Comparisons of Social Structure of Columbus Crabs Living on Loggerhead Sea Turtles and Inanimate Flotsam

1997 ◽  
Vol 77 (1) ◽  
pp. 185-194 ◽  
Author(s):  
Thomas Dellinger ◽  
John Davenport ◽  
Peter Wirtz
Keyword(s):  
Life History ◽  
Social Structure ◽  
Group Size ◽  
Sea Turtles ◽  
Caretta Caretta ◽  
Open Ocean ◽  
Life History Strategies ◽  
Loggerhead Sea Turtles ◽  
Loggerhead Turtles

Columbus crabs, Planes minutus (Crustacea: Brachyura) live in the open ocean attached to floating substrata including Sargassum, flotsam, and sea turtles. Eighty-two percent of 128 loggerhead turtles (Caretta caretta) checked, harboured a total of 172 crabs. Crabs inhabiting flotsam occurred in mixed sex groups of adults and juveniles, with a mean group size of 8.2 ±;11.8 (N=17). In contrast, crabs living on sea turtles around Madeira occur in smaller groups 1.6 ±0.5 (N=105) which are typically adult heterosexual pairs (61 out of 105). Crabs on turtles were bigger than on flotsam and a higher proportion of female crabs were brooding eggs. Columbus crabs exhibit different life history strategies depending on the substratum they inhabit.

scholarly journals Large-scale movement patterns of male loggerhead sea turtles (Caretta caretta) in Shark Bay, Australia

2012 ◽  
Vol 63 (11) ◽  
pp. 1108 ◽  
Author(s):  
Erica L. Olson ◽  
Anne K. Salomon ◽  
Aaron J. Wirsing ◽  
Michael R. Heithaus
Keyword(s):  
Breeding Season ◽  
Large Scale ◽  
Sea Turtles ◽  
Spatial Scales ◽  
Management Strategies ◽  
Caretta Caretta ◽  
Breeding Population ◽  
Loggerhead Sea Turtles ◽  
Shark Bay ◽  
Loggerhead Turtles

Large marine vertebrates are particularly susceptible to anthropogenic threats because they tend to be long-lived, late to mature and wide-ranging. Loggerhead sea turtles (Caretta caretta) are characterised by such life history traits and are listed as ‘Endangered’ by The World Conservation Union. Although juvenile movements and at-sea behaviour of adult females are relatively well studied, little is known about the movements of males and their subsequent exposure to threats. Shark Bay, Western Australia, is home to the largest breeding population of loggerhead turtles in Australia. We assessed the large-scale movements of nine adult male loggerhead turtles, with the goal of aiding conservation and management policies. During 7 months outside the breeding season, all nine turtles stayed within the Shark Bay World Heritage Area, with most showing fidelity to small coastal foraging areas. Several turtles, however, showed relatively large movements between core foraging areas. None of the four turtles that continued transmitting through the breeding season exhibited obvious movements towards nesting beaches, suggesting that mating may occur on foraging grounds or that males are not mating every year. Quantifying male loggerhead movements assists conservation planning by identifying biologically relevant spatial scales at which research and management strategies should be designed.

Hatch rates of loggerhead turtles and physical characteristics of the beach at Fethiye, Turkey

2003 ◽  
Vol 83 (1) ◽  
pp. 231-232 ◽  
Author(s):  
Oğuz Türkozan ◽  
Çetin Ilgaz ◽  
Ertan Taşkavak ◽  
Adem Özdemir
Keyword(s):  
Environmental Factors ◽  
Moisture Content ◽  
Incubation Time ◽  
Hatching Success ◽  
Sea Turtles ◽  
Caretta Caretta ◽  
Physical Characteristics ◽  
Loggerhead Sea Turtles ◽  
Loggerhead Turtles ◽  
Nest Depth

The relation of moisture content, temperature, nest depth, incubation, distance from sea and vegetation to hatching success of loggerhead sea turtles, Caretta caretta, in Turkey was studied. Nineteen randomly selected clutches were examined. Moisture was found to be negatively correlated with distance from the sea (P<0·05) but positively correlated with temperature (P<0·01). Temperature was negatively correlated with incubation time. Hatching success was not correlated with any of the environmental factors examined.

Sex ratio of hatchling loggerhead sea turtles: data and estimates from a 5-year study

1992 ◽  
Vol 70 (3) ◽  
pp. 530-538 ◽  
Author(s):  
N. Mrosovsky ◽  
Jane Provancha
Keyword(s):  
Global Warming ◽  
Sex Ratio ◽  
Sea Turtles ◽  
Sex Ratios ◽  
Caretta Caretta ◽  
Loggerhead Sea Turtles ◽  
Loggerhead Turtles ◽  
Biased Sex Ratio ◽  
Nesting Season

Hatchling loggerhead sea turtles (Caretta caretta) were collected over three nesting seasons from a rookery at Cape Canaveral, Florida. From data on the distribution of nests over the season, we estimated that 92.6–96.7, 94.7–99.9, and 87.0–89.0% of the hatchlings produced on this beach in 1986, 1987, and 1988, respectively, were females. These skewed sex ratios were consistent with the fact that for most of the season, sand temperatures were above the pivotal level for loggerhead turtles. The present results show that the female-biased sex ratio reported previously by these authors for the 1986 nesting season at this site was not an isolated, atypical event. In addition to a total of 3 years of sampling for sex ratio, measurements of beach temperatures at the depth of turtle nests were extended to cover 5 years. These temperatures were commonly above the pivotal level. The strongly female-biased hatchling sex ratio found in this population of loggerhead turtles poses theoretical challenges. It may also complicate conservation efforts, since global warming might be expected to skew the sex ratio still further toward females.

scholarly journals Tursiocola denysii sp. nov. (Bacillariophyta) from the neck skin of Loggerhead sea turtles (Caretta caretta)

Phytotaxa ◽  
2015 ◽  
Vol 234 (3) ◽  
pp. 227 ◽  
Author(s):  
Thomas Anthony Frankovich ◽  
Michael J. Sullivan ◽  
Nicole Indra Stacy
Keyword(s):  
Sea Turtles ◽  
Morphological Diversity ◽  
Caretta Caretta ◽  
Diatom Species ◽  
Loggerhead Sea Turtles ◽  
First Report ◽  
Loggerhead Turtles ◽  
First Time

Tursiocola denysii sp. nov. is described from the dorsal neck skin of loggerhead sea turtles (Caretta caretta), bringing the total number of known species in the genus Tursiocola to eight. A gradient of striae density on the valve face, the low length:width ratio of the valves, radiate striae at mid-valve, and a second partial row of pores on the valvocopulae are characteristics that expand the range of morphological diversity within the genus. The different morphology of the pars interior and the pars exterior of the valvocopula is described for the first time in the genus. T. denysii accounted for up to ca. 40% of all diatom valves on the skin of loggerhead turtles. This is the first report of a new epizoic diatom species from the skin of loggerhead sea turtles.

Sex ratio of loggerhead sea turtles hatching on a Florida beach

1989 ◽  
Vol 67 (10) ◽  
pp. 2533-2539 ◽  
Author(s):  
N. Mrosovsky ◽  
Jane Provancha
Keyword(s):  
Global Warming ◽  
Sex Ratio ◽  
Sea Turtles ◽  
Caretta Caretta ◽  
Loggerhead Sea Turtles ◽  
Histological Criteria ◽  
The Future ◽  
Loggerhead Turtles ◽  
Nesting Season

Hatchling loggerhead sea turtles (Caretta caretta) were collected over the summer nesting season from a major rookery at Cape Canaveral, Florida, in 1986. Sex was assessed using histological criteria. From data on the distribution of nests over the season, we estimated that in 1986, > 93% of the hatchlings produced on this beach were females. This huge bias toward females is consistent with sand temperatures at the depth of turtle nests; for most of the season these temperatures were above the pivotal level for loggerhead turtles. The results suggest that in the future, turtles in this area will encounter difficulty in overcoming the feminizing effect of global warming and that biologists should pay more attention to the beaches at the northern end of the loggerhead's nesting range.

Pharmacokinetics of Marbofloxacin in Loggerhead Sea Turtles (Caretta caretta) after Single Intravenous and Intramuscular Doses

2009 ◽  
Vol 40 (3) ◽  
pp. 501-507 ◽  
Author(s):  
Olimpia R. Lai ◽  
Pedro Marín ◽  
Pietro Laricchiuta ◽  
Giacomo Marzano ◽  
Giuseppe Crescenzo ◽  
...  
Keyword(s):  
Sea Turtles ◽  
Caretta Caretta ◽  
Loggerhead Sea Turtles
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