Altitudinal variation in size and composition of eggs in the land snail Arianta arbustorum

1998 ◽  
Vol 76 (11) ◽  
pp. 2067-2074 ◽  
Author(s):  
A Baur ◽  
B Baur
Keyword(s):  
Clutch Size ◽  
Carbon Concentration ◽  
Egg Size ◽  
Nitrogen Concentration ◽  
Reproductive Investment ◽  
Land Snail ◽  
Dry Mass ◽  
Altitudinal Variation ◽  
Arianta Arbustorum ◽  
Carbon Concentrations

Egg size and egg provisioning are crucial for the survival of offspring in invertebrates without postlaying egg care. The effects of elevation and size of the mother on egg size and on nitrogen and carbon concentrations in eggs were examined in eight populations of the land snail Arianta arbustorum over an altitudinal gradient from 370 to 2340 m in Switzerland. The dry mass of single eggs ranged from 1.48 to 2.79 mg and decreased with increasing altitude. Adult snail size (shell volume) also decreased with increasing elevation as did clutch size and reproductive investment (clutch size x egg dry mass) of mothers. Hatching success of eggs varied among populations, but showed no altitudinal pattern. When differences in parental shell size were taken into account, correlations between altitude and egg size, clutch size, and reproductive investment disappeared. Thus, the altitudinal decreases in egg size, clutch size, and reproductive investment were mainly due to smaller snail sizes at higher elevations. The nitrogen concentration in eggs ranged from 3.4 to 4.5% and decreased with increasing elevation. In contrast to egg and clutch size, the altitudinal variation in nitrogen concentration of eggs cannot be explained by differences in snail size. The carbon concentration in eggs ranged from 31.1 to 33.1%, but showed no altitudinal variation. Nitrogen and carbon concentrations in the eggshell and egg fluid in eggs from four populations were examined separately. The nitrogen concentration in the eggshell ranged from 0.7 to 1.8% and was lower than that of the egg fluid (5.1-5.8%). Similarly, the carbon concentration in the eggshell was lower (20.2-22.8%) than that in the egg fluid (35.8-0.2%). Interpopulation differences in egg composition may affect growth, size, and survival of hatchlings and the extent of egg cannibalism in A. arbustorum.

Clutch and egg size of the tropical lizard Tropidurus torquatus (Tropiduridae) along its geographic range in coastal eastern Brazil

2008 ◽  
Vol 86 (12) ◽  
pp. 1376-1388 ◽  
Author(s):  
M. C. Kiefer ◽  
M. Van Sluys ◽  
C. F.D. Rocha
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Female Body ◽  
Egg Size ◽  
Reproductive Investment ◽  
Geographic Range ◽  
Minimum Size ◽  
Brazilian Coast ◽  
Female Body Size ◽  
Almost All

The tropidurid lizard Tropidurus torquatus (Wied, 1820) has a set of populations inhabiting coastal sand dune habitats (“restinga”) along the eastern Brazilian coast. Despite its wide geographic range, there is no information about geographic variation in reproductive features among its populations. In the present study we compared some reproductive aspects of females in 10 coastal populations of T. torquatus, aiming to evaluate to what extension they vary geographically. The minimum size at maturity was relatively similar to most populations, but mean female body size had a considerable variation. Clutch size of almost all coastal populations of T. torquatus had little variation and was composed predominantly of two eggs. Interpopulational variation in the mean egg volume was relatively wide and strongly influenced by the variation in mean female body size. The data of the present study indicated that females of almost all coastal populations of T. torquatus produce, predominantly, clutches with two eggs and invest more energy in egg size instead of clutch size, probably as a consequence of morphological and environmental factors. The increased reproductive investment in egg size was confirmed by the values obtained for the relative clutch mass, which remained relatively constant along the coastal geographic distribution of T. torquatus.

scholarly journals Male size does not correlate with fertilization success in two bufonid toads that show size-assortative mating

2013 ◽  
Vol 59 (6) ◽  
pp. 740-746 ◽  
Author(s):  
Xiao-Li Fan ◽  
Zhi-Hua Lin ◽  
Xiang Ji
Keyword(s):  
Body Size ◽  
Assortative Mating ◽  
Clutch Size ◽  
Egg Size ◽  
Dry Mass ◽  
Fertilization Success ◽  
Male Body ◽  
Mating Pattern ◽  
Male Size ◽  
Male Preference

Abstract We examined sexual size dimorphism (SSD), mating pattern, fertilization efficiency and female reproductive traits in two bufonid toads (Bufo gargarizans and Duttaphrynus melanostictus) to test the idea that importance of male body size for egg fertilization success depends on the mating pattern. Female-biased SSD was evident only in D. melanostictus. Female B. gar-garizans laid fewer larger eggs nearly three months earlier than did female D. melanostictus. Fertilization efficiencies on average were higher in B. gargarizans (95%) than in D. melanostictus (91%). Though differing in the degree of SSD, body size, breeding season, clutch size, egg size and fertilization efficiency, the two toads were similar in four aspects: (1) both showed size-assortative mating; (2) females did not tradeoff egg size against egg number; (3) male size, clutch size and clutch dry mass were greater in male-larger than in female-larger pairs after accounting for female snout-vent length (SVL); and (4) the ratio of male to female SVL did not affect fertilization efficiency. Our data show that: (1) a female preference for large males is likely not important in terms of egg fertilization success; (2) a male preference for large females is likely important because larger females are more fecund; and (3) size-assortative mating arises from a male preference for large females. Our study demonstrates that male size is not always important for egg fertilization success in anurans that show size-assortative mating.

Factors affecting vegetative growth and the production of perithecia in culture by Ophiobolus graminis. I. Variations in media and age of mycelium

1970 ◽  
Vol 18 (1) ◽  
pp. 1 ◽  
Author(s):  
G Weste
Keyword(s):  
Carbon Concentration ◽  
Vegetative Growth ◽  
Solid Medium ◽  
Nitrogen Concentration ◽  
Restricted Range ◽  
Factors Affecting ◽  
Carbon And Nitrogen ◽  
Nitrogen Concentrations ◽  
High Concentrations ◽  
Carbon Concentrations

Perithecia were readily produced in culture on a suitable solid medium under certain conditions of light and temperature, once vegetative growth was established. Investigations into the carbon and nitrogen requirements for both vegetative growth and fruiting showed that, whereas vegetative growth increased with increasing carbon supplies up to10%, reproduction occurred only within a restricted range of carbon and nitrogen concentrations. No perithecia were produced on a starvation medium. Factors involved in fruiting included concentration of nutrients and the balance between them; both were important. A suitable fruiting medium required a minimum carbon concentration of 3000 p.p.m., supplied as 0.75 % glucose or fructose, and an optimum carbon concentration of 6000 p.p.m. supplied as 1.5 % glucose or fructose. The maximum number of perithecia was produced on a medium containing 1% glucose and 0.2 % asparagine (400 p.p.m. nitrogen), which had a carbonlnitrogen ratio of 11.8. A higher than optimum nitrogen concentration was partially offset by increasing the carbon concentration, that is by keeping the carbonlnitrogen ratio approximately constant. The actual concentrations inhibiting and promoting fruiting of the fungus were influenced by the balance between carbon and nitrogen supplies. High concentrations of carbon and nitrogen increased vegetative growth but decreased the number of perithecia. There was no sudden inhibition of perithecia with increased carbon concentrations, but at 10% glucose (40,000 p.p.m. carbon) vegetative growth and pigmentation were maximal but few or no perithecia developed. No evidence was obtained that perithecial production was influenced by ageing of the mycelium, the presence of staling factors, or exhaustion of food supplies.

Composition of body storage compounds influences egg quality and reproductive investment in the land snail Cornu aspersum

2012 ◽  
Vol 90 (9) ◽  
pp. 1161-1170 ◽  
Author(s):  
Annegret Nicolai ◽  
Juliane Filser ◽  
Roman Lenz ◽  
Briand Valérie ◽  
Maryvonne Charrier
Keyword(s):  
Clutch Size ◽  
Energy Content ◽  
Reproductive Investment ◽  
Land Snail ◽  
The Body ◽  
Nutrient Allocation ◽  
Energy Investment ◽  
Storage Compounds ◽  
Investment In Reproduction ◽  
Cornu Aspersum

In invertebrates, resources available for growth and reproduction might influence the composition of body stores and subsequently nutrient allocation to eggs, thereby adjusting energy investment in reproduction. We investigated in the land snail Cornu aspersum (Müller, 1774) the efficiency of growth and the main storage compounds in the body and in eggs with respect to lipid content in food (5.5% versus 2.5%). The high body dry mass density of snails fed on lipid-rich diet underlined the high storage capacity of neutral lipids acquired during growth (high growth efficiency) without changing energy content because of the prevailing carbohydrate storage compounds. Reproductive investment was lower in these snails, and maternal effects decreased clutch size. Triglyceride allocation to eggs might enhance survival probability of offspring and therefore compensate for smaller clutch size. Snails fed on lipid-poor diet maximized their investment in clutch size whatever the amount of body stores, and allocated a higher amount of cholesterol to eggs. Cholesterol could be essential for embryo growth, as it ensures membrane functioning. In conclusion, the availability of resources can differentially affect nutrient allocation and energy investment in reproduction. Thus, the investigation of physiological processes becomes essential to understand population dynamics in fluctuating or changing habitats.

scholarly journals Glucocorticoids, state-dependent reproductive investment and success in the face of danger in a long-lived bird

2020 ◽  
Author(s):  
Kristina Noreikienė ◽  
Kim Jaatinen ◽  
Benjamin B. Steele ◽  
Markus Öst
Keyword(s):  
Predation Risk ◽  
Telomere Length ◽  
Clutch Size ◽  
Body Condition ◽  
Nest Predation ◽  
Hatching Success ◽  
Reproductive Investment ◽  
Trade Off ◽  
Relative Telomere Length ◽  
Future Reproduction

AbstractGlucocorticoid hormones may mediate trade-offs between current and future reproduction. However, understanding their role is complicated by predation risk, which simultaneously affects the value of the current reproductive investment and elevates glucocorticoid levels. Here, we shed light on these issues in long-lived female Eiders (Somateria mollissima) by investigating how current reproductive investment (clutch size) and hatching success relate to faecal glucocorticoid metabolite [fGCM] level and residual reproductive value (minimum years of breeding experience, body condition, relative telomere length) under spatially variable predation risk. Our results showed a positive relationship between colony-specific predation risk and mean colony-specific fGCM levels. Clutch size and female fGCM were negatively correlated only under high nest predation and in females in good body condition, previously shown to have a longer life expectancy. We also found that younger females with longer telomeres had smaller clutches. The drop in hatching success with increasing fGCM levels was least pronounced under high nest predation risk, suggesting that elevated fGCM levels may allow females to ensure some reproductive success under such conditions. Hatching success was positively associated with female body condition, with relative telomere length, particularly in younger females, and with female minimum age, particularly under low predation risk, showing the utility of these metrics as indicators of individual quality. In line with a trade-off between current and future reproduction, our results show that high potential for future breeding prospects and increased predation risk shift the balance toward investment in future reproduction, with glucocorticoids playing a role in the resolution of this trade-off.

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