Egg Components and Hatchling Lipid Reserves: Parental Investment in Kinosternid Turtles from the Southeastern United States

Nagle, Roy D.; Burke, Vincent J.; Congdon, Justin D.

doi:10.1016/s0305-0491(98)10003-2

Cited by 38 publications

(31 citation statements)

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“…Residual yolk in reptiles and birds has long been recognized as critical to the survival of neonates. Lipid contents in hatchling turtles reach around 30% (Rowe et al, 1995;Nagle et al, 1998). Triacylglycerols (TAG), the principal yolk lipid…”

Section: Oxidative Metabolismmentioning

confidence: 99%

“…Therefore, stored lipids are used mainly to maintain the energy demand during the early stages of development. According to Nagle et al (1998), lipid reserves represent a substantial proportion of kinosternid parental investment and the stored lipids may sustain standard metabolic rates of 0.06 mL O 2 g -1 h -1 for more than 180 days. However, lipids may not be the sole fuel used to meet the energy needs of an animal.…”

Section: Introductionmentioning

confidence: 99%

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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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Section: Oxidative Metabolismmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

2009

Braz. J. Biol.

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“…Because energy exchange for individual eggs and hatchlings is limited to water, gases, and occasionally materials in the nest soil (Packard et al 2001;Costanzo et al 2003), extended periods spent in the nest require hatchlings to have high levels of energy reserves (Congdon 1989;Congdon and Gibbons 1990;Nagle et al 1998). In general, species whose hatchlings delay emergence from the nest allocate higher amounts of energy storage lipids, such as triacylglycerol, to eggs compared with species whose hatchlings exhibit early emergence (Congdon andGibbons 1985, 1990;Rowe et al 1995;Nagle et al 1998Nagle et al , 2003. Although patterns of lipid storage and utilization in G. geographica eggs and hatchlings have not been investigated, we predict that compared with other turtle species, they contain high amounts of energy storage lipids.…”

Section: Discussionmentioning

confidence: 97%

Overwintering in the nest by hatchling map turtles (Graptemys geographica)

Nagle¹,

Lutz²,

Pyle³

2004

Can. J. Zool.

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We monitored 75 natural nests of Graptemys geographica (Lesueur, 1817) in central Pennsylvania to determine the tactics and patterns of hatchling emergence. Following incubation, all hatchlings in 95% of nests delayed emergence from their natal nest cavities throughout autumn and winter until the following spring. Nests were constructed in a variety of substrates ranging from loose sand or coal to hard-packed clay mixed with gravel. Time from egg deposition to natural hatchling emergence averaged 333 days. During winter, hatchlings tolerated subzero temperatures as low as -8°C, which are lethal to hatchlings of some sympatric species. Emergence occurred from 10 April to 25 May, and most hatchlings were found during morning following rain. There was an interactive effect of minimum daily air temperature and rainfall level 1 day prior to emergence on the number of hatchlings emerging each day. One half of all hatchlings found dead were contained in nests in which autumn emergence had apparently occurred. We speculate that autumn emergence by hatchlings of some turtle species may be an adaptive response to nest conditions likely to provide poor environments for successful overwintering.Résumé : Nous avons suivi 75 nids naturels de Graptemys geographica (Lesueur, 1817) dans le centre de la Pennsylvanie afin de déterminer les stratégies et les patterns d'émergence des nouveau-nés. Après l'incubation, dans 95 % des nids, tous les nouveau-nés retardent leur émergence de la cavité du nid natal pendant l'automne et l'hiver jusqu'au printemps suivant. Les nids sont construits dans une variété de substrats, allant de sable ou de charbon non consolidé à de la glaise compacte mêlée de gravier. Le temps entre la ponte des oeufs et l'émergence naturelle des petits est en moyenne de 333 jours. En hiver, les petits supportent le gel jusqu'à -8°C, des températures létales pour les nouveaunés de quelques autres espèces sympatriques. L'émergence a eu lieu du 10 avril au 25 mai et la plupart des petits ont été retrouvés le matin après une pluie. Il y a un effet interactif entre la température minimale journalière de l'air et la quantité de précipitations la veille de l'émergence, d'une part, et le nombre de petits qui émergent chaque jour, d'autre part. La moitié de tous les nouveau-nés trouvés morts proviennent de nids où il s'est apparemment produit une émer-gence d'automne. Nous posons l'hypothèse que l'émergence à l'automne des nouveau-nés chez certaines espèces de tortues peut être une réaction adaptative à des conditions dans le nid qui vont vraisemblablement fournir un mauvais environnement pour survivre à l'hiver.[Traduit par la Rédaction] Nagle et al. 1218

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“…But the structure, composition and the mechanism of mineralization of them have not been investigated clearly by modern methodology and instrumentation. Actually, the metabolism of calcium during the incubation of an egg embryo has attracted much attention (Cheville and Coignoul, 1984;Riazi et al, 1988;Nagle et al, 1998;Davis and Ackerman, 1987;Ono and Tuan, 1991;Lue et al, 1999;Packard et al, 1998). The methodology employed in most of the previous work was using a weighing process to measure the change of mass fraction of calcium during different development periods; however, little work considered the compound state of the calcium, the potential organic template and its templation effect in the mineralization of spherocrystals.…”

Section: Introductionmentioning

confidence: 99%