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1.
BACKGROUND: The radiated tortoise (Geochelone radiata) is a critically endangered species in its native land, the southern portion of the island of Madagascar. Captive breeding programs have generated data on the breeding behavior and ecology of G radiata; however, hematologic and biochemical data also are critically important in managing populations. OBJECTIVE: The purpose of this study was to evaluate sex and seasonal effects on hematologic and biochemical data from captive radiated tortoises. METHODS: Whole blood was collected in January and August 2001 from 18 radiated tortoises (10 male, 8 female) housed at the Wildlife Survival Center on St Catherines Island, Georgia, as part of a routine health assessment. Routine hematologic and plasma biochemical analyses and electrophoresis were done using standard methods. Data from male and female tortoises were compared within and between seasons using 2-way ANOVA. RESULTS: RBC and HCT values were significantly higher in summer than in winter and were higher in males than in females. Total protein concentration did not differ significantly between males and females; however, female tortoises had significantly higher concentrations of alpha1- and beta-globulins in winter and summer compared to males. Male tortoises had significantly higher sodium and uric acid concentrations and LDH activity during winter, and higher urea concentration and LDH and CK activities in summer, compared with females. Female tortoises had significantly higher triglyceride and phosphorus concentrations in winter, and higher phosphorus, cholesterol, and triglyceride concentrations in summer, compared with males. CONCLUSION: Sex and seasonal differences in hematologic and biochemical values for radiated tortoises likely reflect vitellogenesis and egg production in females, and altered hydration status and activity in summer. Data from the tortoises in this study will be useful for the seasonal health assessment of this species.  相似文献   

2.
The diet of 745 Oreochromis mossambicus (Peters) of less than 0,5 up to 2000 g wet mass, in Hartbeespoort Dam, was determined from stomach content analysis. Samples of fish were selected to cover a whole annual cycle. Small fish fed initially on zoobenthos and zooplankton, but fish with a mass of over 4 g fed increasingly on Microcystis aeruginosa Kutzing and detritus until these food items formed the dominant food source in O. mossambicus over 8 g. Some cannibalism was encountered in fish up to 64 g in the summer months. The ratio of intestinal length to total length of fish ranged from 0,58 in the smaller fish to 11,02 in larger fish and this indicated that there was an ontogenetic adaptation from a carnivorous to a phytoplanktivorous/detritivorous diet. Feeding in juvenile fish studied over 24 h was found to be most intense in the early morning and late afternoon but remained high throughout daylight hours decreasing considerably at night. The daily ingestion rate of food in O. mossambicus in Hartbeespoort Dam was estimated at 453 mg/g of fish. This comprised 45% M. aeruginosa and 55% detritus. It was apparent that of this matter ingested only a small percentage would be assimilated. Oreochromis mossambicus shows feeding and breeding preadaptations which enable it to successfully exploit a lacustrine environment. These adaptations enable it to maintain a large population in Hartbeespoort Dam despite frequent winter mortalities caused by water temperatures below their tolerance limits.  相似文献   

3.
Background: Hematologic and plasma biochemical evaluations are routinely used in evaluating the chelonian patient, but appropriate processing techniques have been minimally defined.
Objectives: This study was designed to compare the effects of temperature, time, anticoagulant, and species on sodium and potassium values in the Aldabra tortoise ( Geochelone gigantea ) and the Burmese mountain tortoise ( Manouria emys ).
Methods: Blood samples from 7 Aldabra tortoises and 8 Burmese mountain tortoises were collected into tubes without anticoagulant and tubes containing lithium heparin. Sodium and potassium concentrations were measured by flame photometry in serum and plasma harvested immediately after collection and from aliquots of whole blood stored at 4°C and 25°C for 5 to 120 minutes.
Results: In Aldabra tortoises, storage time and temperature had no significant effect on potassium concentrations in heparinized blood and in blood without anticoagulant. However, sodium concentrations in serum and plasma decreased significantly in samples without anticoagulant stored at 4°C and 25°C and in heparinized samples stored at 4°C. In Burmese mountain tortoises, potassium concentrations in serum and plasma increased significantly with time in samples without anticoagulant and in heparinized samples stored at 4°C and 25°C, but the increases were less at 4°C. Sodium concentrations in serum and plasma decreased significantly in blood without anticoagulant and heparinized blood stored at 4°C and 25°C.
Conclusions: Storage of blood samples with and without anticoagulant at 4°C significantly improved the stability of potassium and sodium concentrations in both species of tortoises. Early separation of red cells from serum or plasma after blood collection is especially important to ensure the reliability of potassium measurements.  相似文献   

4.
《African Zoology》2013,48(3):249-257
Understanding fish movement patterns and migrations is important for fisheries management as well as the identification and conservation of critical habitats. Data collected by the Oceanographic Research Institute's Cooperative Fish Tagging Project (ORI-CFTP) were used to describe the large-scale movement patterns of Lichia amia along the South African coastline. A total of 10 762 L. amia were tagged between 1984 and 2012, of which 744 (7%) were recaptured. Most tagging effort, mainly on juvenile and subadult individuals, took place along the south-eastern (i.e. Eastern Cape) and south-western (i.e. Western Cape) regions of the country during summer. Conversely, more L. amia were tagged and recaptured (mostly adults) during winter and spring (July to November) along the north-east coast (i.e. KwaZulu-Natal). Movements (dispersal distance in kilometres) by juveniles were restricted and largely confined to estuaries within the south-eastern and south-western regions of the country. There was a significant effect of fish size on distance moved (ANOVA: p<0.001), with evidence of a distinct seasonal (winter) longshore migration by adults to KwaZulu-Natal. The consequences of juvenile residency in estuarine habitats and high recapture rate of adults during a directed, seasonal spawning migration are discussed in light of improving current fisheries management.  相似文献   

5.
ObjectiveTo characterise four different intramuscular (IM) anaesthetic protocols, two with alfaxalone and two with alfaxalone in combination with medetomidine in terrestrial tortoises.Study designBlinded, randomized, cross‐over experimental study.AnimalsNine healthy adult male Horsfield's tortoises (Agrionemys horsfieldii).MethodsEach tortoise was randomly assigned to one of four different protocols: 1) 10 mg kg?1 alfaxalone; 2) 10 mg kg?1 alfaxalone + 0.10 mg kg?1 medetomidine; 3) 20 mg kg?1 alfaxalone; and 4) 20 mg kg?1 alfaxalone + 0.05 mg kg?1 medetomidine. During the experiment, the following variables were recorded: heart rate; respiratory rate; peripheral nociceptive responses; muscle strength; ability to intubate; palpebral, corneal and tap reflexes; and cloacal temperature.ResultsProtocols 1 and 2 resulted in moderate sedation with no analgesia, and moderate to deep sedation with minimal analgesia, respectively. Protocols 3 and 4 resulted in deep sedation or anaesthesia with variable analgesic effect; these two protocols had the longest total anaesthetic time and allowed intubation in 6/9 and 8/9 tortoises respectively. The total anaesthesia/sedation time produced by alfaxalone was significantly increased (p <0.05) by the addition of medetomidine. There were no significant differences regarding time to plateau phase and duration of plateau phase. Baseline heart rate of 53 ± 6 beats minute?1 decreased significantly (p <0.05) with all protocols, and was lower (p <0.05) in protocols 3 and 4. Heart rate increased after atipamezole administration, but the increase was transient. In two tortoises, extreme bradycardia with no cardiac activity for 10 minutes was observed with protocols 3 and 4.Conclusion and clinical relevanceAlfaxalone 10 and 20 mg kg?1 IM can be used for sedation for non‐painful procedures. Alfaxalone in combination with medetomidine can be used for deeper sedation or anaesthesia, but the observed respiratory and cardiovascular depression may limit its use.  相似文献   

6.
Studies on the diurnal and seasonal availability of Glossina brevipalpis Newstead and G. austeni Newstead to stationary targets were conducted in north-eastern KwaZulu-Natal, South Africa. G. brevipalpis showed a bimodal, and occasionally trimodal, partly crepuscular cycle. Periods of the availability of flies to stationary, odour-baited targets (here referred to as diurnal "activity" patterns) were mainly early in the morning and late afternoon until dark, especially at dawn and dusk. The main diurnal activity period was the late afternoon peak, which occurred during the 1-2 h before sunset until dark. The amplitude of the morning and afternoon peaks seemed to be mainly modulated by temperature. This species was also active throughout the remainder of the day, depending on the season. Glossina austeni was day-active and activity seemed to increase with increasing temperature and decreasing relative humidity (RH). The species remained available to targets throughout the day, but during the hottest part of the day the diurnal pattern decreased somewhat, resulting in a U-shaped but still more or less unimodal pattern. The diurnal pattern was strongly modulated by ambient temperature, although seemingly more by a combined temperature-RH effect. Both species' availability to targets ceased after dark, although night activity was observed on various other occasions. The use of artificial refuges for G. brevipalpis and G. austeni as a possible means of escaping climatic extremes is briefly discussed and speculated on.  相似文献   

7.
Woody plant encroachment is increasing in arid and semi-arid regions of the world. We investigated the structure and fine-scale spatial pattern of encroaching species and how these patterns vary with different grazing regimes in semi-arid regions. In this study, we investigated how four encroaching shrub species (Searsia erosa, S. burchellii, Diospyros lycioides and Eriocephalus ericoides) in Middelburg (Eastern Cape, South Africa) coexist and partition space under different grazing regimes (viz. continuous rest, and continuous, summer and winter grazing). We used point-pattern analysis to assess the spatial ecology of these species. We also used an index of integration (mingling index), where low values indicate that they are surrounded by conspecifics and high values indicate that they are surrounded by heterospecifics. The three shrub species were highly mingled except in the winter-grazing plot, where S. burchellii and D. lycioides clustered. We found that the shrub species were generally aggregated in most of the grazing plots. These findings indicate that (1) at a fine spatial scale, grazing in the wet season promotes shrub encroachment, and (2) there is a tendency to aggregation among encroaching shrub species in the grazing plots.  相似文献   

8.
蜂花粉干燥温度和时间对其活性和水份影响的初步研究   总被引:1,自引:0,他引:1  
本实验以新鲜蜂花粉为材料,通过不同的干燥温度和时间的处理,测定其活性。以初步探求干燥温度、时间对蜂花粉活性的影响。实验结果表明:蜂花粉活性与干燥温度、时问有密切的关系,在适宜的范围内,呈现出负相关的现象。  相似文献   

9.
蜂花粉干燥温度和时间对其活性和水分影响的初步研究   总被引:1,自引:0,他引:1  
本实验以新鲜蜂花粉为材料,通过不同的干燥温度和时间的处理,测定其活性,以初步探求干燥温度、时间对蜂花粉活性的影响。实验结果表明:蜂花粉活性与干燥温度、时间有密切的关系,在适宜的范围内,呈现出负相关的现象。  相似文献   

10.
The objective of this study was to determine the effects of lairage time (short vs. long), behavior (aggressive vs. non‐aggressive) and gender (gilts, barrows and boars) on stress and meat quality parameters in pigs (n = 100). In the group with short lairage, aggressive behavior of gilts and boars was observed. At exsanguination, blood samples were collected and levels of blood lactate and plasma cortisol were determined. Post mortem pH value, temperature, drip loss, sensory and instrumental color and meat quality class were determined on the muscle Longissimus dorsi. Higher blood lactate concentration (P < 0.05) and skin blemish score (P <0.001), lower temperature (P < 0.05) and drip loss (P < 0.01), as well as darker, less red and yellow meat color (P < 0.001) were found after long lairage compared to short lairage. Gilts had higher plasma cortisol concentrations than barrows (P < 0.05), while barrows had lower skin blemish scores (P < 0.05) than gilts and boars after long lairage. The highest incidence of PSE (pale, soft and exudative) meat was observed in barrows (100.00%) and boars (91.67%) after short lairage, while the lowest incidence of PSE meat was found in barrows (28.89%) after long lairage. Aggressiveness affected meat temperature, as aggressive pigs had higher meat temperature (P < 0.05) than non‐aggressive pigs.  相似文献   

11.
The length/frequency distribution, length/mass relationship, seasonal occurrence, growth and diet of Sparodon durbanensis from tidal pools in the Eastern Cape was investigated over a two-year period. The fish were predominantly small (mean length of 53 mm TL) with the smallest specimens being found in summer. Juveniles were found to be omnivorous, consuming algae, crustaceans and polychaetes, although, with the acquisition of adult dentition (ie. crushing molars), hard-shelled molluscs became important in the diet.  相似文献   

12.
A model is proposed for the evolution of three morphotypes of the girdled lizard Cordylus cordylus (Linnaeus) in the south-western Cape. The available data are interpreted as indicating that a vicariant splitting of a warm-adapted ancestral population during the last glacial period occurred. Differential evolution of the two daughter populations in response to different environmental pressures resulted. One of the daughter populations remaining in the coastal lowlands to the west of the Cape Fold Mountains, became cold-adapted, an event which was followed by a rapid range expansion. The other daughter population to the south and east of the Cape Fold Mountains apparently experienced less severe climatic conditions, maintained a larger population size, and for these reasons remained warm-adapted. During the subsequent warmer, interglacial period the now cold-adapted daughter population was again fragmented into two populations. Of these, one is presently found along the south-western coast and the other along the higher peaks of the western section of the Cape Fold Mountains. On the other hand the amelioration of the climate during the interglacial allowed the warm-adapted daughter population to the south and east to expand its range, eventually penetrating into the areas formerly occupied by the cold-adapted populations. Subsequently zones of secondary contact were established. In the area under discussion similar patterns of contraction and expansion can be observed in other closely related species. Our data support the turnover-pulse hypothesis of Vrba (1985)  相似文献   

13.
本实验以两种野桂花蜂蜜样品为实验材料,在不同温度和时间条件下处理,通过试管法测定蜂蜜中淀粉酶值。结果表明:随着温度的升高和处理时间的延长,蜂蜜中的淀粉酶值呈下降趋势。  相似文献   

14.
In the present study, 48 crossbred does (Nubian × Baladi) were used to investigate physiological (mucus and hormonal) traits as affected by gestation pattern (pre‐, full‐ and post‐term parturitions). The incidence of full‐term (does with a gestation length of 146–152 days) was the highest (54.5%), followed by pre‐term (does with a gestation length of 140–145 days; 36.9%) and post‐term (does with a gestation length of 153 days; 8.9%), respectively. Prediction of gestation pattern by using some body measurements was also studied. Cervical mucus samples were collected during estrus to determine spinnbarkeit (i.e. strength, viscosity or stretchability) and pH values of the mucus. Mucus was also collected pre‐parturition daily from day 140 of gestation until delivery, to evaluate the ferning arborization. Blood samples were collected on the day before mating (0 time), 1 (at mating), 30, 60, 90 and 145 days after mating. The results showed that spinnbarkeit and pH in cervical mucus at estrus, serum estradiol‐17α (E2) at day 5 before delivery, and progesterone (P4) levels differed insignificantly according to gestation pattern. The fern degree between day 140 of gestation and day of delivery was the highest in pre‐term does, while it was the lowest in post‐ and full‐term does. The gestation length was the highest in post‐term does (157.5 days), and the lowest in pre‐term does (141.5 days). During winter, the incidence of pre‐term deliveries was the highest (54.5%), but in spring, full‐term deliveries were the most common (58.3%). Most of the traits studied were insignificantly affected by season of birth. Post‐term delivery can be estimated by doe weight and wither height, while full‐term delivery can be anticipated using by hip height and abdomen girth. Pre‐term does can be detected by cervical mucus fern between day 140 of gestation and day of delivery. Post‐term does can be defined by doe weight and wither height, while full‐term deliveries can be defined by hip height and abdomen girth, during pregnancy.  相似文献   

15.
为探究不同紫花苜蓿氮代谢差异及氮代谢差异的生理机制,采用盆栽砂培法,通过对2个具有典型特征的紫花苜蓿品种(LW6010和陇东苜蓿)在2个氮素水平及3个生育时期下其氮代谢产物及氮代谢酶活性差异进行研究,探讨氮代谢产物与氮代谢酶活性的相互关系。结果表明:LW6010和陇东苜蓿在N210水平下其干物质重、氮含量、氮积累量及硝酸还原酶(NR)、谷氨酰胺合成酶(GS)活性均高于N21。在2个氮水平下,LW6010的干物质重、NR和GS活性均显著大于陇东苜蓿,而LW6010的氮含量显著低于陇东苜蓿。其中,LW6010的NR活性比陇东苜蓿在N210和N21下分别高24%和15%(苗期)、31%和40%(现蕾期)、20%和11%(盛花期);GS活性分别高30%和29%(苗期)、33%和20%(现蕾期)、7%和14%(盛花期)。在苗期和盛花期时,LW6010的氮积累量显著大于陇东苜蓿,而在现蕾期差异不显著。LW6010的氮积累量在N210下各生育期分别比陇东苜蓿高25%,3%和16%,而在N21下LW6010的氮积累量在苗期和盛花期下比陇东苜蓿高45%和12%。同时,紫花苜蓿干物质重、氮积累量、NR活性与GS活性呈极显著正相关关系。综上分析,紫花苜蓿的不同品种在不同氮素水平下其氮代谢能力不同,不同紫花苜蓿品种间氮代谢具有差异;LW6010较陇东苜蓿具有较好的氮代谢能力;NR和GS活性可为不同紫花苜蓿氮代谢差异评价提供参考。  相似文献   

16.
The Nama-Karoo is the largest of the three biomes that comprise the semi-arid Karoo-Namib ecoregion of southern Africa. Large tracts of Nama-Karoo rangeland have been invaded by alien leguminous trees of the genus Prosopis. We assessed the impact of Prosopis invasion and clearing on vegetation cover in heavily grazed Nama-Karoo rangeland on two sheep farms in the Beaufort West district of the Western Cape province of South Africa. Our results suggest that, below critical threshold cover levels, Prosopis trees do not affect indigenous vegetation and add to overall rangeland vegetation cover. However, once Prosopis cover exceeds critical thresholds, the trees begin to negatively impact on indigenous vegetation (especially grasses) and overall vegetation cover. In addition, our data suggest that vegetation cover recovers after Prosopis clearing, being temporarily higher than pre-invasion levels possibly as a result of enhanced post-invasion soil fertility. Lastly, our results suggest that Prosopis trees reduce rangeland erosion potential at low cover and increase it after they exceed critical threshold cover. Information about thresholds of Prosopis impact can be used to direct clearing efforts for maximum benefit when resources are limited.  相似文献   

17.
The rates of absorption into various microsites in Karoo soils were compared. The absorption of water by hard, bare intershrub soils was significantly increased by the presence of emergence holes of adult cicadas (Homoptera: Cicadidae) and near nest‐mounds of the harvester ant Messor capensis. Both these insects play an important role in raising the amount of water that penetrates into the soil after rains. Absorption rates were also high in the soils of heuweltjie mounds but were reduced by sustained use of an area by sheep and were particularly poor on sheep paths.  相似文献   

18.
本文旨在描述可能引起南非Borakalalo国家公园内二斑沙鸡(Pterocles bicinctus)迁移行为的内在(繁殖)及外在因素(降雨量及植被情况)。该公园位于西北省比勒陀利亚以北80km,Jericho以北30km处。2010年,采取乘车辆沿固定路线穿越该保护区的方式搜集数据。车速为每小时10km,固定路线长为32km,调查强度为每月2天。二斑沙鸡平均每群2.47个个体。种群内雄性与雌性的比例为1:0.87。该鸟常出现在路边、遭踩踏过的矮草丛中或经焚烧但长出新叶的金合欢丛中。二斑沙鸡在该保护区主要出现在两个相对干燥的季节,即2–3月及7–9月。早晨在该公园的腹地能更多地观察到该鸟,而下午晚些时候,在Klipvoor河坝的水体边则可多见该鸟。讨论了可能影响二斑沙鸡迁移的5个因素,包括年降雨量、雨季中短时雨量大小、2–4km的日间饮水飞行、繁殖及草原植被情况。  相似文献   

19.
本文对浙农大1号意蜂(E_a)和本地意蜂(E_b)的工蜂、蜂王、雄蜂的发育时龄(从卵到成虫羽化)进行了研究。其结果是:E_a和E_b的平均发育时龄,工蜂分别为504.7和506.8小时,蜂王分别为387.5和395.5小时,雄蜂分别为581.5和585.6小时。E_a和E_b三型蜂的发育时龄均存有差异,E_a的工蜂、蜂王、雄蜂发育时龄分别比E_b缩短2.1、8.0和4.1小时。此外,还发现受精卵的胚胎发育比未受精卵快。  相似文献   

20.
Two introduced beachfleas, Orchestia gammarellus and Platorchestia platensis, have been recorded from South Africa, but have been misidentified by some earlier researchers and, prior to this study, each was also known from just a few, scattered observations, such that their true distributions remained obscure. We illustrate both species to clarify the features that identify and distinguish them and determine their true distributions by re-examining historical samples and by collecting new material from estuaries and lagoons along the west and south coasts of South Africa. Adult males of O. gammarellus have slender antennae and characteristic expanded, flattened, oar-like distal segments on pereopod 7. Adult males of P. platensis have the peduncle of antenna 2 strongly swollen and have bulbous, but not flattened, distal segments on pereopod 7. Both species occur under wrack and other debris along the banks of estuaries and sheltered lagoons. Orchestia gammarellus is found only along the south-west coast, in the Berg River Estuary, Langebaan Lagoon and the Diep River Estuary. Previous records from Knysna were misidentifications of P. platensis. Platorchestia platensis is found at one west coast site, Langebaan Lagoon, but is widely distributed from Cape Point eastwards to at least Algoa Bay. Both species share the same habitats as several other native beachfleas and competitive interactions between native and introduced species merit investigation.  相似文献   

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