scholarly journals Shifts in the developmental rate of spadefoot toad larvae cause decreased complexity of post-metamorphic pigmentation patterns

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lee Hyeun-Ji ◽  
Miguel Ángel Rendón ◽  
Hans Christoph Liedtke ◽  
Ivan Gomez-Mestre
Keyword(s):  
Larval Growth ◽  
Developmental Rate ◽  
Pigmentation Pattern ◽  
Pattern Complexity ◽  
Amphibian Larvae ◽  
Spadefoot Toads ◽  
Spadefoot Toad ◽  
Size At Metamorphosis ◽  
Developmental Rates ◽  
The Cost

AbstractAmphibian larvae are plastic organisms that can adjust their growth and developmental rates to local environmental conditions. The consequences of such developmental alterations have been studied in detail, both at the phenotypic and physiological levels. While largely unknown, it is of great importance to assess how developmental alterations affect the pigmentation pattern of the resulting metamorphs, because pigmentation is relevant for communication, mate choice, and camouflage and hence influences the overall fitness of the toads. Here we quantify the variation in several aspects of the pigmentation pattern of juvenile spadefoot toads experimentally induced to accelerate their larval development in response to decreased water level. It is known that induced developmental acceleration comes at the cost of reduced size at metamorphosis, higher metabolic rate, and increased oxidative stress. In this study, we show that spadefoot toads undergoing developmental acceleration metamorphosed with a less complex, more homogeneous, darker dorsal pattern consisting of continuous blotches, compared to the more contrasted pattern with segregated blotches and higher fractal dimension in normally developing individuals, and at a smaller size. We also observed a marked effect of population of origin in the complexity of the pigmentation pattern. Complexity of the post-metamorphic dorsal pigmentation could therefore be linked to pre-metamorphic larval growth and development.

Effect of habitat drying on the development of the Eastern spadefoot toad (Pelobates syriacus) tadpoles

2010 ◽  
Vol 31 (3) ◽  
pp. 425-434 ◽  
Author(s):  
Paul Székely ◽  
Dan Cogălniceanu ◽  
Marian Tudor
Keyword(s):  
Body Size ◽  
Water Level ◽  
Water Volume ◽  
The North ◽  
Reduced Body ◽  
Spadefoot Toads ◽  
Spadefoot Toad ◽  
Size At Metamorphosis ◽  
Drying Conditions ◽  
Response To Water

AbstractAmphibians exhibit plasticity in the timing of metamorphosis, and tadpoles of many species respond to pond drying by accelerating their development. In the present study we investigated the phenotypic plasticity of the developmental response to water volume reduction in tadpoles of Eastern spadefoot toad Pelobates syriacus. The response of tadpoles to the simulated drying conditions was evaluated by gradually reducing the water level in the experimental containers under controlled laboratory conditions. Four water level treatments were used: constant high, slow decrease, fast decrease and constant low level. We tested if (i) tadpoles can speed up their development in a drying aquatic habitat, and (ii) if the accelerated development causes a reduced body size at metamorphosis. Our results showed that P. syriacus tadpoles were able to respond to pond drying by speeding up their metamorphosis and that metamorphosis was not influenced by water level, but by water level decrease rate. The accelerated development caused by the decreasing water level resulted in smaller body size at metamorphosis. The smallest size at metamorphosis was in tadpoles raised in constant low water level treatments and was probably induced by the crowding effect. We compared our results to similar studies which show that the response of the Eastern spadefoot toad tadpoles to pond drying is less impressive, especially if compared to the response of the North American spadefoot toads inhabiting desert environments.

Temperature thresholds and statistical modelling of larval Wuchereria bancrofti (Filariidea: Onchocercidae) developmental rates

Parasitology ◽  
1997 ◽  
Vol 114 (2) ◽  
pp. 123-134 ◽  
Author(s):  
F. LARDEUX ◽  
J. CHEFFORT
Keyword(s):  
Wuchereria Bancrofti ◽  
Developmental Rate ◽  
Statistical Modelling ◽  
Original Method ◽  
Frequency Data ◽  
Larval Stages ◽  
A Value ◽  
Temperature Thresholds ◽  
Developmental Rates ◽  
Aedes Polynesiensis

Developmental rates for Wuchereria bancrofti larvae maturing in the vector Aedes polynesiensis were estimated by analysing stage-frequency data consisting of counts of larval stages in mosquitoes reared at 20, 22·5, 25, 27·5, 30 and 32 °C. Base temperatures (i.e. low temperature thresholds) for W. bancrofti development were estimated by the x-intercept method and the model of Lactin et al. (1995). Resulting values were similar with both methods and were ≈12·5 °C for microfilariae (mf) in thorax, ≈17 °C for L1, 15·5 °C for L2 and 16·5 °C for L3. Upper thresholds estimated by the Lactin et al. model were 29·3 °C for mf, 29·1 °C for L1, 32·2 °C for L2 and 31·5 °C for L3. In addition, an original method was devised for computing the L3 upper threshold, by modelling L3 length shrinkage with temperature. It gave a value of 31·4 °C. At 32 °C, L2 and L3 stages exhibited altered morphology, larvae being shorter and wider than expected. The model of Lactin et al. described adequately the non-linear relationship between developmental rate and temperature, but a linear degree-day approach may be applied for temperatures below 27–28 °C.

scholarly journals De Novo Assembly and Annotation of the Larval Transcriptome of Two Spadefoot Toads Widely Divergent in Developmental Rate

2019 ◽  
Vol 9 (8) ◽  
pp. 2647-2655 ◽  
Author(s):  
H. Christoph Liedtke ◽  
Jèssica Gómez Garrido ◽  
Anna Esteve-Codina ◽  
Marta Gut ◽  
Tyler Alioto ◽  
...  
Keyword(s):  
De Novo Assembly ◽  
De Novo ◽  
Developmental Rate ◽  
Spadefoot Toads

Size and Age at Metamorphosis in Marine Fishes: An Analysis of Laboratory-Reared Winter Flounder (Pseudopleutonectes americanus) with a Review of Variation in Other Species

1987 ◽  
Vol 44 (11) ◽  
pp. 1936-1947 ◽  
Author(s):  
R. Christopher Chambers ◽  
William C. Leggett
Keyword(s):  
Larval Period ◽  
Marine Fishes ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Competitive Effects ◽  
Pooled Data ◽  
Risk Of Predation ◽  
Size At Metamorphosis ◽  
Developmental Rates ◽  
Positive Correlations

Offspring of adult winter flounder (Pseudopleuronectes americanus) collected from Conception Bay, Newfoundland, were reared from fertilization to metamorphosis. We tested two hypotheses: 1) length and age at metamorphosis are equally variable among individuals and (2) length and age at metamorphosis are not correlated. Length at metamorphosis was significantly less variable than age at metamorphosis when data from all laboratory populations were pooled and in 15 of 18 populations. Coefficients of variation for length and age at metamorphosis for the pooled data were 0.051 and 0.123, respectively. Length and age at metamorphosis were positively correlated when the data were pooled (r = 0.42, p < 0.001) and within 8 of 18 populations. Larvae that metamorphose late do so at larger sizes. When length and age at metamorphosis were converted to growth and developmental rates for the full larval period, significant positive correlations were evident between these rates for the pooled data (r = 0.68, p < 0.001) and within 16 of 18 populations. Larvae that grow slowly, therefore, remain as larvae longer. An examination of published values on size and age at metamorphosis in marine fishes revealed a pattern consistent with our findings both within and among populations and environments: (1) variation in length was less than variation in age at metamorphosis and (2) positive correlations between growth and developmental rates were evident through the larval period. Increased size at metamorphosis may ameliorate competitive effects and reduce the risk of predation in the period immediately following metamorphosis. Due to the considerable variation in the duration of the larval period (age at metamorphosis) the number of individuals that successfully metamorphose and subsequently enter the mature population could be significantly altered under differing environmental conditions.

Influence of desiccation, predatory cues, and density on metamorphic traits of the bronze frog Hylarana temporalis

2016 ◽  
Vol 37 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Santosh Mogali ◽  
Srinivas Saidapur ◽  
Bhagyashri Shanbhag
Keyword(s):  
Ecological Factors ◽  
Larval Period ◽  
Ecological Factor ◽  
Water Quantity ◽  
Predation Threat ◽  
Predator Pressure ◽  
Size At Metamorphosis ◽  
The Cost ◽  
Pantala Flavescens

We conducted an experiment to understand the influence of ecological factors (desiccation, predation threat and density) on two major metamorphic traits, larval period and size at metamorphosis, in the Indian bronze frog,Hylarana temporalis. Tadpoles were reared in groups of 15 (low), 30 (medium) and 60 (high) densities. We created the threat of desiccation by removing 0.5 l water at 10 days intervals until the water quantity reached 0.5 l. Caged dragonfly larvae (Pantala flavescens) provided the predation threat. Results show that each ecological factor independently influenced metamorphic traits but not in an interactive way. Under desiccation threat the tadpoles metamorphosed earlier and at smaller sizes compared to those reared in constant water (at corresponding densities) regardless of presence/absence of predator. In contrast, under predation threat, tadpoles metamorphosed early and at a bigger size than those reared without predator regardless of density of rearing, and desiccation threat. Alternatively, an increase in density of rearing delayed metamorphosis with smaller metamorphic size in constant water and also under threat of desiccation regardless of whether predation threat existed or not. Thus, our study revealed thatH. temporalistadpoles can modify their response to each ecological factor regardless of what other factors operate simultaneously; the threat of desiccation shortens larval period at the cost of growth. Whereas, predator pressure shortens larval period along with increased growth; while greater density increases larval period and slows down growth inH. temporalis.

The evolution of adult body size in black-bellied salamanders (Desmognathus quadramaculatus complex)

2000 ◽  
Vol 78 (10) ◽  
pp. 1712-1722 ◽  
Author(s):  
Carlos D Camp ◽  
Jeremy L Marshall ◽  
Richard M Austin, Jr.
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Larval Growth ◽  
Larval Period ◽  
Moisture Level ◽  
Adult Body Size ◽  
Larval Growth Rate ◽  
Size At Metamorphosis ◽  
Adult Body ◽  
Desmognathus Quadramaculatus

We investigated the possible role of environmental variables in determining body size within a complex of salamander species (Desmognathus quadramaculatus). We analyzed data generated from life-history studies on populations from throughout the range of this species complex. We incorporated an alternative-hypothesis framework (sensu Platt) to determine the better predictor of adult body size, age at maturity, or size at metamorphosis. We found that almost 90% of the variation in adult body size was explained by size at metamorphosis, which was determined by a combination of rate of larval growth and length of the larval period. Environmental temperature and moisture level were positively correlated with larval growth rate and length of the larval period, respectively. We propose a simple model of body-size evolution that incorporates both adaptive and plastic components. We suggest that the length of the larval period may adaptively respond to moisture-level predictability. In addition, we suggest that the response of the larval growth rate to temperature may be plastic. Because the selection pressure due to drying-induced mortality is pervasive among species of amphibians, it may have played a role in shaping body-size radiation in desmognathines as well as the ecological structure of Appalachian streamside communities.

Relationship of larval density and heterozygosity to growth and survival of juvenile marbled salamanders (Ambystoma opacum)

1996 ◽  
Vol 74 (6) ◽  
pp. 1122-1129 ◽  
Author(s):  
Anne C. Chazal ◽  
John D. Krenz ◽  
David E. Scott
Keyword(s):  
Body Size ◽  
Larval Density ◽  
Larval Growth ◽  
Adult Survival ◽  
Growth And Survival ◽  
Ambystoma Opacum ◽  
Size At Metamorphosis ◽  
Body Sizes ◽  
Marbled Salamander ◽  
Relationship Of

Intraspecific competition and enzyme variability have been observed to influence the bioenergetics of many organisms. In amphibians, larval growth affects body size at metamorphosis, which in turn can lead to differences in adult survival and fecundity. We manipulated larval density in a population of the marbled salamander, Ambystoma opacum, and measured body size and enzyme variability in surviving newly metamorphosed juveniles. Crowded larval conditions resulted in lower survival and smaller body sizes at metamorphosis. Multilocus heterozygosity showed no relation to body size at high larval densities; however, at low larval densities relatively homozygous animals were larger. There was a significant interaction between heterozygosity and larval density in their effects on larval traits. Competition had a greater effect on body size at metamorphosis than did heterozygosity. Survival may be enhanced by heterozygosity but in a manner unrelated to body size.

scholarly journals 43IMPROVED IN VITRO DEVELOPMENT OF PORCINE NUCLEAR TRANSFER EMBRYOS WITH 6-DMAP FOLLOWING FUSION

2004 ◽  
Vol 16 (2) ◽  
pp. 144
Author(s):  
G.-S. IM ◽  
L. Lai ◽  
Z. Liu ◽  
Y. Hao ◽  
C.M. Murphy ◽  
...  
Keyword(s):  
Nuclear Transfer ◽  
Electric Pulse ◽  
Developmental Rate ◽  
Cell Number ◽  
Blastocyst Stage ◽  
In Vitro Development ◽  
Electric Pulses ◽  
Developmental Rates ◽  
Vitro Development

Although nuclear transfer (NT) has successfully produced cloned piglets, the development to blastocyst and to term is still low. Activation of the NT embryos is one of the key factors to improve the developmental ability of porcine NT embryos. Electric pulses as well as chemicals have been used to activate porcine NT embryos. This study was conducted to investigate the effect of continued activation following fusion pulses on in vitro development of porcine NT Embryos. Oocytes derived from a local abattoir were matured for 42 to 44h and enucleated. Ear skin cells were obtained from a 4-day-old transgenic pig transduced with eGFP recombinant retrovirus. Enucleated oocytes were reconstructed and cultured in PZM-3 in a gas atmosphere of 5% CO2 in air. Cleavage and blastocyst developmental rates were assessed under a stereomicroscope on Day 3 or 6. Blastocysts were stained with 5μg of Hoechst 33342 and total cell number was determined with an epifluorescent microscope. In Experiment 1, oocytes were activated with two 1.2kV/cm for 30μs (E) in 0.3M mannitol supplemented with either 0.1 or 1.0mM Ca2+. In each treatment, activated oocytes were divided into three groups. The first group was control (E). Other two groups were exposed to either ionomycin and 6-DMAP (E+I+D) or 6-DMAP (E+D) immediately after the electric pulses. In Experiment 2, fusion was conducted by using 1.0mM Ca2+ in the fusion medium. Fused NT embryos were divided into three treatments. NT embryos were fused and activated simultaneously with electric pulse as a control (C); the second group was treated with 6-DMAP immediately after fusion treatment (D0); and the third group was treated with 6-DMAP at 20min (D20) after fusion. In experiment 1, for 0.1mM Ca2+, developmental rates to the blastocyst stage for E, E+I+D or E+D were 12.5, 26.7 and 22.5%, respectively. For 1.0mM Ca2+, developmental rates to the blastocyst stage were 11.4, 28.3 and 35.6%, respectively. The activated oocytes treated with 6-DMAP following the electric pulses by using 1.0mM Ca2+ in fusion medium had higher (P&lt;0.05) developmental rates to the blastocyst stage. In Experiment 2, developmental rates to the blastocyst stage for C, D0 or D20 were 10.0, 12.3, and 19.9%, respectively. Developmental rate to the blastocyst stage was higher (P&lt;0.05) in D20. Fragmentation rates were 19.9, 10.8, and 9.0%, respectively. Regardless of Ca2+ concentration in fusion medium, continued treatments with chemicals following electric pulses supported more development of porcine activated oocytes. Treating NT embryos with 6-DMAP alone after fusion was completed by using 1.0mM Ca2+ in fusion medium improved the developmental rates to the blastocyst stage and prevented fragmentation accompanied by electric fusion. This study was supported by NIH NCRR 13438 and Food for the 21st Century.

Developmental divergence among hatchery strains of rainbow trout (Salmo gairdneri). II. Hybrids

1985 ◽  
Vol 27 (3) ◽  
pp. 298-307 ◽  
Author(s):  
Moira M. Ferguson ◽  
Roy G. Danzmann ◽  
Fred W. Allendorf
Keyword(s):  
Rainbow Trout ◽  
First Generation ◽  
Developmental Rate ◽  
Salmo Gairdneri ◽  
Maternal Parent ◽  
Reciprocal Hybrids ◽  
Hatching Time ◽  
Developmental Rates ◽  
Developmental Divergence ◽  
Additive Genetic Effects

The developmental rates of first generation hybrids between six closely related hatchery strains of rainbow trout are compared using hatching time, morphology, and the pattern of ontogenetic change of four enzymes. Hybrid developmental rates can not be explained by additive genetic effects. Nine of 14 hybrid types developed slower than their maternal parent. These results are consistent with a hypothesis of regulatory divergence between the hybridizing strains. Heterotic effects were observed in five hybrid groups in that hybrids developed faster than their maternal parent. A strong dominance component was observed in the reciprocal hybrids of one strain. There was no association between the degree of perturbation of hybrid developmental rates and the genetic distance between hybridizing strains. Hybrids between more distantly related strains were no more delayed in their development than those from closely related strains.Key words: developmental rate, rainbow trout, hybrids, gene regulation.

scholarly journals Embryonic communication in the nest: metabolic responses of reptilian embryos to developmental rates of siblings

2011 ◽  
Vol 279 (1734) ◽  
pp. 1709-1715 ◽  
Author(s):  
Jessica K. McGlashan ◽  
Ricky-John Spencer ◽  
Julie M. Old
Keyword(s):  
Developmental Stages ◽  
Incubation Temperature ◽  
Developmental Rate ◽  
Freshwater Turtle ◽  
Heart Rates ◽  
Developmental Rates ◽  
Environmentally Cued Hatching ◽  
Developmental Asynchrony ◽  
Developmental Conditions ◽  
Australian Freshwater

Incubation temperature affects developmental rates and defines many phenotypes and fitness characteristics of reptilian embryos. In turtles, eggs are deposited in layers within the nest, such that thermal gradients create independent developmental conditions for each egg. Despite differences in developmental rate, several studies have revealed unexpected synchronicity in hatching, however, the mechanisms through which synchrony are achieved may be different between species. Here, we examine the phenomenon of synchronous hatching in turtles by assessing proximate mechanisms in an Australian freshwater turtle ( Emydura macquarii ). We tested whether embryos hatch prematurely or developmentally compensate in response to more advanced embryos in a clutch. We established developmental asynchrony within a clutch of turtle eggs and assessed both metabolic and heart rates throughout incubation in constant and fluctuating temperatures. Turtles appeared to hatch at similar developmental stages, with less-developed embryos in experimental groups responding to the presence of more developed eggs in a clutch by increasing both metabolic and heart rates. Early hatching did not appear to reduce neuromuscular ability at hatching. These results support developmental adjustment mechanisms of the ‘catch-up hypothesis’ for synchronous hatching in E. macquarii and implies some level of embryo–embryo communication. The group environment of a nest strongly supports the development of adaptive communication mechanisms between siblings and the evolution of environmentally cued hatching.

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