Fish Lecture Final Exam Flashcards
How can a fish deal with gravity (sustain buoyancy in water)? (6 ways)
- ACTIVE: Swimming forward through the water using fin modifications, provides lift (Pelvic fins, Caudal fins)
- SEMI-ACTIVE: Filling body up with air, gas or swim bladder
- STATIC: Reducing density of certain structures to make them lighter (having thin bones)
- Cartilage can be used in replacement to bone up which is lighter than bone.
- Use UREA and OILS to make solid parts of the body neutrally buoyant
- Some fish do not sustain buoyance, they live on benthic surface
Specific gravity of:
a) freshwater
b) saltwater
c) overall bony fish
a) Freshwater: 1.000
b) Saltwater: 1.026
c) Overall bony fish: 1.06 - 1.09
Descibe PHYSOSTOMES
- Species that have gas bladder connected to a tube to gut (more primitive fish) allows for gas bladder to be filled or emptied
Describe PHYSOCLIST
- Species with closed gas bladder
What is unique about the fishes eye lens?
- The lens is SPHERICAL in shape, this would normally result in a fuzzy image
- The composition of the fish’s eye lens changes from the center to the outer edge resulting in changing refractive index
What percentage of the worlds fish are:
a) Freshwater
b) Marine
c) Diadromous
a) 41.2%
b) 58.2%
c) 0.6%
Diadromous
Moving from freshwater to marine environments and vice vera
Anadromous
Spawning in freshwater and rearing in marine environments (ex. salmon)
Catadromous
Spawning in marine environments and rearing in freshwater (ex. eels)
What percentage the earths water is freshwater?
1%
Describe PELAGIC
Open oceans
Define EPIPELAGIC
Area of the ocean where enough sunlight can enter for photosynthetic processes (generally up to 200m in depth)
Describe BENTHIC
Sea floor
Littoral
Shallow regions near shoreline of ocean or freshwater lakes
What is the difference between TROLLING and LONGLINING?
- TROLLING: A fishing method where line and hooks are dragged behind a vessel
- LONGLINING: Large number of short lines carrying hooks are attached to a longer main line at regular intervals. The short lines are suspended horizontally at a predetermined depth with the help of surface floats
How many lines are allowed when trolling?
6 lines
Describe the following trolling gear:
- Gurdy
- Block
- Davit
- Pig
- Cannon ball
- Gurdy: WINCH that reels line in and out
- Block: PULLY in which line runs through from the gurdy
- Davit: ARM which hangs over the edge of the boat, raises, or lowers gear
- Pig/float: rectangular Styrofoam FLOAT that keeps the lines apart
- Cannon ball: Lead WEIGHT attached to the end of the line
Describe the following trolling gear:
- Flasher
- Hoochie
- Lures
- Leader
- Snap
- Flasher: Metal or plastic ATTRACTOR
- Hoochie: Plastic LURES
- Lures: spoons and plugs
- Leader: LINES from main line to hook
- Snap: CONNECTS the leader and hook to the main line
What are the three types of trawling and briefly describe?
1) Mid-water otter trawl: Net is towed in mid-water
2) Rock-hopper/bottom trawl: Net is dragged along sea bed
3) Beam trawl: Mouth of the trawl has metal beam which is dragged along the sea bed, used a lot for shellfish.
Name the 7 parts of a trawl net
1) Wings
2) Belly
3) Cod end
4) Trawl wrap
5) Otter doors
6) Headrope float
7) Iron bobbins
Why is bottom trawling so bad?
Highly damaging to the sea bed
Describe longlining
Large number of short lines carrying hooks are attached to a longer main line at regular intervals. The short lines are suspended horizontally at a predetermined depth with the help of surface floats
What are the following pieces of equipment used for longlining?
- Skate
- Gangion
- Radar reflector
- Gaff
- Skate: main long line with baited hooks set on the ocean floor
- Gangion: short line with baited hooks attached to main skate
- *See diagram pg. 39**
- Radar reflector: metal device on top of buoy to indicate where the line is or to indicate where your boat is to other vessels
- Gaff: hook on a pole used for lifting fish
What are the 3 types of hooks?
J shaped hook
Circle shaped hook
Barbless hook
Name 3 pieces of fly fishing gear.
Fly rod
Reel
Line
Sport fishing gear (5)
Reels (Level-wind reel, center pin reel) Lures Hooks Line Weights
Describe a superior mouth and give an example of a fish with this type of mouth
- Mouth pointed more upwards
Example: Freshwater hatchet fishes, halfbeaks
Describe a terminal mouth and give an example of a fish with this type of mouth
- Mouth pointing straight ahead
Example: Salmon, Trout, Cod
Describe a inferior mouth and give an example of a fish with this type of mouth
- Mouth pointing more down
Example: Suckers, Hillstream loaches
Name the 5 parts of a fishes eye
1) Cornea
2) Iris
3) Crystalline lens
4) Retina
5) Tapetum lucidum
What is tapetum lucidum?
A layer of tissue behind the retina which is a retroreflector resulting in the reflective glare in eyes of some animals. Allows light to bounce around enhancing the image in low light settings.
Do fish have eyelids?
No
Why do fish have scales?
Protection
Describe and give an example of a GANOID scale
Small block shaped scales
Example: sturgeon
Describe and give an example of a PLACOID scale
Pointed scales, somewhat triangular
Example: Sharks
**See diagram on page 17
Pulp, dentin, enamel, epidermis, dermis
Describe and give an example of a CYCLOID scale
Circular scales
Example: Salmon, carp
**See diagram on page 19
Focus, annulus, circuli, exposed portion
Describe and give an example of a CTENTOID scale
Toothed like scales
Example: Perch
**See diagram on page 20
Focus, radii, ctenii
Describe the fins in a fish, and what role they play in supporting the fish
- DORSAL and ANAL fin: control ROLL
- PELVIC fin: controls PITCH
- PECTORAL fin: controls PITCH and YAW
- CAUDLE fin: controls THRUST in projecting fish forwars
Describe caudle fin shapes
- Heterocercal
- Homocercal
- Diphycercal
- Lunate
Heterocercal: Lobes are different in length (Shark, Sturgeon)
Homocercal: Lobes are the uniform in shape and size (Salmon, Trout)
Diphycercal: Spear shaped caudle fin (Lungfish)
Lunate: Crescent moon shaped caudle fin (Tuna)
What is the “wrist” in a fishes tail called?
Caudle peduncle
Give an example of a fish that does not necessarily spend all of its time in water.
- Mudskippers (“skip” about on land)
- Black mudfish (aestivating: spends period of hot or dry in prolonged dormancy)
- Grunion (beach spawning)
- Flying fish (gliding)
What are the functions (3) of a gas bladder?
- Maintain BUOYANCY in water column
- SOUNG reception (midshipman) and generation (piranhas)
- BREATHING (lungfishes)
Where is the gas bladder generally located?
- Dorsal part of the cavity, high centered
What is the structure RETE MIRABLE?
- Complex of arteries and veins which transports oxygen to the swim bladder
Name the structure in the pars superior section of the ear. (3)
- Semi-circular canal
- Utriculus
- Lapillus
Name the structures in the pars inferior section of the ear. (4)
- Lagena
- Asteriscus
- Sacculus
- Sagitta
What is the WEBERIAN OSSICLE? Give an example of a fish with this structure.
- A series of bones that makes a connection between the gas bladder and the inner ear
- Herring
How does the OTOLITH work?
- Structure oscillates above the macula and hair cells, hairs then send signals to the nerves
What is the SACUAL GROOVE?
Center of the OTOLITH
Why is the otolith useful for fisheries management?
- Can be used to determine age and life history in fishes
Give 5 examples of the efficiency of fish gills
- Large surface area for gas exchanges to happen. More oxygen can enter the bloodstream over a given period
- Short diffusion or travel distance for the oxygen increasing the rate of oxygen to enter the blood
- Counter current circulation in the gills
- Very little physiological dead space
- Water flows continuously in one direction over the gills. Not wasting time, movement, energy!
How many gill rakers do “most” bony fish have?
4 on either side
How many gill rakers do sharks have?
5 on either side, generally
What is meant by the term COUNTER CURRENT?
- When water flows the opposite direction as blood flows through the gills. Allows for most efficient transfer of gases (oxygen).
Describe the term DIFFUSION
- DIFFUSION is when molecules transfer through semi-permeable membrane from high concentration to low concentration.
Water with higher amounts of oxygen transfers to lower gradient of oxygen
ex. when oxygen levels are high in water (high concentration), but low in the blood (low concentration), oxygen transfers from high to low (water to blood)
Does warm water, or cold water contain higher amounts of dissolved oxyger?
- COLD water
Describe RAM VENTILATION. Give an example of a type of fish that uses this technique.
- When mouth is left open to force water through the mouth and through gills automatically.
- Sharks!
Other ways some fish can breath without relying fully on their gills (2)?
- Absorb oxygen through their SKIN
- GAS BLADDER
Define OSMOSIS (5):
- DIFFUSION of a SOLVENT (water) through a SEMIPERMEABLE membrane, from a SOLUTION of LOW solute concentration (low salt), to a solution of HIGH solute concentration (high salt)
Describe:
- HYPERTONIC (give example)
- HYPOTONIC (give example)
- ISOTONIC
- Hypertonic: Fish has higher concentrations of salt than outside water so retain salt, and expels water by drinking and urinate a lot to release water. FRESHWATER FISH
- Hypotonic: Fish has lower concentration of salt than outside water so retains water, and expels salt by drinking and not urinate much to retain water but have gill chloride cells which excrete the salt MARINE FISH
- Isotonic: “Equal” concentrations
What is an example of a fish that can:
- NOT tolerate a wide range in salinity (provide term)
- CAN tolerate a wide range of salinity (provide term)
- Goldfish, Tuna - can NOT tolerate wide range STENOHALINE
- Salmon, Trout - CAN tolerate wide range EURYHALINE
What is the function of the GALL BLADER?
- Produces bilirubin and biliverdin which are used in emulsification of fats
Describe the following and provide an example:
- OVIPAROUS
- VIVIPAROUS
- OVOVIPAROUS
- OVIPAROUS: Egg laying (herring, salmon, sturgeon)
- VIVIPAROUS: Live-bearing (Shark)
- OVOVIPAROUS: Semi-live bearing, egg inside mothers body until ready to hatch (Tiger rock fish)
Describe:
- R-selected
- K-selected
- R-selected: those that put a lot of energy into producing lots of gametes in hopes that at least a few survive.
- K-selected: those that put a lot of energy into protecting the few that they produce survive.
What is PARTHENOGENESIS (gynogenesis)?
- Offspring do not receive contribution DNA from father. Embryo contains only maternal chromosomes
Example: Amazon Molly
What is HERMAPHRODITIC?
- Both male and female organs in the body
- Protandry: Male to female (ex. Clownfish)
- Protogyny: Female to male (ex. Wrasses)
- Simultaneous: (ex. Hamlets)
What is HETEROSEXUAL?
- Males mate with females
What is the term for “giving names to things”?
Taxonomy
“Kinky People Come Over For Good Sex”
KPCOFGS
Kingdom, Phylum, Class, Order, Family, Genus, Species
Who came up with the binomial nomenclature?
Carl Linnaeus
How many species of fish on earth?
24,600
What are the 4 characteristics of the phylum CHORDATA?
1) Hollow nerve cord in the dorsal side of the body
2) Have a notochord
3) Gill structure in the pharynx
4) Post-anal tail
What is the CLASS (2) of extant primitive fish?
1) Lampreys (petromyzontiformes)
2) Hagfishes (mixini)
What is a distinct feature of the superclass AGNATHA?
JAWLESS
What is a distinct feature of the superclass GNATHOSTOMATA?
JAWED
Give 2 main features of VERTEBRATA
- Skull
- Backbone
What are some defining features of the LAMPREY?
- R-SELECTED
- 7 gill slits
- Well developed eye
- Horny teeth
- Sucker mouth
- Pineal eye
- Lamprey velum
What is lamprey velum?
- Curtain of flesh that separates gill pouches from the esophagus
What are some defining features of the HAGFISH?
- K-SELECTED
- 12 gill slits
- Not well developed eye
- Pineal eye (light sensitive)
- Always in saltwater
- No vertebrae
- Isotonic
- One semi-circular canal
Name 2 species of HAGFISH in BC
- Black hagfish
- Pacific hagfish
Name 2 marine species of LAMPREY in BC
- River lamprey
- Pacific lamprey
Name 2 freshwater species of LAMPREY in BC
- Brook lamprey (not parasitic)
- Cowichan lamprey
What is a nictitating membrane and what species has this feature?
- Nictitating membrane is a clear bit of membrane that acts as an eyelid keeping dirt out of the eye.
- SHARKS have nictitating membrane but fish do not
What are CHROMATOSPHORES?
- Cell that can open and close rapidly to change colours of the cells
What is COUNTERSHADING?
- Dark on top, light on bottom
- Fish blend in with light when predator is hunting from below, or blends in with the sea floor when predator looking from above
What is CAMOUFLAGE?
- Changing skin, feathers, fur coloration to match surrounding habitat to blend in
What is it that makes fish look shiny?
- Guanine, a crystal under the fishes scales that reflect light giving it the shiny appearance
What is the term used for an animal showing its “dangerous” properties to other organisms?
- APOSEMATISM
What is DISRUPTIVE COLORATION?
- When outlines of an animal are broken up making them hard to distinguish
ex. Salmon par lines, Zebra
Example of a fish that uses color for:
- sexual signaling
- countershading
- camouflage
- mimicry
- disruptive coloration
- Sexual Signaling: Sockeye salmon
- Countershading: Salmon
- Camouflage: Cuttlefish
- Mimicry: Eels
- Disruptive Coloration: Salmon par marks
What is WARNING COLORATION and provide an example
- WARNING COLORATION: A specific type of aposematism - organism uses bright colors or patterns to warn predators
- LION FISH
What is the term for the bony internal elements that support the rays and spines on a fishes fin rays?
- PTERYGIOPHORES
What is meant by FRESHWATER TELOSTS?
- A group of freshwater fish that have kidneys that allow for the continuous expel of water through urine, and re-absorption of salts
What is unique about the sharks digestive tract?
- Has a SPIRAL valve to increase surface area for digestion instead of a long winding digestive tract
- This structure results in very fast digestion for the shark
What is ADAPTIVE RADIATION?
- Diversification of a species into several different forms that are adapted to specific environment
- Example: African Cichlids
What is GENETIC STOCK IDENTIFICATION (GSI)?
- Molecular technique to determine stock composition of fish caught in mixed-stock fisheries
- Example: Salish suckers vs. Longnose suckers
