Fishes

no

are fishes a monophyletic group?

all vertebrates that aren’t tetrapods

what are fish in evolutionary terms?

swim bladders

used in fish to control buoyancy

salt and water

fish have specialized organs for the exchange of ____ due to their evironment

1/20

fraction of oxygen in water compared to air

lateral line system

detects water current and vibrations in fish

Ostracoderms

Earliest jawless agnathan fishes

hagfishes, lampreys

Agnathan fishes have adapted to scavenging like ________, which lack vertebrae, and to being parasitic, as in _________, which have rudimentary vertebrae.

modification of 1st gill arch

what creates jaws

cartilaginous fishes

group that includes sharks, rays, and chimaeras

bony fishes

dominant group of living fishes today

jaws, internal ossification, paired fins

what do hagfishes and lampreys lack?

keretinized toungue plates

used for parisitation in hagfishes

anadromous

Marine forms of lampreys are _______ (going back to stream where they were born to reproduce) so they can \n leave the sea as adults to spawn upstream in streams

ammoceotes larvae

hatches from lamprey eggs

anticoagulent

injected into wounds by lampreys to keep blood flowing

they don’t

how do nonparasitic lampreys feed after metapmorphosis

marine

habitat of most chondrichthyes

heterocercal tail

provides thrust and lift in sharks

2 lobes are different sizes

what does heterocercal mean?

spiracle

remnant of 1st gill slit

clasper

male medial part of pelvic fin used in copulation

strong olfactory organs and sensing vibrations

why can sharks sense prey from far away?

neuromasts

makes up the lateral line system

bioelectric fields

guide sharks up close to prey

J

shape of shark stomach

spiral valve

in the intestine to slow passage of food and increase absorptive area

internal

type of fertilization in chondrichthyes

oviparous

lay large, yolky eggs that take time tohatch

ovoviviparous

embryos are retained in the reproductive tract and fed by the yolk for some time until being released

viviparous

embryos get nourishment from maternal bloodstream via placenta or uterine milk

mermaid’s purse

a keratinized capsule encasing eggs that has tendrils which cling onto firm substrate upon contact.

venom glands

located at the base of stingray tail

Osteichthyes

fish with bony endoskeletons that gave rise to a clade that contains 96% of living fishes and all living tetrapods

bone replaces cartilage, lungs or swim bladder

feature uniting bony fishes

operculum

bony plates connected to muscles and cover the gills and increase respiratory efficiency

homocercal

bony fish tail type with two lobes of equal size

cycloid and ctentoid

types of scales in bony fishes, light thin and flexible

dorsal fin

often modified for bizarre functions

sarcopterygian clade

fishes that can survive droughts for long periods of time

w

shape seen in fish muscle

Adjusting volume of gas in its swim bladder

how does a fish control its depth?

Weberian ossicles

small bones that allow them to hear faint sounds over a \n much broader range than other teleosts

compressed, expands

bladder ________ as fish descends and _______ as it ascends

anadromous

Most salmon are ___________, meaning that they grow up in seabut return to freshwater to spawn.

atlantic does it multiple times while pacific spawns once and dies

difference in atlantic and pacific salmon spawning

rings in scales and otoliths

how are fish aged?

diphycercal

caudal fin that is symmetrical and pointed

homocercal

caudal fin that has 2 lobes of equal size

ganoid

rhomboid scales seen in nonteleost bony fish

placoid

spiny scales found in cartilaginous fishes