Fishes

Fishes

Multiple species of fish

Who was the first vertebrate to evolve?

Fish, specifically Haikouella lanceolata 530 million years ago

Where did all life begin?

The water

What percentage of vertebrates are fish and why?

50%, because they’ve had longer to evolve

Agnatha

Jawless vertebrates

Gnathostomes

Jawed vertebrates

Name the 5 classes of fish

Myxini

Petromyzontida

Chondrichthyes

Sarcopterygii

Actinopterygii

Myxini (Hagfish)

Agnatha that scavenge, live in deep waters, and create slime for protection that is used in Kevlar for bulletproof vests

Scavenger

Eats dead things

Petromyzontida (Lamprey)

Parasitic agnatha that undergo metamorphosis and are anadromous

Anadromous

Invasive animal that migrates, undergoes metamorphosis where it mostly lives in the sand, & grows a tail before moving above the sand

Which animal is anadromous?

Petromyzontida (Lamprey)

Invasive Species

Species that isn’t natural to an environment that establishes causing a large ecological impact

Chondrichthyes (Sharks, Skates, Rays, & Chimera)

Cartilaginous fish meaning they lack bones

Name the 2 infraclasses of Chondrichthyes

Holocephali

Elasmobranchii

Holocephali

Chimaera with 40 species

Elasmobranchii

Sharks, Skates, & Rays that are endangered due to shark finning and getting stuck in nets and has 1,200 species

Ram Ventilation

Seen in most Sharks where they have to swim to breath

4 types of Shark Fins

Dorsal Fin

Pectoral Fin

Caudal Fin

Pelvic Fin

Dorsal Fin

Fin on top that helps with hydrodynamics

Pectoral Fin

Fin on the side that helps with balance

Caudal Fin

Tail fin that helps with steering and forward propulsion

Pelvic Fin

Second fin on the bottom

Dorsal Side

Toward the back or upper side of the body

Lateral Side

Toward the side or away from the middle of the body

Heterocercal Tail

Different on top & bottom and seen in all Sharks

Placoid Scales

Seen in all Sharks, Skates, & Rays to make them more hydrodynamic

Hydrodynamic

Ability to move easily through the water

How far away can sharks hear?

1.6 km away

How far away can Sharks smell?

0.5 km away

Why do most aquatic animals have bad sight but good hearing?

Sound moves further in water than air

Ampullae of Lorenzini

Jelly filled sacks in the skin that allow Sharks to detect electrical currents in water & things close up

Ex: Hammerhead Sharks having a weird shaped head to detect electricity

Lateral Line

Sensory organ system in most fish that helps detect movement in water

Liver

Fatty organ that makes up most of the body in Sharks that helps detect buoyancy

2 types of fertilization

Internal Fertilization

External Fertilization

Internal Fertilization

Gametes meeting inside the body

External Fertilization

Gametes meeting outside the body

How do male Sharks mate?

Using Claspers which are rod-like appendages on their pelvic fins to transfer sperm directly into females reproductive tracts

3 ways Elasmobranchii give birth

Viviparous

Oviparous

Ovoviviparous

Viviparous

Birthing live young

Oviparous

Laying eggs

Ovoviviparous

Eggs hatching in the Uterus and are born live

Ex: Sharks

What kind of fertilization do all elasmobranchii have?

Internal Fertilization

3 ways Elasmobranchii eat

Durophagous

Mass Feeding

Filter Feeding

Durophagous

Eating hard things like crabs and clams

Ex: Skates & Rays

Mass Feeding

Taking big bites so they replace their teeth through out their entire life

Filter Feeding

Filter food from water. Predominantly eat Plankton and see in bigger Sharks

What type of feeder are most Sharks

Mass feeders and carnivores

Why do some Elasmobranchii have small teeth?

Durophagous

Spiral Valve Intestine

Cork-screw shaped intestine that keeps food in the intestine longer allowing it to be further broken down

Ex: Cartilaginous fish, Actinopterygii, & Sarcopterygii

Cambrian Explosion

Explosion 541 million years ago where most animal phyla evolved

Devonian

“Age of fishes” 400 million years ago

Osteichthyes

Boney fish

Operculum

Bony covering of the gills in all Osteichthyes

Swim Bladder

Sack filled with air by taking in Oxygen from the water to control buoyancy in all Osteichthyes

Sarcopterygii (Coelocanths & Lungfish)

Lob-finned fish with 5-6 species

What do Lungfish breath in?

Air

Diphycercal Tail

3 lobed tail seen in all Sarcopterygii that isn’t very hydrodynamic

Where did all other vertebrates evolve from?

Sarcopterygii, their lobed-fins became legs

Actinopterygii