The Biology of Amphibians Agnes Scott College Mark Mandica - PowerPoint PPT Presentation

The Biology of Amphibians Agnes Scott College Mark Mandica Executive Director The Amphibian Foundation mark@amphibianfoundation.org 678 379 TOAD (8623) Cryptobranchidae: Cryptobranchus alleganiensis

3.1 : Salamander Biology Ambystomatidae: Ambystoma tigrinum

salamanders posses tails in larval and adult forms most have limbs of equal size Salamandridae: Taricha rivularis

anatomy Plethodontidae: Plethodon cinereus

eye socket hindlimb rib hyoid tail forelimb vertebrae sacral vertebrae (1) skeletal anatomy Cryptobranchidae: Andrias japonicus

m = maxilla n = nasal pm = pre-max sph = sphenethmoid f-p = frontoparietal pro = prootic sq = squamosal eo = exoccipital q = quadrate qj = quadrato-jugal pt = pterygoid pal = palatine ps = parasphenoid sta = stapes skeletal anatomy

skeletal anatomy Proteidae: Necturus maculosus

skeletal anatomy Sirenidae: Siren lacertina

skeletal anatomy Ambystomatidae: Ambystoma tigrinum

hyoid apparatus An arrangement of bones and cartilage in the floor of the mouth and throat. skeletal anatomy Cryptobranchidae: Andrias japonicus

‘Hellbender’ exhibiting suction feeding by depressing the hyoid apparatus Functional morphology Cryptobranchidae: Cryptobranchus alleganiensis

Reproduction

Salamander Life Cycle

� � Sexual dimorphism in the cloaca of adult salamanders

S A L A M A N D E R R E P R O D U C T I O N F E M A L E S P I C K U P T H E S P E R M AT O P H O R E A N D F E R T I L I Z E T H E E G G S S P E R M AT O P H O R E S T H I S O N E H A S B E E N P I C K E D U P B Y A F E M A L E

S A L A M A N D E R R E P R O D U C T I O N E G G S A R E L A I D I N WAT E R O R O N L A N D D E P E N D I N G O N T H E S P E C I E S Ambystomatidae: Ambystoma maculatum Plethodontidae: Eurycea cirrigera

Ambystomatidae: Ambystoma maculatum

S A L A M A N D E R L A R VA E

PA E D O M O R P H O S I S R E T E N T I O N O F J U V E N I L E C H A R A C T E R I S T I C S I N T H E A D U LT F O R M M A N Y S A L A M A N D E R S P E C I E S A R E PA E D O M O R P H I C A N D D O N O T M E TA M O R P H O S E F U L LY ( O B L I G AT E ) . O T H E R S P E C I E S , L I K E T I G E R S A L A M A N D E R S , C A N B E PA E D O M O R P H I C I F T H E S I T UAT I O N I S S U I TA B L E A N D T H E N M E TA M O R P H O S E L AT E R I F N E C E S S A R Y ( FA C U LTAT I V E ) T H I S I S A N A D U LT M U D P U P PY ( N E C T U R U S M AC U L AT U S ) E V E N T H O U G H I T H A S J U V E N I L E S A L A M A N D E R C H A R A C T E R S L I K E A Q UAT I C ( F L AT ) TA I L A N D L A R G E E X T E R N A L G I L L S . T H I S A N I M A L C E A S E D D E V E LO P I N G P H Y S I O LO G I C A L LY ( S O M AT I C A L LY ) B U T C O N T I N U E D T O D E V E LO P S E X UA L LY. T H I S P R O C E S S I S C A L L E D N E OT E N Y .

I N T Y P I C A L D E V E LO P M E N T, A G I N G A N D M AT U R I T Y A R E S Y N C H R O N I Z E D . I N PA E D O M O R P H O S I S , T H E T W O P R O C E S S E S B E C O M E S E PA R AT E D . T H I S P H E N O M E N O N I S C A L L E D H E T E R O C H R O N Y . Paedomorphosis The result from either neoteny or progenesis

PA E D O M O R P H O S I S R E T E N T I O N O F J U V E N I L E C H A R A C T E R I S T I C S I N T H E A D U LT F O R M T H I S I S A N A D U LT M O L E S A L A M A N D E R ( A M B Y S T O M A TA L P O I D E U M ) E V E N T H O U G H I T H A S J U V E N I L E S A L A M A N D E R C H A R A C T E R S L I K E A Q UAT I C ( F L AT ) TA I L A N D L A R G E E X T E R N A L G I L L S . T H I S A N I M A L R E A C H E D S E X UA L M AT U R I T Y AT A M U C H E A R L I E R A G E T H A N M O S T M O L E S A L A M A N D E R S , W H I L E S T I L L I N L A R VA L F O R M . T H I S P R O C E S S I S C A L L E D P R O G E N E S I S .

PA E D O M O R P H O S I S R E T E N T I O N O F J U V E N I L E C H A R A C T E R I S T I C S I N T H E A D U LT F O R M T H I S I S A N A D U LT ( L E U C I S T I C ) A XO LO T L ( A M B Y S T O M A M E X I C A N U M ) E V E N T H O U G H I T H A S J U V E N I L E S A L A M A N D E R C H A R A C T E R S L I K E A Q UAT I C ( F L AT ) TA I L A N D L A R G E E X T E R N A L G I L L S .

Regeneration

Limb Regeneration Has been well documented in Axolotls and Firebelly Newts Ambystomatidae: Ambystoma mexicanum Salamandridae: Cynops sp.

Stages of Limb Regeneration Salamandridae: Cynops sp.