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- Title
- EVIDENCE FOR THE INDEPENDENT EVOLUTION OF VISUAL PERCEPTION DURING SEAFINDING BY HATCHLING LEATHERBACK SEA TURTLES (DERMOCHELYS CORIACEA).
- Creator
- Trail, Samantha E., Salmon, Michael, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Hatchling marine turtles exhibit a positive phototaxis by crawling toward the lowest and brightest horizon when they emerge from nests on the beach at night, which should lead them to the ocean (“seafinding”). Previous research with cheloniid (loggerhead and green turtle) hatchlings demonstrated that the perceptual spectral sensitivities are well below the light available on the beach regardless of lunar phase. The goal of this research was to determine the perceptual spectral sensitivities...
Show moreHatchling marine turtles exhibit a positive phototaxis by crawling toward the lowest and brightest horizon when they emerge from nests on the beach at night, which should lead them to the ocean (“seafinding”). Previous research with cheloniid (loggerhead and green turtle) hatchlings demonstrated that the perceptual spectral sensitivities are well below the light available on the beach regardless of lunar phase. The goal of this research was to determine the perceptual spectral sensitivities of leatherback hatchlings, the most distantly related of all extant sea turtle species. This study revealed that, like cheloniids, leatherbacks are most sensitive to shorter wavelengths (< 500 nm). However, leatherbacks were 10 – 100x less sensitive than cheloniids at all tested wavelengths. This difference in sensitivity corresponds with increased crawl duration and circling behavior under new moon conditions when light levels are lowest and the difference in radiance between the landward and seaward direction is small.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013790
- Subject Headings
- Leatherback turtle, Dermochelys coriacea, Phototaxis, Spectral sensitivity
- Format
- Document (PDF)
- Title
- Visual spectral sensitivity of loggerhead (Caretta caretta L.) and leatherback (Dermochelys coriacea L.) hatchlings: A comparative study.
- Creator
- Gocke, Judith P., Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
In the ocean, lighting varies with habitat; the eye's spectral sensitivity must vary with visual ecology. Green turtles are the only sea turtle whose spectral sensitivity has been studied. Loggerheads and leatherbacks see visible light between 340 and 700 nm. However, the wavelengths detected with the greatest sensitivity by both species are those best transmitted at the specific depths where food, mates and predators are likely to be encountered. Both species have trichromatic vision, but...
Show moreIn the ocean, lighting varies with habitat; the eye's spectral sensitivity must vary with visual ecology. Green turtles are the only sea turtle whose spectral sensitivity has been studied. Loggerheads and leatherbacks see visible light between 340 and 700 nm. However, the wavelengths detected with the greatest sensitivity by both species are those best transmitted at the specific depths where food, mates and predators are likely to be encountered. Both species have trichromatic vision, but the species differ in the concentration and peak sensitivity of each visual pigment resulting in either a broadly tuned (loggerhead) or finely tuned (leatherback) spectral sensitivity. Spectral sensitivity of leatherbacks overlaps both bioluminescence of prey, and light available in clear, deep, oceanic waters.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13029
- Subject Headings
- Loggerhead turtle, Leatherback turtle, Spectral sensitivity
- Format
- Document (PDF)
- Title
- How leatherback hatchlings recognize their prey: Sensory predispositions and behavioral responses.
- Creator
- Constantino, Maricela Alcantara., Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
Leatherback sea turtles (Dermochelys coriacea) feed exclusively on gelatinous prey. Hatchlings are solitary and must possess a predisposition to respond to prey. In laboratory experiments, I studied the responses of nineteen leatherback hatchlings to visual (jellyfish model and shapes: circle, square, diamond) and chemical (homogenates of three prey) stimuli presented alone or as paired (visual + chemical) treatments once daily. When presented alone visual stimuli resembling jellyfish...
Show moreLeatherback sea turtles (Dermochelys coriacea) feed exclusively on gelatinous prey. Hatchlings are solitary and must possess a predisposition to respond to prey. In laboratory experiments, I studied the responses of nineteen leatherback hatchlings to visual (jellyfish model and shapes: circle, square, diamond) and chemical (homogenates of three prey) stimuli presented alone or as paired (visual + chemical) treatments once daily. When presented alone visual stimuli resembling jellyfish outlines elicited stronger feeding responses (changes in locomotion and orientation) than those not resembling jellyfish. Chemical stimuli alone induced a rheotaxis, but responses evoked by some homogenates were stronger than responses to others. Paired stimuli evoked stronger orientation and more consistent increases in swimming (flipper stroke) rate, indicating additive effects. Results suggest that both stimuli elicit food searching behavior and when they begin to forage, hatchlings already possess predispositions to respond to an adaptive array of prey shapes and odors.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12873
- Subject Headings
- Leatherback turtle, Predation (Biology)
- Format
- Document (PDF)
