Body temperature variation of free-ranging and captive southern brown bandicoots Isoodon obesulus (Marsupialia: Peramelidae)

To investigate patterns of thermoregulation in free-ranging and captive southern brown bandicoots Isoodon obesulus, we measured abdominal body temperature (T_b) of five free-ranging bandicoots over 42 days using implanted data loggers and T_b of three captive bandicoots over 3 months using implanted temperature-sensitive radio transmitters. Bandicoots in the wild had a mean T_b of 36.5±1.0 °C (range 33.4–39.8 °C) and showed a pronounced nychthemeral pattern with two distinct temperature phases. T_b increased at 13:30±2.6 h each day and remained high for 10.65±2.07 h, suggesting a crepuscular and early evening activity pattern. Daily T_b variation of I. obesulus would save considerable energy by reducing daytime thermoregulatory costs in the wild. Captive bandicoots had a similar mean body temperature (36.9±0.2°C) and range (33.0–39.9°C) as free-ranging bandicoots. However, the nychthemeral T_b pattern of captive bandicoots was different from free-ranging bandicoots, with a less pronounced daily cycle and the nocturnal rise in T_b occurring mainly at sunset and the daily decline occurring mainly at dawn.     

Body size and the daily rhythm of body temperature in dogs

Practically every physiological variable exhibits daily rhythmicity. The daily rhythm of body temperature, like that of many other variables, is often weak in newborns and gains strength as the animals grow. Because of the natural association between physiological maturation and gain in body size, these two processes are naturally confounded. To differentiate between the effects of maturation and the effects of body growth, we took advantage of the large variation in body size that exists among different breeds of the domestic dog. We compared the body temperature rhythms of developing puppies of different dog breeds. Puppies of none of the breeds exhibited statistically significant daily rhythmicity for several days after birth. Regardless of breed or sex, rhythmicity matured over several weeks and attained a stable level by 6 weeks after birth. Body size did not seem to be an important element in the development of rhythmicity because the development was similar in three breeds that differed greatly in body size (Basset Hound, Boxer, and Neapolitan Mastiff). On the other hand, the difference in body size associated with the different breeds had a strong impact on the absolute level of body temperature regardless of age: we found a strong inverse correlation between temperature and body size among the puppies and dams of the three breeds and among 115 adult dogs from 19 different breeds ranging from 2-kg Yorkshire Terriers to 80-kg Great Danes.     

Establishing the presence of a body temperature rhythm in chimpanzees (Pan troglodytes) using a tympanic membrane thermometer

Seven chimpanzees (Pan troglodytes) were trained to present their ears so that a tympanic nembrane thermometer could be inserted. Temperatures were collected from both ears of each subject every 3 hours for 72 consecutive hours. The presence of a body temperature rhythm, well documented in other mammals, was established. Each ear demonstrated its own rhythm, but the rhythms in both ears generally mirrored each other. Similarities in the temperature rhythms of cagemates were found. These data are the first evidence of a body temperature rhythm in chimpanzees, and they represent a non-invasive method of measuring the 24-hr rhythms in both human and non-human primates.     

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.     

温度对麦长管蚜体色变化的影响

研究了温度对麦长管蚜体色变化的影响及不同温度下麦长管蚜种群数量变动的规律.结果表明:在21(CK)、23、26、29、31℃5个温度处理下,随着温度的升高,红色型麦长管蚜在实验种群中所占比例逐渐升高;绿色型麦长管蚜的种群增长的高峰先缩短后延长,而红色型麦长管蚜的种群增长的高峰逐渐延长;绿色型蚜虫的平均世代时间呈先缩短再延长的趋势,红色型蚜虫的平均世代时间仅仅呈延长的趋势.结论:麦长管蚜体色变化受温度影响,红色型蚜虫为高温诱导所产生的生物型.当温度为25.91℃时(T50 =25.91℃),麦长管蚜的后代中有50％的个体是红色型蚜虫.该结论为蚜虫生态遗传与进化提供理论依据.     

Comparative study of floral development in Onobrychis melanotricha, Hedysarum varium and Alhagi persarum (Leguminosae: Papilionoideae: Hedysareae)

Floral initiation and development of Hedysarum varium, Onobrychis melanotricha and Alhagi persarum was studied using epi-illumination light-microscopy techniques. The studied species belong to the tribe Hedysareae of the inverted repeat loss clade (IRLC clade), which is characterized by missing the large inverted repeat in the chloroplast genome. The main aim of our study was to determine developmental bases for similarities and differences among the three taxa and to verify the position of Alhagi relative to other genera of the IRLC clade. According to our observations, bracteoles are missing in Onobrychis melanotricha, but are present in the other two species. All three species share unidirectional sepal initiation starting with a median abaxial sepal and bidirectional petal initiation. Stamen initiation is unidirectional in all except in the outer stamen whorl of Hedysarum varium, where it is bidirectional. An important ontogenetic feature in O. melanotricha is the existence of five common primordia, which give rise to petal and stamen primordia. Although in H. varium and O. melanotricha common primordia are observed at some stages in floral organ initiations, in Alhagi all organs are initiated separately. Moreover, overlap in time of floral organs initiation occurs in H. varium and O. melanotricha, but not in A. persarum. The carpel initiates concurrently with the petal primordia in all. It might be presumed that Alhagi is primitive in relation to the other studied Hedysareae taxa, due to the presence of bracteoles, the absence of common primordia, and the lack of overlap in time of different organ initiations.     

Food consumption does not affect the preferred body temperature of Yarrow's spiny lizard (Sceloporus jarrovi)

When animals consume less food, they must reduce their body temperature to maximize growth. However, high temperatures enhance locomotion and other performances that determine survival and reproduction. Therefore, thermoregulatory behaviors during different metabolic states reveal the relative importance of conserving energy and sustaining performance. Using artificial thermal gradients, we measured preferred body temperatures of male spiny lizards (Sceloporus jarrovi) in fed and fasted states. Both the mean and maximal body temperatures (33° and 35 °C, respectively) were unaffected by metabolic state. This finding suggests that the benefits of foraging effectively, evading predators, and defending territory outweigh the energetic cost of a high body temperature during fasting.     

Genetic structure of Phlebotomus (Larroussius) ariasi populations, the vector of Leishmania infantum in the western Mediterranean: Epidemiological implications

In recent years there has been growing interest in analyzing the geographical variations between populations of different Phlebotomus spp. by comparing the sequences of various genes. However, little is known about the genetic structure of Phlebotomus ariasi. In this study, we were able to sequence a fragment of the mitochondrial Cyt b gene in 133 sandflies morphologically identified as P. ariasi and proceeding from a wide geographical range covering 35 locations in 11 different regions from five countries. The intra-specific diversity of P. ariasi is high, with 45 haplotypes differing from each other by one to 26 bases and they are distributed in two mitochondrial lineages, one limited geographically to Algeria and the other widely dispersed across Mediterranean countries. The Algerian lineage is characterized by having 13 fixed polymorphisms and is made up of one sole haplotype. The European/Moroccan P. ariasi lineage is characterized by being made up of a great diversity of haplotypes (44) which display some geographical structuring. This could be one of the multiple factors involved in the epidemiological heterogeneity of the foci of leishmaniasis. Phlebotomus chadlii is the sister group of European/Moroccan P. ariasi. The separation of the Algerian haplotype, H45, from the rest of the specimens, European/Moroccan P. ariasi and P. chadlii, is well supported by the bootstrap analysis.     

The effect of body coloration and group size on social partner preferences in female fighting fish (Betta splendens)

Females of the fighting fish Betta splendens have been shown to associate with other B. splendens females in a manner reminiscent of shoaling behavior. Since body coloration varies dramatically in this species, and since body coloration has been shown to affect shoalmate choice in other species of fish, we examined the influence of body coloration on association preferences in female B. splendens. In dichotomous choice tests, B. splendens females spent more time swimming near groups of females (regardless of coloration) than swimming near an empty chamber, and chose to swim near fish of similar coloration to their own when choosing between two distinctly colored groups of females. When examining the interplay between body coloration and group size, focal fish spent more time swimming near larger groups (N = 5) of similarly colored fish than swimming near an individual female of similar coloration. However, focal fish showed no preference when presented with an individual female of similar coloration and a larger group of females of dissimilar coloration. These results suggest that association choices in B. splendens females are strongly affected by both body coloration and by group size.     

Changes in zoeae of the snow crab, Chionoecetes opilio, with variation in incubation temperature

The purpose of this study was to evaluate the effect of embryonic incubation temperature on the morphology, energetic content, and individual weights of C. opilio zoeae. Ovigerous female C. opilio were collected by trawl from the eastern Bering Sea in the summer of 2002 and were held in the laboratory at five temperature treatments (− 1, 0, 1, 3, and 6 °C) from embryo stage five to hatching. The mean duration of incubation ranged from 240 d at 6 °C to 353 d at − 1 °C. No relationship between larval weight and caloric content with incubation temperature was detected, indicating that increased development time at cooler temperatures may not have an energetic cost. However, several morphological features varied with temperature. Most larval characters including rostro-dorsal length, rostral spine length, lateral spine length, and carapace width were smaller at the warmest incubation temperature. Protopodite length did not differ with temperature. The length of the 3rd abdominal somite consistently increased with increased temperature and may serve as a suitable indicator that could be used in field populations to infer temperature of incubation. Variation in morphology with temperature could confound identification of C. opilio zoeae from those of a congener, Chionoecetes bairdi because identification of C. bairdi is based on the length of the 3rd abdominal somite.     

Effect of an invasive crab upon a marine fishery: green crab, Carcinus maenas, predation upon a venerid clam, Katelysia scalarina, in Tasmania (Australia)

Nonindigenous species are increasingly recognized as altering marine and estuarine communities, causing significant changes in abundance and distribution of native species. Such effects are of particular concern to coastal fisheries. We experimentally determined the effect of the nonindigenous European green crab, Carcinus maenas, upon the stepped venerid clam, Katelysia scalarina, the basis for a fledgling clam fishery in Tasmania, Australia. First, we observed a trend of decreased juvenile (<13-mm shell length or SL) abundance of K. scalarina at sites with C. maenas relative to those without this invasive predator. Additionally, relative predation intensity on these juveniles was significantly higher in invaded areas. To better understand the dynamics of predation by this invader, we conducted a number of manipulative experiments. In cage experiments testing per capita predation rates, we found that: (1) of the various sizes of C. maenas, large C. maenas were the most significant predators; (2) the smallest size class of K. scalarina tested (6-12-mm SL) was preferred by C. maenas; (3) C. maenas had much higher predation rates than any native predator tested; and (4) while the native shore crab, Paragrapsus gaimardii, was found to have a constant predation rate over an eightfold range of densities of juvenile K. scalarina (16-128 individuals·m⁻²), C. maenas significantly increased its per capita predation with increasing prey density. Notably, in open field plots at a site where C. maenas was abundant, predation was constant over the range of tested prey densities. We predict, therefore, that the invasion of C. maenas will have significant negative consequences for the Tasmanian K. scalarina fishery.     

Use of spent mushroom substrates from Agaricus subrufescens (syn. A. blazei, A. brasiliensis) and Lentinula edodes productions in the enrichment of a soil-based potting media for lettuce (Lactuca sativa) cultivation: Growth promotion and soil bioremediation

This study aimed to assess physicochemical and microbiological properties of fresh spent mushroom substrates (SMSs) – without post-crop heat treatment – from Agaricus subrufescens and Lentinula edodes production to optimize the use of these residues in the soil enrichment for lettuce growth promotion and soil remediation. Organic matter and C content of both SMSs were high. Fresh A. subrufescens SMS was a good source of N, P and K. On the other hand, L. edodes SMS presented a lower concentration of these nutrients and a high level of immaturity. Both SMSs presented high electric conductivity values (2.5–3.4 mS/cm). Microbiological analysis, based upon enumeration of culturable bacteria (thermophilic and mesophilic) and fungi, and also evolution of CO₂, showed that SMSs played higher microbial diversity than soil control. Laccase activity from A. subrufescens SMS tended to remain constant during a 2-month period, while L. edodes SMS presented low laccase activity throughout the same period. Agaricus subrufescens and L. edodes were able to grow on a PDA (Potato Dextrose Agar) media supplemented with different concentrations of atrazine (1–50 μg/ml), degraded the herbicide, attaining rates of 35% and 26%, respectively. On experiments of lettuce growth promotion using a soil-based potting media with different SMS rates, 5% and 10% (dw) rates of A. subrufescens SMS resulted in higher lettuce aerial dry weights than the rates of 25% and 40%, the chemical fertilization (NPK) and the control (soil). At 10% supplementation, lettuce aerial dry weight increased 2.2 and 1.3 times compared to the control and the NPK treatment, respectively. Protein content increased along with SMS rates. Fresh A. subrufescens SMS was an excellent supplement for lettuce growth promotion and showed potential for remediation of biocides possibly due to improved microbial diversity and enzymatic activity. Fresh L. edodes SMS was not a good fertilizer, at least under the conditions tested. However, microbiological analysis showed that promising results may be achieved when using fresh L. edodes SMS for soil remediation.     

Effects of acclimation and egg-incubation temperature on selected temperature by hatchling western painted turtles (Chrysemys picta bellii)

The ability of hatchling turtles to detect environmental temperature differences and to effectively select preferred temperature is a function that critically impacts survival. In some turtle species, temperature preference may be influenced by embryonic and post-hatching conditions, such as egg-incubation and acclimation temperature. We tested for effects of embryonic incubation temperature (27.5 °C, 30 °C) and acclimation temperature (20 °C, 25 °C) on the selected temperature and movement patterns of 32 Chrysemys picta bellii (Reptilia: Emydidae) hatchlings in an aquatic thermal gradient of 14-34 °C and in single-temperature (20 °C, 25 °C) control tests. Among 10-11 month old hatchlings, acclimation temperature and egg-incubation temperature influenced temperature selection and movement patterns. Acclimation temperature affected activity and movement: in thermal gradient and single-temperature control tests, 25 °C-acclimated turtles relocated between chambers significantly more frequently than individuals acclimated to 20 °C. Acclimation temperature also affected temperature selection: 20 °C-acclimated turtles selected a specific temperature during gradient tests, but 25 °C-acclimated turtles did not. Among 20 °C-acclimated turtles, egg-incubation temperature was inversely related to selected temperature: hatchling turtles incubated at 27.5 °C selected the warmest temperature available (34 °C); individuals incubated at 30 °C selected the coldest temperature (14 °C). These results suggest that interactions of environmental conditions may influence post-hatching thermoregulatory behavior in C. picta bellii, a factor that ultimately affects fitness.     

低温导致中华蜜蜂后翅翅脉的新变异

在封盖发育期,将中华蜜蜂Apis cerana cerana封盖子放入24℃低温环境中分别处理24、48、72 h,再恢复到正常的发育温度35℃至羽化,或将封盖子放在30℃低温中培养至羽化,发现羽化后的蜜蜂后翅翅脉发生明显变异。发现翅脉变异有3种类型,翅脉增加、翅脉突出和翅脉缺失。后翅翅脉增加的变异只发现一种,基室、缘室共有的径分脉与基室、盘室共有的中脉之间,新增径中横脉。新增的径中横脉发生的程度不同,有的在径分脉和中脉相对的位置相向伸出,有的形成完整的新脉,新增的径中横脉与原径中横脉相似,在末端均有"弱化点"。由于原有径中横脉较短,一直忽略其存在,这次径中横脉的确定,可以判定原来公认的"中脉分叉"应分别是径分脉和中脉延伸出来的两条翅脉。后翅突出的变异有2种,中脉向基室突出,径分脉向基室突出。翅脉突出的程度不同,有的略突出,有的明显突出,有的伸出翅脉较长。中脉突出均发生在中脉的转折点上,且此类翅脉变异,仅发生在雄蜂样本中,在工蜂样本中还未见。后翅翅脉缺失的变异有2种,发生在肘臀横脉和中脉。肘臀横脉"弱化点"处缺失。将中华蜜蜂雄蜂封盖子放入低温30℃恒温培养箱中发育,发现2个羽化的雄蜂样本发生肘臀横脉在"弱化点"处缺失。中脉向盘室伸出的部分发生缺失。翅脉缺失的程度不同,有的明显缩短,有的仅存痕迹,有的缺失大部分或完全缺失。中脉向盘室伸出的部分是东方蜜蜂Apis cerana区别于西方蜜蜂Apis mellifera的主要形态特征之一,如果东方蜜蜂这段翅脉全部缺失,此部位的形态与西方蜜蜂完全相同。这意味着这个翅脉作为区分东方蜜蜂和西方蜜蜂的翅脉特征将面临挑战。对蜜蜂种质资源鉴定,蜜蜂的系统发育和进化生物学等领域的研究将具有重要影响。温度影响翅脉发育的深入研究,为研究蜜蜂翅脉发育过程,揭示翅脉发育调控机制,以及蜜蜂发育的温度适应生理机制提供一个新思路。     

Mutagenic and physiological responses in the juveniles of African catfish, Clarias gariepinus (Burchell 1822) following short term exposure to praziquantel

Praziquantel (PZQ) is an acylated quinoline-pyrazine originally developed for veterinary application but now one of the most used anti-helminthic drugs for treatment of certain trematodes and cestodes in both human and other animals. The present study investigated the mutagenic and physiological responses in the juveniles of African catfish, Clarias gariepinus following short term exposure to praziquantel. Based on the 53.52 mg/l 96 h LC₅₀ of PZQ obtained, two sublethal concentrations of 5.35 and 10.70 mg/l of the drug were selected and fish were exposed to these concentrations and control for 15 days. Micronuclei induction in the peripheral blood of PZQ-exposed fish was highest on day 10 but the fish morphological parameters were not affected. The packed cell volume (PCV) was significantly reduced (p < 0.05) from day 5 while red blood cells (RBC) and hemoglobin (Hb) significantly declined (p < 0.05) on day 15. Macrocytic anemia was observed on day 1 of study and thereafter microcytic anemia developed on day 5 of study. The white blood cell (WBC) was significantly (p < 0.05) elevated from day 10 of exposure while values of mean cellular volume (MCV), mean cellular hemoglobin (MCH) and mean cellular hemoglobin concentration (MCHC) were not significantly different (p > 0.05) from the control. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and glucose levels significantly increased while protein reduced (p < 0.05) throughout the exposure period but a mixed trend was observed in the leukocyte differentials. PZQ should be used with caution as sublethal exposure elicited micronucleus induction and alterations of hematological and biochemical parameters in the fish.     

Influence of dietary protein levels and water temperature on growth,body composition and nutrient utilization of Cirrhinus mrigala (Hamilton, 1822) fry

The experiment was conducted to determine the protein requirement of Cirrhinus mrigala fry at three different water temperatures, 28, 30 and 32 °C, and to investigate the influence of dietary protein levels and water temperatures on weight gain, body composition, food and nutrient utilization. The 36% protein concentration in the diet yielded highest weight gain at all temperatures from 28 to 32 °C. However, daily protein intake was lower at 28 °C than at 30 and 32 °C. The diet with 36% dietary protein and 32.17% carbohydrate produced the best weight gain and gross conversion efficiency (GCE) at 30 °C. The protein-sparing effect was observed at temperatures 30 and 32 °C in diets 1 and 2, having carbohydrate levels 37.36–44.91%. Highest protein efficiency ratio (PER) was recorded at 28% dietary protein level, while it was lowest at 40% dietary protein level in all three temperatures. Lipid in the body of fishes increased at the end of the experiment in comparison to the initial body lipid. The body protein was found to be related to daily protein intake at 30 and 32 °C. Significant difference (P<0.05) was also noted between temperatures, the hepatosomatic index (HSI) and viscerosomatic index (VSI). The diet with 36% dietary protein and 32.17% carbohydrate was observed to be the best diet for C. mrigala fry at 28–32 °C.     

Entrainment of the larval release rhythm of the crab Rhithropanopeus harrisii (Brachyura: Xanthidae) by cycles in hydrostatic pressure

This study investigated the entrainment of a larval release rhythm by determining whether a tidal cycle in hydrostatic pressure could entrain the circatidal rhythm in larval release by the crab Rhithropanopeus harrisii (Gould). Ovigerous females were collected from a non-tidal estuary. The time of larval release by individual crabs was monitored under constant conditions with a time-lapse video system. Crabs with mature embryos at the time of collection had a pronounced circadian rhythm in larval release with a free running period of 25.1 h. Crabs with immature embryos that were maintained under constant conditions from the time of collection until larval release retained a weak circadian rhythm. Other crabs with immature embryos were exposed to a tidal cycle in step changes in hydrostatic pressure equivalent to 1 m of water. This cycle entrained a circatidal rhythm in larval release. The free-running period was 12.1 h and larvae were released at the time of the transition from low to high pressure. Although past studies demonstrated that a tidal cycle in hydrostatic pressure could entrain activity rhythms in crustaceans, this is the first study to show that pressure can entrain a larval release rhythm.