scholarly journals Embryonic temperature influences juvenile temperature choice and growth rate in snapping turtles Chelydra serpentina.

1998 ◽  
Vol 201 (3) ◽  
pp. 439-449
Author(s):  
S O'Steen

Snapping turtles (Chelydra serpentina) demonstrate temperature-dependent sex determination (TSD): intermediate egg incubation temperatures (23-27 degreesC) produce males, while extreme temperatures produce females. Snapping turtles are also sexually dimorphic: adult males are typically larger than females. Previous researchers hypothesized that male-producing egg temperatures enhanced the growth rate of juvenile turtles, resulting in the adult dimorphism and potentially providing an adaptive benefit for TSD. In reptiles, the choice of ambient temperature can also influence growth. I measured the effect of egg incubation temperature on juvenile growth rate and water temperature choice of C. serpentina. Eggs were incubated in the laboratory at 21.5, 24.5, 27.5 or 30.5 degreesC to produce both sexes, all males, both sexes or all females, respectively. Egg temperature was linearly and negatively correlated with growth rate of both male and female juveniles. Thus, growth was enhanced, but not maximized, by male-producing egg temperatures. Egg temperature was also negatively correlated with juvenile temperature choice such that, on average, turtles from 21.5 degreesC eggs selected 28 degreesC water, while turtles from 30.5 degreesC eggs chose 24.5 degreesC water. Additionally, these temperature choices were highly repeatable, even following a 6 month hibernation period at 7 degreesC. Thus, while male egg temperatures do not directly maximize growth, multiple effects of embryonic temperature may combine to create long-lasting differences in the behavioral physiology of male and female C. serpentina. Such differences could be important to the ecology and evolution of TSD.

2021 ◽  
Vol 21 (2) ◽  
pp. 315
Author(s):  
Nisa Nafiyanti ◽  
Mustahal Mustahal ◽  
Mas Bayu Syamsunarno ◽  
Muh. Herjayanto

Oryzias woworae is one of Muna Island's endemic fish, Sulawesi, which needs to be developed in cultivation and can be used as ornamental fish with high economic value. However, information on fish farming is not yet well available, especially at egg incubation temperatures. This study aims to determine the optimal temperature of the incubation water medium for the hatching performance of O. woworae eggs. The study used experimental methods with the treatment of differences in egg incubation temperatures at 24-26°C (temperature fluctuations in the laboratory), 24°C, 28°C and 32°C. The research parameters were analyzed descriptively, namely embryogenesis, hatching time, and hatching rates. The results showed that differences in incubation temperature affected the embryogenesis of O. woworae eggs. The obtained fastest time for hatching eggs O. woworae at a temperature of 32°C with six days 5 hours 49 minutes and 100% hatching. The egg incubation temperature 24-26°C is the lowest hatching time and hatching rate, nine days 11 hours 38 minutes and 53.33%. The use of 32°C in the incubation medium is the optimal temperature to accelerate embryogenesis and the hatching rate of O. woworae eggs.


2009 ◽  
Vol 123 (4) ◽  
pp. 329 ◽  
Author(s):  
R. Neal Paisley ◽  
John F. Wetzel ◽  
John S. Nelson ◽  
Cindy Stetzer ◽  
Mark G. Hamernick ◽  
...  

We studied the survival and spatial ecology of adult Snapping Turtles (Chelydra serpentina) on Pool 8 of the Upper Mississippi River (UMR) during 1997-2001. We captured 597 Snapping Turtles 745 times (333 adult males; 238 adult females; and 26 juveniles) at two study sites; Goose Island, Wisconsin and Lawrence Lake, Minnesota. From this sample, we radio-marked 104 Snapping Turtles of legal harvest size 128 times. Annual survival ranged from 0.857 to 1.000 and averaged 0.944 with Goose Island and Lawrence Lake estimates pooled. Legal harvest was the most important cause of mortality and accounted for 57% of documented deaths. Annual home range size using the Poly-Buff (PB) method averaged 11.13 ha and ranged from 2.20 ha to 37.18 ha. Emergent and rooted-floating aquatic vegetation were used disproportionally more than their availability and 72% of all locations collected during the active period occurred within these habitat types. Overall, radio-marked Snapping Turtles selected hibernacula in the following habitat categories; marshes (38%), main/side channels (28%), backwater sloughs and small ponds (14%), spring areas (10%), small tributary streams (7%), and tertiary channels (3%). Developing conservative, consistent harvest regulations among the states that border the UMR should be a management priority.


Copeia ◽  
1989 ◽  
Vol 1989 (4) ◽  
pp. 896 ◽  
Author(s):  
David A. Galbraith ◽  
Ronald J. Brooks ◽  
Martyn E. Obbard

1991 ◽  
Vol 69 (10) ◽  
pp. 2667-2676 ◽  
Author(s):  
Ronald J. Brooks ◽  
Michele L. Bobyn ◽  
David A. Galbraith ◽  
James A. Layfield ◽  
E. Graham Nancekivell

Clutches of six female snapping turtles (Chelydra serpentina) each were distributed among six incubators set at one of three constant temperatures (22.0, 25.6, and 28.6 °C) in either a wet (−100 kPa) or a dry (−500 kPa) vermiculite substrate. We tested for influences of egg mass, clutch, and incubation temperature and moisture on survival of embryos and hatchlings, on size at hatching, and on rate of post-hatching growth over 7 months. Intraclutch variation in egg mass had no effect on embryonic mortality. Mass at hatching was correlated with egg mass, but neither variable was related significantly to post-hatching survival or rate of growth. Eggs incubated at the highest temperature produced smaller hatchlings which subsequently grew more slowly than those from eggs incubated at the low and intermediate temperatures. Eggs incubated at the intermediate temperature produced larger turtles at 7 months post-hatching than did eggs incubated at the low or high temperatures. Eggs incubated in wet substrates produced larger hatchlings than those in dry substrates, but post-hatching growth rates were independent of these effects of moisture. Eggs incubated at the two extreme temperatures produced mostly females; those at 25.6 °C produced only males. Interclutch variation was significant for egg mass, mass at hatching, and survival of embryos, and was the most important influence on variation in post-hatching rates of growth. These results indicate that egg size and size at hatching may not be useful indicators of intraspecific variation in egg quality or post-hatching success in turtles, unless differences among clutches and embryonic thermal experience are also considered, particularly in relation to parental investment in the amount, quality, and apportionment of the egg's yolk.


2008 ◽  
Vol 25 (No. 5) ◽  
pp. 272-282 ◽  
Author(s):  
D. Liptáková ◽  
Ľ. Valík ◽  
A. Lauková ◽  
V. Strompfová

The combined effect of initial amount of 18 h <i>L. rhamnosus</i> VT1 inoculum and incubation temperature on the growth of <i>Candida maltosa</i> YP1, an oxidative food spoilage yeast strain, was primarily modelled and studied by standard response surface methodology. This study resulted in the following linear regression equations characterising lag time and growth rate of <i>C. maltosa</i> YP1 in milk in competition with the potentially protective lactobacillus strain. Lag-phase of <i>C. maltosa</i> was strongly influenced by the amount of lactobacillus inoculum (<i>V</i><sub>0</sub>) and incubation temperature (1/<i>T</i>). The synergic effect of both these factors was also evident as results from the equation lag = –33.50 + 186.38 × <i>V</i><sub>0</sub> × 1/<i>T</i> + 512.27 × 1/<i>T</i> – 5.511 × <i>V</i><sub>0</sub> (<i>R</i><sup>2</sup><sub>(λ)</sub> = 0.849). The growth rate was sufficiently described by the linear relation: <i>Gr</i><sub>Cm</sub> = –0.00046 + 0.0033 × <i>T</i> – 0.0016 × <i>V</i><sub>0 (<i>R</i><sup>2</sup><sub>(Gr)</sub> = 0.847). On the basis of these equations, the mutual microbial interactions and the potential application of the lactobacillus strains to food protection are discussed.


Weed Science ◽  
1979 ◽  
Vol 27 (6) ◽  
pp. 595-598 ◽  
Author(s):  
T. V. Toai ◽  
D. L. Linscott

We studied the effects of temperature (5, 10, 20, and 30 C) on the phytotoxic activity of decaying quackgrass [Agropyron repens (L.) Beauv.] leaves and rhizomes that were incubated in soils for 0, 1, 2, 4, and 6 weeks. Alfalfa (Medicago sativa L.) seeds were grown for 96 h in water, water extracts of control soils, and water extracts of soil with quackgrass rhizomes or leaves. Dried quackgrass rhizomes and leaves contained water-soluble toxins that inhibited alfalfa seedling development and growth. There was a strong interaction between incubation time and temperature on the development of additional toxins by decomposing quackgrass. High incubation temperature (30 C) accelerated toxin formation and ultimate decay. Intermediate temperature (20 C) delayed toxin formation and decay. Low incubation temperatures (5 C and 10 C) prevented formation of additional toxin. In all extracts of quackgrass and soil that had been incubated for 6 weeks, normal alfalfa seedling number equaled that in water. However, seedling growth varied with incubation temperatures.Treatment of quackgrass with glyphosate [N-(phosphonomethyl) glycine] in the greenhouse did not influence the toxicity of decaying quackgrass leaves. The highest toxic effect was noted after 1 week of decay on the soil surface.


1978 ◽  
Vol 56 (2) ◽  
pp. 298-306 ◽  
Author(s):  
Albert W. Franzmann ◽  
Robert E. LeResche ◽  
Robert A. Rausch ◽  
John L. Oldemeyer

A total of 1329 Alaskan moose (Alces alces gigas) were measured for total length, 1340 for chest girth, 1317 for hind foot, 618 for shoulder height, and 1219 for ear length. Five hundred and four moose were weighed. These data were classified by sex, age, month sampled, and location. Growth rates were plotted and discussed. No morphometric differences were detected by sex and location classifications up to age 36 months. Location differences were detected which corresponded to general condition, productivity, and condition related blood parameters of the populations. Seasonal weight patterns demonstrated increases from 21 to 55% from spring to late fall. Measurements, particularly total lengths, were better indicators of growth rate than were weights. All body measurements were significantly correlated with weight: total length, r (correlation coefficient) = 0.94; chest girth, r = 0.90; shoulder height, r = 0.87; and hind foot, r = 0.81. Combined sex regression equations were derived because the slight differences between the male and female regression lines were unimportant in field application. These regression equations were as follows: weight (kilograms) = −239.7 + 2.07(total length); weight (kilograms) = −245.3 + 3.14(chest girth).


2001 ◽  
Vol 35 (3) ◽  
pp. 514 ◽  
Author(s):  
Paul A. Sims ◽  
Gary C. Packard ◽  
Philip L. Chapman

Sign in / Sign up

Export Citation Format

Share Document