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172 Cards in this Set

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ossicles
little bony plates under the skin of echinoderms which are joined by connective tissue
*some project outward as spines
Echinoderm: greek/latin definition
spiny skin
How many species of echinoderms?
about 6 K. (relatively small)
ecological and evolutionary importance of echinoderms?
abundant in marine ecosystems.

last invertebrate phylum leading to vertebrates.
-humans are more closely related to echinoderms than any other invertebrate group based on RNA and EMBRYONIC evidence.
Symmetry of echinoderms?
radial, but with bilateral larva

*had bilateral ancestors but returned to radial symmetry! SECONDARILY DERIVED (advances, not primitive)
secondary radial symmetry
evolved from bilateral ancestor
Echinoderm Nervous system?
-reduced/ absent cephalization
-decentralized, no brain, no ganglia or swelling of nerves
- NERVE RING at center attached to RADIAL NERVE CORDS.
-most are active, mobile animals
echinoderm diet?
small organic particles/ algae,
or small prey
* some are efficient predators despite lack of central nervous system/cephalization!
What organ system is unique to Echinoderms?
WATER VASCULAR SYSTEM
* with tube feet for locomotion!
list 3 Functions of Water Vascular System?
respiration, excretion, locomotion.
Describe locomotion in echinoderms' water vascular system.
Water flows from:
1.Madreporite (filtering sieve plate) aka:"stone canal"
2. Internal system of canals (ring canal & radial canals, then a later canal connects to each ampulla)
3. ampulla (like muscular dropper)
4. tube feet
tube feet and ampulla mechanism
(in echinoderms)
ampullae squeeze water into foot in the forward direction to extend it forward and pull it back.

*ampullae and tube feet are muscular.
function of coelom in echinoderms?

mechanism for these functions?
circulation, respiration, excretion
(coelom is large)

- fluid is circulated by cilia on the peritoneum lining the eucoelom
excretion and gas exchange in echinoderms?
tube feet and papulae (dermal branchae) which project out between the ossicles.
Pedicillariae
-small pincers of SEA STARS and URCHINS extending from skin
-clean skin of debris, protect papulae and may aid in food capture in some
-
osmoregulation in echinoderms?
NO
strictly marine animals
only use DIFFUSION
Reproduction in echinoderms?
-mostly dioecious
-autonomy is common
-can regenerate complete organism with one arm and 1/5th of oral disk. (takes about a year)
What CLASS are sea stars in?
Asteroidea
(greek/latin: star shaped!)

*arms are always in multiples of 5.
Sea star digestion?
Predators of polychaetes, crustaceans, fish and other sea stars.
EVERSIBLE stomach!
insert (very elastic) CARDIAC stomach into open bivalve shell, excretes enzymes and turns prey into a soup!
asteroidea (starfish) : use of tube feet?
locomotion
gripping bivalve shell to pull it open
What class of echinoderm includes sea urchins and sand dollars?
Echinoidea
Modifications of body plan for class Echinoidea (urchins)?
-oral surfaces has extended to aboral side
-fused ossicles form a rigid TEST with long movable spines (locomotion), tube feet and pedicillariae (little pincers).
Echinoidea diet (urchins/sand dollars)?
grazers
-feed on algae, detritus,or small particles of food, although some feed on larger prey, such as abalone.
*on sand dollars, organic particles settle on aboral surface and cilia move them down to its mouth!

*all have Aristotle's lantern
Echinodea (urchin/sand dollar) mouth?
Aristotle's lantern, for grinding and tearing.
longest living echinoderm?
lifespan?
RED SEA URCHIN

over 200 years!!
what CLASS are sand dollars in?
ECHINODEA
same as urchins
anatomy of a sand dollar?
small spines used to burrow just below surface of sand
-fused dermal ossicles form a rigid TEST with tube feet and pedicellariae
-aboral surface covered in cilia for food particle locomotion
digestion in sand dollars?
chew food for up to 15 minutes, and may take 2 days for food to digest.
age of sand dollars?
6 -10 years
- you can age them by counting the growth ring on the plate of the exoskeleton!
What is the largest class of echinoderms and what is the common name for organisms in this group?
OPHIUROIDEA

brittle stars and basket stars

*abundant in oceans, often cover the sea bottom...some arms have spines and some have baskets for catching things in.
diet and digestion in ophiuroidea (brittle stars and basket stars)?
detritivores - eat on decaying matter and plankton via MOVABLE JAWS in central disk.
greek/latin meaning of ophiuroidea (brittle stars and basket stars)?
"snake tail shaped"
brittle stars vs sea stars:
locomotion
digestion
papullae & pedicellariae
autonomy & regeneration
Locomotion:
sea stars- tube feet, brittle stars- movable arms
Digestion:
brittle stars have incomplete digestive system - no intestine or anus
papullae & pedicellariae:
only sea stars...brittle stars have none
Autonomy & regeneration:
better developed in brittle stars...lose limbs easily and grow them back readily.
shedding of an appendage (as in sea stars and brittle stars)?
AUTONOMY
tube feet in sea stars & brittle stars? (ophiuroidea)
used for diffusion and sensory, NOT locomotion.
What class includes sea cucumbers?
Holothuroidea
"whole animal shaped"
How do holothuroidea differ from other echinoderms?
-elongated oral-aboral axis
-reduced ossicled- soft body
-arrangement of tube feet modified for crawling
-some have external gills
feeding in holothuroidea (sea cucumbers)?
trap food on tentacles and stuff into mouth one by one.
defense in holothuroidea (sea cucumbers)?
"Throw up" intestines
-some parts of viscera contain sticky toxins
-sometimes it contains undigested food- sea cucumber is able to crawl away and slowly regrow digestive system.
What class includes the most ancient echinoderms with plant-like bodies?
CRINOIDEA

sea lilies & feather stars
*many of these fossils are found in the River Falls area!
what is the differnce between sea lilies & feather stars?
Both start out as sessile
(attached to substrate via stalk)
-and continue much of life as sessile, but feather stars can detach and swim
crinoidea anatomy (sea lilies & feather stars?
-arms are tentacle-like with leathery skin and small branches and mucus for trapping and eating suspended phytoplankton-cilia transport food to mouth
(other animals like to hide in them)
Why was radial symmetry first evolved in the most primitive echinoderms (crinoidea)?
-probably an adaptation for filter feeding since they trap food coming from any direction.
-radial symmetry was retained by other echinoderms who obtain food by different means
What are the 2 groups that eucoelomates are divided into?
PROTOSTOMES: annelids, mollusks, arthropods

DEUTEROSTOMES: Echinoderms,Hemichordates, Chordates
PROTOSTOME phyla?
annelids, mollusks, arthropods
DEUTEROSTOME phyla?
Echinoderms,Hemichordates, Chordates
Cleavage (define)
cells diving but not growing (in the development of embryos)
Differences between Protostomes and Deuterostomes:
formation of digestive tract?
proto: pore become mouth, other end becomes anus

deutero: pore becomes anus, other end becomes mouth
Differences between Protostomes and Deuterostomes:
cleavage (cells dividing)?
Proto: spiral (there is a shift with the small ones sitting on top)

Deutero: radial (symmetrical)
Differences between Protostomes and Deuterostomes:
coelom formation?
proto: SCHIZOCOELOUS (Splitting the mesodermal embryonic tissue.)

deutero: ENTEROCOELOUS (outgrowths/pouches off pore are pinched off embryoinc gut and develop into mesoderm)
Differences between Protostomes and Deuterostomes:
type of embryo (if cell excised)?
proto: MOSAIC (cell excised from embryo dies)

Deutero: REGULATIVE (cell excised from embryo becomes twin/ another larvae)
Phylum which contains acorn worms?
HEMICHORDATA

*small phylum, about 70 species.
Where are acorn worms (hemichordates) found?
mud, sand flats of inter-tidal zones-
-sluggish, live in burrows under stones
Evolutionarily significant anatomy of hemichordates (acorn worms)?
1- hollow dorsal nerve cord
2- gill slits

*2 out of 5 chordate characteristics
small phylum (about 70 species) that includes acorn worms?
hemichordata
Where are hemichordates (acorn worms) found?
mud/sand in inter-tidal zone
-sluggish, live in burrows or under rocks
What evolutionarily significant features do hemichordates (acorn worms) have?
-dorsal hollow nerve chord
-gill slits
(2 of 5 chordate characteristics)
What type of larva do hemichordates have and what does is strongly resemble?
TORNARIA larva
- strongly resemble the bipinnaria larva of sea stars (may be evidence of evolutionary link between the 2)
The branch of the animal kingdom called the DEUTEROSTOMES contains which phyla?
hemichordata
echinodermata
chordata
Evidence of evolutionary link between hemichordata echinodermata & chordata (2 things)?
2 of 5 chordate characteristics found in hemichordates.
-RNA evidence supports a common ancestor of these 3 phyla (which belong to a branch of the animal kingdom called the DEUTEROSTOMES)
5 FEATURES
of all chordates?
(at some point in their development)
1) Notochord
2) Dorsal nerve cord
3) pharyngeal slits
4) post-anal tail
5) endostyle (protochordates) or thyroid gland (vertebrates)
Function of notochord?
first supporting structure of the chordate body
-present in all life stages of primitive chordates, but only in early stages in advanced chordates, then is replaced by vertebral column
function of vertebral column (present in advanced chordates)?
-protects dorsal hollow nerve cord (often filled in during development)
-protects clusters of ganglia at the anterior end of nerve cord (brain, central nervous system)
How did pharyngeal gill slits arise?
outer ectoderm comes in contact with endoderm of pharynx and openings are formed.
-original use was pharyngeal filter feeding ...later gills were added to arches between slits
How do vertebrates show evidence of gill arches in embryos?
- they are retained but put to other uses
- 1st forms jaw & inner ear
-2, 3 & 4th form tonsils, parathyroid, thymus and Eustachian tube.
Endostyle??
*like the vertebrate THYROID
-secretes mucus that traps small food particles brought into pharyngeal cavity.
- secretes iodine-containing proteins
purpose of post-anal tail?
-propulsion through water
(retains this function in many vertebrates, and is present in the embryos of all chordates)
protochordates?
2 subphyla:
Cephalochordata
Urochordata

*these are the invertebrate chordates.
3 subphyla in the phylum CHORDATA?
Cephalochordata (lancelets)
Urochordata (tunicates, sea squirts)
Vertebrata (lamprey, anything with a spine)
subphylum which includes tunicates?
UROCHORDATA (uro- "tail")

sometimes called "tunicata"
subphylum which includes lancelets?
CEPHALOCHORDATES
subphylum which includes lamprey, fish, amphibians, reptiles, birds, mammmals?
VERTEBRATA
3 subphyla in phylum CHORDATES?
UROCHORDATA
CEPHALOCHORDATES
VERTEBRATA
superclasses in subphyla VERTEBRATA?
AGNATHA (lamprey, hagfish)
GNATHOSTOMATA (jawed animals)
7 classes of superclass GNATHOSTOMATA?
CHONDRICHTHYES (sharks, rays skates, chimeras-cartilage)
ACTINOPTERYGII ("ray finned" bony fish-primitive condition)
SARCOPTERYGII ("flesh finned" lobe-finned bony fish)
AMPHIBIA
REPTILIA
AVES
MAMMALIA
living arrangement for Urochordates (tunicates)?
-live inside a cellulose "tunic" with incurrent and excurrent siphons
-squirt water from excurrent siphon when irritated, so callled "sea squirts"
-2K species, mostly sessile
-solitary, colonial or compound (solitary is most common)
feeding in tunicates?
adults are PHARYNGEAL FILTER FEEDERS.
-they pull water into their basket-like pharynx via the action of cilia
-water &waste exits excurrent siphon
When do Urochordates (tunicates) have all 5 chordate characteristics?
-free swimming, tadpole like larva posses all5 characteristics
--during metamorphosis chord and tail are reduced and becomes sessile adult.
living habit of Cephalochordates (lanclets)?
-2-3 inches long
-lives in sandy bottoms of marine coastal areas around the world.
-anchors itself to bottom and filter feeds (like all primitive chordates)
*only 25 species
feeding in cephalochordates (lancelets)?
(similar to urochordates)
water in mouth, then through pharyngeal gill slits.
-endostyle produces mucus to capture food particles
-water exits pharynx and leaves body through ARTIOPORE
-food in mucus cord enter the digestive track
circulatory, reproductive and sensory in cephalochordates (lancelets)?
CLOSED circulatory
-sexes separate
-simple nervous system and sense organs
-have all 5 characteristics as adults
sensory in vertebrata (general)?
cranium (braincase)
3 part brain
head with paired sense organs
primitive characteristics of lampreys?
-jawlessness (but ARE VERTEBRATES!)
-smooth scaleless skin
-paired pectoral and pelvic fins absent- only a single dorsal fin
-notochord persists throughout development and through adulthood
Primitive jawless ancestors of lampreys?
OSTRACODERMIS
"shell skin"
(haven't changed much in 300 mill years!)
How is the circulatoryt system of a lamprey similar to that of a true fish?
ventrally located 2 chambered heart ...all fish have.
How is they life cycle of the lamprey different from that of most other vertebrates??
they undergo metamorphosis from AMMOCOETE larva to adult
*these ammocoete larva probably resemble the ancestors of the subphylum vertebrata
What do adult lampreys feed on?
parasitize fish with sucker-like mouth.
-others eat vegetation and aren't parasitic.
Why are lampreys so destructive?
they are invasive in the US and they kill fish & have no predators.
Were let in through Welland canal in ballast water- bad for Great Lakes fishing industry.
What has been used to control they invasion of lampreys?
they are ANADROMOUS ("running up") -marine forms spawn in freshwater steams, so we use LAMPREYCIDES during migrations.
scientific hypothesis of vertebrate origins?
*Developed by Garstang
PAEDOMORPHOSIS
-tadpole like larva failed to metamorphose into adult Urochordate (like tunicate), developed gonads and reproduced in larval stage.
These free swimming animals became the ancestors of cephalochordates and vertebrates.
(tunicate adult characteristics are secondary)

(refer to graphic on orange paper for more detailed derivations)
term for the retention of larval characteristics into reproductive stage?
paedomorphosis

(As in current hypothesis of tunicate larva reproducing to begin line of vertebrates)
How is a jaw an advantage?
more complex prey arena, better predation

*first gnathostomes were jawed fish.
From which structures did jaws arise?
from gill supports/arches.

*relics of this transformation are seen in the development of modern sharks
class which includes rays skates, sharks and chimeras?
Chondrichthyes
Class which includes ray finned bony fish?
Actinopterygii
Class which includes lobe finned bony fish?
Sarcpterygii
What adaptations in gnathostomates was first seen in the class chondrichthyes?
paired pectoral and pelvic appendages
-living endoskeleton (no need to molt)
the classes amphibia, reptilia, aves and mammalia form what monophyletic group?
TETRAPODS
Most "dramatic" event in animal evolution?
movement from water to land
challenges to life on land vs. water?
- more hazardous for many processes , especially reproduction (eggs desiccate)
-animals are mostly water in composition and cellular activities occur in water
- invasion of land required mjor modifications to EVERY organ system of the vertebrate body! (Even though air is more readily available in the air, extraction required major modifications!)
What group of fish did the earliest tetrapods (amphibians) evolve from?
lobe finned fish (sarcopterygii)
similar to a coelacanth.
Names of fish in this order of evolution:
1. pectoral bones foreshadow the forelimb of amphibians?
2.8 toes replace the dermal fin rays
3. 7 digits on hindlimb & stronger vertebrae, muscles to raise head off ground & more protective skeleton
4. Even better for land, with 5 digits on each limb and limb support from beneath instead of outspread.
1. Eusthenopteron "true strength of wing"
2. Acanthostega "spine covering"
3. Ichthyostega "fish covering"
4. Limnoscelis
pentadactyl
condition with 5 digits/limb

*first found in limnoscelis
What effect did the disadvantages of life on land (strength, repro, organs needing to be modified) have on amphibian evolution?
Tetrapods were tied to the water, particularly for reproduction.
How did amphibians overcome the failure of gills to work in air?
developed lungs from SWIM BLADDER!!
Swim bladder modified to exchange gases with blood.
Limitations to amphibian respiratory?
-no diaphragm so must use BUCCAL breathing (air forced into lungs by elevating floor of mouth)
-supplement with CUTANEOUS respiration
explain cutaneous respiration.
extensive vascular nets in skin (in amphibians) skin must be permeable for this to work!!
(wont work in reptiles, because their skin isn't permeable)
specialized structures in a frogs respiratory...
1. the "nostrils"
2. pinches off lung from rest of system
1. NARES
2. GLOTTIS
loss of gills happens in what stage of frog development?
post-metamorphic froglet
What kind of the 3 respirations is used in aquatic tadpoles the most extensively?
Cutaneous!

*Cutaneous: 60%, Gills 40%

(*Cutaneous respiration is at its climax as the gills and lungs switch off, then once lungs are established they do >80% of breathing)
How has cutaneous respiration restricted adaptive radiation of amphibians?
-permeable skin allows greater water loss, so adult reqire a moist environment to prevent desiccation
-permeable skin also abborbs chemicals (unwanted)
Reproduction in amphibians?
-water permeable eggs- adults must reproduce in water
-AMPLEXUS (special embrace) allows eggs to fertilized externally as the female sheds them
-some use creative ways to allow young to develop on or in the body.
special sex hug that frogs use in water for external fertilization?
Amplexus

(male is smaller than female, as not to crush her during this move)
metamorphosis of frog...
hindlimbs appear, then the forelimbs...all while the tail degenerates
*tadpole feeds on algae & has external gills
what does bi-colored mean in frogs?
POISON
frogs vs. toads?
frogs: smooth, Toads: bumpy
frogs eyes bulge, toads have eye ridges
toads are fatter
frogs have longer legs
Reproduction in SALAMANDERS?
internal
use of SPERMATOPHORE
-most are metamorphic (aquatic larvae with external gills and terrestrial adults)
-some are entirely terrestrial, lay eggs in moist earth and have direct development.
type of salamander that exhibits paedomorphosis?
mud puppies

They never undergo metamorphosis, retain juvenile characteristics

*axolotls is similar, but WILL metamorphose if their pond dries up! (nearly extinct)
salamanders with the most complex life cycles?
NEWTS
Life cycles of Newts
larvae metamorphose into terrestrial juvenile (Red Eft), then later metamorphose into SECONDARILY AQUATIC breeding adults.
*some stages skip red eft stage and are entirley aquatic, while some remain terrestrial, returning to water only to breed.
terrestrial juvenile stage of newts
"red eft"
toxicity of amphibians
ALL are toxic to SOMETHING...newts are toxic to us.
*wash hands after handling.
How does the circulatory system of amphibians differ from that of fish?
Fish: 2 chambered, single circulation
Amphibians: 3 chambered, double circulation
Bloodflow in amphibian heart
Pulmonary: heart to lungs
Systemic: heart to body
Blood from body enters R. atrium, shallowly, mixes a bit, then to lungs.
Blood from lungs enters L. atrium, deep into ventrical, then mixes with de-oxygenated blood slightly, but most travels to systemic circuit.
3 fundamental parts of amphibian brain?
Forebrain:olfactory (Well dev) & cerebellum (small...not a lot of "thinking")
Midbrain: optic lobe (well dev)
Hindbrain: cerebellum (small) and medulla oblongata
function of cerebellum?
coordination

(small in amphibians- don't need much)
lateral line system in amphibians?
(vibration sensation... for schooling and such)
Only present in larval stage...can't use it in air.
How is hearing in amphibians different from hearing in mammals?
-They have a TYMPANIC MEMBRANE (or "eardrum")

-amphibians have 1 bone (COLUMELLA), versus our 3 inner ear bones (maleus, incus & stapes)
skin gland in amphibians (*that contribute to ecological success)?
MUCOUS GLAND - for protective waterproofing

SEROUS GLAND- produce whitish watery poison that is highly irritating to would-be predators.
adaptations of aquatic eyes to the air?
-LACHRYMAL GLANDS- produce tears
-NICTATING MEMBRANE -clear eyelids
-Eyelids
-CORNEA- assists lens in bending light rays to focus them on the retina
-LENS moves forward and backward to focus (lens doesn't move in other tetrapods, but actually changes its shape instead)
What family of frogs produces one of the most lethal venoms known (worse than any snake or spider)?
DENDROBATIDAE -poison dart/poison arrow frog

-name means "tree walker"
-brightly colored
disadvantage of permeable amphibian skin?
-restricted to wet/moist environments
-toxins can enter bodies (acid rain, pesticides, herbicides, etc)
"canaries in the coal mine"- indicate poisonous environments
What has contributed to the worldwide loss of amphibian species?
habitat loss from drainage of wetlands
-unscrupulous collecting
-200 million bullfrogs killed annually for their legs (increase in insect pests due to this!)
legless amphibians (endangered because of loss of tropical habitat)?
CAECILIANS

(live underground, seldom seen by humans)
evolution of cartilage in chondrichthyes is _______ _______.
Secondarily derived.

Ancestors had true bone!
largest fish in the world?
Whale shark!

*this filter feeder collects plankton in a sieve mesh over its gills, as in megamouth and basking mouth sharks.
What anatomical feature of (most) sharks' jaws are an adaptation to predation?
replaceable teeth

(always have sharp new teeth)
What adaptation do sharks have for "smelling" prey underwater?
Large olfactory can....
-detect prey from over a km away
-can detect patricles in water to as low as 1 ppb.
-frequencies 10-800 hz. (lower than humans, which begin at 25 hz)

*special separation of nostrils in hammerhead enhances this sense.
What adaptation do sharks have for detecting low-frequency vibrations from long distances?
Lateral line system.

(of neuromast cells)
Lateral line system....compostiton, and which species employ this?
Composed of special neuromast cells in pores that connect to canal which extends the length of the body.

lamprey, sharks, bony fish and amphibian tadpoles use this.
Adaptation that sharks have for sensing bio-electric fields of other animals?

(Also possibly sensetive to teperature, salinity and water pressure)
Ampullae of Lorenzini

*along with excellent vision, this enhances their final stages of prey attack.

*hammerhead can sense 1 billionth of a volt!
Benefits of smooth skin of sharks?
allows attack speeds of up to 18 mph (bursts of speed)

-allows them to be HYDRODYNAMICALLY quiet
What adaptations do sharks have to maintain buoyancy in spite of their weight?
relatively large liver is filled with SQUALENE, an oil which has a density 86% of water's.

Also, HETEROCERCAL tail directs them upward
What adaptation allows chondrichthyes (sharks, skates, rays, chimeras) to live in salt water?
they retain nitrogenous compounds (urea) in the blood to raise the blood solute concentration above that of the sea water.
Rectal gland secretes fluid containing high concentrations of NaCl.
What makes sharks especially vulnerable to overfishing?
slow maturation & reproductive turnover.
Many species breed every other year and have 13 month gestation.
*some shark population are down 77%...an't keep uo with overfishing
smallest shark?
dwarf lanternshark
circulatory system of sharks?
2 chambered heart, closed system
Reproduction sharks?
-dioecious, as in all vertebrates
internal fertilization
-oviparous, ovviviparous (eggs that hatch inside body) and viviaparous species.
term for egg laying species?
oviparous
term for species whose eggs hatch internally and give birth to live young?
ovoviviparous
term for species that give birth to live young? (no internal egg hatching)
viviparous
How do skates and rays differ from sharks?
-specialized for bottom dwelling
-dorsoventrally flattened with greatly enlarged pectoral fins that are fused to the head and used like wings for swimming
***water enters gill chambers through dorsally located SPIRACLES behind the eyes. (prevents gills from clogging with sand(bottom feeding))
Gills slits on ventral surface.
How do skates and rays differ from one another?
rays are VIVIPAROUS
skates are OVIPAROUS and may have a fin on tail
what adaptations do skates and rays have for feeding?
-most with crushing teeth to feed on mollusks,crustaceans, occasional fish
-some (like electric ray) stun prey with electric discharge (can also use this for protection)
-some (like manta ray) are plankton filter feeders
How do chimeras differ from sharks, skates and rays?
-only descendants from a VERY ancient lineage!
-jaws bear flat plated teeth
-feed on seaweed, echinoderms, mollusks, etc *the upper jaw is fused to the cranium which is VERY UNUSUAL for a fish.
Beautifully colored... iridescent and green
bony fish evolved from....
same common ancestor cartilaginous fish evolved from, not from cartilaginous fish! ... some went the cartilage way, some went the bony way. :)
What kind of tail is a primitive morphology in ray finned fish?
heterocirco
How does the bony fish tail differ from shark tails?
made from endochondral bone (bone that replaces cartilage developmentally) ...the shark tail only contains cartilage.
-important evolutionarly because the ray finned fish are the sister group to the al land vertebrates (tetrapods).
**Bone is necessary to support weight of large land animals!!
What respiratory adaptation do bony fish have that cartilaginous fish don't have?
OPERCULUM
covers gill openings and contributes to resp efficiency!
(suck, rather than flow)

- when muscles move operculum, negative pressure is created and pulls water over gills, also prevents back flow.
strategies for respiration in sharks?
some have gill pumps

some use RAM VENTILATION - these must always swim or they will die, because water must flow in through mouth!
What is a key adaptation to bony fish resp/circulatory?
COUNTER-CURRENT BLOODFLOW.
blood in capillaries flows in the opposite directionfrom water flow to filaments, so water is oxygenating blood the whole way.
-this increases efficiency, and removes about 85% of O2 from water (otherwise only 50% max)
What key adaptation allows bony fish to regulate their own buoyancy (height in water column)?
SWIM BLADDER
(future lungs!)
-originally an extension of the pharynx that served as a primitive "lung", then was retained as a swimm bladder.
osmoregulation in FRESHWATER bony fish?
(gills gain water through osmosis- opposite of marine!)
primitive kidneys secrete a dilute urine.
-salt ABSORBING cells absorb salt from water into blood (because salt is constantly being lost by diffusion)
osmoregulation in MARINE bony fish?
(gills lose water through osmosis- opposite of freshwater!!)
-They drink seawater to avoid dehydration.
-get rid of excess salt with salt SECRETING cells in the gills
-some salt is voided with feces, and some is secreted by kidney (different kidney from freshwater fish though!)
term for muscle segments in bony fish?
myomeres
speed of fish?
(difficult to move through water)
trout: 10 body lenghts/sec (6.5 mph)
swordfish: 68 mph for brief periods...like 5 sec
*complex arrangement of myomeres (muscle segments)
Reproduction in bony fish?
MOST: external fertilization & egg laying
BUT, some lay eggs that hatch internally - only tropical fish though.
*Bony fish are never viviparous as sharks may be.
Notablebe characteristic of the life cycle of Pacific Salmon?
ANADRAMOUS "running up"
They feed for 3- 4 years, then follow odor of parent stream back to birthplace for spawning, after which they die.
Migratory behavior of the freshwater eel?
CATADROMOUS "running down"

ALL of them, from all over the world migrate to the SARGASSO SEA to spawn
-larval eels take up to 3 years to migrate back to freshwater streams.
Electric eel...what is it?
Not a true eel- actually a knife fish!
Modern examples of Sarcopterygii?
coelacanth, lungfishes
Anatomical characteristics of Sarcoperygii (external)?
-fleshy lobed fins
-fin is on a fleshy, scaly stalk extending from the body
-arranged in a pattern similar to tetrapods, allows ARTICULATION (motion at joints)