Fish Quiz
Ctenoid scales
(bony ridge elasmoid scales) - similar to cycloid, except tiny comb-like projections growing from posterior edge of scale. Fish with these scales feel rougher when handled. scales may increase hydrodynamic efficiency EX: fish with spiny fins
Cycloid scales
(bony ridge elasmoid scales) -round, flat, thin, center around which scale enlarges, fish feel slippery EX: trout, minnows, herring
*Adipose fin
(some species trout, salmon, smelt, catfish) - located b/w dorsal and caudal on dorsal surface - lacks stiffening way purpose is unknown
Coloring techniques in fishes
-bright, silvery, shiny -coutner-shading -cryptic coloring -cirri -disruptive coloring -poster coloration -eye ornaments/eye spots -red coloration
Surface-oriented and bottom fish
-dorsoventrally flattened
Pectoral fin uses
-flying fish use to glide -
*Caudal fin and 2 types
All fish have, shapes sized radically different -responsible for the forward thrust of swimming Two main: 1. heterocercal tails 2. homoceracal tails
*Sit-and-wait
Ambush predators. -Elongate body, topedo shape -Terminal mouth, flattened head -Caudal fin and peduncle are large and median fins are placed far back on body EX: barracuda, needlefish, freshwater pikes and gars
(M) Three categories of fish undulatory movement
Anguilliform, Carangiform, Ostraciiform
Disruptive coloration
In extremely clear waters where patterns break up outline of fish. Including vertical bars. often found around beds of aquatic vegetation
FINS cart vs bony
cart: fin rays are stiff, unbranced, and unsegmented bony: flexible, segemented and branched
Cryptically colored
colored to match background (EX: flounders)
(Movement) Aquatic enviroments are
dense mediums, fish can reduce density become neutrally buoyant
rattail
evolved in both carilaginous and bony fishes -long pointed tail, often large pointed head EX: chimeras and grenadiers
Poster coloration
exhibit extremely bright complex color patters. Many reasons, maturity, warning, blending in bright env.
*Deep bodied fish
extreme latteral flattening and have body form (compressiform) that's excellent for maneruvering in tight quarters. -depth is 1/3 stnrd length. -most have sharp dorsal spines EX: coral reef fish, freshwater sunfishes (pumpkinseed, bluegill, crappie, rock bass)
*Pelvic Fins
extrmly varied in size, position and function -eel like greatly reduced or lost, bottom dwellers modify to serve as clinging
SCALES
fast fish / fish in fast waters - small scales for reduced turbulance - slower fish larger scales - eel like lack or deeply embedded move around crevasses - large bottom dwellers - large heavy scales act as armor
Bright, silvery, shiny scales
fish in clear sunlit inshore waters and school making it difficult to identify single fish for attack
Bottom hiders
hide under things, similar to clingers but w/ longer bodies, smaller heads, lack clinging abilities EX: darters, blennies
red coloration
in clear, shallow water red is used for social signaling -in deeper waters are red but water filters out that color so they appear darker. -crepuscular and nocturnal are red in full light but appear dark when active
(M) *Ostraciiform
inflexible, often armored body, movement is restricted to caudal fin
Sexual size dimorphism
large size often favored by female. EX salmon, bluegill sunfish
Ganoid scales
most ancestral, found in gars - large, hard, diamond shaped, no overlap, very tough armor
Mouth in bony fishes
mouth tends to be positioned terminally (at the end of the snout).
Thoracic position (pelvic fin)
moved forward under pectoral fins
Sexual selection
odd structures that are due to female choice or male-male competition EX: hooked mouth parts of salmon, or enlarged dorsal fins
indeterminate growth
posses the capacity for continuous growth through out their life
*Heterocercal tails
re found almost universally among the Chondrichthyes because the larger upper lobe generates lift to counteract their tendency to sink (because they are denser than water). -
(M) *Balistiform movements
refer to undulations of the median fins (anal, dorsal or both)
Catlilagenous vs bony fishes
scales evolved independently - C: placoid scales. Tooth like composed of dentine and enamel, small, rough and strong (sting on stingray modified placoid scale)
Bottim clingers
small fish w/ flat heads and some structure lets them cling to bottom (like pelvic fin) -large pectoral fins -live in fast running streams EX: sculpins
*Surface oriented
small, fusiform body, large eyes, mouth located at terminal end near dorsal surface -prey eaten from the air-water interface EXAMPLES: killifish, mosquitofish, marine fishes like flying fish/half beaks
lateral bands
sometimes converge on tail, directing attention from head. Often run horizontally run the length of the body producing confusion in school species.
Eye ornaments
spots around eyes or stripes running thru make it difficult to identify eye, as for signaling brightly colored eye ring/tinge to eye color.
*Rover-predators
stream lined (fusiform) bodies -Mouth is terminal, tail large and forked connected by narrow caudal penduncle. Fins distributed evenly over body. EX: tuna, mackerel, swordfish, trout many minnows and bass
Barbels
tentacles around the mouth
(MOUTH PARTS AND FEEDING) Mouth in chondrichthtes
the mouth is ventrally positioned (inferior), and most are predators with large teeth present on the jaw.
(M) *Carangiform
Undulations restricted largely to caudal region or at most the posterior 1/2 of body
Crepuscular
active at dawn and dusk
Abdominal position (pelvic fin)
ancestreal and towards posterior end
Jugular position (pelvic)
anterior to pectoral fins
Median fins BLAH
. When swimming fast, many species (e.g., tuna) can depress the dorsal fin into a slot to reduce drag. Among fish with anguilliform locomotion (the eel-like species) the dorsal and anal fins often merge and fuse with the caudal fin. These fins provide the propulsive force for fish with balistiform locomotion.
*3 types of bony fish scales
1. Ganoid 2. Cycloid 3. Ctenoid
*Bottom fish 5 types
1. rover-predator 2. bottom clingers 3. bottom hiders 4. flatfish 5. rattails
(Body shape and Behavior) 6 Categories
1. rover-predators 2. sit-and-wait predators 3. surface-oriented 4. bottom fish 5. deep-bodied fish 6. eel-like fish
(M) Carangiform vs Anguilliform Movement
A - generate drag from frictions of long undulations C - less friction, force comes from muscular contractions transferred through the caudal peduncle to the tail to generate thrust
Jawless fish
Agnatha
*Homocercal tails
Bony fishes have the swim bladder, tend not to sink, and nearly all of them have homocercal tails (equal-sized upper and lower lobes).
Two types of Gnathostomata
Chondrichthyes (cartilaginous fish) Osteichthyes (bony fish)
*Median fins
Dorsal (on back) Anal (on belly) -long on deep bodied, fast, and eel like, also add stability
Counter-shading
Dorsal surface dark but ventral is light
flatfish
EX: Skates and rays (flounders too but born deep bodied) show extreme dorsal flattening
Bottom rovers
EX: catfish, sturgeon, many sharks - extreme differences in moth position (terminal catfish, ventral sturgeon and sharks) -Often in murkey waters with small eyes and often have barbels
(M) *Modified Carangiform
Fastest swimming fish (jacks,tuna,sharks) have very narrow peduncle & greatly expanded tail. Also often have bony plates called scutes positioned latterally on caudal peduncle. Appear as knife edge to water.
(Movement) Most fish have ___ body type
Generalized fusiform (torpedo-like)
(M) How fish move foward
Generate force to produce lift (opposing gravity) and thrust (opposing drag). TO move foward fish push backwards against water (newtons 3rd law action and rxn) For NONostraciiform speed is increased by increasing frequency of undulations
Jawed
Gnathostomata
(M) *Anguilliform
Highly flexible fish, MORE than 1/2 of body undulates
(M) Contractions
How fish move. Contractions move anterior to posterior. One side body contracts while opposite relaxes. As result, fish bends and lateral undulations pass from head to tail.
*eel-like fish
Long stinuous bodies, blunt wedge shaped heads, tapering or rounded tails -lateral fins lost or reduced while median fins tend to be long, - scaled reduced or absent EX: eels, sand fish, loaches
Pectoral fins
Many functions Sharks - solely stabilize and diving planes Bony - when located high on side provide great maneuverability --fast swimming have long pointed located toward midline --slow have rounded ventral surface: bottom dwell/sitandwait - flying fish use to glide -used in display to startle by flying gurnards and lion fish threat or warn
Eye spots
Near tails, directs predators from head
(M) and lateral fins
Often don't provide propulsion. (sometimes use pectoral and median fins) Simply stabilize. Oppose pitch (up and down) yawl (side to side) roll (spinning)
(M) *Labriform movement
Pectoral fins are rowed to generate movement. Typical in coral reef fish. (name stems from labridae/wrasses found in reefs) These fish can also use carangiform movement for bursts of speed
(M) *Rajiform
Rays (cartilaginous fish) Use large pectoral fin, which is fused to head, undulates from anterior to posterior simultaneously on both sides of the body to generate thrust. Large rays flap pectoral fins like wings.
Cirri
Structures that evolved to resemble coral rock or algae