Life Sciences Commons^™

The Cost Of Hatching Early: Vulnerability And Exposure To Predators [Poster], M. S. Palmer, B. Willink, T. Landberg, James R. Vonesh, K. M. Warkentin

Biology Presentations

Arboreal red-eyed treefrog embryos can hatch prematurely in response to egg predators. Induced early hatchlings face aquatic predators when less developed and for longer than do later hatchlings; both factors may alter survival through the high-risk early larval period. Prior work focused on developmental effects of induced hatching. In 24 h trials, less developed hatchlings were more vulnerable to three aquatic predators (shrimp, fish, water bugs) but had similar or better survival than full-term hatchlings with libellulid and aeschnid dragonfly nymphs. However, it is unknown how developmental effects and duration of exposure to predators combine to create the net effect …

Habitat Use And Population Densities Of Rain Forest Chameleons In The East Usambara Mountains Of Tanzania [Poster], Philip Shirk, David A. Patrick, James R. Vonesh, Kim Howell

Biology Presentations

Conclusions:

• Chamaeleo dilepis and Ri. brevicaudatus are absent from forest at this elevation (852-1103m), while K. matschiei, K. vosseleri, K. tenuis, and R. spinosus are relatively scarce in the forest. Trioceros deremensis and R. temporalis are common, but density varies greatly.
• The endemic and scarce K. matschiei and K. vosseleri may be of concern given their scarcity in forest habitat. Density estimates in other habitat types are needed to determine status.
• For accurate density estimates, it is important to consider seasonal variation in density and animals too high to be observed in surveys.

Behavior And Development Of Red-Eyed Treefrogs During Metamorphosis [Poster], Robin Greene, Clay Noss, Tobias Lanberg, James R. Vonesh, Karen Warkentin

Biology Presentations

Anuran metamorphosis is an extreme transformation from tadpole to frog that involves tremendous morphological and behavioral change. During this transition (Gosner stages 42-46), metamorphs are exposed to both aquatic and terrestrial selective pressures (e.g., predators, desiccation). Their behavior may be crucial for survival, but it is not well studied. Our goal was to describe morphological and behavioral patterns during metamorphosis in red-eyed treefrogs, Agalychnis callidryas. We first quantified development through metamorphosis by measuring and staging 25 wild-caught individuals every 8 h. We then conducted field behavioral observations of 37 metamorphs, at various developmental stages, that had emerged from a …

An Intermediate In The Evolution Of Superfast Sonic Muscles., Hin-Kiu Mok, Eric Parmentier, Kuo-Hsun Chiu, Michael L. Fine

Biology Publications

Background

Intermediate forms in the evolution of new adaptations such as transitions from water to land and the evolution of flight are often poorly understood. Similarly, the evolution of superfast sonic muscles in fishes, often considered the fastest muscles in vertebrates, has been a mystery because slow bladder movement does not generate sound. Slow muscles that stretch the swimbladder and then produce sound during recoil have recently been discovered in ophidiiform fishes. Here we describe the disturbance call (produced when fish are held) and sonic mechanism in an unrelated perciform pearl perch (Glaucosomatidae) that represents an intermediate condition in the …

Effects Of Hatching Timing On Red-Eyed Treefrog Tadpoles: Relative Vulnerability Varies Among Predators But Not With Hatchling Age-Structure, Growth Varies With The Presence Of More Vulnerable Tadpoles [Poster], B. Willink, T. Landberg, James R. Vonesh, K. M. Warkentin

Biology Presentations

In Gamboa, Panama, undisturbed red-eyed treefrog embryos typically hatch at age 6 days, but they can hatch as early as 4 days if attacked by egg predators. Early hatchlings are less developed and more vulnerable to predatory shrimp and fish. Here we assess the effect of hatching timing on risk of predation by three common insects, with different foraging styles, that prey on red-eyed treefrog larvae. Further, we examine whether the consequences of hatching early vary with the presence of later-hatched tadpoles. We induced hatching at 4 and 6 days and exposed tadpoles to giant water bugs or aeshnid or …

Tadpole Density Changes The Relationship Of Red-Eyed Treefrog Morphology And Jumping Performance [Poster], Julie Charbonnier, T. Landberg

Biology Presentations

As organisms develop, increased body size is often accompanied by shape changes that alter the morphology–performance relationship. Animals with different growth histories may also have different shapes at similar body sizes. To investigate how larval growth history affects the morphology–performance relationship, we raised red-eyed treefrog tadpoles (Agalychnis callidryas) at three densities (5, 25 and 50 tadpoles per 400 L tank) and measured jump distance during metamorphosis. We predicted that tadpoles grown at low density would metamorphose into larger frogs with relatively longer legs than those grown at higher densities. We also expected low density frogs to jump further …