Lecture 18- Fish characteristics 2 Flashcards
whats the difference between supracarinalis and infracarinalis?
supracarinalis runs along dorsal ridge and is a red muscle, used to be fish into a sway back posture
Infracarinalis runs along the belly and is a red muscle, bend body into a humpbacked posture.
why is the vertebral column in fish unique among vertebrates?
the head and trunk move together, they do not have an atlas and axis vertebrate that allows their head to move independently of their trunk
describe the gill formation?
Gills are the most important respiratory organ in most fish! in teleosts each gill arch supports a pair of gill filaments that support secondary lamellae. secondary lamella is the site of gas exchange
what are gill rakers and what purpose do they serve?
the gill arch is often equipped with gill rakers on the inner surface. Gill rakers catch food and protect the gill from damage (debris hits the gill rakers before it gets to the gill filaments)
Basically acting like a filter!
what is the gas bladder? what did evolve to be?
the gas bladder evolved as a lung for aerial respiration but now functions primarily to regulate buoyancyl though several species can still draw oxygen from the gas bladder and some have maintained the lung.
the gas bladder develops from what?
develops from the gut of the embryo and becomes filled with gas shortly after the fish hatches!
a gas bladder is often absent or vestigal in what kind of fish?
bottom dwelling fishes
gas bladders can also be modified for what?
for sound production or to assist hearing!
describe the digestive tract of fish?
there is considerable variation among species! Gnerally short in carnivores and long in herbivores. Pyloric ceca is a series of blind pouches found just posterior to the pyloric valve of the stomach. this increases the absorptive area of the gut
