FISH FISH
Agnatha = Jawless fish Lampreys Hagfish
Chondrichthyes= Cartilage fish Sharks Rays Skates
Taxonomy Osteichthyes = bony fish soft rayed spiney rayed
BIOLOGY
Fins supported by rays two types of rays soft spines
Fin Identification unpaired fins paired fins dorsal caudal anal pectoral pelvic
Skin epidermis dermis hypodermis mucous glands alarm cells cuticle scales hypodermis
Scales placoid ganoid cycloid ctenoid absent
Lateral line sensory system a line of pores lead to mechanoreceptors environmental information pressure, currents, sound
Color cells control chromatophores iridophores endocrine system pigments iridophores reflective substances control endocrine system nervous system
Anatomy overview
Respiratory system lungs gills bilateral operculum
Gill structure gill arches primary lamellae (filaments) secondary lamellae
Cardiovascular system 2 chamber heart atrium ventricle sinus venosus bulbus arteriosus
Circulation venous blood to heart heart to gills gills to body hepatic portal system renal portal system heart to gills via ventral aorta gills to body via dorsal aorta
Red blood cells elliptical and nucleated no bone marrow main source head kidney
White blood cells Similar to mammalian no lymph nodes or GALT lymphocytes > neutrophils lymphoid tissues thymus head kidney spleen melanomacrophage centers
Excretory system gills kidneys anterior kidney posterior kidney
Osmoregulation electrolyte balance freshwater vs saltwater
Osmoregulation freshwater fish saltwater fish water diffuses in ions diffuse out drink little lots of dilute urine actively reabsorb ions kidneys gills saltwater fish water diffuses out ions diffuse in drink a lot concentrated urine actively excrete ions kidneys gills gut
Swim bladder Two types functions physoclistic physostomatous buoyancy capillary network physostomatous pneumatic duct functions buoyancy sound, pressure detection
Digestive system Stomach intestine liver pancreas pyloric middle rectal spiral colon pyloric cecae liver pancreas
Nutrition Species variation general fish nutrition food feeding behavior time location obtaining food general fish nutrition protein and lipids > carbohydrates
Neuroendocrine system brain forebrain olfactory bulbs midbrain optic lobes cerebellum spinal cord
Electrical system electric organs electroreceptors examples electric eel electric catfish electric ray
Biolumination self -luminous photophores luciferase symbiotic bacteria