelminthes

flatworms, tapeworms, and flukes
triploblastic, acoelomate, bilateral (which means that they move)
marine, freshwater, and moist terrestrial habitats
no specialised circulatory and respiratory system (implications for size and shape; can't get big but can be long and thin)
turbellarians mostly free

phylum platyhelminthes, class trematoda

parasitic flatworms

phylum mollusca

mollusks include snails, slugs, mussels, scallops, squid, octopus, nautilus, chitons, nudibranch
seven classes; 50,000 extant species
mostly aquatic but some terrestrial
limited by humidity and calcium (for shell)
large variety of feeding mechanisms
bilaterial
well

phylum mollusca functions of body regions

visceral mass \= digestion, reproduction, circulation
head/foot \= orientation, feeding, locomotion
shell \= protection
mantle \= shell secretion, respiration by lung/gills increasingly important in larger molluscs
altering proportions of different body parts \= makes different lifestyles possible

phylum mollusca class monoplacophora

metameric segmentation; serial repetition of gills, retractor muscles, etc (so only need 1 set of genes for a segment and another set of genes for how many segments you need)

phylum mollusca class polyplacophora

chitons; 3mm to 40cm long (big enough to be erosive) and scrape algae from rocks using radulla
have metameric segmentation
very efficient respiratory system; ciliated gills, constantly beating and sucking water in, then pushing it along the inside of the body; allows them to get very big

phylum mollusca class gastropoda

snails
most diverse, 40,000 extant and 15,000 estinct
shell present or absent
slow

phylum mollusca, class bivalvia

clams
reduced head and foot because they're sedentary
very large gill and mantle cavity that allows for lots of filter feeding and respiration, which means they can be very large (ex: giant clams)
open (low pressure) circulation through visceral mass

phylum mollusca class cephalopoda

nautilus, squid, cuttlefish, octopus
physiological equivalent to chordate group
active predators
all marine
foot divided into multiple tentacles

squid (cephalopod) form and function

fast movement: high metabolic rate, efficient respiration (gills and active circulation of water by mantle) and digestion (aided by beak); closed, high pressure circulation, 3 hearts (one under each gill, and one primary heart)
coordination: well

phylum annelida

earthworms, freshwater worms, leeches
15,000 species
marine, freshwater, and terrestrial
variety of feeding mechanisms; free living bottomfeeders, burrowers, filter feeders, sediment feeders, etc
organ

annelid form and function

complete gut (mouth and anus): higher

leech (phylum annelida) terrestrial adaptation

rapid evaporation due to high surface/volume ratio (they're long and thin) AND use body for respiratory exchange

ecdysozoa

8 phyla
all excrete cuticle (allows them structure, flexibility, reduces water loss, muscle attachment for locomotion)
moult outer cuticle (ecdysis \= molting)
two body plans: worm

lophotrochozoa

18 phyla
some have lophophore for feeding
some have trochophore larva
spiral cleavage of embryo

phylum nematoda

roundworms
collagenous cuticle (contains hydrostatic pressure exerted by fluid in pseudocoelom)
longitudinal muscles, no circular muscles
hydrostatic skeleton
no segmentation
free

phylum nematomorpha

horsehair worms
parasitic larvae, free

panarthropoda

includes onychophora, tardigrada, and arthropoda
all have reduction of coelom (no hydrostatic skeleton), ventrolateral appendages, open circulatory system (works because they are so small; oxygen can just diffuse into their tissue, don't need oxygen to be delivered places), and paired walking appendages

phylum onychophora

worm

phylum tardigrada

water bears
lobopods (unjointed limbs)
buccal stylets as mouth
no thorax because they don't need it, unlike arthropod or onychophoran
have segmented nervous system, nerves in each leg, and anterior brain

phylum arthropoda

bilateral symmetry
coelomate
moulting cuticle
exoskeleton
jointed legs and segmentation; efficient locomotion
specialised appendages like wings, mouth parts, jointed legs, claws
most abundant group of animals on earth
wide range of sizes, mm to meters
highly developed sensory organs
open circulatory system

phylum arthropoda, subphylum trilobita

marine taxa
extinct for 250 million years, lived during cambrian and ordovician
bottom dwellers and scavengers
most have eyes

phylum arthropoda, subphylum chelicerata

contains spider class
no mandibles or antennae
have chelicerae (mouth claws)
1 pair of pedipalps (push food into mouth) and 4 pairs of walking legs

phylum arthropoda, class merostomata

giant water scorpions and horseshoe crabs
have regular arthropod setup but with big shell

phylum arthropoda, class arachnida

spiders, scorpions, ticks, mites
80,000 species described
many are venomous with poison fangs adapted from chelicerae
many eyes
pedipalps to capture prey (big pincers in scorpions), chelicerata to rip apart

phylum arthropoda, class arachnida, order acari

ticks and mites
mouth parts on captiulum, more external than other orders within arachnida
some are free living, most are parasites

phylum arthropoda, subphylum myriapoda

centipedes, millipedes
have mandible jaws like crustaceans and hexapods, used for biting, cutting, holding food, and chewing (more variable than chelicerata)
all have antennae
over 13,000 species
first animals on land
two tagmata (head and trunk)
mouthparts: mandible and one (millipedes) or two (centipedes) pairs of maxillae
legs are uniramous, 10 to 750 pairs
simple eyes

phylum anthropoda, subphylum myriapoda, class chilopoda

centipedes
predatory
each segment has one pair of legs
maxillipeds on first segment are modified to venom fangs
pair of simple eyes

phylum anthropoda, subphylum myriapoda, class diplopoda

millipedes
cylindrical bodies
antenna for feeling
mandible mouthpart

mandibulata hypothesis

groups together the three arthropod subphyla with mandibles (chewing mouthparts/jaws): myriapoda, hexapoda and crustacea

phylum arthropoda, subphylum crustacea

lobsters, crayfish, shrimp, barnacles
67,000 described species
two pairs of antennae
head has pair of mandibles and two pairs of maxillae to form jaw
one pair of appendages on each additional segment
some biramous appendages (ex: antennae)
extremely segmented

phylum arthropoda, class malacostraca

woodlice, pill bugs
flat
aquatic and land forms
includes decapoda: lobsters, shrimp, crabs. 5 pairs legs, in crabs first pair of walking legs forms pincers (chelae)

phylum arthropoda, subphylum hexapoda

6 legs
tagmata \= head, thorax, abdomen
mandibulate, closest relatives are crustacea
single pair of antennae
compound eyes
two classes: entognatha and insecta

phylum arthropoda, subphylum hexapoda, class insecta

bases of mouth parts visible
have mouthpart including labrum, mandibles, maxillae, labium, hypopharynx that all aid eating
have brain (collection of ganglia)
size is restricted because their respiration is not super efficient, used to be larger but lower atmospheric oxygen now \= smaller insects
feeding determined by mouthparts: chewing or sucking

phylum arthropoda, subphylum hexapoda, class insecta, superorder holometabola

butterflies, ants, bees, wasps, beetles, fleas, flies, moths
undergo complete metamorphosis
inlcudes 88% of all insects

phylum arthropoda, subphylum hexapoda, class insecta, superorder hemipterodea

stoneflies, stickbugs, mantids, cockroaches, lice
externally developing wings
don't go through metamorphosis; go through nymph stages instead

phylum echinodermata

starfish
all have calcareous skeleton; spiny endoskeleton that acts like an exoskeleton. Made of dermal calcareous ossicles called stereom, covered by ciliated epidermis
unique water vascular system; coelomic, extends from body surface as tentacle projections filled with fluid. Usually have opening to exterior called madreporite
pentaradial (five

phylum echinodermata class asteroidea

starfish
mouth on underside of oral surface, anus on top
abulacrum runs from mouth to tip of each arm. papulae along each ambulacral groove, function in respiration; the gills of the sea star
two coelomic cavities; coelom with papulae and water vascular system with tube feet
can regenerate arms

phylum echinodermata class ophiuroidea

shaped like a starfish but with thin wobbly arms
arms are thin
ambulacral groove is closed and coated with ossicles
tube feet lack suckers

phylum echinodermata class echinoidea

spiky sea urchins
lack arms but still have five

phylum chordata

characteristics they share with inverts:
bilateral symmetry
tube

characteristics unique to chordates (important):
notochord (flexible rod, fluid

filled cells, attached to muscles. in humans, is fluid spongy tissue within spine)
dorsal tubular nerve cord (in inverts, nerve cord is ventral underneath digestive system and is solid, so this is unique)
pharyngeal pouches or slits (form gills or pharyngeal grooves. Used as filter

phylum chordata subphylum urochordata

sea squirts
adults only retain 2 chordate features, retain pharyngeal gill slits and endostyle (but have all 5 as larvae)

phylum chordata subphylum cephalochordata

amphioxus
features that suggest the vertebrate body plan; might be the ancestral chordate
segmented muscle blocks down either side
closed circulation but no heart; its movement moves materials

phylum chordata subphylum vertebrata

earliest vertebrates
modifications of skeletal structures and muscles permitted increased speed and mobility
segmented body muscles (myomeres) changed from v

agnathans

jawless fish (paraphyletic group)
includes lambrey

gnathostome fishes

cartilaginous fishes (chondrichthyes). ex: sharks rays. gills and gill slits.
bony fishes (osteichthyes), dominant ones today. 2 major clades: ray

actinopterygii

ray

sarcopterygii

lobe

fish tails and buoyancy

lunfish have diphycercal tail
perch have homocercal tail (normal fish tail)

fish buoyancy

sharks have lipid called squalene that's lighter than water and makes them more buoyant. Also, fins are angled up to keep them from sinking.
swim bladder is a gas

fish respiration

water flow is opposite to blood flow, called countercurrent flow, maximizes the exchange of gases
very efficient; can remove up to 85% of oxygen from water passing over gills
some active fishes use ram ventilation; swimming with mouth open and forward movement is enough to force water across gills, but will suffocate and die if they stop swimming

characteristics necessary for the origin of tetrapods

air

live in terrestrial environment; need special adaptations
stronger bones because air is a less buoyant medium
muscles to elevate the head, support the body in air
stronger shoulder and hip girdles
modified ear structure
longer snout

amphibian adaptations

mucous covered skin to avoiddesiccation and UV light damage
capillary network underneath skin, can obtain oxygen. lungless salamanders only use skin for oxygen, called "buccopharyngeal respiration"
exaptation features \= features that evolved for a different reason. used to have air

phylum chordata class amphibia order apoda

called caecilians
looks like a worm
ectotherms
eggs easily desiccate; must be laid in moist terrestrial places

phylum chordata class amphibia order caudata

salamanders
most have aquatic larvae and terrestrial adults
internal fertilization in most
species that are completely terrestrial lay their eggs in small clusters in moist places
respiration through gills, lungs, both or neither. vascular nets in skin that exchange CO2 and carbon dioxide