Journal
JOURNAL OF EXPERIMENTAL BIOLOGY
Volume 225, Issue 20, Pages -Publisher
COMPANY BIOLOGISTS LTD
DOI: 10.1242/jeb.244533
Keywords
Behavioral latency; Embryo behavior; Environmentally cued hatching; Information sampling; Ontogenetic adaptation; Phenotypic plasticity
Categories
Funding
- National Science Foundation [IOS-1354072, STRI-REU DBI-1359299]
- Boston University
- Smithsonian Tropical Research Institute
Ask authors/readers for more resources
Arboreal embryos of red-eyed treefrogs hatch prematurely in response to hypoxia and mechanosensory cues in snake attacks. However, hatching later improves tadpole survival. Risk assessment decreases as hatchling survival improves, and hatching performance increases as embryos develop. Snakes eat faster than embryos asphyxiate, leading to embryos deciding to hatch sooner and hatch faster in response to mechanosensory cues.
Arboreal embryos of red-eyed treefrogs, Agalychnis callidryas, hatch prematurely in response to hypoxia when flooded and to mechanosensory cues in snake attacks, but hatching later improves tadpole survival. We studied ontogenetic changes in risk assessment and hatching performance of embryos in response to flooding and physical disturbance. We hypothesized that risk assessment decreases as hatchling survival improves and hatching performance increases as embryos develop. Because snakes eat faster than embryos asphyxiate, we hypothesized that embryos decide to hatch sooner and hatch faster in response to mechanosensory cues. We video-recorded individual embryos hatching in response to each cue type, then compared the incidence and timing of a series of events and behaviors from cue onset to complete hatching across ages and stimuli. Latency from cue to hatching decreased developmentally in both contexts and was shorter with mechanosensory cues, but the elements contributing to those changes differed. Hypoxia assessment involved position changes, which decreased developmentally along with assessment time. Mechanosensory cue assessment occurred more rapidly, without movement, and decreased with age. The first stages of hatching, membrane rupture and head emergence, were surprisingly age independent but faster with mechanosensory cues, congruent with greater effort under more immediate risk. In contrast, body emergence and compression showed ontogenetic improvement consistent with morphological constraints but no cue effect. Both appropriate timing and effective performance of hatching are necessary for continued development. Different stages of the process vary with development and environmental context, suggesting combinations of adaptive context- and stage-dependent behavior, cue-related constraints on information acquisition, and ontogenetic constraints on elements of performance.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available