The adaptive significance of a complex caudal adaptation in the tropical gekkonid lizard Lygodactylus klugei

1982 ◽  
Vol 60 (11) ◽  
pp. 2582-2587 ◽  
Author(s):  
Laurie J. Vitt ◽  
Royce E. Ballinger
Keyword(s):  
Natural Population ◽  
Energy Content ◽  
Adaptive Significance ◽  
Tail Loss ◽  
Tail Autotomy ◽  
Rapid Regeneration

The tail of the Brazilian gekkonid lizard, Lygodactylus klugei, exhibits a suite of characteristics associated with both tail retention and tail loss adaptations. Tails are specialized for locomotion, possess specialized cutaneous glands, and are high in lipid and energy content. Tail loss in a natural population, however, is high and presumably associated with escape from predation via tail autotomy. The importance of the presence of a complete tail both functionally and for future predator escape is reflected by rapid regeneration of a tail complete with specialized functionally important structures.

Sexual Dimorphism in the Ease of Tail Autotomy: Uta stansburiana with and without Previous Tail Loss

Copeia ◽  
1998 ◽  
Vol 1998 (2) ◽  
pp. 376 ◽  
Author(s):  
Stanley F. Fox ◽  
Jason M. Conder ◽  
Allie E. Smith
Keyword(s):  
Sexual Dimorphism ◽  
Tail Loss ◽  
Uta Stansburiana ◽  
Tail Autotomy

Unveiling a spatial tail breakage outbreak in a lizard population

2017 ◽  
Vol 38 (2) ◽  
pp. 238-242
Author(s):  
Conrado Galdino ◽  
Stefânia Ventura ◽  
Gladston Moreira
Keyword(s):  
Body Size ◽  
Cluster Formation ◽  
Spatial Relation ◽  
Spatial Cluster ◽  
Intraspecific Aggression ◽  
Agonistic Interactions ◽  
Ecological Attributes ◽  
Tail Loss ◽  
Tail Autotomy

Many ecological attributes of organisms vary spatially. This strict dependency upon space generally arises by individuals occupying places with the necessary resources and conditions for survival. For lizards, losing the tail is an evolved mechanism that allows them to escape predators or to avoid aggressive intraspecific agonistic interactions. We evaluated the spatial relation of tail loss in a population of the lizard Tropidurus montanus. Our results support the occurrence of a spatial cluster of autotomized lizards. However, we cannot relate the cluster formation to the crowding of neighbouring lizards nor to individuals’ body size. Tail loss in lizards is known to be related to predatory attacks or intraspecific aggression, and we now show that tail autotomy occurs in a non-random way regarding space, and thus is also related to the space occupied by individuals in populations.

scholarly journals Tail loss affects fecundity but not offspring traits in the Chinese skink Eumeces chinensis

2012 ◽  
Vol 58 (2) ◽  
pp. 228-235 ◽  
Author(s):  
Hongliang Lu ◽  
Jianfang Gao ◽  
Xiaohao Ma ◽  
Zhihua Lin ◽  
Xiang Ji
Keyword(s):  
Reproductive Investment ◽  
Distal Portion ◽  
Abdominal Fat ◽  
Offspring Size ◽  
Middle Portion ◽  
Major Site ◽  
Tail Loss ◽  
Tail Autotomy ◽  
Model Animal ◽  
Fat Bodies

Abstract We used the Chinese skink Eumeces chinensis as a model animal to study the effects of tail loss on reproductive investment and offspring traits. A total of 147 wild-captured adult females were divided into four groups according to their tail conditions. Tail breaks occurred most frequently in the proximal portion of the tail and least frequently in the distal portion, with the middle portion in between. This finding suggests that tail breaks occurring in nature often entails substantial energetic costs in E. chinensis where the tail is a major site of energy storage. The proportion of females that laid eggs was higher in females with intact or completely regenerated tails than in those with broken tails. Following whole-tail autotomy, the clutch size was reduced by 17%, and the clutch mass was reduced by 14%. Females undergoing substantial tail autotomy reduced reproductive investment, and they did so by reducing the number but not the size of eggs produced. None of the egg and hatchling traits was affected by tail loss. Comparing our data with those reported for other oviparous and viviparous skinks allows us to draw two general conclusions: one is that fecundity (clutch or litter size) is affected by tail loss in all species so far studied, whereas offspring size is affected by tail loss in some species, but not in others; the other is that the reduction in fecundity following tail loss is more evident in species lacking abdominal fat bodies [Current Zoology 58 (2): 228–235, 2012].

Another potential cost of tail autotomy: tail loss may result in high ectoparasite loads in Sceloporus lizards

2018 ◽  
Vol 39 (2) ◽  
pp. 191-202 ◽  
Author(s):  
Víctor Argaez ◽  
Israel Solano-Zavaleta ◽  
J. Jaime Zúñiga-Vega
Keyword(s):  
Body Condition ◽  
Rainy Season ◽  
Lizard Species ◽  
Potential Cost ◽  
Tail Regeneration ◽  
Tail Loss ◽  
Tail Autotomy ◽  
Vital Functions ◽  
Trade Offs ◽  
Ectoparasite Load

Abstract Tail autotomy is a common phenomenon in lizards that increases the chances of immediate survival during a predation event or agonistic encounter. However, despite short-term benefits, tail regeneration may also impose costs. Several studies have demonstrated that tail loss compromises other vital functions such as lipid storage, reproduction, and the immune system. Several lizard species are hosts of mites and ticks. Here we evaluated in three lizard species from the genus Sceloporus, whether individuals that have lost their tails and invested energy in tail regeneration are more susceptible to ectoparasites. Using a multimodel inference framework, we examined if tail loss and regeneration, as well as sex, body condition, and season (dry or rainy) predict ectoparasite load. Our results indicate that investing energy and resources in tail regeneration compromises defence against ectoparasites. These costs differed between sexes and among species. Overall, ectoparasite load increases during the rainy season and is on average higher in males. In S. grammicus, during the rainy season, males with regenerated tails and in poor body condition had more ectoparasites than males with intact tails in good body condition. In S. megalepidurus, we observed the same effect during the rainy season but in females rather than males. In S. torquatus, we found no effect of tail loss on ectoparasite load. We discuss the possibility that differences observed among species reflect differences in both species-specific physiological trade-offs and local environmental conditions.

Geckos: Adaptive Significance and Energetics of Tail Autotomy

Science ◽  
1974 ◽  
Vol 184 (4144) ◽  
pp. 1379-1380 ◽  
Author(s):  
J. D. Congdon ◽  
L. J. Vitt ◽  
W. W. King
Keyword(s):  
Adaptive Significance ◽  
Tail Autotomy

scholarly journals Cutaneous tactile sensitivity before and after tail loss and regeneration in the leopard gecko (Eublepharis macularius)

2021 ◽  
pp. jeb.234054
Author(s):  
Stefanie S. Bradley ◽  
Erika Howe ◽  
Leah R. Bent ◽  
Matthew K. Vickaryous
Keyword(s):  
Sudden Change ◽  
The Body ◽  
Tactile Sensitivity ◽  
Predator Detection ◽  
Natural Form ◽  
Tail Regeneration ◽  
Tail Loss ◽  
Eublepharis Macularius ◽  
Tail Autotomy ◽  
Leopard Gecko

Amongst tetrapods, mechanoreceptors on the feet establish a sense of body placement and help to facilitate posture and biomechanics. Mechanoreceptors are necessary for stabilizing the body while navigating through changing terrains or responding to a sudden change in body mass and orientation. Lizards such as the leopard gecko (Eublepharis macularius) employ autotomy – a voluntary detachment of a portion of the tail, to escape predation. Tail autotomy represents a natural form of significant (and localized) mass loss. Semmes-Weinstein monofilaments were used to investigate the effect of tail autotomy (and subsequent tail regeneration) on tactile sensitivity of each appendage of the leopard gecko. Prior to autotomy, we identified site-specific differences in tactile sensitivity across the ventral surfaces of the hindlimbs, forelimbs, and tail. Repeated monofilament testing of both control (tail-intact) and tail loss geckos had a significant sensitization effect (i.e., decrease in tactile threshold, maintained over time) in all regions of interest except the palmar surfaces of the forelimbs in post-autotomy geckos, compared to baseline testing. Although the regenerated tail is not an exact replica of the original, tactile sensitivity is shown to be effectively restored at this site. Re-establishment of tactile sensitivity on the ventral surface of the regenerate tail points towards a (continued) role in predator detection.

Tail loss reduces locomotor ability but not metabolic rate in a viviparous skink, Sphenomorphus indicus

2013 ◽  
Vol 63 (3) ◽  
pp. 369-380 ◽  
Author(s):  
Hong-Liang Lu ◽  
Xiang Ji ◽  
Wei-Guo Du
Keyword(s):  
Metabolic Rate ◽  
Stride Length ◽  
Stride Frequency ◽  
Minor Effect ◽  
Lizard Species ◽  
Tail Regeneration ◽  
Tail Loss ◽  
Tail Autotomy ◽  
Locomotor Impairment ◽  
Locomotor Costs

Tail autotomy is an efficient predator escape form, but imposes locomotor costs in many lizard species. It has been hypothesized that locomotor impairment following tail autotomy results from the altered running dynamics or loss of energy available for locomotion, but there is a paucity of data available to demonstrate such effects. We evaluated the locomotor costs of tail loss in a viviparous skink, Sphenomorphus indicus, and examined whether locomotor costs were related to changes in gait characteristics and metabolic rate. Of 24 field-captured adult males with original intact tails, 12 individuals were used as experimental animals, and the remaining 12 as controls. Locomotor performance and CO2 production were measured for the experimental skinks before and after tail removal; the same parameters were measured at the same time for the control skinks. Compared with tailed skinks, the mean locomotor speed and stamina of tailless skinks was reduced by approximately 26% and 17%, respectively. At any given speed, tailless skinks had a shorter stride length for hindlimbs (but not for forelimbs) and a greater stride frequency than did tailed skinks. In S. indicus, locomotor impairment may be a result of the reduced stride length, and energetic constraints on stride frequency. We found no significant change in standard metabolic rate after the skinks underwent tail removal, which may reflect a minor effect on energy expenditure for maintenance. Although the reduction in metabolically active tissue might cause a lower metabolic rate, tail regeneration counteracted such an effect because it was energetically expensive.

Demonstrating Nutrient Cost Gradients: A Brooklyn Case Study

2014 ◽  
Vol 84 (5-6) ◽  
pp. 244-251 ◽  
Author(s):  
Robert J. Karp ◽  
Gary Wong ◽  
Marguerite Orsi
Keyword(s):  
Low Income ◽  
Energy Content ◽  
Food Selection ◽  
The United States ◽  
United States Department ◽  
Micronutrient Deficiencies ◽  
Caloric Density ◽  
Low Income Families ◽  
The Cost ◽  
The Impact

Abstract. Introduction: Foods dense in micronutrients are generally more expensive than those with higher energy content. These cost-differentials may put low-income families at risk of diminished micronutrient intake. Objectives: We sought to determine differences in the cost for iron, folate, and choline in foods available for purchase in a low-income community when assessed for energy content and serving size. Methods: Sixty-nine foods listed in the menu plans provided by the United States Department of Agriculture (USDA) for low-income families were considered, in 10 domains. The cost and micronutrient content for-energy and per-serving of these foods were determined for the three micronutrients. Exact Kruskal-Wallis tests were used for comparisons of energy costs; Spearman rho tests for comparisons of micronutrient content. Ninety families were interviewed in a pediatric clinic to assess the impact of food cost on food selection. Results: Significant differences between domains were shown for energy density with both cost-for-energy (p < 0.001) and cost-per-serving (p < 0.05) comparisons. All three micronutrient contents were significantly correlated with cost-for-energy (p < 0.01). Both iron and choline contents were significantly correlated with cost-per-serving (p < 0.05). Of the 90 families, 38 (42 %) worried about food costs; 40 (44 %) had chosen foods of high caloric density in response to that fear, and 29 of 40 families experiencing both worry and making such food selection. Conclusion: Adjustments to USDA meal plans using cost-for-energy analysis showed differentials for both energy and micronutrients. These differentials were reduced using cost-per-serving analysis, but were not eliminated. A substantial proportion of low-income families are vulnerable to micronutrient deficiencies.

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