Post Natal Lecithotroph: A New Age Class in the Ontogeny of Reptiles

Lance, Valentine A.; Morafka, David J.

doi:10.2307/1467040

Cited by 24 publications

(25 citation statements)

References 42 publications

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“…We found good accord between ice-nucleating activity in isolated yolk and the Tc values determined for live turtles reared on paper or vermiculite. Also, egested feces, probably derived from yolk, which is heavily mobilized after hatching (Table 2; see Filoramo and Janzen, 1999;Lance and Morafka, 2001) contained INA whose activity also matched the supercooling limit of these summer turtles (Tables 1, 4). Given their apparent insolubility, defecation should eliminate these INA from the body, and, indeed, supercooling capacity was markedly improved in the winter turtles, which had voided their guts.…”

Section: Evidence For Endogenous Ina In Summer Turtlesmentioning

confidence: 99%

“…Turtles urinate on their nests after ovipositing (see Carr, 1952), possibly introducing beneficial microbes, flushed from the cloaca, into the nest chamber. Coprophagy permits some neonatal reptiles to inoculate themselves with the symbiotic gut flora required for proper digestive efficiency (Troyer, 1983;Lance and Morafka, 2001).…”

Section: Changes In Supercooling Capacitymentioning

confidence: 99%

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Endogenous and exogenous ice-nucleating agents constrain supercooling in the hatchling painted turtle

Costanzo

Baker

Dinkelacker

et al. 2003

Journal of Experimental Biology

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SUMMARYHatchlings of the painted turtle (Chrysemys picta) commonly hibernate in their shallow, natal nests. Survival at temperatures below the limit of freeze tolerance (approximately -4°C) apparently depends on their ability to remain supercooled, and, whereas previous studies have reported that supercooling capacity improves markedly with cold acclimation, the mechanistic basis for this change is incompletely understood. We report that the crystallization temperature (Tc) of recently hatched(summer) turtles acclimated to 22°C and reared on a substratum of vermiculite or nesting soil was approximately 5°C higher than the Tc determined for turtles acclimated to 4°C and tested in winter. This increase in supercooling capacity coincided with elimination of substratum (and, in fewer cases, eggshell) that the hatchlings had ingested; however, this association was not necessarily causal because turtles reared on a paper-covered substratum did not ingest exogenous matter but nevertheless showed a similar increase in supercooling capacity. Our results for turtles reared on paper revealed that seasonal development of supercooling capacity fundamentally requires elimination of ice-nucleating agents (INA) of endogenous origin: summer turtles, but not winter turtles, produced feces(perhaps derived from residual yolk) that expressed ice-nucleating activity. Ingestion of vermiculite or eggshell, which had modest ice-nucleating activity, had no effect on the Tc, whereas ingestion of nesting soil, which contained two classes of potent INA, markedly reduced the supercooling capacity of summer turtles. This effect persisted long after the turtles had purged their guts of soil particles, because the Tc of winter turtles reared on nesting soil (mean ±S.E.M.=-11.6±1.4°C) was approximately 6°C higher than the Tc of winter turtles reared on vermiculite or paper. Experiments in which winter turtles were fed INA commonly found in nesting soil showed that water-soluble, organic agents can remain fully active for at least one month. Such INA may account for the limited supercooling capacity(Tc≈-7.5°C) we found in turtles overwintering in natural nests and may therefore pose a formidable challenge to the winter survival of hatchling C. picta.

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Section: Evidence For Endogenous Ina In Summer Turtlesmentioning

confidence: 99%

Section: Changes In Supercooling Capacitymentioning

confidence: 99%

Endogenous and exogenous ice-nucleating agents constrain supercooling in the hatchling painted turtle

Costanzo

Baker

Dinkelacker

et al. 2003

Journal of Experimental Biology

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“…Females were not fed during the entire reproductive period as they typically are aphagic during this time, but water was available ad libitum except when the females were brooding their eggs. In snakes, neonates rely primarily on their body reserves [fat stores and remaining vitellus (Charland, 1989;Lance and Morafka, 2001;Pandav et al, 2006)] for their first weeks of life. Thus, they were not fed during the study period, but were provided water ad libitum.…”

Section: Breeding Protocolmentioning

confidence: 99%

Maternal influences on early development: preferred temperature prior to oviposition hastens embryogenesis and enhances offspring traits in the Children’s python, Antaresia childreni

Lorioux

DeNardo

Gorelick

et al. 2012

Journal of Experimental Biology

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SUMMARYEmbryonic life is particularly sensitive to its surroundings, and the developmental environment can have long-lasting effects on offspring. In oviparous species, the impacts of the developmental environment on offspring traits are mostly examined during development within the egg. However, as more than 25% of the development of squamate reptiles can occur prior to oviposition, we explored the effect of thermal conditions on development prior to oviposition in an oviparous snake species, the Childrenʼs python (Antaresia childreni). We housed gravid female pythons under three thermal cycles: an optimal regime that reflected maternal preference in a non-constrained environment (constant preferred body temperature of gravid females, T set 31.5°C) and two mildly suboptimal regimes that shared the same mean temperature of 27.7°C, but differed in the duration at T set . In one of the constraining regimes, females had access to T set for 4h daily whereas in the other regime, females never reached T set (maximal temperature of 29.0°C). Thermal treatments were maintained throughout gravidity in all three groups, but, after oviposition, all eggs were incubated at T set until hatching. Compared with the optimal regime, the two suboptimal regimes had a longer duration of gravidity, which resulted in delayed hatching. Between the two suboptimal regimes, gravidity was significantly shorter in the treatment that included time at T set . Furthermore, suboptimal regimes influenced offspring traits at hatching, including body morphology, antipredator behavior, strength and metabolism. However, partial access to maternal T set significantly enhanced several offspring traits, including performance. Our results demonstrate the importance of time at T set on early development and suggest an adaptive significance of maternal thermoregulation prior to oviposition. Supplementary material available online at

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“…NA, not assayed. in oviparous amniotes, are the main source of metabolic energy during development and following hatching during a nutritional stage termed postnatal lecithotrophy (Lance and Morafka, 2001). Total TAG was the major lipid class in the residual yolk (61%) and in hatchlings (52%) of Emydura macquarii, an omnivore Australian freshwater turtle (Thompson et al, 1999).…”

Section: Gdhmentioning

confidence: 99%

“…Residual yolk contains the major nutrients required for sustaining the hatchling for several weeks posthatching (Rowe et al, 1995;Thompson et al, 1999;Lance and Morafka, 2001). Lipids are the major component of residual yolk, representing 30-50% of dry mass.…”

Section: Introductionmentioning

confidence: 99%

Enzymes of energy metabolism in hatchlings of amazonian freshwater turtles (Testudines, Podocnemididae)

2009

Braz. J. Biol.

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The metabolic profiles of selected tissues were analyzed in hatchlings of the Amazonian freshwater turtles Podocnemis expansa, P. unifilis and P. sextuberculata. Metabolic design in these species was judged based on the key enzymes of energy metabolism, with special emphasis on carbohydrate, lipid, amino acid and ketone body metabolism. All species showed a high glycolytic potential in all sampled tissues. Based on low levels of hexokinase, glycogen may be an important fuel for these species. The high lactate dehydrogenase activity in the liver may play a significant role in carbohydrate catabolism, possibly during diving. Oxidative metabolism in P. sextuberculata appears to be designed for the use of lipids, amino acids and ketone bodies. The maximal activities of 3-hydroxyacyl-CoA dehydrogenase, malate dehydrogenase, glutamine dehydrogenase, alanine aminotransferase and succinyl-CoA keto transferase display high aerobic potential, especially in muscle and liver tissues of this species. Although amino acids and ketone bodies may be important fuels for oxidative metabolism, carbohydrates and lipids are the major fuels used by P. expansa and P. unifilis. Our results are consistent with the food habits and lifestyle of Amazonian freshwater turtles. The metabolic design, based on enzyme activities, suggests that hatchlings of P. unifilis and P. expansa are predominately herbivorous, whereas P. sextuberculata rely on a mixed diet of animal matter and vegetation.Keywords: amazonian freshwater turtles, Podocnemis, energy metabolism. Enzimas do metabolismo energético em quelônios amazônicos (Testudines, Podocnemididae) recém-eclodidosResumo O perfil metabólico de vários tecidos foi analisado em quelônios aquáticos recém-eclodidos: Podocnemis expansa, P. unifilis e P. sextuberculata. O potencial metabólico dessas espécies foi avaliado por meio das atividades absolutas das enzimas do metabolismo energético com ênfase no metabolismo dos carboidratos, lipídios, aminoácidos e corpos cetônicos. Todas as espécies estudadas apresentaram alto potencial glicolítico em todos os tecidos analisados. Com base nos baixos níveis da enzima hexoquinase, as reservas de glicogênio podem ser importantes substratos energéticos para estas espécies. A alta atividade da lactato desidrogenase no fígado pode indicar que este órgão desempenha um importante papel no metabolismo dos carboidratos, possivelmente relacionado com a resistência ao mergulho prolongado. O perfil metabólico de P. sextuberculata parece organizado para utilizar preferencialmente lipídios, aminoácidos e corpos cetônicos. Os dados das atividades máximas das enzimas 3-hidroxi-acil-Co A desidrogenase, malato desidrogenase e succinil-Co A ceto-transferase, especialmente no músculo branco e no fígado dessa espécie corroboram esta hipótese. Por outro lado, os carboidratos e os lipídios parecem ser os principais substratos metabólicos de P. expansa e P. unifilis, muito embora, os corpos cetônicos e aminoácidos sejam importantes metabólitos para sustentar o potencial oxidativ...

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Post Natal Lecithotroph: A New Age Class in the Ontogeny of Reptiles

Cited by 24 publications

References 42 publications

Endogenous and exogenous ice-nucleating agents constrain supercooling in the hatchling painted turtle

Endogenous and exogenous ice-nucleating agents constrain supercooling in the hatchling painted turtle

Maternal influences on early development: preferred temperature prior to oviposition hastens embryogenesis and enhances offspring traits in the Children’s python, Antaresia childreni

Enzymes of energy metabolism in hatchlings of amazonian freshwater turtles (Testudines, Podocnemididae)

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