Incubation Temperature Influences Sex and Hatchling Size in the Neotropical Turtle Podocnemis unifilis

1994 ◽  
Vol 28 (4) ◽  
pp. 453 ◽  
Author(s):  
Roselis Remor de Souza ◽  
Richard C. Vogt
2020 ◽  
Author(s):  
Hong-Liang Lu ◽  
Yan-Fu Qu ◽  
Hong Li ◽  
Xiang Ji

Abstract Phenotypic plasticity and local adaptation are viewed as the main factors that result in between-population variation in phenotypic traits, but contributions of these factors to phenotypic variation vary between traits and between species and have only been explored in a few species of reptiles. Here, we incubated eggs of the Chinese skink (Plestiodon chinensis) from 7 geographically separated populations in Southeast China at 3 constant temperatures (24, 28, and 32 °C) to evaluate the combined effects of clutch origin, source population, and incubation temperature on hatchling traits. The relative importance of these factors varied between traits. Nearly all examined hatchling traits, including body mass, snout–vent length (SVL), tail length, head size, limb length, tympanum diameter, and locomotor speed, varied among populations and were affected by incubation temperature. Measures for hatchling size (body mass and SVL) varied considerably among clutches. Source population explained much of the variation in hatchling body mass, whereas incubation temperature explained much of the variation in other examined traits. Our results indicate that between-population variation in hatchling traits of P. chinensis likely reflects the difference in natural incubation conditions and genetic divergence.


2004 ◽  
Vol 263 (1) ◽  
pp. 77-87 ◽  
Author(s):  
Nicola J. Nelson ◽  
Michael B. Thompson ◽  
Shirley Pledger ◽  
Susan N. Keall ◽  
Charles H. Daugherty

2001 ◽  
Vol 49 (4) ◽  
pp. 389 ◽  
Author(s):  
David T. Booth ◽  
Katherine Astill

Eggs from the Heron Island, Great Barrier Reef, nesting population of green turtles (Chelonia mydas) were incubated at all-male-determining (26˚C) and all-female-determining (30˚C) temperatures. Oxygen consumption and embryonic growth were monitored throughout incubation, and hatchling masses and body dimensions were measured from both temperatures. Eggs hatched after 79 and 53 days incubation at 26˚C and 30˚C respectively. Oxygen consumption at both temperatures increased to a peak several days before hatching, a pattern typical of turtle embryos, and the rate of oxygen was higher at 30˚C than 26˚C. The total amount of energy consumed during incubation, and hatchling dimensions, were similar at both temperatures, but hatchlings from 26˚C had larger mass, larger yolk-free mass and smaller residual yolks than hatchlings from 30˚C. Because of the difference in mass of hatchlings, hatchlings from 30˚C had a higher production cost.


2014 ◽  
Vol 98 (4) ◽  
pp. 1151-1161 ◽  
Author(s):  
Takeshi Kikko ◽  
Takahiro Usuki ◽  
Daisuke Ishizaki ◽  
Yoshiaki Kai ◽  
Yasuhiro Fujioka

2003 ◽  
Vol 53 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Lu Shou ◽  
Wei-Guo Du ◽  
Ji-Ke Liu

AbstractEggs of the skink, Eumeces elegans were incubated at 24, 27, 30 and 33°C to assess the effect of temperature on hatchling traits and embryonic use of energy. The mean incubation periods of eggs incubated at 24, 27, 30 and 33°C were 44.1, 28.0, 23.6 and 20.0 days, respectively. The mortality of embryos incubated at these temperatures did not differ significantly. The mean snoutvent lengths of hatchlings from 30 and 33°C were smaller than those of hatchlings from 24°C. In contrast, the body masses of hatchlings were not affected by temperature. Incubation temperature can also modify limb lengths of hatchlings. The fore and hind limb lengths of hatchlings from 24°C were longer than those of hatchlings from 33°C. However, tail length and head size (length and width) for hatchlings from different temperatures were similar. The locomotor capacity of hatchlings incubated at 33°C was completely destroyed, whereas that of hatchlings from the other three temperatures did not differ significantly in spite of the existence of differences in hatchling size. Moreover, incubation temperature affected the allocation of energy between carcass and yolk sac in the hatchling, although the overall conversion of energy from eggs to hatchlings was not influenced by temperature. Hatchlings from 30 and 33°C had a less developed carcass and more energy in yolk sac than those from 24°C. Thus, we can conclude that 33°C is not suitable for the incubation of E. elegans eggs, due to damage to the embryo.


2004 ◽  
Vol 55 (4) ◽  
pp. 387 ◽  
Author(s):  
G. T. Pecl ◽  
M. A. Steer ◽  
K. E. Hodgson

Cephalopods are characterised by extreme variability in size-at-age, with much of this variation attributed to effects of temperature and food. However, even siblings reared under identical conditions display a wide range of sizes after a period of growth. Hatchling size may represent a source of variation encompassed within adult size-at-age data (i) within a given cohort (variation in hatchling size suggests that a cohort’s growth trajectory will have a ‘staggered start’) and (ii) as hatchling size also varies as a function of incubation temperature this will vary across broader scales (i.e. between cohorts). Field-hatchling size data for Sepioteuthis australis were used in simple deterministic simulations, extending Forsythe’s (1993) temperature hypothesis, to investigate the influence of hatchling size on adult size-at-age variability. Within a cohort, our growth projections suggest that after 90 days, a large hatchling growing at a specific constant percentage daily growth rate (%BW day–1), would be approximately double the size of the small hatchling growing at exactly the same rate, irrespective of the growth rate used. When considering growth of different cohorts, decreases in hatchling size, as temperatures increase during a spring/summer spawning season, may be partially counteracting the ‘Forsythe-effect’ of increased growth rate at higher temperatures.


Planta Medica ◽  
2015 ◽  
Vol 81 (16) ◽  
Author(s):  
YA Jeon ◽  
HS Lee ◽  
ES Park ◽  
YY Lee ◽  
JS Sung ◽  
...  

2020 ◽  
Vol 3 (1) ◽  
pp. ACCEPTED
Author(s):  
Rho-Jeong Rae

This study investigated the boreal digging frog, Kaloula borealis, to determine the egg hatching period and whether the hatching period is affected by incubation temperature. The results of this study showed that all the eggs hatched within 48 h after spawning, with 28.1% (±10.8, n=52) hatching within 24 h and 99.9% (±0.23, n=49) within 48 h after spawning. A significant difference was noted in the mean hatching proportion of tadpoles at different water temperatures. The mean hatching rates between 15 and 24 h after spawning was higher at a water temperature of 21.1 (±0.2) °C than at 24.1 (±0.2) °C. These results suggest that incubation temperature affected the early life stages of the boreal digging frog, since they spawn in ponds or puddles that form during the rainy season.


2011 ◽  
Vol 4 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Ritwik Dasgupta

The facts that small hatchlings emerged from small eggs laid under high predation levels prevailing at the lower altitudes of distribution of this species in Darjeeling while larger hatchlings emerged from larger eggs laid under lower levels of predation at higher altitudes, show that predation is not selected for large egg and initial hatchling size in this salamandrid species. Metamorphic size was small under high predation rates because this species relied on crypsis for evading predators. Egg and hatchling size are related inversely to levels of primary productivity and zooplankton abundance in lentic habitats. Hatchling sizes are related positively to egg size and size frequency distribution of zooplankton. Small egg and small hatchling size have been selected for at the lower altitudes of distribution of this salamandrid in Darjeeling because predation rates increased in step with improvement in trophic conditions at the lower altitudes.


2008 ◽  
Vol 2 (1) ◽  
pp. 63-75
Author(s):  
Augusto Fachín Terán ◽  
Eduardo Matheus Von Mülhen

In this study the nesting biology of Podocnem is unifilis was investigated from July to November 1998 at the Mamirauá Sustainable Development Reserve, located in the Solimões river, near Tefé, Amazonas, Brazil. Podocnemis unifilis nested in August and September, with the hatching event occurring in October and November. Nests were excavated in clay soils (67.5%), sand (25%), and leaf litter (7.5%). Hatching success was highest in the sand beach nests and lowest in the clay banks nests. Humans and the tegu lizard (Tupinambis) were the main egg predators. This turtle population can recover only by the protection of nesting beaches, educational programs for the in habitants of the Reserve, participation of the community in the conservation and management program , and permanent guarding of the nesting beaches by Instituto Brasileiro do Meio Ambiente e Dos Recursos Naturais Renováveis-IBAMA authorities.


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