LAB QUIZ #2 Flashcards
Sharks, Osteichthyes
What are the main 2 classes of Superclass Gnathastoma?
class Chondrichthyes and class Osteichthyes.
What are the 2 subclasses of Class Chondrichthyes?
subclass Elasmobranchii and subclass Holocephali.
What are the 2 subclasses of Class Osteichthyes?
subclass Actinopterygii and subclass Sarcopterygii.
What are the main anatomical features of Chondrichthyes?
- placoid scales
- 2-chambered heart
- cartilaginous skeleton
What anatomical features aid in buoyancy in Chondrichthyes?
combination of:
- fin placement
- oily liver
- cartilaginous skeleton
Subclass Elasmobranchii
sharks, skates, rays, and sawfish.
What are common anatomical features of Subclass Elasmobranchii?
- 5-7 gill slits
- spiracle (to bring water over gills)
- sub-terminal mouth
- hyostylic or amphiphilic jaw suspension
- ampullae of lorenzini (electroreception)
- cloaca
- claspers (in males)
- internal fertilization
Hyostylic Jaw Suspension
mandibular arch is not clearly attatched to the cranium, but connected by the hyoid arch.
Amphystylic Jaw Suspension
the upper mandibular arch is attatched to the cranium and the lower mandibular arch is connected to the hyoid arch.
PRIMATIVE
- frilled shark, 7-gilled shark
What is the difference between skates and rays?
skates:
- thick tail
- oviparous
rays:
- thin tail
- stinging spine
- viviparous
Subclass Holocephali
“whole head”
chimera and ratfish
What are common anatomical features of Subclass Holocephalii?
- 4 gill slits w/ single opening
- holosylic suspension
- oviparous
- NO CLOACA
- claspers on forehead
- slime coat (no scales)
Holostylic Jaw Suspension
upper mandibular arch is fused to the cranium and lower mandibular arch is suspensed from the upper.
- hyoid arch seperate
What are the general characteristics of Osteichthyes?
- 1st appearance of endochondrial bone
- operculum
- swim bladder (offset bone density, can be air or fat)
What is the main function of the operculum?
increase suction through buccal pumping, which increases flow of water over the gills.
most efficient.
Subclass Actinopterygii
ray-finned fishes
- derived
- fins supported by bony rays
- placement of pectoral fins are not conductive to limb developement.
Subclass Sarcopterygii
lobe-finned fishes
- ancestral
- fins supported by bone in fleshy stalks
- placement of paired pectoral and pelvic fins lead to the tetrapod limb.
Heterocercal Tail
dorsal and ventral lobes are not the same size.
chondrichchthyes
Homocercal Tail
dorsal and ventral lobes are the same size.
osteichthyes
What are the main points to remember about the Muscular System in sharks?
- only contract in a single plane
- increase in musculature allows increase in movement
Horizontal Septum
- lies between the epaxial and hypaxial muscles
- allows for movement within a single plane
Muscle Groups:
Epaxial = dorsal to the horizontal septum.
Hypaxial = ventral to the horizontal septum.
- inc. some vertebral muscles, diaphragm, abdominal muscles, and limb muscles.
Linea Alba = connective tissue separating the L and R myomers midventrally.
Abductor Muscles
pull a structure away from the midventral line.
Adductor Muscles
pull a structure toward the midventral line.
Spiracle
opening between the gill chamber and the environment to push water over the gills.
RAM Ventillation
associated with very active sharks, swim with mouth open.
- higher rate using spiracle.
Gill Lamellae
used to increase SA in contact with the environment.
gill SA for gas exchange is DIRECTLY RELATED to activity level.
Hemibranch
- gill 1
- only posterior side of gill has lamellae
Holobranch
- gills 2-5
- both sides of gills have lamellae
Gill Rays
support for gill lamellae.
Gill Rakers
keep food inside of oral cavity and seperate from the gills.
What is the main function of the Digestive System?
allows organisms to get nutrients, carbon, fats, and protein from their environment.
Rugae
(of stomach)
longitudinal fold that expand like an accordian to allow the stomach to expand and accomodate for a large meal.
- protein break down starts in stomach
Pyloric Sphincter
seperation point between the stomach aand intestine that keeps stomach acids out of the intestine.
Spiral Valve
increases intestinal SA and nutrient exchange.
Pancreas
secretes enzymes that start breaking down proteins.
Digitiform Gland
secretes salts, aid in excess salt removal.
Liver
- aid in buoyancy (large fat content).
- detoxifies metabolites and creates bile for digestion.
Sinous Venosus
a thin, non-muscular sac where deoxygenated blood enters the heart.
Atrium
pumps blood from the sinus venosus to the ventricle.
Ventricle
pumps blood to the conus arteriosus.
Conus Arteriosus
semilunar valves that control blood flow before the gills.
How does diffusion aid in the Cardiovascular System?
the heart gains enough of a supply of blood from diffusion, and does not have to work as hard because sharks are a flat animal and dont really have to work against gravity.
What does the male shark reproductive system consist of?
- paired testes
- paired genital ducts
- urogenital papillae
- claspers
What does the female shark reproductive system consist of?
- paired ovaries/oviducts
- nidamental gland
- uterus
- urinary papilla
Seasonal Breeders
reproductively active during only parts of the year, where gestation lasts several months.
ex. oceanic whitetips, threshers
Punctuated Breeders
often pregnant for a full year but spend one or more intervening years not pregnant.
ex. tiger sharks
Continuous Breeders
reproductively active all year long.
ex. gulper sharks
Oviparity
externally deposited eggs, typically in leathery/durable shells.
Viviparity
live birth.
Oviviparity
eggs develop and hatch inside the mother and then are birthed.
Parthenogenesis
clonal or “virgin” birth.
- we know this happens in sharks bc of aquariums.
Yolk-Sac
retention of fertilized eggs throughout developement of the embryo within the uterus.
- no other maternal input is supplied
elasmobranchs
Histotrophy
initial nutrition by the yolk-sac, then by “uterin milk” or histotroph.
- can be limited mucoid or lipid rich
Placental
most advanced form of nutrition.
Oophagy
“egg eating”
the initial nutrition by the yolk-sac and then embryos feed on unfertilized eggs.
Adelphophagy
Embryonic Cannibalism
embryos ingest other embryos and unfertilized eggs.
Lecithotrophy
the entire duration of embryonic developement is supported by the yolk-sacs nutritional content.
ex. yolk-sac
Matrotrophy
at least part of the fetal developement is supplemented by maternal input of nutruents during fetal developement.
ex. placental, histotrophy
What are the main sensory systems in sharks?
- chemoreception = taste/smell.
- mechanoreception = touch/vibration, response to change in pressure.
- vision = resonse to changes in light stimuli, (not all species see the same spectrum of light).
- electroreception = response to electrical currents.
(ordered in distance from furthest to closest).
What is the Tripartite brain?
-
prosencephalon - forebrain
- telencephalon
- diencephalon -
Mesencephalon - midbrain
- optic lobes -
Rhombencephalon - hindbrain
- metencephalon
- myelencephalon
all 3 regions are conserved in all vertebrates
Spinal Cord
part of the nervous system contained in the spinal column.
Cerebrum
- principal and most anterior part of the brain that consists of a L and R hemishere separated by a fissure.
- responsible for the integration of complex sensory and neural functions and the initiation of coordination of voluntary activity in the body.
Cerebellum
the part of the brain at the back of the skull that coordinates and regulates muscular activity.
Olfactory Sacs
function in smell/olfaction.
Cranial Nerves
come directly from the brain
Meninges
membrane surrounding the brain, containing cerebrospinal fluid.
