Stress and Well-being

Bobb, V.T. and D.C. Jackson (2005). Effect of graded hypoxic and acidotic stress on contractile force of heart muscle from hypoxia-tolerant and hypoxia-intolerant turtles. Journal of Experimental Zoology. Part A, Comparative Experimental Biology 303(5): 345-353. ISSN: print: 1548-8969; online: 1552-499X.
NAL Call Number: QL1.J854
Descriptors: turtles, hypoxic, acidotic, stress, heart muscle, contractile force, hypoxia tolerant, intolerant, effect.

Cree, A., C.L. Tyrrell, M.R. Preest, D. Thorburn, and L.J. Guillette (2003). Protecting embryos from stress: corticosterone effects and the corticosterone response to capture and confinement during pregnancy in a live-bearing lizard (Hoplodactylus maculatus). General and Comparative Endocrinology 134(3): 316-329. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: Hormones in the embryonic environment, including those of the hypothalamo-pituitary-adrenal (HPA) axis, have profound effects on development in eutherian mammals. However, little is known about their effects in reptiles that have independently evolved viviparity. We investigated whether exogenous corticosterone affected embryonic development in the viviparous gecko Hoplodactylus maculatus, and whether pregnant geckos have a corticosterone response to capture and confinement that is suppressed relative to that in non-pregnant (vitellogenic) females and males. Corticosterone implants (5 mg, slow-release) administered to females in mid-pregnancy caused a large elevation of corticosterone in maternal plasma (P<0.001), probable reductions in embryonic growth and development (P=0.069-0.073), developmental abnormalities and eventual abortions. Cool temperature produced similar reductions in embryonic growth and development (P< or =0.036 cf. warm controls), but pregnancies were eventually successful. Despite the potentially harmful effects of elevated plasma corticosterone, pregnant females did not suppress their corticosterone response to capture and confinement relative to vitellogenic females, and both groups of females had higher responses than males. Future research should address whether lower maternal doses of corticosterone produce non-lethal effects on development that could contribute to phenotypic plasticity. Corticosterone implants also led to increased basking in pregnant females (P<0.001), and basal corticosterone in wild geckos (independent of reproductive condition) was positively correlated with body temperature (P<0.001). Interactions between temperature and corticosterone may have broad significance to other terrestrial ectotherms, and body temperature should be considered as a variable influencing plasma corticosterone concentrations in all future studies on reptiles.
Descriptors: reptiles, lizard, gecko, embryo stress, protecting, corticosterone, effects, response, capture, confinement, pregnancy.

DeNardo, D.F. (2004). Stress and its influence on clinical disease in reptiles. In: Small Animal and Exotics Book Two: Pain Management Zoonosis Proceedings of the North American Veterinary Conference, January 17, 2004-January 21, 2004, Orlando, Florida, Eastern States Veterinary Association: Gainesville, USA, Vol. 18, p. 1326-1328. ISSN: 0341-6953.
Descriptors: reptiles, stress, influence on clinical disease, restraint.

Franklin, C.E., B.M. Davis, S.K. Peucker, H. Stephenson, R. Mayer, J. Whittier, J. Lever, and G.C. Grigg (2003). Comparison of stress induced by manual restraint and immobilisation in the estuarine crocodile, Crocodylus porosus. Journal of Experimental Zoology. Part A, Comparative Experimental Biology 298(2): 86-92. ISSN: print: 1548-8969; online: 1552-499X.
NAL Call Number: QL1.J854
Descriptors: reptiles, estuarine crocodile, Crocodylus porosus, stress, manual restraint, immobilization, electrostunning, comparison, handling methods.

French, S.S., K.S. Matt, and M.C. Moore (2006). The effects of stress on wound healing in male tree lizards (Urosaurus ornatus). General and Comparative Endocrinology 145(2): 128-132. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: Exposure to stress can affect an organism's partitioning of resources among immune function and other organismal functions. However, measuring immune function is often difficult. Recent studies show that the rate of cutaneous wound healing in laboratory rodents is a simple, integrated measure of stress-sensitive immune function. We investigated the use of this technique in tree lizards to test the hypotheses (1) that stress compromises wound healing and (2) that this effect is at least partially mediated by corticosterone. Laboratory-housed male tree lizards randomly assigned to the experimental and control treatment groups received a 3.5 mm cutaneous biopsy on the dorsal surface of the pelvis. Experimental group males were restrained in cloth bags for 60 min every day for 21 days during the healing profile, whereas control males were left in their cages. Wound sizes were measured every other day by image analysis. Control animals healed faster than stressed animals. The difference in wound surface area between the groups was most pronounced early in the healing profile. Stressed animals also had higher corticosterone levels and corticosterone was negatively correlated with healing rate in the stressed animals. These observations support both hypotheses that stress compromises healing and that corticosterone may act to mediate the effects of stress.
Descriptors: tree lizards, Urosaurus ornatus, corticosterone blood, lizards physiology, stress blood, wound healing physiology, restraint, physical, stress immunology.

Ganesh, C.B. and H.N. Yajurvedi (2002). Stress inhibits seasonal and FSH-induced ovarian recrudescence in the lizard, Mabuya carinata. Journal of Experimental Zoology. 292(7): 640-648. ISSN: print: 0022-104X; online: 1097-010X.
NAL Call Number: 410 J825
Descriptors: reptiles, lizard, Mabuya carinata, stress, inhibits, FSH induced, ovarian recrudescence.

Harms, C.A., K.M. Mallo, P.M. Ross, and A. Segars (2003). Venous blood gases and lactates of wild loggerhead sea turtles (Caretta caretta) following two capture techniques. Journal of Wildlife Diseases 39(2): 366-374. ISSN: 0090-3558.
NAL Call Number: 41.9 W64B
Abstract: During summer of 2001, venous blood gases were determined in loggerhead sea turtles (Caretta caretta) captured by trawl (n = 16) in coastal waters of South Carolina and Georgia (USA) as part of a sea turtle census program and captured in pound nets (n = 6) in coastal North Carolina (USA) during a study of sea turtle population biology. Trawls were towed for 30 min, so turtles captured were forcibly submerged for < or = 30 min. Pound nets are passive gear in which fish and sea turtles are funneled into a concentrated area and removed periodically. Sea turtles in pound nets are free to surface and to feed at will. Blood was obtained from the dorsal cervical sinus as quickly as possible after landing on the boat (range 2-10 min trawl, 1-2 min pound net) and at 30 min after landing just prior to release. Blood gases including pH, partial pressures of O2 and CO2 (pO2, pCO2), and lactate were measured within 10 min. Instrument measurements for pH, pO2, and pCO2 made at 37 C were corrected to cloacal temperature and HCO3- was calculated from temperature-corrected pH and pCO2. Venous blood pH and bicarbonate were higher, and pO2 and lactate were lower from pound net-captured turtles compared to trawl captured turtles at the initial sampling time. In pound net turtles, pH and bicarbonate declined and lactate increased during 30 min on deck. In trawled sea turtles, venous blood pH increased and pCO2 and pO2 decreased during the 30 min on deck. Both capture systems caused perturbations in blood gas, acid-base, and lactate status, though alterations were greater in trawl captured turtles.
Descriptors: reptiles, loggerhead sea turtles, Caretta caretta, wild, capture techniques, venous blood gases, lactates, acid-base.

Jessop, T.S., J.M. Sumner, C.J. Limpus, and J.M. Whittier (2004). Interplay between plasma hormone profiles, sex and body condition in immature hawksbill turtles (Eretmochelys imbricata) subjected to a capture stress protocol. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 137(1): 197-204. ISSN: 1095-6433.
Abstract: We investigated plasma hormone profiles of corticosterone and testosterone in immature hawksbill turtles (Eretmochelys imbricata) in response to a capture stress protocol. Further, we examined whether sex and body condition were covariates associated with variation in the adrenocortical response of immature turtles. Hawksbill turtles responded to the capture stress protocol by significantly increasing plasma levels of corticosterone over a 5 h period. There was no significant sex difference in the corticosterone stress response of immature turtles. Plasma testosterone profiles, while significantly different between the sexes, did not exhibit a significant change during the 5 h capture stress protocol. An index of body condition was not significantly associated with a turtle's capacity to produce plasma corticosterone both prior to and during exposure to the capture stress protocol. In summary, while immature hawksbill turtles exhibited an adrenocortical response to a capture stress protocol, neither their sex nor body condition was responsible for variation in endocrine responses. This lack of interaction between the adrenocortical response and these internal factors suggests that the inactive reproductive- and the current energetic- status of these immature turtles are important factors that could influence plasma hormone profiles during stress.
Descriptors: reptiles, immature hawksbill turtle, Eretmochelys imbricata, capture stress protocol, interplay, plasma hormone profiles, sex and body condition.

Lance, V.A., R.M. Elsey, G. Butterstein, and P.L.I. Trosclair (2004). Rapid suppression of testosterone secretion after capture in male American alligators (Alligator mississippiensis). General and Comparative Endocrinology 135(2): 217-222. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Descriptors: reptiles, alligator, Alligator mississippiensis, capture, stress, testosterone suppression, corticosterone increase.

Langkilde, T. and R. Shine (2006). How much stress do researchers inflict on their study animals? A case study using a scincid lizard, Eulamprus heatwolei. Journal of Experimental Biology. 209(Pt 6): 1035-1043. ISSN: 0022-0949.
Online: http://dx.doi.org/10.1242/jeb.02112
NAL Call Number: 442.8 B77
Abstract: Research on live vertebrates is regulated by ethics committees, who prohibit ;excessively stressful' procedures. That judgment is based on intuition - a notoriously unreliable criterion when dealing with animals phylogenetically distant from humans. To objectively evaluate the stress imposed by research practices, we measured plasma corticosterone levels in lizards (Eulamprus heatwolei Wells & Wellington, Scincidae). Some procedures (handling and measuring, toe-clipping for identification, exposure to predator scent) did not induce significant increases in corticosterone levels, suggesting that these stimuli generated relatively little stress. However, other stimuli (testing locomotor speed, microchip implantation, blood sampling, an unfamiliar enclosure, tail autotomy, exposure to a heterospecific lizard) were more stressful, with corticosterone levels increasing only transiently in some treatments (<2 h for tail autotomy), but persisting much longer in others (14 days for microchip implantation). Overall, our data suggest that the levels of stress induced by routine laboratory procedures are no greater than those often experienced by lizards in nature; but that intuition provides a poor basis for evaluating the levels of stress induced by research. For example, toe-clipping is often criticized and sometimes banned; but our data suggest that this method is actually less stressful than the technique frequently recommended to replace it on ethical grounds (microchip implantation). Toe-clipping also was less stressful than superficially trivial manipulations such as housing the animal in an unfamiliar enclosure. More generally, we urge researchers to seek objective information on the effects of their activities on research subjects, rather than relying upon subjectivity and anthropomorphism in making these evaluations.
Descriptors: lizards (Eulamprus heatwolei) laboratory, corticosterone blood, lizards physiology, stress, psychological etiology, acclimatization, lizard husbandry methods, lizardl husbandry standards, handling psychology.

Lutterschmidt, D.I. and R.T. Mason (2005). A serotonin receptor antagonist, but not melatonin, modulates hormonal responses to capture stress in two populations of garter snakes (Thamnophis sirtalis parietalis and Thamnophis sirtalis concinnus). General and Comparative Endocrinology 141(3): 259-270. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: Hormonal and behavioral responses to a stressor depend on many factors, including the influence of other hormones. We examined the role of melatonin in modulating hormonal responses to capture stress in two populations of male garter snakes, Thamnophis sirtalis. Studies of red-sided (T. sirtalis parietalis) and red-spotted (T. sirtalis concinnus) garter snakes were conducted in the field with free-living snakes. Populations of red-sided garter snakes in south-central Manitoba, Canada undergo a period of winter dormancy for approximately 8 months each year followed by an attenuated mating season (4-5 weeks) in early spring. In contrast, the mid-latitude red-spotted garter snake in western Oregon, USA has an extended breeding season and can be active during 10-12 months of the year given appropriate environmental conditions. We chose to study these two populations of garter snakes to investigate possible variation in melatonin function among snakes with different suites of environmental adaptations. To better address these questions, we also examined the effects of 5-hydroxytryptophan (a precursor of melatonin synthesis) and ketanserin (a serotonergic type 2A receptor antagonist) on hormonal responses to capture stress. We observed a trend of increased corticosterone and decreased androgen concentrations in northern-latitude red-sided garter snakes (T. sirtalis parietalis) subjected to 4 h of capture stress during the spring. However, these differences were not statistically significant. During the fall, red-sided garter snakes showed no change in corticosterone or androgen concentrations in response to the capture stress treatments. We speculate that northern-latitude red-sided garter snakes suppress hormonal responses to capture stress during preparation for winter dormancy. Treatment with melatonin, 5-hydroxytryptophan, or ketanserin did not significantly influence corticosterone or androgen concentrations of northern-latitude red-sided garter snakes during the spring or fall. Mid-latitude red-spotted garter snakes (T. sirtalis concinnus) from Oregon showed a statistically significant increase in corticosterone concentrations in response to 4 h of capture stress; treatment with melatonin, 5-hydroxytryptophan, or ketanserin prior to capture stress had no significant influence on plasma corticosterone concentrations. Androgen concentrations of mid-latitude red-spotted garter snakes in response to capture stress were significantly lower than those of non-stressed control snakes. Neither melatonin nor 5-hydroxytryptophan influenced the change in androgen concentrations during capture stress. However, androgen concentrations of snakes treated with ketanserin prior to 4 h of capture stress did not differ significantly from those of non-stressed control snakes. These studies suggest that melatonin does not modulate hormonal responses to capture stress in this ectothermic model. Our results also suggest that a serotonin-regulated system may play a role in modulating the activity of the hypothalamic-pituitary-gonadal axis during physiological stress responses.
Descriptors: garter snakes, Thamnophis sirtalis parietalis and Thamnophis sirtalis concinnus, capture stress, serotonin receptor antagonist, melatonin, hormonal response, modulates, stressor, behavioral response.

McMann, S. and A.V. Paterson (2003). Effects of capture, observer presence, and captivity on display behavior in a lizard. Journal of Herpetology 37(3): 538-540. ISSN: 0022-1511.
NAL Call Number: QL640.J6
Descriptors: reptiles, lizard, behavior, captivity, display, observer presence, capture, effects.

Woodley, S.K. and M.C. Moore (2002). Plasma corticosterone response to an acute stressor varies according to reproductive condition in female tree lizards (Urosaurus ornatus). General and Comparative Endocrinology 128(2): 143-148. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: The magnitude of the glucocorticoid response to a stressor can depend on both environmental and physiological context. One factor that has not been examined is whether females of different reproductive states have different responses to a stressor. We examined whether corticosterone (CORT) increased after a 10 min handling stress in oviparous female tree lizards (Urosaurus ornatus) that were vitellogenic (yolking follicles) or gravid (post-ovulatory). We found that stressed vitellogenic females had a large increase in plasma CORT whereas gravid females did not. Baseline levels of CORT in gravid females were relatively high and similar to those in stressed vitellogenic females. The lack of a stress response in gravid females may be due to an inability to secrete higher levels of CORT or a suppression of the stress response. In addition, within vitellogenic females, CORT was positively correlated with ovarian weight, suggesting that CORT may function in some aspect of ovarian development during vitellogenesis.
Descriptors: reptiles, female tree lizards, Urosaurus ornatus, plasma corticosterone response, acute stressor, reproductive condition.

Yajurvedi, H.N. and S. Menon (2005). Influence of stress on gonadotrophin induced testicular recrudescence in the lizard Mabuya Carinata. Journal of Experimental Zoology. Part A, Comparative Experimental Biology 303(7): 534-540. ISSN: print: 1548-8969; online: 1552-499X.
NAL Call Number: QL1.J854
Abstract: Administration (ip) of FSH (10 IU/0.1 ml distilled water (dw)/lizard/alternate days/30 days) to adult male lizards, Mabuya carinata, during the early recrudescence phase of the reproductive cycle caused activation of spermatogenic and steroidogenic activity of the testis, as shown by a significant increase in mean number of spermatogonia, primary spermatocytes and spermatids, and serum levels of testosterone, as compared to initial controls. In addition, there were abundant spermatozoa in the lumen of the seminiferous tubules. Interestingly, administration of a similar dosage of FSH to lizards exposed to stressors (handling, chasing, and noise randomly applied, five times a day for 30 days) resulted in a significant increase in mean number of spermatogonia and primary spermatocytes over initial control values, whereas the number of secondary spermatocytes and spermatids and serum levels of testosterone did not significantly differ from those of initial controls, and were significantly lower than FSH treated normal lizards. Further, spermatozoa were infrequently found in the seminiferous tubules of these lizards. Treatment controls (receiving 0.1 ml dw/lizard/alternate days for 30 days) did not show significant variation in mean number of spermatogonia, spermatocytes and spermatids, and serum levels of testosterone from initial controls. Another group of lizards was exposed to stressors and did not receive FSH. These lizards showed a significant decrease in mean number of secondary spermatocytes compared to treatment controls and all other parameters did not significantly differ from those of both control groups. The results reveal that gonadotrophin-induced spermatogonial proliferation occurs under stressful conditions, whereas progress of spermatogenesis beyond primary spermatocyte stage is impaired due to inhibition (under stress) of gonadotrophin induced steroidogenic activity in M. carinata.
Descriptors: lizard, Mabuya carinata, stress, influence, gonadotrophin, induced testicular recrudescence, reproductive cycle, distilled water, testosterone, serum levels.

Zhou, X., C. Niu, and R. Sun (2004). The effects of vitamin E on antiacid stress ability in juvenile soft-shelled turtles (Pelodiscus sinensis). Comparative Biochemistry and Physiology. Part C Toxicology and Pharmacology 137(4): 299-305. ISSN: 1532-0456.
Abstract: We determined the effect of dietary supplementation with vitamin E (0-, 50-, 250-, 500-, 1000- and 5000-mg/kg diet for 4 weeks) on antistress ability in juvenile soft-shelled turtle (Pelodiscus sinensis). Half of the turtles per dose group were treated by acid stress for 24 h. The results showed that phagocytosis of blood cells in the control group significantly decreased after acid stress while the other five groups had no significant changes compared with those of before stress. Serum bacteriolytic activity in the control group and the group supplemented with 50-mg vitamin E/kg diet significantly decreased after acid stress. The other four groups showed no significant differences compared with those before stress. Serum bactericidal activities in all groups notably decreased after acid stress, but the difference of serum bactericidal activity in before and after stress had a decreased tendency from the control group to the highest dose group. Serum cortisol levels in the control group were significantly increased while the other five groups had no notable increases after acid stress. Liver vitamin E levels in all groups had no notable changes compared with those before stress but there was a tendency to decrease after acid stress. These results suggest that acid stress depress immune function and increase serum cortisol levels in turtles while vitamin E alleviate the adverse effects caused by acid stress.
Descriptors: reptiles, soft-shelled turtles, Pelodiscus sinensis, antacid stress ability, vitamine E, effects, juvenile, dietary supplementation, immune function.

Zhou, X.Q., C.J. Niu, and R.Y. Sun (2005). The effect of vitamin C on stress withstanding capability in the juvenile soft-shelled turtle (Pelodiscus sinensis). Aquaculture Nutrition 11(3): 169-174. ISSN: 1353-5773.
NAL Call Number: SH156.A658
Descriptors: reptiles, turtle culture, soft-shelled turtle, Pelodiscus sinensis, juveniles, ascorbic acid, dietary supplements, erythrocytes, phagocytosis, animal stress, pH, water quality, blood serum, Vibrio parahaemolyticus, antimicrobial agents, disease control, Pelodiscus sinensis, acid stress.