Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Sea turtle”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed1979

Ventilatory response to inspired CO2 in the sea turtle: effects of body size and temperature.

The ventilatory response of green turtles (Chelonia mydas) to inspired CO2 was tested. Both immature (0.9--1.35 kg) and adult (59--130 kg) animals responded with increased ventilation (VE) that was primarily (immature) or exclusively (adult) due to increased respiratory frequency. The VE of the immature turtles while breathing air increased with temperatures between 15 and 35 degrees C with a Q10 of 1.95, but the peak VE of these turtles while breathing 4.5% CO2 in air was not significantly different at 15, 25 or 35 degrees C. VE increased irregularly with time throughout an hour of CO2 breathing in both groups, although several of the adult animals exhibited a first-breath response to CO2 and all animals increased VE within 5 min after the onset of CO2 breathing. The VE of an immature turtle at 35 degrees C increased with graded increases in CO2 up to 6%, but at 15 and 25 degrees C VE increased only up to 4.5% and decreased with 6% CO2. The results are discussed in terms of possible receptor mechanisms involved.

Aging↗
PubMed1994

Investigating sea turtle migration using DNA markers.

The past year has seen a further marshaling of genetic evidence for 'natal homing' in several species of marine turtles, a phenomenon wherein females, upon reaching sexual maturity, exhibit a propensity to return to nest at or near the respective beaches upon which they hatched some two or more decades earlier. This genetics-based inference stems from the strong spatial patterning observed in mitochondrial DNA lineages among nesting sites. Rookery-specific mitochondrial DNA markers are now being employed to monitor the natal sources of individuals captured at other phases of the life cycle, and the genetic findings have important conservation ramifications.

Animals↗
PubMed2006

Sea turtles.

Explore the source record for details and available documents.

Animal Migration↗
PubMed1991

Ocular dimensions and schematic eyes of freshwater and sea turtles.

Measurements were made of the ocular dimensions from living and frozen eyes of one species of freshwater turtle, Pseudemys scripta elegans, and of three species of marine turtles, Chelonia mydas, Dermochelys cariacea, and Eretmochelys imbricata. Estimates of refractive error by retinoscopy were also obtained with eyes in air and under water. The results suggest that unaccommodated eyes of all four species are approximately emmetropic in air but strongly hyperopic in water. Schematic eyes were calculated for each species in both air and water.

Adaptation, Physiological↗
PubMed2004

Reproduction in shark-attacked sea turtles is supported by stress-reduction mechanisms.

Vertebrates exhibit varied behavioural and physiological tactics to promote reproductive success. We examined mechanisms that could enable female loggerhead turtles to undertake nesting activities and maintain seasonal reproduction despite recent shark injuries of varying severity. We proposed that endocrinal mechanisms that regulate both a turtle's stress response and reproductive ability are modified to promote successful and continued reproduction. Irrespective of the degree of injury, females did not exhibit increased levels of the stress hormone corticosterone, nor decreased levels of the reproductive steroid testosterone; hormone responses consistent with stress. When exposed to a capture stressor, females with shark injury did not exhibit any greater corticosterone response than controls. In addition, breeding females showed a reduced corticosterone stress response compared to non-breeding females. Reduced endocrinal responses following shark injury, and during breeding in general may, in part, enable females to maintain behavioural and physiological commitment to reproduction.

Analysis of Variance↗
PubMed2002

Unfolding of the loggerhead sea turtle (Caretta caretta) myoglobin: A (1)H-NMR and electronic absorbance study.

The effect of urea concentration on the backbone solution structure of the cyanide derivative of ferric Caretta caretta myoglobin (at pH 5.4) is reported. By addition of urea, sequential and long-range nuclear Overhauser effects (NOEs) are gradually lost. By using the residual NOE constraints to build the molecular model, a picture of the unfolding pathway was obtained. When the urea concentration is raised to 2.2 M, helices A and B appear largely disordered; helices C, D, and F loose structural constraints at 3.0 M urea. At urea concentration >6 M, the protein appears to be fully unfolded, including the GH hairpin and helix E stabilizing the prosthetic group. Reversible and cooperative denaturation isotherms obtained by following NOE peaks are considerably different from those obtained by monitoring electronic absorption changes. The reversible and cooperative urea-dependent folding-unfolding process of C. caretta myoglobin follows the minimum three-state mechanism N long left and right arrow X long left and right arrow D, where X represents a disordered globin structure (occurring at approximately 4 M urea) that still binds the heme.

Animals↗