Phylum Chordata Fish

Subphylum Vertebrata: Vertebrae surround nerve cord and serves as a primary support; skeleton modified into a skull for protection of the brain. This group includes fish, amphibians, reptiles, birds, and mammals Notocord is replaced by a vertebral column.

Superclass Agnatha: lack jaws and paired appendages; cartilaginous skeleton; persistent notochord Pouch lamprey, hagfish, and lamprey eel

Other General Characteristics - aquatic, scales, fins, and pharyngeal slits Nervous system: well developed with brain and spinal cord Control smell, sight, body movement Vertebral column for protection Chemoreceptors Closed circulatory system –Heart ->ventricle->Aorta-> gills

Excretory: Kidneys remove ammonia Respiration: Gills: water in mouth, through gills, and out through gill slits- exchange Oxygen and CO2 Some use lungs Swim bladder- open space in fish to regulate buoyancy

Feeding: Herbivores, carnivores, filter feeders, detritivores, parasites Pathway: Mouth->Esophagus->Stomach-> pyloric ceca->intestines- >anus Reproduction: dioecious Oviparous: lay eggs, external fertilization Oviviparous: young develop in mom, but are not nourished by mom Viviparous- bare live young, nurtured by mom

Classes of Fish ***Correction! A: Myxini- Hagfish B. Chondrichthyes- Cartilagenous fish and sharks C. Osteichthyes- bony fish , 40 % of all vertebrates are bony fish D. Petromyzontida- lampreys

Classes of Fish You will summarize the characteristics of the different classes of Fish providing the following information: For CLASSES MYXINI,PETROMYZONTIDA, SARCOPTERYGII 1) EXAMPLES 2)MOUTH CHARACTERISTICS 3)OLFACTORY SACS 4)PHARYNGEAL SLITS (HOW MANY ? 1 OR MORE OPENINGS? 5)FEEDING HABITS

For classes Chondrichthyes and Actinopterygii Examples Digestion Respiration Skin Skeletal system Circulatory system Swim bladder? Movement (fins present and what kind?) Reproduction methods

Sucking mouth with teeth and rasping tongue Characterisitics Class Myxini Class Petromyzontida Examples Hagfishes Lampreys Mouth 4 pairs of tentacles Sucking mouth with teeth and rasping tongue Olfactory sacs Open to mouth Blind sacs Pharyngeal slits 5-15 pairs; one opening 7 pairs; separate openings Feeding Scavenge dead or dying fish; produce copious slime Parasitic or predatory; feed mainly on blood

Characterisitics Chondrichthyes Osteichthyes Examples Sharks, skates, rays All bony fish Digestion Complete, lack pyloric cecum, have a cloaca (a common opening for the reproductive, excretory and digestive systems) Complete, have a pyloric cecum (used to increase absorption in the intestine) Respiration Gills Gills covered by an operculum (helps pump water across the gills) Skin Covered by placoid scales (feel sandpapery) Covered by cycloid or ctenoid scales Skeleton Cartilage endoskeleton Bony endoskeleton Circulation Closed, two chambered heart; 1-loop (from heart past gills to the rest of the body and back to the heart) Closed, two chambered heart; 1-loop

Ectothermic Lacking Present Movement Swim bladder (gas filled sacs that regulate buoyancy) Lacking Typically present Temperature regulation Ectothermic Lateral line system (used to detect movement in the water) Present Movement Paired fins (used for more precise steering and increase agility), heterocercal tail Paired fins, homocercal tail Reproduction Dieocious, internal fertilization, ovoviviparous, males have modified pelvic fins called claspers Dieocious, variable fert.; some are oviparous, some are ovoviviparous