Audrey's study thing based off mrs meaux's

fishes

Characteristics of all fish

Characteristics of all fish

aquatic, bilaterally symmetrical, endoskeleton, ectotherms

Characteristics of most fish

gills, vertebrae, jaws, scales, paired fins

Class Myxini

jawless, live on the seafloor, slimy

ex. Hagfish

Class Cephalaspidormorphi

jawless, parasitic

ex. Lamprey

Class Chondrichthyes

cartilaginous fish

ex. Sharks, skates, and rays

Superclass Osteichthyes

bony fish

in the superclass: Class Actinopterygii

ray-finned fishes

ex. Trout, salmon, tuna, goldfish, angelfish, etc.

in the superclass: Class Sarcopterygii

lobe-finned fishes, muscular fish, some have lungs

ex. Lungfish and coelacanth

Anterior Dorsal Fin

Located on the dorsal side and is used to help balance the shark

Posterior Dorsal Fin

Located on the dorsal side toward the posterior and is used to balance the shark

Pelvic Fin

Located on the ventral side toward the posterior end and also helps to maintain balance

Caudal Fin

Located on the posterior end and provides downward propulsion; “tail fin”

Pectoral Fin

Located on the ventral surface close to the anterior end and they counteract all downward propulsion by providing upward lift

Spiracle

Opening behind the eye that provides oxygenates blood directly tot hey eye and brain through separate blood vessels; ABSENT IN MANY FAST SWIMMMING SHARKS

Lateral Line System

Detects movement in the water; appears as a single groove with many pores along each side; responds to changes in pressure and vibrations

Gill Slits

Covers gills; allows water to exit after it passes over the gills

Ampullae of Lorenzini

Small vesicles and pores that form extensive sensory networks, found around the head, visible as dark spots; detects weak magnetic fields

Internal Anatomy of a Shark

Oily liver, Stomach, Esophagus, Spiral Intestine, Spiral Valve, Spleen, Heart (2 chambered→ Atrium: receives blood (ventricle: pumps blood)) gills→ oxygenates the blood, 5-7 pairs

How Do You Tell if the Shark is Male or Female

Males have claspers on the pelvic fins and females do not

Caudal Fin on Osteichthyes

provides propulsion

Anal Fin on Osteichthyes

Located on the ventral side in the most posterior posotion

Pectoral Fin on Osteichthyes

located on the sides (laterally) behind the operculum. Used for steering and breaking

Operculum

protective flap of tissue covering the gills

water enters the mouth, passes over the gills, and then exits through the operculum

pumps water out of the gills

Nares

“nostrils” usually 2 pairs

Peduncle

junction where the body meets the caudal fin

Swim bladder

Provides buoyancy by absorbing gas from the blood stream

Chondrichtheys

Immovable Fins

Cartilage Skeletons

Placoid Scales

Buoyancy from Oily Liver

Breathe by moving constantly

Gill slits cover the gills

5-7 pairs of gills

Osteichthyes

Movable Fins

Bone Skeletons

Cycloid Scales

Buoyancy from Swim Bladder

Breathe by Pumping Water over the Gills using the Operculum

4 pairs of Gills

Internal Fertilization

fertilization of the egg happens inside the female’s body

Advantage: more protected “parental care”

Disadvantage: less offspring

Energy Input: into “parental care”

External Fertilization

fertilization happens outside of the female’s body; females lay eggs and males spread sperm on them

Advantages: LOTS of offspring to make sure at least some survive

Disadvantages: little to no “parental care” so less survival

Energy Input: into the production of the numerous offspring