Ichthyology Fall22 Exam 2

function of skeletal system

protects and supports the soft organs

cartilage

connective tissue that has an intercellular matrix composed of a complex rubbery protein

chondrocytes

living cartilage cells

lacune

spaces between the cartilaginous matrix

bone

matrix held together by connective tissue fibers, within which cells are buried

osteocytes

living bone cells

types of bone

dermal bone, endochondral bone

dermal bone

"membrane bone" forms directly through ossification of mesenchyme

mesenchyme

loosely associated cells of mesoderm origin

endochondral bone

"cartilage bone", initially formed w/in a cartilaginous matrix, only later ossified

neurocranium

ossified skull, braincase

chondrocranium

cartilaginous skull

splanchocranium

portion of skull derived from visceral arches and composed of endochondral boen

how the skull begins

formed from mesoderm cartilages at the anterior end of the notochord

hagfish cranium development

stunted development, not completely enclosed skull, visceral arches not well developed

lamprey cranium development

rudimentary, partial dorsal roof anteriorly positioned, posterior side walls, branchial basket well developed

elasmobranch cranium development

solid piece of cartilage, without sutures, vertebrae have neural arch, centrum and persistent notochord

teleost cranium development

sutured bones together, individual bones, dermal bones on top of cartilage

functional units of fish skeleton

suspensorium, jaws, opercular apparatus, hyoid apparatus, gill arches, vertebral column, tail, and medial fins, paired fins

ceratotrichia

cartilaginous fin supports of chondrichthys, not segmented, connected to basal cartilage

lepidotrichia

bony fin support of osteichthyes, segmented, connected to pterygiophores

myomeres

series of muscle blocks

myosepta

sheets of connective tissue separated by myomeres

horizontal septum

separator of upper and lower muscle mass in fishes

epaxial muscle

upper muscles

hypaxial muscles

lower muscles

lateralis superficialis

red swimming muscle located between epaxial and hypaxial muscles

protractors

dorsal and anal fin muscles that erect fins, make them stand up

retractors

dorsal and anal fin muscles that depress fins, flattens them

lateral inclinators

dorsal and anal fin muscles that spread out the soft rays

abductors

paired fin muscles that pull ventrally and cranially

adductors

paired fin muscles that pull dorsally and caudally

white muscle

majority of post cranial muscle in most fishes

white muscle uses

quick bursts of anaerobic movement, fatigues quickly, no myoglobin

red muscle

muscle that's a thin, lateral, superficial sheet under the skin between epaxial and hypaxial muscle masses

red muscle uses

continuous aerobic swimming, infused with capillaries, fast recovery of muscles

pink muscle

contains fibers intermediate in character of red and white muscle

pink muscle uses

intermediate swimming velocities, aerobic swimming, mosaic muscle

caudal fin function

propulsion (oscillatory and undulatory), rudder

medial fin function

undulatory propulsion, prevents roll

pelvic fin function

controls pitch, up down movement

pectoral fin function

propulsion, controls turning and brakes

anguilliform locomotion

large side to side amplitude of the wave along the whole body

subcarangiform locomotion

similar to anguilliform but only with posterior half of body

carangiform locomotion

posterior body flexes, anterior half to 2/3 inflexible

thunniform locomotion

significant lateral movement occurs only at the caudal fin and area near the narrow peduncle

ostraciform locomotion

oscillation of caudal fin assisted with pectoral fins

diodontiform locomotion

motion achieved by passing undulations down broad pectoral fins

amiiform locomotion

undulation of usually long based dorsal fin, body axis often held straight while swimming

gymnotiform locomotion

propulsion by undulation of long based anal fin

balistiform locomotion

both anal and dorsal fins undulate to generate propulsion

types of non-swimming locomotion

jet propulsion, terrestrial locomotion, walking, burrowing, jumping, gliding, flying

pattern of blood flow

single pump and single circuit system, heart to gills to body back to heart

number of heart chambers

4

chambers in a series

sinus venosus to atrium to ventricle to conus or bulbus arteriosus

sinus venosus

receive deoxygenate blood from posterior body

atrium

regulates blood flow to heart

ventricle

main pumping chamber of heart

conus arteriosus

prevents back flow into ventricle

bulbus arteriosus

dampens and maintains pressure in heart

hagfish exceptions

4 hearts, main heart lacks conus arteriosus, pumping not synced by central nervous system

lungfish exceptions

incomplete divided chamber (atrium), classified as 3 chambered heart

efferent branchial arteries

takes oxygenated gills to rest of body

afferent branchial arteries

takes deoxygenated blood to gills

dorsal aorta

main route of transport of oxygenated blood to rest of body, becomes caudal artery upon entering heamal canal

postcardinal vein

major return route of deoxygenated blood, empties into the common cardial vein then into sinus venosus

fish blood

liquid plasma and red & white blood cells

blood cell origin in hagfish

tissues surrounding the gut

blood cell origin in lampreys

fatty tissue dorsal to the nerve cord

blood cell origin in elasmobranchs

tissues associated with the esophagus, gonads, and spleen

blood cell origin in bony fishes

thymus, kidney, and spleen

blood oxygen affinity

when hemoglobin releases oxygen

factors impacting blood oxygen affinity

partial pressure of oxygen in water, partial pressure of carbon dioxide in body, pH, temperature, activity of fish

hemoglobin saturation

each molecule of hemoglobin can carry 4 molecules of oxygen

oxygen hemoglobin dissociation curve

the oxygen saturation of hemoglobin across a range of oxygen pressures

factors impacting the O2 hemoglobin dissociation curve

pH and temperature

bohr effect

hemoglobin's oxygen binding affinity is inversely related both to acidity and to the concentration of carbon dioxide

physiological thermoregulation

rete mirabile for heat exchange and conservation, occurs in red muscle, blood flowing in opposite directions, exchange of heat perpendicular to flow

problems breathing in water

lower oxygen concentration, water is more dense than air, water is more viscous than air

warm water holds _______ oxygen than cold

less

gills

specialized breathing apparatus composed of multiple highly vascularized filaments

gill structure

gill arch with number of gill filaments lined with gill lamellae

holobranch

full gill (made up of 2 halves)

hemibranch

half a gill (one half); a single series of filaments

gill lamellae

perpendicular structures along gill filaments

gill function

site of oxygen exchange

lamprey respiration

active respiration, expand and contract branchial area causing water to flow in and out

hagfish repsration

active respiration, intake via nostrils, when buried in prey water comes in and out through gill opening behind last gill

elasmobranch respiration

water intake through spiracles or gills, ram ventilation or pump

elasmobranch gill structure

greater than or equal to 5 individual gill slits, gill arch and ray supports gill filaments, gill rakers protect filaments and collect food, septum separates them

teleost respiration

ram ventilation and buccal/opercular cavity pumps

surface area and thickness of gills is correlated to

activity level

blood flows through lamellae _______ to water

counter current

oxygen flow in fishes is

unidirectional

buccal pump

mouth opens and fills with water, operculum is closed, opercular chamber expands causing negative pressure

opercular pump

mouth is closed, operculum is open, buccal chamber contracts causing positive pressure pushing water over gills

cost of breathing

High density and viscosity of water requires energy for ventilation of gills

when oxygen needs increase fish...

breathe more often, take bigger gulps of water, recruit more lamellae

all air breathing organs function...

only as oxygen absorbers

Biological significance of air breathing

survival in oxygen poor habitats, utilize terrestrial food sources, abandon drying ponds in search of better habitat, invade new territories