Chordates and Fish

What is a chordate? Members of the KINGDOM ANIMALIA and the PHYLUM CHORDATA They have a dorsal, hollow nerve cord and a notocord

Chordates have ●pharyngeal pouches (become gills) ●Tail - extends beyond anus Most chordates are vertebrates (SUBPHYLUM VERTEBRATA)

Chordates that are NOT vertebrates: Sea Squirts or Tunicates

Lancelet

Chordate Anatomy

Consider this.... All vertebrates are chordates But not all chordates are vertebrates. NO WAY!!!!

What is a vertebrate? -Animals with a backbone (and endoskeleton) -Have spinal cord (dorsal, hollow nerve cord) -Front end of spinal cord develops a brain

Crash Course in Chordates - 12 minutes

Vertebrate Classes ● Jawless Fish (lamprey, hagfish) ● Cartilage Fish (sharks, rays…) ● Bony Fish (salmon, catfish, goldfish…) ● Amphibians (frogs, salamanders…) ● Reptiles (lizards, turtles…) ● Birds (sparrows, hawks…) ● Mammals (humans, whales, cats..)

What are Fish? * Anything with gills, scales, and fins… ● 1st Fish were jawless ● Devonian Period - "Age of Fishes” Fossil of a devonian fish with jaws and armored plates ch?v=n4h2UWPyYPM

Form & Function 1. Circulation

Fish have a two chambered heart – blood is passed over the gills where it picks up oxygen

2. Respiration ● Water passes over GILLS, oxygen is added ● Some fish have gill covers – OPERCULUM ● Some fish have special organs to serve as lungs (Lungfish)

3. Excretion ●Homeostasis: maintaining water balance ●Salt water fish tend to lose water ●Freshwater fish tend to gain water *This is why you can’t put a salt water fish in a fresh water tank *The salmon can do both

4. The Nervous System Response - Cerebrum - thinking, voluntary activities - Cerebellum - coordination - Medulla Oblongata - functions of internal organs - Lateral Line System - senses vibrations

Other Fish Adaptations A. Swim Bladder – maintains buoyancy (like a balloon) Sharks do not have a swim bladder, if they stop swimming, they sink.

B. FINS

C. SCALES Scales cover and protect the fish Mucus on scales help fish swim

5. Reproduction Spawning – fish lay eggs that are fertilized externally Some fish bear live young This 1 minute video shows a lemon shark give birth to live young. Some sharks lay eggs.

Salmon Video at National Geographic

TYPES OF FISH Jawless fish: lamprey and hagfish Lamprey is a parasite, it attaches to other fish and sucks their blood Hagfish is a scavenger, it lives in the ocean and is known for its slimy secretions

Cartilage Fish Kingdom Animalia, Phylum Chordata, Subphylum Vertebrata CLASS CHONDRICHTHYES Sharks and Rays

Manta Rays =yfgJx-ShRGI Flying Rays: =cqNxco4xcpI

SHARKS *The pectoral fins of sharks do not move * Sharks do not have an operculum or a swim bladder *sharks will sink if they stop swimming

Basking Shark is a filter feeder

Ninja Sharks!!!!!!!!!!!

BONY FISH Class OSTEICHTHYES Two types of bony fish Ray-Finned – have rays in their fins Lobe- Finned – have thick chunky fins

Is this picture real or fake?

Cichlids

Coelacanth: living fossil, lobe-finned

Clown Fish (Nemo)

Kissing Fish

Lion Fish

The puffer fish uses air to expand its body to look intimidating to predators

Snakehead Catfish

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