Chapter IV. External Anatomy and Adaptive Radiation in Gnathostomes

Dogfish

Dogfish

Cartilaginous or elasmobranch fishes-cartilaginous skeleton and exposed gill slits

Chondrichthyes

Dogfish class

Spiny dogfish

Squalus suckleyi common name

fusiform/spindle-shaped

Squalus suckleyi- body shape

tiny scales/spine

Squalus suckleyi- skin texture

Lateral line

Squalus suckleyi- produce water vibrations

Myotomes

Squalus suckleyi- muscle segments

Rostrum

Squalus suckleyi- triangular and somewhat flattened

Present

Presnet/Absent: teeth of Squalus suckleyi

Olfactory sac, eyes, ears

Squalus suckleyi- 3 pairs of sensory organs

endolymphatic ducts

Squalus suckleyi. Internal ears connected with ______________

Gill slits

Squalus suckleyi - communicate with the pharynx

Spiracle

Squalus suckleyi- first gill slit, behind each eye

unpaired or median fins

Squalus suckleyi-fins found in median lines

Paired or lateral fins

Squalus suckleyi- found in ventral side of trunk

Caudal fin

Squalus suckleyi- asymmetrical type- heterocercal with a large dorsal lobe

Pectoral fins

Squalus suckleyi- fins behind the gill slits

Pelvic fins

Squalus suckleyi- fins found in the junction of trunk and tail

Clasper

Squalus suckleyi- present in males used for mating

Ceratotrichia

Squalus suckleyi- dermal fin rays

Cloacal aperture

Squalus suckleyi- Large opening between the bases of the pelvic fins

Chondrichthyes

Raja, Dasyatis, Torpedo- class

Anterior

Raja, Dasyatis, Torpedo- greatly flattened portion

Slender tail

Raja, Dasyatis, Torpedo-posterior portion

Pelacoid scales

Raja, Dasyatis, Torpedo- Skin texture

Median fins

Raja, Dasyatis, Torpedo- Much reduced fins

Paired fins

Raja, Dasyatis, Torpedo- Two small dorsal fins on the end of the tail

Pectoral fins

Raja, Dasyatis, Torpedo- Enormously, enlarged, forming the lateral trunk continuing along the sides of the head

Pelvic fins

Raja, Dasyatis, Torpedo- Fins smaller with two lobes

Claspers

Raja, Dasyatis, Torpedo- Present at males only

Head

Raja, Dasyatis, Torpedo- Greatly flattened and continuous with pectoral fins

Rostrum

Raja, Dasyatis, Torpedo- Head terminates in a pointed ________

Spiracles

Raja, Dasyatis, Torpedo- First gill slits-entrance of respiratory water

Mouth

Raja, Dasyatis, Torpedo- Bounded by tooth-bearing jaws

Nostrils

Raja, Dasyatis, Torpedo- Found in front of the mouth, with ear-shaped flaps

Nasofrontal process

Raja, Dasyatis, Torpedo- Flap with fringed posterior margins from nostril to mouth

Oronasal groove

Raja, Dasyatis, Torpedo- Deep groove covered by the nasofrontal process

Gill slits

Raja, Dasyatis, Torpedo- Have 5 pairs and it is posterior to the mouth

Anus

Raja, Dasyatis, Torpedo- Large opening between the bases of the pelvic fins

Ghost shark

Chimaera common name

Peculiar-looking fish

Chimaera body shape

Smooth, silvery skin

Chimaera skin texture

Pectoral and Pelvic fins

Chimaera, large reduced hinder body, usually tapering to a long slender tail

Chimaera- fleshy projection on the summit of the head of males

Opercular opening

Chimaera- slot infront of the pectoral fins

Opercular fold

Chimaera- covering the gills

Lateral line system

Chimaera- where lines of sensory organ which are usually evident on body and trunk

Lepisosteus

The gar pike

Ganoid

Lepisosteus scales

Mudpuppy

Necturus maculosus common name

naked and very slimy, without scales or other hardened parts such as are commonly found in vertebrates

Necturus maculosus- skin texture

Terminal mouth

Necturus maculosus- provided with lips and bears the usual three pairs of sense organs

Nostrils or external nares

Necturus maculosus- pair of widely separated openings just back of the upper lip

External gills

Necturus maculosus- fringe of filaments

Gular fold

Necturus maculosus- fold of skin

Common water monitor

Varanus salvator common name

Tokay gekko

Gecko gecko

Head spines or horns

Lizard- projections of the skull bones covered with a thin horny shell

Head shields

Lizards-used in identifying lizards and named after the undelying skull bones

Nictitating membrane

Lizards- third eyelid

Lizards- conspicuous ear

Pineal/Parietal eye

Lizard- third median eye

Gular fold

Lizards- also known as throat fold forming a fan or dewlap

Femoral pores

Lizards- inner surface of the male thighs- secret waxy material during copulation

Painted turtles

Chrysemys common name

Neck

Turtles- unusually long, flexible

Trunk

Turtles- encased in hard shell

Tail

Turtles- diminished in diameter and length

Large horny shields

Turtles- skin texture

Lateral bridges

Turtles- connect carapace and plastron

Flight feathers

large, stout feathers of the wings and tail

Coverts

Small feathers

Filoplumes

The delicacy of the skin

Feather follicles

Numerous deep pits

Beak

Upper and lower jaws of the chicken

Cere

Base of the upper beak, cushion-like protuberance

External auditory meatus

Found in chickens where it is a deep, narrow passage which leads to the middle ear

Remiges

Great flight feathers of the wings

Retrices

Large flight feathers of the tail stump

Uropygial gland

Oil for preening feathers

Vibrissae

Found in mammals; tactile organs also known as whiskers

Digtigrade

type of gaits- cat

Plantigride

Type of gaits in man

unguligrade

Type of gaits in horses

Perineum

Anus and urogenital opening

Penis

Organ of copulation