Phylum Chordata Subphylum Vertebrata Classes of FISH

CLASS AGNATHA DISTINGUISHING CHARACTERISTICS DISTINGUISHING CHARACTERISTICS NO JAWS NO JAWS NO SCALES NO SCALES NO PAIRED APPENDAGES NO PAIRED APPENDAGES

FEEDING AND DIGESTION (Lamprey = ectoparasite of fish) Circular sucking mouth (no jaw) Circular sucking mouth (no jaw) Teeth Teeth Rasping tongue Rasping tongue Cloaca = a single opening for the removal of urine, feces, and reproductive cells from the body. Cloaca = a single opening for the removal of urine, feces, and reproductive cells from the body. LAMPREY HAGFISH

CIRCULATION Two chambered heart Two chambered heart 1 Atrium + 1 Ventricle 1 Atrium + 1 Ventricle Single loop system Single loop system Ectothermic Ectothermic

RESPIRATION Gills Gills *True of ALL fish

Nervous System Smell = best sense Smell = best sense poor vision poor vision Internal ears (no external openings) Internal ears (no external openings) Touch Touch Taste Taste

Muscular/Skeletal Endoskeleton of Cartilage Endoskeleton of Cartilage No paired appendages = No fins. No paired appendages = No fins.

Reproduction External fertilization = egg and sperm unite in the water. External fertilization = egg and sperm unite in the water. Oviparous = egg lacks a shell; Must stay in the water or it will dry out. Oviparous = egg lacks a shell; Must stay in the water or it will dry out.

Lamprey eggs and baby

Class Chondrichthyes Examples = Sharks, Skates, Rays Distinguishing Characteristics * Skin covered with tiny tooth- like scales = Placoid scales (made from the same material as their teeth)

Dogfish Denticles

More placoid scales

FEEDING AND DIGESTION Jaws present, no chewing of food. Jaws present, no chewing of food. Rows of replacement teeth in jaw Rows of replacement teeth in jaw Cloaca present Cloaca present

Shark Stomach Stomach cut open

Shark Jaws

Circulation Same as Agnatha Same as Agnatha

Respiration Gills Gills Most sharks must swim continuously in order to move water over the gills. Most sharks must swim continuously in order to move water over the gills.

Nervous System Smell = #1 sense. Smell = #1 sense. Taste Taste Touch Touch Color vision Color vision Internal ears Internal ears

6th Sense (addition to the 5 basic senses) Lateral Line System = pits along side of body; detects vibration in the water Lateral Line System = pits along side of body; detects vibration in the water

Lateral Line

7 th Sense ElectroreceptionThe abitily to detect the electrical impulses given off by the nervous system of living things. Electroreception = The abitily to detect the electrical impulses given off by the nervous system of living things. Ampoules of Lorenzini

Muscular/Skeletal Endoskeleton of Cartilage Endoskeleton of Cartilage Paired appendages present= but do not move. Paired appendages present= but do not move.

Reproduction Internal fertilization in most sharks Internal fertilization in most sharks Some are oviparous Some are oviparous Others are ovoviviparous or viviparous Others are ovoviviparous or viviparous

Shark eggs

Skate egg cases

Viviparous Shark

Other Examples SKATES AND RAYS

CLASS OSTEICHTHYES (Largest vertebrate class) Examples = salmon, trout, goldfish, tuna, bluegills, bass, clown fish, sea horse, eel Distinguishing Characteristic: Skin covered with bone scales Skin covered with bone scales - scales grow with the fish - scales grow with the fish

Bony Fish Scales

Feeding and Digestion Jaws present with 1 set of teeth Jaws present with 1 set of teeth No chewing of food No chewing of food Cloaca Present Cloaca Present

Circulation Same as Agnatha and Chondrichthyes Same as Agnatha and Chondrichthyes

Respiration Gills protected by a bone covering = the Operculum = opens and closes to move water over the gills even if the fish is not swimming forward. Gills protected by a bone covering = the Operculum = opens and closes to move water over the gills even if the fish is not swimming forward.

Operculum OPERCULUM

OPERCULA

Nervous System Smell = #1 sense Smell = #1 sense Taste Taste Touch Touch Color vision Color vision Internal ears = hearing Internal ears = hearing Lateral line system present Lateral line system present

Muscular/Skeletal Endoskeleton of bone Endoskeleton of bone Pair pectoral and pelvic fins can move. Pair pectoral and pelvic fins can move.

Reproduction External fertilization = referred to as “spawning”. External fertilization = referred to as “spawning”. Most are oviparous Most are oviparous Some are ovoviviparous Some are ovoviviparous

Fish Eggs

Gravid Female Fish Egg Mass inside female

Other Characteristic All have a SWIM BLADDER = an air filled chamber that is used to control buoyancy in the water = won’t sink if they stop swimming! All have a SWIM BLADDER = an air filled chamber that is used to control buoyancy in the water = won’t sink if they stop swimming!

Swim Bladder