zoo lab midterm 1, cartilaginous fish

what kind of caudal tail do sharks have and what is its use

heterocercal means the lobes are two dif sizes, and helps with lift cus they dont have a swim bladder

whats the dif between heterocercal and homocercal tails and what is diphycercal

hetero dif sized lobes, homo same sized lobes, dip means vertebrae extends to tail tip

where are shark gills located and where do they lead

on either side of pharyngeal region, behind head and open into pharynx

where are shark nostrils and job

they are on ventrolateral side of snout, and lead to olfactory sacs just for chemoreceptors

what are ampullae of Lorenzini and job

jelly filled sensory tubes concentrated around shark snout that detect electrical signals from food

what is cloaca in sharks and found where vs urogen papilla

chamber/opening for digestive, urinary and repro systems, located on ventral between pelvic fins, urogen papilla doesn’t do feces

what type of scales do sharks have n job

placoid, point backwards and provide protection and reduce turbulence in the water.

where do placoid scales originate from in skin

inner layer from dermal and outer layer is enamel like part from epidermis

what’s the func of mucous cells in sharks and uni or multicell?

unicell cus basic, produce mucous that coats scales, helps regulate osmotic balance and provide antibacterial protection,

what are melanophores and whats the func in sharks

they are the pigment containing chromatophores in upper dermis and give them that brown camouflage

epidermis vs dermis parts and cell invloved

The epidermis is the outermost layer of skin containing the mucous cells, the dermis is split into stratum spongiosum and stratum compactum

how does shark Skelton differ from hagfish/lamprey

sharks have higher developed cartilage Skelton including jaws, vertebral column and paired fins/girdles

what are the two regions of shark vertebral column

trunk and caudal

what makes up the sharks pectoral girdle

u shaped structure consisting of ventral coracoid bar which connects with two scapular processes

what is glenoid surface in sharks

a depression on scapulas where pectoral fin articulates(attaches)

what a makes up a sharks pelvic gridle

a single ischiopubic bar with two small lateral iliac processes

what are ptergiophores and claspers? in sharks

ptergiophores are cartilage supports at base of fins while claspers are modified male pelvic fins to transfer sperm in mating

which cranial skeleton components are in sharks

chondrocranium and splanchnocranium

what are the 3 types of visceral arches in sharks

part of splanchnocranium

mandibular arch forms jaws, hyoid arch support jaws, and 5 branchial support gills

what are gill rakers and what do they do

on inner surface of branchial arches keep from gill lamellae

how are shark teeth adapted for feeding/ characteristics

rows of serrate triangles with replacement teeth behind

what’s the struct and function of liver in sharks

two large lateral lobes smaller and one medial. they produce bile n store oils for floating

what’s the spleen and rectal gland for in sharks

spleen produce/store red blood cells

rectal gland removes excess salt

whats the shape of a sharks stomach and how do folds help

sharks have a j shape stomach, rugae folds that allow for expansion and increase surface area for digestion.

what are papillae and where are they found in sharks digest track

projections lining esophagus that help move swallowed food toward stomach

what’s the function of shark duodenum

first intestinal part, receives bile from gallbladder and digest enzymes from pancreas

what is spiral valve and importance

it is in ileum that increases surface area to digest

whats the path of food through a sharks digestive tract

mouth to pharynx to esophagus to stomach to duodenum to ileum to colon to rectum to cloaca

how does shark digestive track differ from hagfish/lamprey

they have stomach, duodenum and ileum instead of a simple intestine.

what type of gills do sharks have

septal gills, means gills supported by interbranchial septa

what are spiracles in sharks

as far as we know mostly vestigial, for breathing when buried in dirt

whats the pathways of water through shark gills

unidirection, in mouth to pharynx to internal gill slit, across gill lamellae, to external gill slit

what are the interbrancial septa in sharks and primary lamellae

septa: partitions separating gills

primary lamellae: plate like struct attached to septa that support gas exchange

whats the difference between hemibranch n holobranch

hemibranch: means lamellae on one side of gill arch while holobranch: means lamellae on both sides

how many hemi vs holobranchs do sharks have

most anterior is hemi while subsequent are holo

what are the aortic arches in shaarks

arteries that carry blood from ventral aorta toward gills for oxygenation

how many pairs of aortic arches did sharks originally have and numbered how and dogfish sharks have how many now

6, using roman numerals, dogfish lost the first

what’s the conus arteriosus in sharks

muscular outflow of the heart in sharks carry blood from ventricle to ventral aorta

what’s pathway of blood through shark heart

sinus venous to atrium to ventricle to conus arteriosus to ventral aorta

how shark heart differ from lamprey?

sharks hearts are more muscular and have conus arteriosus vs bulbous arteriosus

how do sharks use urea for osmos reg?

retain high conc urea in tisseus to maintain osmotic balance with seawater.

whats the path of sperm throiugh male shark

testis to efferent ductulus, to modified kidney tubes, to opisthonephric duct, to seminal vesicles, to urogenital sinus, to urogenital papilla, to cloaca

what are the seminal vesicles and sperm sac in sharks

seminal vesicles: enlarged end of opisthenophric duct that stores sperm

sperm sac: is small pouch extending from seminal vesicle

whats the urogenital sinus in male sharks

urogenital sinus is a chamber that receives urine and sperm before they exit urogen papilla and cloaca

what are accessory urinary ducts and which do males and females have them have them

Accessory urinary ducts are additional ducts that transport urine from the kidney to the cloaca separating sperm from urine, found in males only

how does urine leave a female shark

kidney to opisthenophreic duct to urinary papilla to cloaca

what’s the path of an egg through a female shark

ovary, coelom, ostium, oviduct, nidamental gland(makes shell), ovisac, cloaca

whats the purpose of nidamental gland in sharks

stores sperm and produces thin membranous covering around eggs

whats a candle in shark repro

package of several eggs enclosed eggs like bird clutch

what happens in ovisac of sharks and what type of repro does dogfish have

embroys develop in mom nourished by yolk sac, ovoviviparityis a type of reproduction where eggs hatch inside the female's body, allowing the young to be born alive.