Anatomy and Function of Clams, Crayfish, Seastars, and Frogs

Anterior (clam)

towards the umbo (rounded bump near hinge)

Posterior (clam)

opposite the umbo

Valve (clam)

the shell itself; protection

Umbo (clam)

oldest part of the shell; near hinge

Adductor Muscle Scar (clam)

where muscles attach to close the shell

Mantle (clam)

secretes shell; lines inside of valves

Siphon (clam)

brings in and removes water

Gills (clam)

gas exchange and food filtering

Labial Palps (clam)

direct food to mouth

Visceral Mass (clam)

contains organs

Foot (clam)

movement and burrowing

Mouth (clam)

food intake

Stomach (clam)

digestion

Intestine (clam)

nutrient absorption

Anus (clam)

waste removal

Heart (clam)

pumps hemolymph

Cephalothorax (crayfish)

fused head + thorax

Abdomen (crayfish)

tail segment

Carapace (crayfish)

shell covering the cephalothorax

Antennae (crayfish)

long sensory structures

Eye (crayfish)

compound, for vision

Cheliped (crayfish)

claw (defense, catching food)

Pereiopods (crayfish)

locomotion

Pleopods (crayfish)

swimming/reproduction

Caudal/Tail Fin (crayfish)

fast backward movement

Heart (crayfish)

circulates hemolymph

Gills (crayfish)

gas exchange

Mouth (crayfish)

food intake

Mandible (crayfish)

jaw that crushes food

Maxillae (crayfish)

manipulate food

Esophagus (crayfish)

connects mouth to stomach

Stomach (crayfish)

includes gastric mill to grind food

Digestive Gland (crayfish)

enzyme secretion/digestion

Intestine (crayfish)

nutrient absorption

Anus (crayfish)

waste elimination

Oral side (sea star)

mouth side (facing substrate)

Aboral side (sea star)

opposite side (where madreporite is)

Central Disc (sea star)

center of body where arms/rays meet

Ray/Arm (sea star)

locomotion and feeding

Ambulacral Groove (sea star)

runs along each arm, contains tube feet

Tube Feet (sea star)

suction-powered feet for movement and grabbing food

Ampulla (sea star)

bulb that contracts to move tube feet

Madreporite (sea star)

pore that lets water into the water vascular system (on aboral side)

Ring Canal (sea star)

circular canal around central disc (connects radial canals)

Radial Canal (sea star)

extends through each arm, part of the water vascular system

Digestive Glands (seastar)

produce digestive enzymes

Gonads (sea star)

reproductive organs

Male (frog)

testes near kidneys; thumbs sometimes thickened

Female (frog)

large ovaries, oviducts, fat bodies more prominent

Axial Skeleton (frog)

cranium, vertebrae, urostyle, sacrum, sternum

Appendicular Skeleton (frog)

limbs, pelvic and pectoral girdles

Pectoral Girdle (frog)

shoulder area

Pelvic Girdle (frog)

hip area

Integument (frog)

skin (for respiration too)

Eyes (frog)

vision

Tympanic Membrane (frog)

hearing

Nostrils/Internal Nares (frog)

breathing

Mouth (frog)

food intake

Tongue (frog)

food manipulation

Stomach (frog)

digestion

Small Intestine (frog)

nutrient absorption

Large Intestine/Colon (frog)

waste processing

Cloaca (frog)

common exit for urine, feces, gametes

Liver (frog)

detox & bile

Gallbladder (frog)

bile storage

Pancreas (frog)

digestive enzymes

Trachea (frog)

air passage

Lungs (frog)

gas exchange

Heart (frog)

3 chambers: left & right atria, single ventricle

Truncus Arteriosus (frog)

major artery leaving heart

Anterior/Posterior Vena Cava (frog)

bring blood to heart

Kidneys. (frog)

filter blood

Ureters (frog)

tubes leading from kidneys to urinary bladder

Cloaca (frog)

common exit for urine, feces, gametes