Slide 1

Slide 2

What are fish? Aquatic vertebrates Most have Paired fins Scales Gills Wide range of characteristics Belong to different classes

Slide 3

Fish Evolution First fishes: armored bodies, no jaws Cambrian period (510 mya) 505 mya to 410 mya: Adaptive Radiation of fishes variation increased (no armor v. armor; jaws v. jawless)

Slide 4

Fish Evolution Jaw evolution and paired fins seem to have come about together Made out of bone or cartilage Paired fins More control during swimming Tail fins More muscle mass along trunk of body

Slide 5

Fish Evolution Fish evolved into two groups: Class Chondrichthyes Superclass Osteichthyes Lobe finned (Class Sarcopterygii) evolutionary links point to the lobe finned fish sharing a common ancestor with early amphibians Ray finned (Class Actinopterygii)

Slide 6

Orders of Bony Fish 1. Anguilliformes Order 2. Salmoniformes Order 3. Cypriniformes Order 4. Siluriformes Order 5. Perciformes Order Use your computers to research characteristics of one order (body layout, habitat, types of food eaten, modes of feeding, examples). You will present your findings to the class.

Slide 7

Fish Order: Body layout: Habitat Types of food eaten Modes of feeding Examples:

Slide 8

Fish Form and Function Adaptations for life in water Methods of feeding Gills Paired fins

Slide 9

Feeding Display all modes of feeding Herbivores, carnivores, omnivores, parasites, filter feeders, detritus feeders Depending on type of food available Some fish are highly specialized (barracuda - carnivore)

Slide 10

External Fish Anatomy Fins: Dorsal Pectoral Pelvic Anal Caudal

Slide 11

External Structures Fins steering, propulsion through water Lateral Line Operculum covers/protects gills Nares Nasal openings

Slide 12

Lateral Line Senses changes in the water Current Electrical Heat NO external ear Utilizes lateral line for detecting sound vibrations

Slide 13

Key: External Fish Anatomy Nares Eye Fins: Dorsal Pectoral Pelvic Anal Caudal Operculum Mouth Lateral Line

Slide 14

Skeletal System Consists of bone and cartilage Skull Vertebrae Ribs Rays within the fins

Slide 15

Skeletal System

Slide 16

Muscular System Tail and Trunk Muscle Myotomes blocks of muscle that run up and down the fishs body Separated by myosepta Jaw Fin

Slide 17

Digestive System Mouth Pharynx Esophagus Short, expandable (to enable swallowing of large food) Stomach Gastric glands Pyloric ceca Finger-like projections responsible for most digestion Liver and pancreas secrete enzymes to help with digestion Intestines majority of food absorption, length differs in herbivores a carnivores Gizzard

Slide 18

Digestive System

Slide 19

Digestive System Labeling -Mouth -Pharynx -Esophagus -Liver -Gall bladder -Intestine -Anus -Stomach

Slide 20

Respiratory System Gills on either side of the pharynx Made up of filaments Feathery structures with large number of capillaries for increased gas exchange Pull water in through the mouth, over the gills, out the openings on the side of the pharynx

Slide 21

Specialized Respiratory Systems Exception: Lungfish need to go to surface of water to fill air sac (lung) Oxygen poor water

Slide 22

Respiratory System Afferent blood vessels Efferent blood vessels Gills Operculum Heart Dorsal aorta Ventral aorta

Slide 23

Also, describe how fish breathe. What happens to the operculum? What is the purpose of afferent/efferent blood vessels?

Slide 24

Nervous System VERY simplified Brain 3 lobes Forebrain (smell) Midbrain (vision, learning, motor receptors) Hindbrain (medulla oblongata and cerebellum) Coordination Movement Balance Spinal cord serves rest of the body

Slide 25

Nervous System - Brain

Slide 26

Circulatory System Closed circulatory system Single loop around body 4 part heart: (but considered 2 chambered) Sinus venosus Atrium Ventricle Bulbus arteriosus

Slide 27

Circulatory System Blood Flow Sinus venosus receives unoxygenated blood from the body Valve at the end of the sinus venosus opens into the atrium Atrium has thick, muscular walls Atrium receives unoxygenated blood and pumps it into the ventricle Ventricle is the largest and most muscular chamber of the heart Ventricle fills with blood it constricts and forces the blood through the bulbus arteriosus

Slide 28

Circulatory System Blood Flow Bulbus arteriosus is a valve or series of valves that control blood flow out of the ventricle and into the ventral aorta. Blood passes through the bulbus arteriosus to the ventral aorta. From the ventral aorta, blood flows to the gill filaments, where it is oxygenated. Blood flows out of gills through the dorsal aorta and through the fishs body.

Slide 29

Label the heart of a fish Sinus venosus Atrium Ventricle Bulbus arteriosus Vein Ventral Aorta Also, draw in direction of blood flow.

Slide 30

Circulatory System Red blood cell production Spleen Kidney Bones

Slide 31

Blood Flow

Slide 32

Excretory System Release nitrogenous waste as ammonia Gills Kidneys filter blood to excrete liquid waste Kidneys allow fish to maintain salt balance Salt water fish Fresh water fish Cloaca

Slide 33

Reproduction External fertilization Oviparous completely separate from both parents Females release eggs into water Males release sperm Ovoviviparous One parent carries fertilized eggs until they hatch no direct connection to the parent (yolk sac is nourishment) Viviparous Carry fertilized eggs internally direct connection between mother and offspring (no yolk sac) Live birth Sharks

Slide 34

Slide 35

Growth and Development Fish are able to live independently when hatched Some species build nests, care for young for long periods of time Aquatic life minimal strain on organs, bone, muscle Can grow large Limits on circulatory system, brain function

Slide 36

Life Cycle of Bony Fish Egg Larval fish/Alevin Fry Juvenile Adult Spawning adult

Slide 37

Other Structures Swim Bladder Between the stomach and the spine Allows for buoyancy Fills with air to keep fish afloat If the fish does not have a swim bladder, they will sink if they stop swimming

Slide 38

Slide 39

You will need to sketch and label the following systems: External fish anatomy Respiratory system Reproductive system Digestive system Heart I expect these to be turned in with the dissection packet and questions.

Slide 40

Also You will be removing organs from your perch. Throughout the dissection I will be circulating to see which organ(s) we will save for future comparisons. You will be graded on the dissection as well as the post-dissection packet. I will collect 1 packet from each person The answers to the questions throughout the procedure should be on a separate sheet of paper these can be completed after the dissection Each group will receive a dissection grade.

Slide 41

Dissection of the Perch

Slide 42