Amphibian Anatomy

The External Parts of a Frog Head Front Legs Fingers Palm Wrist Lower Arm Upper Arm Elbow Trunk Hind Legs Thigh Knee Ankle Sole Webbing Toes

The External Parts Functions The Frog body is divided into a head, a short neck and a trunk. The head contains a mouth, eyes, ears, nose, and, of course, a brain. Since their necks are so short they can’t move their heads much.

Salamander

Skeletal anatomy of a frog

The Internal Parts of a Frog Male Large Intestine Small Intestine Lung Lobes Liver Lobes Heart Stomach Gall Bladder Testis Fat body Urinary bladder Female Liver Lobes Heart Ovary with eggs Gall Bladder Small Intestine Stomach Oviduct

Digestive system The frog's digestive system starts in the mouth with its tongue. For the most part, frog tongues are attached near the back of the jaw and folded on the base of the mouth with the tip of the tongue pointing back toward its throat. Their tongues can be flipped out very rapidly and accurately in order to catch an insect. Most frogs do have tooth-like structures which are attached to the jaw and aid in breaking up the food so that it can be digested. The food then goes down their short esophagus into the stomach, where the food is digested. The waste goes into the coiled, winding intestines where it can be later removed.

Cardiovascular system They have a 3-chambered heart, arteries, veins, and lymphatics. A prominent ventral abdominal vein is present in amphibians -Amphibian hearts have 2 atria and one ventricle Some mixing of oxygenated and deoxygenated blood occurs in ventricle

Reparatory System They have four modalities of respiration: 1.- Branchial 2.- Boccopharyngeal 3.- Cutaneous 4.- Pulmonic Amphibian lungs are paired

Gas exchange occurs through lungs, gills, and/or the skin Some salamanders have no lungs (secondarily lost) Adults have double circulation Both a pulmonary and a systemic circuit

Excretory system The kidney of amphibians is mesonephric and empties into a urinary bladder. The urinary blader of some amphibians may be biolobate.

Reproductive system Amphibians have paired internal gonads that are hormonally regulated. The testes of the frog are collection of seminiferous tubules connected to the mesenteric by collecting ducts. The amphibian ovaries are located in proximity to the kidneys as seen in higher vertebrates. Eggs are funneled into the osteum of the oviduct and then passed to the cloaca

Gender Determination Most not sexually dimorphic -Size -Color Observe courtship Candling abdomen for eggs Swelling = repro active male salamanders observe the actual courtship - morphology and behavior. male’s vocal sacs become more prominent during breeding Xenopus leaves females have larger ventral flaps and a larger body than males Male Xenopus have black surfaces on the inner aspect of the forelimbs & larger digits during the breeding season. In bullfrogs the tympanic m. is = diameter as the eye female and in males 2x > eye. http://www.xlaevis.com/sexing.html 14

Gender Determination Females More rotund body shape http://www.telegraph.co.uk/

Gender Determination Males Caudata Crests, bright colors, tail swellings in some during breeding season Anura Vocal sacs, nuptial pads during breeding season http://www.xlaevis.com/sexing.html

Males are smaller than females

Resources Frog Biology - http://www.biology.about.com/science/biology/library/blfrogdissect.htm Frog Biology - http://library.thinkquest.org/11034/anat.htm Anatomy of Amphibians - http://www.lookd.com/frogs/anatomy.html Images - http://www-itg.lbl.gov/ITG/Whole.Frog/frog/frog.anatomy.html