Chapter 42 Flashcards
The earliest branches of the animal phylogenic tree include…
sponges, cnidarians, ctenophores, placozoans
How many animals species are there?
1.5 million have been described; estimates 5-30+ million exist
Fungi, Plantae, and Animalia separately evolved from…
single-celled eukaryotes
Is Eukarya monophyletic, paraphyletic, or polyphyletic?
monophyletic
Is Animalia monophyletic, paraphyletic, or polyphyletic?
monophyletic
Choanoflagellates
protist; sister taxon relationship to animals
There are ___ phyla within Metazoa
35
______ are the most basal metazoans
sponges
Is the phylum Porifera monophyletic?
no
Metazoa is broken into two Subkingdoms of Animals:
Parazoa and Eumetazoa
Metazoan phylogeny is based in part on…
body plan and early development patterns
Parazoans have…
only cellular grade of complexity
Eumetazoa have…
at least a tissue grade of complexity
Do parazoans have a gut?
no
Do eumetazoans have a gut?
yes
Porifera
Sponges
choanocytes
flagellated cells in sponges that capture food; also called collar cells and are similar to choanoflagellates
Sponge skeletons are made of…
collagen and/or mineralized spicules
Sponges lack…
tissues and guts
Sponge habits include:
filter-feeding, sex, and a larval stage
Sponges are chemically _____
exotic; chemicals aid in competitive interactions + defend against predators
Sponge larvae are _______ that either drift to settle to stick to parent
blastulae
Are eumetazoans diploblastic or triploblastic
they are either
Are sponges diploblastic or triploblastic
have no tissue layers therefore not a eumetazoan
The ___ is formed with the second tissue layer, which first appears in the diploblastic animals
gut
diploblasts
have an ectoderm and endoderm with gelatinous material between
ectoderm
outermost tissue layer; forms the skin and nervous system
endoderm
innermost tissue layer; forms the gut and it is formed during gastrulation
Are Eumetazoa radially or bilaterally symmetric
could be either
radially symmetrical animals are usually…
attached to a surface or they float
Do radially symmetrical animals have a central nervous system?
no, they have a diffuse nerve net
Cnidarians
corals and jellyfish and their relatives
Characteristics of Cnidarians
diploblastic, radially symmetric, blind gut, a species can have a polyp stage or medusa or both, solitary or colonial
Cnidarians have tentacles with ______
cnidocytes or stinging cells
examples of cnidaria
hydra (polyps), coral, sea anemone, jellyfish (medusa)
Ctenophora
comb jelly
Characteristics of ctenophora
diploblastic, radially symmetric, predators, swim with cilia
bilaterians including protostomes and deuterostomes have…
bilateral symmetry and develop from 3 germ layers
two of the phyla of Ecdysozoa that make up most of the animals on Earth are…
Nematoda and Arthropoda
The _____ is part of the exoskeleton
cuticle
Ecdysozoans grow by…
ecdysis
Ecdysozoans are
protostome bilaterians
Phylum Nematoda
unsegmented, move by undulation, estimated to be over 1 million species; some pest species and some parasites (ex. roundworm)
Phylum Tardigrada common name
water bears
Tardigrada characteristics
segmented body, lack jointed limbs, microscopic; live in mosses, soil, or bottom of lakes/ocean
Phylum Onychophora common name
velvet worms
Onychophora characteristics
Live in moist leaf little, prey on small invertebrates, segmented body, limbs are not jointed, catch prey by shooting sticky slime
Phylum Arthropoda characteristics
segmented, jointed appendages, cuticle is stiff (chitin); open circulatory system, several types of metamorphosis; higher level relationships
What are the 3 kinds of metamorphosis?
ametabolous, hemimetabolous, holometabolous
Ametabolous
young and adults wingless; only change in size (ex. silverfish)
Hemimetabolous
Young (nymphs) resemble adults (ex. grasshopper)
Holometabolous
Young (larvae) completely different from adults; pass through a sessile pupil stage (ex. butterfly)
ecdysis
molting of the cuticle
Characteristics of Subphylum Chelicerata, Class Arachnida
named for chelicerae near mouth, segmented body, joined limbs, 2 tagmata, NO metamorphosis (do molt)
Order Araneae common name
the Spiders
Order Opiliones common name
The Harvestmen
All species of Araneae have…
venom
Order Opiliones mostly feed on…
dead organic material (plants); some predatory
Opiliones form…
defensive swarms
Class Arachnida, Order Solifugae common name
sun spiders (ex. camel spiders, wind scorpions, solifuges)
Class Arachnida, Order Scorpiones characteristics
Good mothers, glow in UV
Class Arachnida, Order Acari common names
mites ticks
Class Arachnida, Order Acari characteristics
some ectoparasites (parasite that lives outside of its host), some detritivores
Class Xiphosura common name
horseshoe crabs
Class Xiphosura characteristics
mating is highly social + timed, glow in UV light
Class Diplopoda common name
Millipedes
Class Chilopoda common name
Centipedes
Class diplopoda characteristics
2 pairs legs/ segments; detritovores
Class chilopoda characteristics
1 pair legs/ segment; venom glands, predators
Subphylum Crustacea characteristics
many have a carapace, a plate-section of exoskeleton that protects the cephalothorax; only arthropods with two pairs of antennae; compound eyes are often mounted on stalks; highly modified legs
Subphylum Crustacea, Class Malacostraca includes
crabs, lobsters, shrimp, crayfish, and woodlice
Subphylum Crustacea, Class Maxillopoda
barnacles, copepods
Subphylum Hexapoda, Class Insecta
About 1 mill spp known, more than half of all known animals are insects; adaptations for life on land: exoskeleton, waxy coating, spiracles, wings; evolution with plants
Class Insecta
3 tagmata (head, thorax, abdomen); 3 pairs of legs
Order Coleoptera
Beetles
Order Lepidoptera
butterflies and moths
Order Diptera
Fly
Order Hymenoptera
A large order of insects including sawflies, wasps, bees, and ants
What are the four main groups of arthropods?
insects, chelicerates, myriapods, crustaceans
What 2 groups make up the protostomes?
Lophotrochozoa and ecdysozoa
lophophore
tentacle lined organ for filter feeding
In which groups is the lophophore found
phoronida, bryozoa, brachiopoda
trochophore
a ciliated larval form
trochophore is found in which groups
Annelida, Mollusca
Rotifera common name
‘wheel bearer’
Rotifera characteristics
microscopic, pseudocoelomate
phylum platyhelminthes common name
flat worms
Platyhelminthes characteristics
dorsoventrally flattened, hermaphrodites, acoelomates, range of life styles
Platyhelminthes: Trematoda
the “flukes”
Characteristics of Trematoda
parasitic; unique larval stage; have an intermediate host to eventually reproduce in a definite host
Platyhelminthes: Cestoda common name
tape worm
characteristics of Cestoda
NO digestive tract; proglottids contain reproductive organs; numerous attachment structures; many vertebrate hosts
Platyhelminthes are protostomes that lack…
a coelom and an anus
Characteristics of the Phylum Annelida
Trochophore larva, coelomates, hydrostatic skeleton; closed circulatory system
Annelida Oligochaeta common name
Earth worms (some marine worms)
Oligochaeta characteristics
bundles of 4 setae on every segment; eat soil; hermaphrodites; cross fertilize; can breathe through skin
Annelida: Polychaeta characteristics
most diverse annelids; live in oceans
Annelid: Hirudinea common name
leech
Hirudinea characteristics
parasitic and predatory; hermaphrodites
Characteristics of Mollusca phylum
trochophore larva, coelomates, MANTLE!
defining feature of Mollusca
mantle
Mollusca: Gastropoda common name
snail
gastropoda characteristics
gills and anus above head, muscular foot; radula- rasping tongue
Mollusca Bivalvia characteristics
lost cephalization; use siphons for filter feeding
mollusca: cephalopoda common name
octopus
cephalopoda characteristics
foot divided into muscular tentacles, jet propulsion, display complex behavior, mimicry
3 major phyla of deuterostomes
echinoderms, hemichordates, chordates
Hemichordates
marine-dwelling bottom feeders or filter feeders
Hermichordates are the sister group to…
echinodermata
characteristics of hemichordates
pharyngeal slits, dorsal hollow nerve cord; not the same body plan as other deuterostomes; ex. acorn worms and pterobranches
Echinoderms
sea stars, brittle stars, sea urchins, sand dollars, sea cucumbers, sea lilies
Characteristics of echinoderms
deuterostomes, unsegmented, radial symmetry, endoskeleton, fluid-filled canals, tube feet
echinoderm larvae…
bilaterally symmetrical
echinoderm adult…
pentaradially symmetrical; no head, oral + aboral sides, moves in any direction
Do echinoderms show segmentation?
No
Tunicates and Lancelets are chordates without
backbone
hagfishes and lampreys are vertebrates without
jaws (agnathans)
most vertebrates have a…
bony cranium and vertebral column
chordate characters
myotomes, post-anal tail, dorse nerve cord, pharyngeal slits
What group in the vertebrate phylogeny do not have a vertebrae but did at one point?
hagfish (Myxini)
Jawless vertebrates
hagfish and lampreys
Class Myxini
hagfish
Class Hyperoartia
Lamprey
Osteichthyes
Bony Fish
What is the most diverse group of all vertebrates?
osteichthyes
Two main groups of bony fish
ray-finned fish and lobe/fleshy-finned fish
Ray-finned fishes
paired fins are supported by internal skeletons; more diverse than other groups of vertebrates
Lobe-finned/ Fleshy-finned fishes
bones in the fin bases extending out from the body; only 4 spp; rest are the tetrapods
___ animal groups made transitions from water to land
11
coelacanth and lungfish are sister group to ______
tetrapods
Sauropsids
Amniotes
Are reptiles amniotes?
Yes
Reptilia include
turtles, lizards, snakes, crocodilians, and birds
Endotherms
use internal metabolic heat to sustain elevated and stable internal temps (more heat; less lost)
Matrotrophy
direct nourishment of embryo by mother
The mammals are…
amniotes with hair and skin glands
Monotremes
mammals that lay eggs and make milk but do not have nipples
Marsupials
mammals that have a placenta but give birth very early in development
Eutherians
more complex placenta and are well developed at birth
3 groups of mammals
monotremes, marsupials, and eutherians
