Use of portable ultrasonography as a nondestructive method for estimating reproductive effort in lizards

Gilman, Casey; Wolf, Blair O.

doi:10.1242/jeb.001875

Cited by 35 publications

(47 citation statements)

References 41 publications

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“…A similar result was found in the closely related viviparous blotched blue-tongue lizard, Tiliqua nigrolutea, in which gestation could not be confirmed radiographically until the presence of fetal skulls and mandibles in late gestation (Gartrell et al, 2002). Ultrasonography was found to have moderate to high accuracy in determining gestation throughout the reproductive cycle in T. nigrolutea (Gartrell et al, 2002) and in five species of oviparous lizards (Gilman and Wolf, 2007); however, the heavily ossified scales in T. rugosa result in poor signal penetrance and thus ultrasonography is not useful in determining gestation in this species (S.L.M., personal observation).…”

Section: Discussion Imagingsupporting

confidence: 70%

Gestation increases the energetic cost of breathing in the lizard, Tiliqua rugosa

Munns

2012

Journal of Experimental Biology

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SUMMARYHigh gestational loads result in fetuses that occupy a large proportion of the body cavity and may compress maternal organs. Compression of the lungs results in alterations in breathing patterns during gestation, which may affect the energetic cost of breathing. In this study, the energetic cost of breathing during gestation was determined in the viviparous skink Tiliqua rugosa. Radiographic imaging showed progressive lung compression during gestation and a 30% reduction in the lung inflation index (rib number at which the caudal margin of the lung was imaged divided by total rib number). Pneumotachography and open flow respirometry were used to measure breathing patterns and metabolic rates. Gestation induced a twofold increase in minute ventilation via increases in breathing frequency, but no change in inspired tidal volume. The rates of O 2 consumption and CO 2 production did not change significantly during gestation. Together, these results suggest that a relative hyperventilation occurs during gestation in T. rugosa, which in turn suggests that diffusion and/or perfusion limitations may exist at the lung during gestation. The energetic cost of breathing was estimated as a percentage of resting metabolic rate using hypercapnia to stimulate ventilation at different stages of pregnancy. The energetic cost of breathing in non-pregnant lizards was 19.96±3.85% of resting metabolic rate and increased threefold to 62.80±10.11% during late gestation. This significant increase in the energetic cost of breathing may have significant consequences for energy budgets during gestation.

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Section: Discussion Imagingsupporting

confidence: 70%

Gestation increases the energetic cost of breathing in the lizard, Tiliqua rugosa

Munns

2012

Journal of Experimental Biology

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“…A visualização adequada dos folículosovarianos sofre influência do ciclo reprodutivo, conforme descrições de Bizerra et al (2005), Martinez-Torres et al (2006) e (Gilman & Wolf (2007). Quando visualizados, os folículos apresentaram aparência ultra-sonográfica definidas como estruturas anecóicas com margens anecogênicas e conteúdo parenquimal misto, particularmente pelo acúmulo de vitelo, semelhante ao que foi observado por Rostal & Robeck (1989) e por Rostal et al (1998) e Robeck et al (1990 em repteis.…”

Section: Discussionunclassified

Ultra-sonografia do fígado, aparelho renal e reprodutivo da jibóia (Boa constrictor)

et al. 2009

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RESUMO.-Atualmente os animais silvestres têm despertado o interesse particular na criação domestica. Na medicina de animais selvagens, os exames ultra-sonográficos podem ser considerados como ferramenta para diagnosticar e prevenir doenças. Deste modo, realizou-se um estudo em 20 jibóias (Boa constrictor), a fim de caracterizar a morfologia e aparência ultra-sonográfica das estruturas presentes da cavidade celomática desses animais. Ultra-sonograficamente, o fígado apresentou-se variando de hipoecóica a levemente hiperecogênica, com margens ecogênicas e ecotextura homogênea em toda sua extensão. Os rins mostraram formato elipsóide, com cápsula fina, regular e hiperecóica. Os folículos ovarianos apresentaram formato ovóide, margens finas, regulares e discretamente hiperecóicas. As estruturas do sistema reprodutor do macho não foram evidenciadas com precisão, devido a sua ecogenicidade similar em relação às Currently, wild animals have been received special attention for domestic breeding. In Wild Animal Medicine, ultrasonographic exams could be considered as a tool to diagnose and prevent disease. Ultrasonographic examination of twenty snakes (Boa constrictor) was performed in order to describe the morphological and ultrasonography appearance of their coelomic structures. Examination by ultrasonography revealed the parechymal liver ranging from slightly hypoechogenic to hyperechogenic, with echogenic margins and homogeneous echotexture in total scanning of this organ. The kidney was accessible for examination by sagittal ultrasound, showing an ellipsoid shape, a hyperechogenic capsule with a thin and regular wall. Ultrasonographic scanning of ovarian follicle showed an ovoid shape, as well as a thin, regular and slightly hyperechogenic edge. No evident structures from male reproductive system were identified by ultrasound examination because of their similar echogenic appearance to the tissues around and the "body fat" that lies in this region. Examination by ultrasound of the coelomic structures was a fast and repeatable technique, which provides useful data to recognize the morphology, sintopy and ultrasonographic appearance of organs such as liver, kidneys and vitellogenic follicles.INDEX TERMS: Boa constrictor snake, ultrasound, wild animals, Amazon.

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“…After each V O2 measurement, the female underwent an ultrasound (Sonosite MicroMaxx, Inc., Bothell, WA, USA) examination to determine when the female went from the vitellogenic stage (spherical follicles in the middle of the coelomic cavity) to the post-ovulation stage (ellipsoidal ova aligned in the uterus) (Gilman and Wolf, 2007). This enabled us to identify for each female a vitellogenic stage (VIT) and, about 8-9 days later, an early postovulation stage (OV).…”

Section: Ultrasound Monitoring and Identification Of Reproductive Stagesmentioning

confidence: 99%

Influence of reproductive mode on metabolic costs of reproduction: insight from the bimodal lizard Zootoca vivipara

Foucart

Lourdais

DeNardo

et al. 2014

Journal of Experimental Biology

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Examination of the selective forces behind the transition from oviparity to viviparity in vertebrates must include an understanding of the relative energy costs of the two reproductive modes. However, interspecific comparisons of reproductive mode are confounded by numerous other inherent differences among the species. Therefore, we compared oxygen consumption, as a reflection of energy costs, during reproduction in oviparous and viviparous females of the reproductively bimodal lizard Zootoca vivipara (Jaquin 1787). Female oxygen consumption progressively increased over the course of reproduction, peaking just prior to parition when it was 46% (oviparous form) and 82% (viviparous form) higher than it was at the pre-reproductive stage. Total increase in oxygen consumption (TIOC) during the pre-ovulation period was not different between the reproductive modes. Conversely, post-ovulation TIOC was more than three times higher in viviparous females, reflecting a dramatic increase in embryonic metabolism as well as maternal metabolic costs of pregnancy (MCP). MCP accounted for 22% of total metabolism in viviparous females, whereas it was negligible in oviparous females. Our results demonstrate that egg retention through the first third of development, as is typical of most oviparous squamates, entails minimal maternal energy demand, while extending retention imposes much greater metabolic constraints. Selection for transition from oviparity to viviparity must therefore provide benefits that outweigh not only the added burden associated with prolonged embryonic retention, but also the substantial additional energy costs that are incurred.

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Use of portable ultrasonography as a nondestructive method for estimating reproductive effort in lizards

Cited by 35 publications

References 41 publications

Gestation increases the energetic cost of breathing in the lizard, Tiliqua rugosa

Gestation increases the energetic cost of breathing in the lizard, Tiliqua rugosa

Ultra-sonografia do fígado, aparelho renal e reprodutivo da jibóia (Boa constrictor)

Influence of reproductive mode on metabolic costs of reproduction: insight from the bimodal lizard Zootoca vivipara

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