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Integument. Integument. Ecdysis Frequent when growing Requires humidity/bathing Piece-meal in chelonia & lizards One-piece in healthy snakes. Important for Behavior, thermoregulation, sensory detection, protection, water/gas exchange. Waterproof Skin.
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Integument • Ecdysis • Frequent when growing • Requires humidity/bathing • Piece-meal in chelonia & lizards • One-piece in healthy snakes • Important for • Behavior, thermoregulation, sensory detection, protection, water/gas exchange
Waterproof Skin • dry body covering of horny scales or plates • develops as surface cells fill w/ keratin - same stuff as bird feathers and fingernails • prevent water loss • protect from wear and tear associated w/ living in rugged terrestrial environments • unlike amphibians who can’t be far from water or they’ll dry out
Acellular keratinized layer Stratum corneum Intermediate Zone Stratum germinativum Dermis Integument
Integument Integument
Gastro-intestinal • No mandibular symphysis, flexible rami-snake • All teeth shed-snake • Esophageal papillae-sea turtles
Gastrointestinal • Herbivorous vs. carnivorous • Liver-melanin • Most-gallbladders • Some use variety of bile acids (3alpha) • Some lack biliverdin reductase • Pancreas • Splenopancreas
Excretion • conserve water by excreting nitrogenous wastes in dry or pasty form as crystals of uric acid
Respiratory • Gular flap-crocs • Trachea • Closed rings in chelonia & crocs • Open rings in squamata • Lungs • Position: cranial-lizards, dorsal-chelonia, 12-50% snakes • Paired in chelonia, crocs, lizards & boids • Right only in most snakes
Urinary • Paired kidneys • Caudodorsal coelom or intrapelvic • Close to gonads • Renal portal sys • Bladder • May be absent
Genital • Gender • Dimorphism • Ventral pores • Conformation • Hemipenes
Lizards- Sex Determination • Leopard gecko showing pre-anal pores found only in the male. Many other geckoes exhibit similar dimorphism • This male gecko has hemipenal bulges on the ventral tail base, below the cloacal opening, that are seen in most mature male lizards. The femoral pores, located on the ventral midline of the rear legs, are relatively larger than those of the female
Bearded Dragon • Male • Female
Lizards • Many lizards are sexed by their dimorphic appearance. Old World chameleons such as this Pardalis chameleon are characterized by brightly colored and larger males • This female Pardalis chameleon is much smaller and duller than the male.
Turtles • Male turtles, such as this ornate box turtle, have longer tails, with the cloacal opening more distally located than that of females. Males tend to have a more concave plastron (bottom shell) than females, which tend to have an almost flat plastron • This female box turtle has a shorter tail with the cloacal opening close to the shell
Genital In males the probe advances farther than in females
Genital • Ovaries • Oviducts • Testes (internal) • Hemipenes/penis • Internal fertilization • Oviparous • Incubation • Viviparous
The allantois stores the nitrogenous wastes produced by the embryo until the egg hatches an egg with a protective membrane and a porous shell enclosing the developing embryo. -It forms a “nursery” to protect the embryo They yolk sac encloses the yolk, a protein rich food supply for the developing embryo Amniote Egg
The chorion lines the outer shell and thus encloses the embryo and all the other membranes. It regulates the exchange of oxygen and carbon dioxide between the egg and the outside environment. • The entire amniote egg is surrounded by a leathery shell that may be hard in some species because of the presence of calcium carbonate. -The egg is water proof, however it allows gases to flow between the environment and the chorion. • The male places the sperm inside the female before the shell is formed. This is called internal fertilization, makes water transport of sperm unnecessary.
