shark bio test 2

what is the structural system made of

cartilage, fetal cartilage that hardens into bone, collagen, elastin, and a matrix of salts and minerals

what does the skeletal system provide

structural support

why is cartilage better than bone for elasmobranchs

more flexible and maneuverable

Lighter so it's more buoyancy

what are the 2 main skeletal parts

Axial & appendicular skeleton

out of the 2 main skeletal parts, what is the major one and why

the axial skeleton as it contains the skull and vertebrae

what does the chondrocranium make up

the skull and rostrum

what does the neurocranium do

it hold the brain and the sensory organs (eyes and ears)

what does the splanchnocranium do

supports jaw, gills, tongue, and pharynx

what is the vertebral column

String of spool-like calcified vertebrae

where does the vertebral column extend from

the chondrocranium to caudal fin

True or false: the vertebral column is part of the axial skeleton

True

what are the structures of the vertebrae

-- Neural arch (holds spinal cord)

-- Central arch (central part excluding notochord)

-- hemal arch (caudal artery; in tail vertebrae)

-- transverse process (in trunk vertebrae; 2 hooks or points)

what part of the skeleton moves

Appendicular skeleton

what is attached to the appendicular skeleton

Pectoral, pelvic fins, and their girdle

What type of fins have a gridle

paired fins

what are the 3 types of basals

-- Propterygium (anterior)

-- Mesopterygium (middle)

-- Metapterygium (posterior)

what makes up the fin

basals, radials, and ceratotrichia

what is the scapulocoracoid bar

pectoral fin girdle that supports pectoral fin

what are the 2 fin types

Aplesodic & Plesodic

which pectoral fin type has radials that extend <60% into fin

Aplesodic

what fin allows for walking along the bottom

Aplesodic

what lifestyle do sharks with aplesodic fins have

Slow cruising pelagic or maneuvering benthic species

draw an aplesodic fin

draw a plesodic fin

what type of pectoral fins allow for fast swimming for pelagic species

Plesodic

what pectoral fin has the most ceratotrichia

Aplesodic

what pectoral fin gives the most support

Plesodic

what pectoral fin is more streamlined

Plesodic

True or false: dorsal and anal fins have girdles

false

what is the integument system

the skin

True or false: the caudal fin is part of the appendicular skeletion

False

what does the integument system do

acts as a protective barrier, separates the internal from the external, minimizing friction

what are the layers of the integument

-- Epidermis

-- Dermis

-- Muscle

describe the epidermis

-- outer layer

-- non vascular

-- dermal denticles pass through

what is contained in the epidermis

glands, sensory organs, lateral line organs, photophore

what is in the dermis

-- Connective tissue

-- nerves

-- blood vessels

-- lymph vessels

-- origin of dermal denticles

when dermal denticles are absent, what provides protection

mucous

how are dermal denticles related to speed

the faster the animals, the smaller and lighter the scale

what at the types of drag

frictional drag & form drag

what is frictional drag caused by 

water hitting the surface of the organism slowing them

what is the boundary layer

the non moving water layer the creates friction with surrounding water

does speed affect frictional drag

no

how can frictional drag be reduced

-- Fold in fins (fin pockets/slots)

-- Reduce scale size

-- Reduction of surface area

what is form drag caused by

the organisms shape moving through the water

what drag is more powerful

form drag

is form drag affected by speed

yes

how is form drag reduced

-- increasing surface roughness

-- streamlining shape

-- Reduction of fin surface area

True or false: teeth dictate diet

True

if an organism has a large central cusp with lateral cusps what does it do

Clutching and holding fish

if an organism teeth that are long thin and pointed, angled inward what do they do

Catch slippery fish & squid, tearing flesh

if an organism has teeth that are serrated and triangular, angles to help tear what does it do

Cutting or sawing chunks of flesh

if an organism has teeth like flat millstone or pavement like what do they do

Grind shellfish and crabs

if an organism has teeth that are low molar like what does it do

Crush crustaceans

if an organism has hundreds of tiny teeth what does it do

Filter plankton and small fish

True or false: elasmobrachs can chew food into smaller pieces

False

how do elasmobranchs feed

they are opportunistic predators so they forage followed by long periods of digestion

What can sharks do with their stomachs

evert stomach (regurgitate) to get rid of items that are indigestible or harmful

what organs does food pass through

-- Mouth

-- Oral cavity

-- Esophagous

-- Intestine

-- Rectum

-- Cloaca

what are Accessory organs

organs food doesn’t pass through

-- Pancreas

-- Liver

-- Gall bladder

what are the types of spiral valves and the groups associated with them

Scroll (sphyrnids)

Posterior funnel (rays & skates)

Spiral (holocephalans & most sharks)

what does the liver do

-- Produces bile that is sent to gall bladder till its needed

-- Detoxifies blood and regulates blood products

-- holds fats and other lipids for bouyancy

what does liver size have to do with lifestyle

bigger liver = larger slower shark

True or false: most sharks have a specialized diet

False: usually only planktivores have a specialized diet

what are foraging rates

time period needed to locate, capture, and eat prey

what are digestion rates affected by

-- type of food

-- species

-- temperature

-- food amount

-- spiral valve as it slows digestion rate

what temperature has the fastest digestion

high temperature as there is more secretion of digestion enzymes

what is the site of gas exchange

Secondary lamellae of the gills

where does water pass in the gills 

between primary & secondary lamellae

what are the 2 types of ventilation

Ram & buccal ventilation

what is ram ventilation

Forward movement used to pass water over gills with mouth open and is used in highly active species

what are the 2 types of ram ventilation

-- Obligate (Must be moving at all times)

-- Facultative (Use ram when moving but can actively ventilate when at low speeds or when stopped)

what is buccal ventilation

Use muscles to pass water over gills and is used in benthic species

what does the excretory system do

-- keeping proper conc of internal ions, body volume (water content), osmotic balance

-- Removes metabolic waste & foreign substances

what does urotelic mean

produce urea as a waste product after blood filtration

what is the main excretory organ

kidney

what does the kidney do

filter blood and produce urea

what is the flow of blood in the circulatory system

Arteries → arterioles → capillaries → venuoles →veins

where do arteries carry blood

away from the heart

what is the difference between arteries and veins

Arteries carry oxygenated blood while veins carry deoxygenated blood to the heart

what is Hemopoiesis

the production of red blood cells

what are the 3 parts of blood

plasma

Erythrocytes (red blood cells)

Leukocytes (white blood cells)

what organ makes most of the blood

spleen

true or false: elasmobrach blood is nucleated

true

what is the relationship between blood and activity

more RBCs = more active species

what do white blood cells do

immune system, help with blood clotting, get rid of foregin materials

what are the 4 parts of the heart

-- Sinus venosus

-- atrium

-- ventricle

-- Conus arteriosus

what does the Conus arteriosus do

send blood to gills & rest of body

what does the Sinus venosus do

receives deoxygenated blood

how does blood flow through the heart

Sinus venosus → Atrium → Ventricle → Conus arteriosus

what is the main source of heat loss

gills

how do elasmobranch maintain body temperature

Migrate to areas with optimal water temperature

what type of thermy are most elasmobranchs

Ectothermic

what are the 2 types of endothermy

Whole body and regional

what is regional endothermy

the brain, eye, and parts of digestive system are kept warm

what is the morphilogical difference of an endotherm

The red muscle is shifted toward the core of the body

what are the advantages of endothermy

-- Increased muscle power

-- Increased sustained swimming (migration)

-- Can invade other habitats bellow thermocline

-- More O2 for working tissues

-- Keeps brain alert

-- Increased lactate clearance

-- Increased digestive efficiency

what are the disadvantages of endothermy

-- Greater metabolic need

-- Lower population density

what is Osmoregulation

Balance of water & salt between tissues & external environment

what are the 2 methods of Osmoregulation

Osmoconformers & Osmoregulators