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