Muscles and Scales

red muscle

• highly vascularized (has blood flow)

• thin layer under the skin on body sides of fish

• aerobic oxidation

• rarely tires, quickly recovers

lots of myoglobin

red muscle= ___________ (3x more capillaries per unit volume than white)

white!

what muscle type do we primarily see in fish?

myomeres

individual muscle bands

myosepta

connective tissue between myomeres

more red

what muscle type do tunas mostly have? (highly pelagic)

more white

what muscle type do rock fish mostly have? (highly benthic)

regional heterothermy

location of red muscle can aid in ________; keeps parts of body warmer than water temp

interior, exterior, in between

where are red muscles placed on these species?

tuna, non-thunniform fish and lamnid shark

tunas, lamniformes, highly migratory species

in what species are their white muscles are kind of red?

extra layer of protection, helps with hydrodynamics, UV protection, protection from parasites

what are scales used for?

placoid scale

What scale type is this?

dermal denticles

• placoid scale is know as the ________; placoid scales

• most Chondrichthyes

• feels like sandpaper

• they don’t grow and are very small in size

• highly vascularized

• can vary in shape → spiked, smooth or in between

ganiod scale

What type of scale is this?

armor-like

• heavy, thick, _______ plates/bricks stacked on top of each other; ganoid scales

• plates/scales sit next to each other → rhomboid in shape

• embedded in the skin

• grows with the animal

• sturgeon, gar, bowfin → primitive bony fish

scutes

What type of scale is this?

reptilian armor

• referred to as ________; scutes

• modified ganoid scales

• very sharp

• grows with the fish

cycloid/ctenoid

What type of scales are these?

modern scales

• known as _________; cycloid/ctenoid

• loosely embedded in skin, very light and fragile

• found in nearly all teleosts

• “cyclo”= circle, “cteno”=comb

• lets teleosts be faster and more nimble

• overlap: posterior edge of one scale overlaps anterior edge of another

one part

scales are just ________ of the integumentary system. that contains epidermis and dermis (bony fish)

thin epidermis

contains substrate for mucous layer (exterior to scales)

mucous layer

aids in immune protection, hydrodynamic

cartilaginous fish

in which species is there no mucus layer, so they have rough skin and their scales are firmly embedded into dermis so there is blood flow?

no scales

jawless fish have _______

coelacanth scales

lobe-finned fishes have ________

placoid scales

cartilaginous fish have ________

ganoid scales

primitive bony fish have ________

cycloid scales

teleosts have _________

ctenoid scales

most common scale type in euteleosts _________