Effect of water temperature on dietary protein requirement,growth and body composition of Asian catfish, Clarias batrachus fry

This study aimed to evaluate the protein requirement of Clarias batrachus fry, were estimated at two different water temperatures, 28 and 32 °C. The influence of dietary protein level and water temperature on body composition, weight gain, food and nutrient utilization were estimated. The Asian catfish, C. batrachus fry were fed four diets containing 28% (diet 1), 32% (diet 2), 36% (diet 3) and 40% (diet 4) protein levels and reared at two water temperatures 28 and 32 °C for 60 days. Fry fed with diet 3 containing 36% protein showed the highest mean final body weight at 32 °C. Final body weight was significantly (P<0.05) affected by dietary treatments and temperatures. Clarias batrachus fry raised at 28 °C had higher feed efficiency (93.20%) than the fry reared at 32 °C (87.58%) with 28% dietary protein level. Further, feed efficiency decreased with increase in dietary protein level. Higher daily protein retention (0.089%) observed at lower (0.0217 g) daily protein intake at 28 °C than 0.0283 g at 32 °C. While, optimal (0.0282 g) daily protein intake showed higher daily weight gain at 32 °C. Productive protein value (% PPV) was maximum (1.76%) at 32 °C than at 28 °C (0.76%). Final body lipid recorded higher value than initial body lipid at both the temperatures. Hepatosomatic index (HSI) observed to have been influenced (P<0.05) by diets and temperatures, while viscerosomatic index (VSI) affected (P<0.05) by only diets and not (P>0.05) by temperatures. The study concluded that the diet 3 containing 36% protein was optimal for growth of C. batrachus fry at both the temperatures.     

The effects of water temperature and ration size on growth and body composition of fry of common carp, Cyprinus carpio

Experiment was conducted with the aim of determining the effect of varying water temperature and ration size on growth and body composition of fry of the common carp, Cyprinus carpio. Common carp fry with an initial body weight (BW) of 0.86 g were fed a diet (34.9% protein, 18.3 KJ/g diet) at four ration sizes 4%, 5%, 6% and 7% of their body weight per day and reared at two water temperatures 28 and 32 °C for 60 days. Fry fed with 6% ration showed the highest mean final body weight at 28 °C. Final body weight was significantly (P<0.05) affected by ration and temperature. Cyprinus carpio fry raised at 28 °C had higher feed efficiency (FE) (44.36%) than the fry reared at 32 °C (40.98%) with 4% ration. Further, feed efficiency decreased with increase in ration levels in both temperatures. Protein efficiency ratio (PER) was higher (1.26) at 28 °C than at 32 °C (1.17). At 6% ration, common carp fry showed highest specific growth rate (SGR) (3.82%/day) at 28 °C as compared with at 32 °C (3.57%/day). A linear increase in protein and lipid contents was evident with increasing ration levels up to 6% body weight at both temperatures 28 and 32 °C. Second-order polynomial regression analysis of weight gain and SGR indicated the breakpoints at ration level 6.04% and 6.08% body weight per day at 28 and 32 °C. Hepatosomatic index (HSI) not affected by temperature and ration size while, viscerosomatic index (VSI) influenced (P<0.05) by ration size and temperature. Based on the above results, it may be concluded that 6% BW/day ration is optimal for growth of Cyprinus carpio fry at both the temperatures 28 and 32 °C.     

The effect of dietary protein and carbohydrate concentration on the biochemical composition and gametogenic condition of the sea urchin Lytechinus variegatus

Previously starved urchins, Lytechinus variegatus, (36.0 ± 0.8 (SE) mm test diameter) were held in replicated (3) 10-L aquaria with artificial seawater at 22 ± 2  °C and 32‰ salinity and fed three diet treatments. Urchins were fed diets containing 9 : 35, 20 : 23 or 31 : 12% dry protein: % dry carbohydrate (P : C) ad libitum for a 65-day period. Gonads from urchins fed the 9 : 35 P : C diet had similar organic, lower ash, and lower water content than urchins fed the 31 : 12 P : C protein diet. Water content varied with both diet and nutritional history; consequently, water content may have limited value as a predictor of gonad nutritional status. Protein and carbohydrate concentrations in the gonad were directly related to the dietary composition of these nutrients; gonad lipids did not vary with diet. Excess carbohydrates are frequently stored as fats in fish and mammals but this does not appear to be the case in L. variegatus. Test carbohydrate storage and gut protein storage also reflected dietary composition. Image analysis of ovaries indicated decreased nutritive phagocyte volume, increased germinal epithelium volume and larger oocyte diameters in urchins fed high protein, low carbohydrate diets. Analysis of testes also indicated decreased nutritive phagocyte volume and increased gamete volume with urchins fed high protein, low carbohydrate diets, but differences among treatments were less obvious than in ovaries. This study suggests that high protein, low carbohydrate diets promote gamete growth and development. In addition, the biochemical and gametic composition of gonads can be altered by manipulating dietary composition. This could affect the quality and value of sea urchin roe for human consumption.     

Evaporative water loss and energy metabolic in two small mammals,voles (Eothenomys miletus) and mice (Apodemus chevrieri), in Hengduan mountains region

Evaporative water loss (EWL) and energy metabolism were measured at different temperatures in Eothenomys miletus and Apodemus chevrieri in dry air. The thermal neutral zone (TNZ) of E. miletus was 22.5–30 °C and that of A. chevrieri was 20–27.5 °C. Mean body temperatures of the two species were 35.75±0.5 and 36.54±0.61 °C. Basal metabolic rates (BMR) were 1.92±0.17 and 2.7±0.5 ml O₂/g h, respectively. Average minimum thermal conductance (C_m) were 0.23±0.08 and 0.25±0.06 ml O₂/g h °C. EWL in E. miletus and A. chevrieri increased with the increase in temperature; the maximal EWL at 35 °C was 4.78±0.6 mg H₂O/g h in E. miletus, and 5.92±0.43 mg H₂O/g h in A. chevrieri. Percentage of evaporative heat loss to total heat production (EHL/HP) increased with the increase in temperature; the maximal EHL/HP was 22.45% at 30 °C in E. miletus, and in A. chevrieri it was 19.96% at 27.5 °C. The results may reflect features of small rodents in the Hengduan mountains region: both E. miletus and A. chevrieri have high levels of BMR and high levels of total thermal conductance, compared with the predicted values based on their body masses, while their body temperatures are relatively low. EWL plays an important role in temperature regulation.     

Diurnal ammonia and urea excretion rates in European sea bass, Dicentrarchus labrax fed diets containing mixtures of canola and cotton seed oil at two different ambient temperature

The knowledge about the combined effects of higher temperature and dietary nutrient quality on the diurnal nitrogenous excretion rates is very limited in farmed fish species including European sea bass. Therefore this study investigated the combined effects of increasing levels (30 vs. 60 %) of dietary fish oil replacement by equal mixture of cotton seed oil (CSO) and canola oils (CO) and two different ambient temperature (24 vs. 30 °C) on diurnal total ammonia and Urea–N excretion rates in European sea bass (Dicentrarchus labrax). Experimental diets were fed to fish three times (08:30–13:30–18:30 h) at a fixed rate of 3 % BW.d⁻¹. The daily consumed nitrogen and energy intake of fish were similar during the investigation in different dietary treatments. However, the daily excretion rates of TAN, total nitrogen (TAN+Urea–N) and total nitrogen expressed as a proportion of consumed nitrogen by the European sea bass maintained at 30 °C were found to be significantly (P<0.001) higher (40 to 50%) than fish maintained at 24 °C in all the dietary treatments suggesting higher rates of deamination of ingested amino acids with increased temperature. Daily urea–nitrogen excretion of fish accounted for between 20–30 % of total ammonia–nitrogen excretion rates for each dietary treatment at 24 and 30 °C and appeared to be slightly increased by the temperature but neither the temperature nor the amount of plant oil mixture inclusion in diets or the interaction of these two factors had a significant effect on the urea nitrogen excretion rates of fish in different dietary treatments. However, Urea–N excretion rates in fish fed fish oil only (FO) diet were significantly higher (P<0.05) compared to that of fish fed diets containing increasing amount of plant oil mixture (VOM30 and VOM 60) during the light-on phase of the sampling period at 24 °C indicating periodic enhancement of permeability for urea at excretion sites. Further research is needed in order to elucidate the mechanism of nitrogenous excretion in European sea bass fed plant oil containing diets under extreme summer time temperatures employing total dietary fish oil replacement to reveal the possible effects of alteration in cell membrane phospholipid composition on enzymes responsible for nitrogenous excretion and/or detoxification.     

Survival and behavioral characteristics of amphidromous goby larvae of Sicyopterus japonicus (Tanaka, 1909) during their downstream migration

To understand the ecology and environmental tolerances of newly hatched larvae of the amphidromous fish Sicyopterus japonicus during their downstream migration, the salinity tolerance of eggs, 0-15 day old larvae, and adults, and the temperature tolerance, specific gravity and phototaxis of hatched larvae were examined. Tolerances of adults were measured as survival after a 24 h challenge in freshwater (FW), brackish water (1/3 SW) and seawater (SW). The survival rate of adult S. japonicus was 100% in FW and 1/3 SW, while none survived in SW. Hatching success of eggs (30 eggs each) was significantly higher in FW (mean: 73%) and 1/3 SW (73%) than in SW (19%). Tolerance of newly hatched larvae to salinity and temperature was investigated in different combinations of salinities (FW, 1/3 SW and SW) and temperatures (18, 23 and 28 °C). Larval survival was significantly different in each salinity and temperature. Survival rate was significantly higher in 1/3 SW than in FW and higher in SW than in FW at 23 °C and 28 °C. At the latter part of the experiment, there was no survival in FW and at 28 °C. Survival was higher in lower temperatures, but larval development did not occur in FW. Specific gravity of newly hatched larvae was 1.036 at 28 °C and 1.034 at 23 °C. When exposed to a light source on one side of an aquarium, larval distribution was not affected. Our results indicated larval S. japonicus are more adapted to brackish water and seawater than freshwater, while the adults and eggs are more adapted to freshwater and brackish water than seawater. This is consistent with their amphidromous life history with growth and spawning occurring in freshwater and the larval stage utilizing marine habitats.     

Thermal adaptability and disease association in common carp (Cyprinus carpio communis) acclimated to different (four) temperatures

The present study was designed to investigate the effect of temperature (20 °C, 24 °C, 28 °C and 32 °C) on the heamato-biochemical and histological alterations of Cyprinus carpio communis. Increase in the temperature showed significant decrease in the serum protein, while a reduced level of blood glucose at high temperature of 32 °C was observed leading to hypoglycemic conditions in the experimental fishes. A significant correlation (P<0.01) was observed between cholesterol (Cho) and triglycerides (TG) for different temperature treatments. Elevated blood urea nitrogen (BUN) at high temperatures was a good indicator of gill osmoregulatory failure. A variation of 86.40% and 38.33%, respectively, was noticed in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) at 32 °C over minimum experimental temperature of 20 °C. The increase in red blood cell (RBC) and Heamoglobin (Hb) concentration is associated with the decrease of mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC), could be the reason for observed poikilo-anisocytosis. Histological studies of different organs of experimental fishes showed accumulation of MMC's (melanomacrophagic centers) and atrophy of the interrenal tissue on exposure to various levels of temperature. These changes were related to severity of thermal stress, being most marked when high temperature was prolonged during acclimatization. Some fishes were found infested by protozoan parasite at elevated temperature of 32 °C. Increased levels of certain biochemical and haemotological parameters studied were strongly correlated with disease in the Cyprinus carpio communis species.     

Phenotypic variation in hatchling Chinese ratsnakes (Zaocys dhumnades) from eggs incubated at constant temperatures

We incubated eggs of the Chinese ratsnake Zaocys dhumnades at four constant temperatures (24, 27, 30 and 30 °C) to examine the effects of incubation temperature on hatching success and hatchling phenotypes. Incubation length increased nonlinearly as temperature decreased, with the mean incubation length being 76.7 d at 24 °C, 57.4 d at 27 °C, 47.3 d at 30 °C, and 44.1 d at 33 °C. Hatching successes were lower at the two extreme temperatures (69% at 24 °C, and 44% at 33 °C) than at the other two moderate temperatures (96% at 27 °C, and 93% at 30 °C). Incubation temperature affected nearly all hatchling traits examined in this study. Incubation of Z. dhumnades eggs at 33 °C resulted in production of smaller hatchlings that characteristically had less-developed carcasses but contained more unutilized yolks. Hatchlings from eggs incubated at 27 and 30 °C did not differ in any examined traits. Taking the rate of embryonic development, hatching success and hatchling phenotypes into account, we conclude that the temperature range optimal for incubation of Z. dhumnades eggs is narrower than the range of 24−33 °C but should be wider than the range of 27−30 °C.     

Embryonic development rate and hatchling phenotypes in the Chinese three-keeled pond turtle (Chinemys reevesii): The influence of fluctuating temperature versus constant temperature

Although the effects of constant temperatures on hatchling traits have been extensively studied in reptiles, the effects of fluctuating temperatures remain poorly understood. Eggs of the Chinese three-keeled pond turtle (Chinemys reevesii) were incubated at a constant temperatures (28 °C) and two fluctuating temperatures (28±3 °C and 28±6 °C) to test for the influence of thermal environment on incubation duration, hatchling traits, and post-hatching growth. Incubation duration was shorter at constant temperature than at fluctuating temperatures. The sex ratio of hatchlings varied among temperature treatments, with more females from 28±6 °C than from 28 °C. The size and mass were greater for hatchlings from a constant temperature than from fluctuating ones, but this difference in body size disappeared when the hatchlings were 3 months old. In addition, the swimming ability, survival, and growth of hatchlings from fluctuating temperatures did not differ from those of hatchlings from constant temperature, when they were kept at an artificial environment without food scarcity or predation. Therefore, the thermal environments with various temperature fluctuations used in this study do not significantly affect fitness-related hatchling traits in this species.     

Lizards in the slow lane: Thermal biology of chameleons

1.

Field body temperatures (T_b's) of Chamaeleo chamaeleon in southwestern Spain averaged 28 °C in October and 30 °C in June. Slopes of regressions of T_b on T_a (ambient temperature at perch height) indicated that individuals were able to maintain a preferred body temperature of about 30 °C in June but not in October.     

Predation activity of two winter-active spiders (Araneae: Anyphaenidae,Philodromidae)

Anyphaena accentuata and Philodromus spp. are cold adapted and winter-active spider species. Their predation activity was investigated at constant temperatures between –4 and 30 °C. The lower temperature threshold for Anyphaena was –3.7 °C, while that of Philodromus was –1.2 °C. At 1 °C the latency to capture and prey consumption was significantly shorter in Anyphaena than in Philodromus. The capture rate increased with temperature and was maximal at 15 °C in Anyphaena and at 30 °C in Philodromus. At 30 °C, the latency to the capture was significantly shorter in Philodromus than in Anyphaena whose mortality significantly increased.     

Condition,growth and food conversion in barbel, Barbus barbus (L.) juveniles under different temperature/diet combinations

Populations of a rheophilic cyprinid Barbus barbus have declined in last decades, which created a need of conservation aquaculture. Production of stocking material in controlled conditions calls for optimization of the two major factors, temperature and diet. Condition, growth and food conversion ratio in fish fed a formulated diet Aller Futura were compared with those on natural food—frozen Chironomidae larvae at 17, 21 and 25 °C. Groups of 60 early juveniles (0.6–3.7 g) were reared in each of 18 aquaria in which six experimental groups were run in triplicate. Daily food ratios were adjusted according to fish biomass, differences in hydration between the two diets and rearing temperature. No mortality occurred during the experiment. Condition coefficient K was significantly higher in fish fed Aller Futura compared to those fed Chironomidae irrespective of temperature tested; body deformities were not recorded. Relative growth rate at the same temperature was always higher in fish on the formulated diet than in those fed Chironomidae, and food conversion ratio was always suppressed, both suggesting an efficient utilization of Aller Futura for growth in B. barbus early juveniles. On both diets the coefficient K was depressed at 21 °C. Relative growth rate (RGR) was accelerated with temperature according the Krogh’s “normal curve” within the range 21–25 °C, while at lower temperatures (17–21 °C) the observed values of temperature coefficient Q₁₀ were much higher than the theoretical Q₁₀ values based on Krogh’s “normal curve”. Food conversion ratios (FCR) were reduced on both diets at 21 and 25 °C. Theoretical optimum temperatures for food conversion were 22.0 and 23.6 °C. Summing up, responses of three independent indices: condition, growth and food utilization locate the optimum temperature for B. barbus between 21 and 25 °C. No evidence was found that the effect of temperature on these indices was substantially modified by the diet.     

The combined influence of sub-optimal temperature and salinity on the in vitro viability of Perkinsus marinus, a protistan parasite of the eastern oyster Crassostrea virginica

Perkinsus marinus is a major cause of mortality in eastern oysters along the Gulf of Mexico and Atlantic coasts. It is also well documented that temperature and salinity are the primary environmental factors affecting P. marinus viability and proliferation. However, little is known about the effects of combined sub-optimal temperatures and salinities on P. marinus viability. This in vitro study examined those effects by acclimating P. marinus at three salinities (7, 15, 25 ppt) to 10 °C to represent the lowest temperatures generally reached in the Gulf of Mexico, and to 2 °C to represent the lowest temperatures reached along the mid-Atlantic coasts and by measuring changes in cell viability and density on days 1, 30, 60 and 90 following acclimation. Cell viability and density were also measured in 7 ppt cultures acclimated to each temperature and then transferred to 3.5 ppt. The largest decreases in cell viability occurred only with combined low temperature and salinity, indicating that there is clearly a synergistic effect. The largest decreases in cell viability occurred only with both low temperature and salinity after 30 days (3.5 ppt, 2 °C: 0% viability), 60 days (3.5 ppt, 10 °C: 0% viability) and 90 days (7 ppt, 2 °C: 0.6 ± 0.7%; 7 ppt, 10 °C: 0.2 ± 0.2%).     

Relatively low upper threshold temperature in lizards from cool habitats

We used the slender forest skink (Scincella modesta) as a model animal to test for the hypothesis that the upper threshold of incubation temperature is relatively low in lizards using shaded (and thus, cool) habitats. Eight gravid females were collected in early May 2005 from a population in Hangzhou, Zhejiang (eastern China). All females laid a single clutch of 7–13 eggs between mid-May and early June. Eggs were incubated at 24, 28 and 30 (±0.2) °C. None of eggs incubated at 30 °C hatched. Eggs incubated at 24 and 28 °C differed in incubation length but not in hatching success. The incubation length at 24 and 28 °C averaged 22.3 and 20.3 days, respectively. Hatchlings from eggs incubated at 24 and 28 °C did not differ in all examined morphological traits, but hatchlings from eggs incubated at 28 °C performed apparently worse in the racetrack than did their counterparts from eggs incubated at 24 °C. The temperature of 28 °C is close to the upper thermal threshold for successful embryonic development in S. modesta. Compared to other oviparous lizards using open (and thus, warm) habitats, the upper thermal threshold and the range of optimal temperatures for embryonic development are both lower in S. modesta. Our study supports the previous conclusion that species living in thermally different habitats may differ in the upper thermal threshold and the range of optimal temperatures for embryonic development.     

The effect of temperature, water level and burial depth on seed germination of Myriophyllum spicatum and Potamogeton malaianus

The effects of temperature, water level and burial depth on seed germination of two submerged species, Myriophyllum spicatum and Potamogeton malaianus, were investigated under controlled laboratory conditions. There was no significant difference in final germination of M. spicatum among water level treatments, but P. malaianus germinations at 1 cm and 12 cm water levels were better than at 0 cm water level at temperatures of 20 °C and 30 °C. Little to no germination was observed for either species at the temperature of 10 °C. At 15 °C, however, germination increased significantly to 66.3-70.6% for M. spicatum and to 29.4-48.1% for P. malaianus under all three water level treatments. Increased temperature from 15 °C to 30 °C had no significant effect on the final germination of M. spicatum except at the 1 cm water level, but enhanced significantly the germination of P. malaianus. Analysis of the mean time to germination revealed that M. spicatum was a faster germinator relative to P. malaianus. The two species’ germination differed markedly in response to burial depth. Germination percentage of M. spicatum was 71.3% at 0 cm burial depth, but decreased to 5.0% and to 2.5% at depths of 1 cm and 2 cm, respectively; whereas germination percentages of P. malaianus were 40.0%, 23.8%, 12.5%, 7.5% and 1.3% at depths of 0 cm, 1 cm, 2 cm, 3 cm and 5 cm, respectively. We concluded that the two species respond differently to germination strategies. The findings provided further insight into how germination strategy contributes to the seed bank formation and species invasion.     

Seasonal acclimation in resting metabolism of the skink, Mabuya brevicollis (Reptilia: Scincidae) from southwestern Saudi Arabia

The resting metabolic rate (RMR) of seasonally-acclimated Mabuya brevicollis of various body masses was determined at 20, 25, 30, 35 and 40 °C, using open-flow respirometry. RMR (ml g⁻¹ h⁻¹) decreased with increasing mass at each temperature. RMRs increaProd. Type: FTPsed as temperature increased. The highest and lowest Q₁₀ values were obtained for the temperature ranges 20–25 °C and 30–35 °C for the summer-acclimated lizards. The exponent of mass “b” in the metabolism-body mass relation ranged from 0.41 to 0.61. b values were lower in the autumn and winter-acclimated lizards than in spring and summer-acclimated lizards. Seasonal acclimation effects were evident at all temperatures (20–40 °C) for M. brevicollis. Winter-acclimated skinks had the lowest metabolic rates at different temperatures. The pattern of acclimation exhibited by M. brevicollis may represent a useful adaptation for lizards inhabiting subtropical deserts to promote activity during their active seasons.     

Thermogenic characteristics and evaporative water loss in the tree shrew (Tupaia belangeri)

Thermogenic characteristics and evaporative water loss were measured at different temperatures in Tupaia belangeri. The thermal neutral zone (TNZ) of T. belangeri was 30–35 °C. Mean body temperature was 39.76±0.27 °C and mean body mass was 100.86±9.09 g. Basal metabolic rate (BMR) was 1.38±0.03 ml O₂/g h. Average minimum thermal conductance (C_m) was 0.13±0.01 ml O₂/g h °C. Evaporative water loss in T. belangeri increased when the temperature rose; the maximal evaporative water loss was 3.88±0.41 mg H₂O/g h at 37.5 °C. The results may reflect features of small mammals in the sub-tropical plateau region: T. belangeri had high basal metabolic rate and high total thermal conductance, compared with the predicted values based on their body mass whilst their body temperatures are relatively high; T. belangeri has high levels of evaporative water loss and poor water-retention capacity. Evaporative water loss plays an important role in temperature regulation.     

Effects of fluctuating moisture and temperature regimes on the persistence of quiescent conidia of Isaria fumosorosea

Conidia of Isaria fumosorosea were submitted to three regimes of temperature and moisture to simulate microclimatic conditions which prevail in temperate (43% RH and 28 °C to 98% RH and 15 °C), subtropical (75% RH and 35 °C to 98% RH and 25 °C), and arid areas (13% RH and 40 °C to 33% RH and 15 °C) with daily fluctuating cycles. Germination, conidial viability, and virulence to Spodoptera frugiperda larvae were less affected after 20 days exposure under temperate cycling conditions than under arid and subtropical conditions. Exposure of conidia for 20 days to constant nocturnal simulated conditions of any tested regime weakly affected conidial persistence, whereas diurnal conditions exerted the most detrimental effects of high temperatures. However, when tested at both 45 °C and 50 °C at 33% RH for 160 h, the persistence of I. fumosorosea conidia was relatively higher than expected. These results emphasize that climatic conditions prevailing in environments and ecological fitness of fungal isolates have to be taken into account for assessing microbial control strategies.     

Diapause termination, post-diapause development and reproduction in the beet webworm, Loxostege sticticalis (Lepidoptera: Pyralidae)

Effects of photoperiod and cold exposure on diapause termination, post-diapause development and reproduction in Loxostege sticticalis were examined. Larvae were reared at diapause inducing condition (22 °C, L:D 12:12) consistently or transferred to long day photoperiod (L:D 16:8) and darkness (L:D 0:24) respectively, after entering into diapause. Diapause was terminated in approximately 40% of the larvae after 36 days, and no significant differences were observed between photoperiods, suggesting larval diapause was terminated spontaneously without being induced by photoperiods. Cold exposure significantly hastened diapause termination. The diapause termination incidence increased significantly with peaks of 98% at both 5 °C and 0 °C exposure for 30 days, as compared to 42% in controls not exposed to cold, while the mortality and number of days required for diapause termination decreased dramatically. The optimal low temperature exposure periods under 5 °C or 0 °C were 20 days and 30 days, showing a higher termination incidence and shorter time for diapause termination. This suggests that the low temperatures in winter play an important role in diapause termination under natural conditions. The threshold temperatures for post-diapause development in prepupae and pupae were 9.13 °C and 10.60 °C respectively, with corresponding accumulations of 125 and 200 degree-days. Adults that experienced larval diapause significantly delayed their first oviposition, oviposition period was prolonged, and the lifetime number of eggs laid was decreased, however both males and females have significantly longer longevity. The field validation of diapause termination, the degree-days model, and the relationship between diapause and migration in L. sticticalis were also discussed.     

Influence of ambient temperature on maternal thermoregulation and neonate phenotypes in a viviparous lizard, Eremias multiocellata, during the gestation period

To assess the potential gestational effects on post-hatching morphology, locomotor performance, and early growth rate, we maintained gravid Eremias multiocellata under four constant treatment temperatures (25, 29, 31, and 35 °C). Ambient temperature had significant effects on some morphometric traits of offspring, including tail length, head size, forelimb length and hindlimb length, but not on body mass or snout-vent length. The data of females' body temperature indirectly support the maternal manipulation hypothesis. Juvenile E. multiocellata had better locomotor performance and faster early growth rate at 29 °C than at the other three treatment temperatures (25, 31, and 35 °C). Our results suggest that gestation temperature may be optimized at 29 °C for E. multiocellata from Tianzhu, Gansu Province, China.