Herpetology: the Science of Tetrapods (BIOEE 470 and 472) - PowerPoint PPT Presentation

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Herpetology: the Science of Tetrapods (BIOEE 470 and 472) PowerPoint Presentation
Herpetology: the Science of Tetrapods (BIOEE 470 and 472)

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Herpetology: the Science of Tetrapods (BIOEE 470 and 472)

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  1. Herpetology: the Biology of Tetrapods (BIOEE 470 and 472) • See the Center for North American Herpetology (http://www.cnah.org) for undergrad summer internships, free publications, and much more of interest… Calling male leaf rog (Phyllomedusa sauvagii) Photo:H.W.Greene Course website: www.eeb.cornell.edu/herpetology/index.html

  2. Phylogenetic classification of living salamanders*… Urodela Sirenidae (2 genera/4 species) Neocaudata Cryptobranchoidea Cryptobranchidae (2/3) Hynobiidae (9/43) Salamandroidea* * Ambystomatidae (1/30) Amphiuma (1/3) Dicamptodontidae (1/4) Plethodontidae (27/360) Proteiidae (2/6) Rhyacotriton (1/4) Salamandridae (15/62) *salamanders, newts, etc. * * unresolved polytomy (Andrias japonicus, Cryptobranchidae, photo:A.Savitzky) (Pseudoeurycea bellii, Plethodontidae, photo:J.Sigala)

  3. More life history diversity… Direct development: • no aquatic larval stage • terrestrial eggs • many plethodontids Viviparity: • live birth of larvae or young • with or without maternal nutrition • only in a few Old World salamandrids Upper: Fire Salamander (Salamandra salamandra (Salamandridae, photo:H.W.Greene); lower, Alpine Black Salamander (S. atra, photo:M.H.Wake)

  4. Innovations in salamander social systems: Japanese Giant Salamander “den masters” • 90 nights of field work, 98 hrs of observations of nest A and 25 hrs of nest B, 103 salamanders were identified individually • A single extra large den master monopolized each nest, but up to 9 females and 17 other males visited his site • Females at a site ate the eggs of other females, and small males attempting to intrude on the nest site were sometimes eaten by the den masters • “All den masters aggressively guarded against attempts by the researchers to collect their eggs…” (T. Kawamichi and H. Ueda, 1998, J. Herpetology 32:133-136)

  5. More innovations in salamander social systems: sexual interference in ambystomatids and plethodontids • Male Spotted Salamanders (Ambystoma maculatum) place their spermatophores on top of those of other males in dense breeding aggregations • Some male Jordan’s Salamanders (Plethodon jordani) mimic a following female so that the lead male regards the intervening male as a female, and the intervening male then deposits a spermatophore in front of the real following female • More on this in an upcoming lecture by Kelly Zamudio

  6. Evolutionary innovations and trends in salamander feeding biology… • Larval and adult salamanders are carnivores • suction feeding (all larvae, cryptobranchids, proteiids) • simple tongue projection (e.g., ambystomatids, most salamandrids) • go see Steve Deban’s incredible feeding movies (www.autodax.net)—don’t miss them!! Spotted Salamander (Ambystoma maculatum, Ambystomatidae, photo:H.W.Greene)

  7. Specialized tongue projection (a few salamandrids, many plethodontids)… • Facilitated by lunglessness and direct development • Hyoid apparatus, skeletal elements freed from primitive roles in larval feeding and adult respiration • Subarcualis rectus and rectus cervicus: what are they? • Functional morphology: how does the whole system work? • Note groove along flank of salamander… and really, go to www.autodax.net Web-toed salamander (Hyrdromantes sp., Plethodontidae, photo:S.Deban)

  8. Diversity in the Salamandridae: Old World Newts • High diversity (13 genera, ca. 56 species; diverse morphology, ecology, behavior) • Dramatic seasonal changes in male external morphology • Diverse, even bizarre antipredator mechanisms (bright colors, skin toxins, spines) Asian newt (Tylototriton andersoni, photo:A.H.Savitzky)

  9. Diversity in the Salamandridae: New World Newts • Taricha (3 species) in the West, Notophthalmus (3 species) in the East • “Hyper complex” life cycle of the Eastern Red-spotted Newt Notopthalmus viridescens ••Aquatic eggs and larvae, terrestrial efts, aquatic adults ••Eft skin toxins, aposematic coloration, mimicry ••Adults, red efts, and mimics in your field guide • Can you see a parallel to the morphological complexities of the Notopthalmus life cycle with those of Taricha and Old World newts? Which is actually more complex?

  10. Salamandrid diversity: western North American newts (Taricha) • At least 3 species in western North America, sister taxon to Notopthalmus • Terrestriality, diurnal vulnerability and defense (tarichotoxin) • Male transformation for breeding season Rough-skinned Newts (T. granulosa, Salamandridae, photos:H.W.Greene

  11. Salamandrid diversity: western North American newts (Taricha) •Mass spawning •Environmental uncertainty and small clutch size California Newts (Taricha torosa, Salamandridae, top photo:M.K.Colbert, bottom photos:M.F.Benard)

  12. Salamandrid diversity: European Fire Salamanders (Salamandra salamandra) Males perch like lizards, ambush migrating females… Photos:W.Kästle

  13. Plethodontid diversity: ensatinas (Ensatina) • Terrestrial vulnerability and defense • Terrestrial courtship and seasonality of activity • Direct development and parental care • Escaping environmental uncertainty Ensatina eschescholtzi (Plethodontidae, photos:H.Greene)

  14. Salamander diversity: some exceptional plethodontids… Arboreal Salamander (Plethodontiade, Aneides lugubris) • Climbs, jumps and bites • Terrestrial direct development Photos:H.Greene

  15. Salamander diversity, another exceptional plethodontid: Spring Salamander (Gyrinophilus porphyriticus) • Burrows among rocks and gravel in streams • Larvae grow quite large before metamorphosis • Adult weighs ≥20 g (2 pens)! • Eats dusky salamanders (Desmognathus) • Locally common! Photo:H.Greene