Plants for back system
Asparagus
 Apple tree
 Easter Egg Plant
 Dwarf pomegranate tree
 Golden apple tree
 Cucumber
 Butternut squash
 Flowering almond
 Eggplant

Lemon Tree
Strawberries
Grapes
Fig tree
Biology of Fish
Fish belong to the group Chordata
Includes around 52,000 species
including fish, mammals,
reptiles, etc.
Characteristics of Chordates

Chordates: named for the notochord structure
found in all chordate embryos.
◦ Notochord: flexible rod that extends through the
length of the body
Diversity of Fish
Fish were the 1st jawed vertebrates
 Make up 30,000 of the +52,000 species
of vertebrates
 Two main groups of fish:

1. Cartilaginous fish: skeleton made of
cartilage
•
•
Ex. sharks and rays
One class: Chondrichthyes
2. Bony fish: skeletons contain bone
hardened by calcium compounds


Ex. ray finned fish, coelacanths, and lungfish
Three classes: Actinopterygii, Actinistia, Dipnoi
Chondricthyes (Sharks, rays, and ratfishes)
850 species
• Bony skeleton replaced with
flexible cartilage for buoyancy
• no swim bladder
• exposed gill slits
• have well developed sensory
organs
•
Actinopterigii (ray-finned fish)
•
•
•
•
•
Flexible rays support fins
Operculum flap protects and ventilates gills
Air-filled swim bladder regulates buoyancy
Skin contains bony scales and lateral line pits
Most are oviparous (lay eggs) with external fertilization,
but many reproductive strategies can be found in this
group including hermaphrodites capable of cloning
themselves and species who give birth to live young
swim bladder
gills
operculum
lateral
line
Actinistia (lobe-finned fish)
•
•
•
Includes the coelacanth and tetrapod lineages
Thick muscles of pectoral and pelvic fins surround rodshaped bones
Coelacanths were thought to be extinct until 1938 when
they were discovered of the coast of east Africa. Since
then a second population has been found in Indonesia
Dipnoi (Lungfish)
Found only in Southern
Hemisphere
 Adaptation to Air Sac
that can function as
lungs during periods of
drought.
 Also have gills to obtain
oxygen from water.

What do fish need?

Clean Water: Good pH, low ammonia, no
harmful chemicals

Oxygen: Take in oxygen dissolved in water

Food: Need high amount of protein

Proper Temperature: Fish are cold-blooded, so
metabolism slows in cold temps

Proper Salinity: Depends on freshwater or
saltwater
Fish Anatomy
Lateral line: sensory organs running along the
body help sense changes in water pressure (feel
other animals)
 Gills: extract oxygen from the surrounding water
 Swim Bladder: aids in “hearing” for many fish
and transmits vibrations to sensory organs
(sharks use electromagnetic fields), the lungfish
use these as a respiratory organ to breath air
 Fins: swimming and defense

Fish External Anatomy - Fins
Fish External Anatomy - Fins

Caudal fin - used for forward propulsion of the fish.

Soft dorsal fin - may be used for forward propulsion
and as a rutter to change direction.

Spiny dorsal fin - used as a keel to maintain fish
balance and stay upright. Can be lowered to increase
streamlining of fish (increase swimming speed)

Pectoral fin - used for steering (braking and turning)
and may be used for forward propulsion.

Pelvic fin - prevents fish from floating upward when
fish brakes (with pectoral fins)

Anal fin - acts as a rudder for balance when turning,
may be used for forward propulsion.
Fish Internal Anatomy
What are the parts of the fish digestive system?
The digestive system is similar to other
animals.
 Size and shape of each component of the
system will vary with the type of fish and
its diet.
 Carnivores

◦ Fish that eats meat.
◦ Have a large stomach and short intestines.
What are the parts of the fish digestive system?

Parts include:
◦ Mouth
 Teeth
 Tongue
 Branchiospines
◦ Esophagus
◦ Stomach
◦ Intestines
◦ Anus
What are the parts of the fish digestive system?

Mouth
◦ Entry point of system.

Carnivores mouth
◦ Have many teeth that point
inwards.
◦ Not used for chewing.
◦ Used to capture and hold
prey.

Other fish
◦ Few or no teeth.
What are the parts of the fish digestive system?

Tongue
◦ Helps move food around in the
mouth.

Branchiospines
◦ Act as filters to capture small
food from water as the fish
swims.
◦ Part of the gill structure that
helps fish swim.

Esophagus
◦ Short tube that connects mouth
to stomach.
What are the parts of the fish digestive system?

Stomach
◦ Organ where digestion begins.
◦ Some stomachs will expand greatly.
 Allows them to eat large quantities of
food.
◦ Other stomachs are small that will
accommodate small amounts of food.
◦ Some fish have almost no stomach.
 Esophagus connects directly to
intestines.
What are the parts of the fish digestive system?
Intestines
◦ Site of food digestion and nutrient absorption.
 Anus
◦ Exterior opening of system.
◦ Unused food and wasted material is exited.

Nervous/Muscular System

Nervous System
Relatively simple system
 Central Nervous System
◦ Brain and Spinal Cord
 Peripheral Nervous System
◦ Cranial Nerves and Spinal Nerves

Muscular System
 Muscle segments in the shape of “W”
 Muscle is the edible part
of the fish

Circulatory/Respiratory System
Heart and Blood Vessels
 2 chambered heart: distributes O2 in the body
◦ Atria-collects blood from body
◦ Ventricle-sends blood to the gills
◦ Humans have a 4 chambered heart – fish need less 02
• Arteries: carry blood away
from the heart
• Veins carry blood back to
the heart
Gills
• Blood-filled membranes
that exchange oxygen and
carbon dioxide
• Like the lungs in a human
EXIT SLIP
Write Name and Date on Top of half sheet
 1. What is one difference between
Cartilaginous Fish and Bony Fish?
 2. What are the three groups of Bony
Fish?
 3. How does a fish’s heart differ from
humans?
 4. What type of Bony fish is a Tilapia?
 5. What organ allows a fish to stay
motionless in the water without sinking?
