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1.
Hyalomma aegyptium ticks were collected from tortoises, Testudo graeca, at localities in northern Africa, the Balkans, and the Near and Middle East. The intensity of infestation ranged from 1-37 ticks per tortoise. The sex ratio of feeding ticks was male-biased in all tested populations. Larger tortoises carried more ticks than did the smaller tortoises. The juveniles were either not infested, or carried only a poor tick load. Hyalomma aegyptium was absent in the western Souss Valley and Ourika Valley in Morocco, the Cyrenaica Peninsula in Libya, Jordan, and the Antilebanon Mountains in Syria. Hemolivia mauritanica, a heteroxenous apicomplexan cycling between T. graeca and H. aegyptium, was confirmed in Algeria, Romania, Turkey, Syria, Lebanon, and Iran. Its prevalence ranged from 84% in Romania (n = 45), 82% in eastern Turkey (n = 28), and 82% in the area of northwestern Syria with adjacent Turkish borderland (n = 90), to 38% in Lebanon (n = 8) and in only 1 of 16 sampled tortoises in Algeria. The intensity of parasitemia in the studied areas ranged from 0.01% up to 28.17%. The percentage of Hemolivia-infected erythrocytes was significantly higher in adults. All tortoises from Hyalomma-free areas were Hemolivia-negative. Remarkably, all 29 T. graeca from Jabal Duruz (southwestern Syria) and 36 T. graeca from the area north of Middle Atlas (Morocco) were Hemolivia-negative, despite the fact that ticks parasitized all adult tortoises in these localities. Identical host preferences of H. aegyptium and H. mauritanica suggest the occurrence of co-evolution within the Testudo-Hyalomma-Hemolivia host-parasite complex.  相似文献   

2.
In April 2008, 585 tortoises illegally imported into Italy from North Africa were examined for the presence of ticks. Of these, 221 tortoises (37.8%) were infested with a mean intensity of 3.9 ± 3.1 ticks (range 1–17 ticks). A total of 798 ticks (672 males, 125 females and one nymph) were collected and identified as Hyalomma aegyptium (L.) (Acari: Ixodidae). The overall male : female ratio observed was 5 : 1. The prevalence and mean intensity [±standard deviation (SD)] of ticks were higher among male (67.4%, 4.0 ± 3.2) than female (55.6%, 3.8 ± 3.1) tortoises, although this difference was not significant. By contrast, the prevalence and mean intensity of ticks were significantly higher on tortoises weighing >100 g (61.5%, 4.0 ± 3.2) compared with tortoises weighing <100 g (12.1%, 2.1 ± 1.1). Of the infested tortoises, 89.8% had ticks on their hind limbs, 21.0% on forelimbs, 18.6% on the tail and pre‐anal area, and 4.8% on the head; thus the hind limbs were evidently the preferred attachment site. The present report highlights the need to develop surveillance systems to prevent the introduction and spreading of exotic ticks and tick‐borne pathogens in Italy and other European countries.  相似文献   

3.
Observations were made of growth rate and variation in colour pattern of the leopard tortoise ( Geochelone pardalis babcocki ) in northern Tanzania between October 1993 and June 1996. Growth rate differed significantly between tortoises, with immature animals (6.9 ± 1.4 mm month−1) and females (5.7 ± 1.3 mm month−1) exhibiting higher rates of growth than adult animals (2.9 ± 0.8 mm month−1) and males (3.2 ± 1.1 mm month−1), respectively. The faster growth rate in immature animals suggested that growth rate declined with age. The difference in growth rates between the sexes was ascribed to sexual dimorphism, adult females being larger and therefore growing faster than males.
The carapacial colour pattern observed in the northern Tanzanian tortoises was generally similar to that described elsewhere in the species' range. The colour pattern varied between Arusha and Serengeti District tortoises. Animals at the Arusha sites tended to be sparsely coloured (55.6%) compared to the Serengeti tortoises, which had a buff colouration with radiating spots (89.3%).; The sparse colouration provides effective camouflage in the drier Arusha habitats, as does the buff colouration with black spots in the wetter, darker habitats in the Serengeti.  相似文献   

4.
The duration of the embryogenic development of Nacobbus aberrans (= N. batatiformis) took 9-10 days at 25 C and 51 days at 15 C. The J₁ molted in the egg; hence the Je emerged from the egg. The effect of distilled water attd root leachates of kochia and sugarbeet was investigated at 5, 10, 15, 20, and 25 C. Root leachates did not significantly affect the percent of cumulative hatch of eggs, but temperature did significantly affect emergence of juveniles (p = 0.05). Less than 1, 5, and 20% of eggs hatched at 5, 10, and 15 C, respectively. The percent of cumulative hatch at 20 C was four times greater than at 15 C, while the highest percentage of juveniles emerged at 25 C. The duration of postembryogenic development from J₂ inoculation until the appearance of mature females with egg masses took 38 days, and the life cycle from egg to egg was completed in 48 days at 25 C. All immature stages, young females and males were migratory endoparasites. Young females were able to leave the root swellings, where they developed from juvenile stages, and re-enter the root, where they formed a true gall and became sedentary. Thirty days after inoculation with J₂ nematodes, specimens were detected in root tissues at 10, 15, 20, 25, and 30 C, hut not at 5 C. Five days after inoculation at 23 C ( ± 2 C), juveniles had penetrated the roots and caused slight swellings of the tip and axis of sugarbeet feeder roots. Large cavities extended from the cortical parenchyma to the periphery of the stelar area, and 50 % of the central cylinder was destroyed 25 days after inoculation at 23 C. No syncytia formation were detected in the sugarbeet root swellings infected with juveniles. Syncytia were associated only with adult females; hyperplasia, abnormal proliferation of lateral roots, and asymmetry of root structure were additional anatomical changes induced by adult females. Only very smooth annules but no cuticular ornamentations were noted by SEM on the perineal area of adult females.  相似文献   

5.
Kim W. Lowe  A. Clark  R. A. Clark 《Ostrich》2013,84(1-3):111-116
Lowe, K. W., Clark, A. & Clark, R. A. 1985. Body measurements, plumage and moult of the Sacred Ibis in South Africa. Ostrich 56: 111–116.

Body measurements, plumage and moult of Sacred Ibis Threskiomas aethiopicus were studied at Pretoria from July 1973 to June 1974. Adult and immature Sacred Ibises are sexually dimorphic in size. Bill length alone can be used to sex most birds. Body mass, wing, tarsus and tail lengths overlap greatly between the sexes but males are generally larger than females. The sexes show similar patterns of variation in body mass and gonad size throughout the year. Juveniles follow a different pattern of variation in these parameters. The plumages of adults, immatures and juveniles are described and compared. There is no sexual dimorphism in plumage pattersn. Moult in adults occurs mainly in the post-breeding period from January to August, and in juveniles and immatures throughout the year. Adult Sacred Ibises have an-extensive, irregular and asymmetrical moult. Factors affecting sexual size dimorphism in African and Australian populations are discussed.  相似文献   

6.
19 juvenile members of known genealogies in two wild baboon groups were studied over a 16-month period to compare the ontogeny of agonistic experience and dominance relations for males and females. Juveniles of all age-sex classes were disproportionately likely to receive aggression from and submit to adult males per unit of time spent in proximity. This pattern intensified with increasing juvenile age. With age, juvenile females more often submitted to unrelated adult females from higher-ranking families, whereas this was not true for juvenile males. All juveniles received aggression from older group members more often during feeding than was expected by chance. High rates of agonistic interaction with unrelated adult females accounted for old juvenile females (3–5.5 years-old) interacting agonistically more frequently than male age peers and young juveniles of either sex (1–2.5 years-old). Adult females were also more aggressive toward females among young juveniles, suggesting that adult females target females among juveniles for aggression and resistance to rank reversal. Within juvenile age groups, males dominated all females and all younger males, irrespective of maternal dominance status. Dominance relations among female age-peers were generally isomorphic with relations among their mothers. No juvenile targeted any older male for rank reversal. Males targeted all older females, whereas females typically targeted only older females from families lower-ranking than their own. The strong sexual dimorphism in adult body size in baboons may explain why juvenile males' dominance relations with peers and adult females are not structured along lines of family membership as is true for the less dimorphic macaques. Acquisition of higher agonistic status probably allows juveniles of both sexes to increase their success in within-group feeding competition during late stages of juvenility, which, in turn, could affect important life-history traits such as age at menarche and adult body size.  相似文献   

7.
We examined habitat use, morphology, jumping and clinging ability for 403 juvenile, female and male green anole lizards, Anolis carolinensis, in a population in south‐eastern Louisiana. We sought to answer three questions: (1) Do age/sex classes differ in habitat use, morphology and performance ability? (2) Do habitat use, morphology and performance correlate among all individuals across three age/sex classes (juveniles, females and males)? (3) Do juveniles compensate for their poor absolute performance capacities by being better performers on a relative scale? The three age/sex classes were found to differ significantly in size‐adjusted morphology, habitat use and size‐adjusted performance capacity. Juveniles tended to occupy perches which were closer together than those of adult males and females. The distal elements of the hindlimb (femur, tibia) were significantly longer in males than in females and juveniles, while females were more stocky than males and juveniles. The only significant overall ecomorphological relationship detected was between the lengths of the distal hindlimb elements and maximum jump acceleration. Our hypothesis that juveniles should be better performers (relative to size) compared to adults was disproved, as adult females were always the best performers relative to size. Our analysis of a mainland anole population presents a different view of population structure compared to similar studies involving Caribbean Anolis lizards, which show more ecological differentiation among age/sex classes, and also show that juveniles are relatively good performers. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 85 , 211–221.  相似文献   

8.
Leaf explants of Cocos nucifera L. (coconut palm) were studied in vitro in order to establish whether or not rapid cellular changes contribute to the well known recalcitrance of coconut cells in tissue culture. Segments from the base of immature leaves were cultured on modified Eeuwens' medium at 30°C in darkness. The mitotic index, nuclear DNA amounts, cell and nuclear size were measured both before and during culture (from 0 to 70 days). There was no basipetal gradient of cell division in immature coconut leaves; the mitotic index never exceeded 2% and showed neither a positional nor temporal relationship with leaf development. Moreover the vast majority of cells were in G1 of the cell cycle. This cell cycle pattern was maintained for most of the period in culture although at 70 days there was an increase in the proportion of cells in S- and G2-phases consistent with low rates of callus formation. The nuclear: cell size ratio was constant in cells within the immature leaf irrespective of developmental age. However upon transfer to culture media, cell size but not nuclear size increased. We suggest that this uncoupling of cell and nuclear size disrupts cell co-ordination and is a key contributor to recalcitrant cellular behaviour of this species in vitro.  相似文献   

9.
This study examines resource use (diet, habitat use, and trophic level) within and among demographic groups (males, females, and juveniles) of bottlenose dolphins (Tursiops truncatus). We analyzed the δ13C and δ15N values of 15 prey species constituting 84% of the species found in stomach contents. We used these data to establish a trophic enrichment factor (TEF) to inform dietary analysis using a Bayesian isotope mixing model. We document a TEF of 0‰ and 2.0‰ for δ13C and δ15N, respectively. The dietary results showed that all demographic groups relied heavily on low trophic level seagrass‐associated prey. Bayesian standard ellipse areas (SEAb) were calculated to assess diversity in resource use. The SEAb of females was nearly four times larger than that of males indicating varied resource use, likely a consequence of small home ranges and habitat specialization. Juveniles possessed an intermediate SEAb, generally feeding at a lower trophic level compared to females, potentially an effect of natal philopatry and immature foraging skills. The small SEAb of males reflects a high degree of specialization on seagrass associated prey. Patterns in resource use by the demographic groups are likely linked to differences in the relative importance of social and ecological factors.  相似文献   

10.
This study examines the swimming speed in amictic females of Brachionus plicatilis in laboratory cultures. Five different stages were examined: recently hatched females, juveniles, adult non-ovigerous females, ovigerous females with 1 attached egg and ovigerous females with 2 attached eggs. We tested the speed at two temperatures, 15 °C and 25 °C, and two feeding conditions, presence and absence of microalgal cells. An automated motion analysis system was used to measure speed which was then video recorded. Swimming speed (μm s−1) increased with increasing body size. There was a slight decrease in the speed of adult females as the number of attached eggs increased. Swimming activity was higher at 25 °C than at 15 °C and in the absence of food than if microalgae were present. Average values under the different experimental conditions ranged between 500 μm s−1 for the recently hatched and fed females and 1500 μm s−1 for the adult non-ovigerous females in the absence of microalgae. Mass-specific swimming speed decreased with body mass increase.  相似文献   

11.
Erythrocyte (RBC) count, packed cell volume (PCV) and haemoglobin (Hb) values were found to be higher in Nigerian domestic fowls than those in Hubbard fowls. PCV and Hb values were higher in males than in females in both breeds. Erythrocytes of the Nigerian fowl were observed to be more susceptible to osmotic haemolysis than were erythrocytes of the Hubbard fowl. Erythrocytes of male fowls were osmotically more fragile than were those of female fowls in both breeds.  相似文献   

12.
A study was carried out in Navarra (northern Spain) on the influence of the weight, sex and reproductive status (lactant, pregnant or lactant + pregnant females and testicular weight for males) of the wild rabbit (Oryctolagus cuniculus) on two cestodes species: Andrya cuniculi and Mosgovoyia ctenoides and four intestinal nematodes: Graphidium strigosum, Trichostrongylus retortaeformis, Nematodiroides zembrae and Dermatoxys hispaniensis. A significantly higher prevalence of A. cuniculi was detected in lactant + pregnant females compared with non-breeding females. Trichostrongylus retortaeformis and N. zembrae showed a significantly higher mean intensity in lactant and lactant + pregnant females than in non-reproductive females. Trichostrongylus retortaeformis presented a higher mean intensity in females than in males, and the mean intensity of the same parasite species was significantly lower in active and inactive males compared with lactant and lactant + pregnant females. There were no significant differences between sexes in the prevalence of helminth parasites. No significant correlation was detected between host weight and the intensity (of infection) of helminths studied. No significant differences in the prevalence and mean intensity of the two cestode species were observed in the three weight categories studied (kittens, juveniles and adults). The prevalence of G. strigosum and mean intensity of T. retortaeformis were significantly higher in older heavier animals than in juveniles.  相似文献   

13.
To place associations among body size, age at maturity, age, and reproductive traits of a long-lived organism in the context of current life history models based on the concept of norms of reaction, we examined data from a mark-recapture study of Blanding's turtles (Emydoidea blandingi) in southeastern Michigan during 24 of the years between 1953 and 1988. Females matured between 14 and 20 years of age. Both the smallest and largest adult females in the population were reproducing for the first time in their lives. This result suggests that a combination of differences in juvenile growth rates and ages at maturity, and not indeterminate growth, are the primary cause of variation in body size among adults. Body size variation among individuals was not related to age at sexual maturity. Females that had slower growth rates as juveniles matured later at similar mean body size compared to those with more rapid growth that matured at an earlier age. As a result, a linear model of age at sexual maturity with growth rates of primiparous females between hatching and maturity was significant and negative (R2 = 0.76). Frequency of reproduction of the largest and smallest females was not significantly different. Clutch size did not vary significantly with age among either primiparous or multiparous females. Clutch sizes of primiparous females and multiparous females were not significantly different. However, older females (>55 years minimum age) reproduced more frequently than did younger females (minimum age <36 y).  相似文献   

14.
The population parameters (morphometrics, population size and biomass) were determined for leopard and angulate tortoises in the Thicket Biome, Eastern Cape, South Africa. Leopard tortoises had a mean total length of 306.47mm (SD = 94.65mm, range 59–496mm, n = 89). Males were smaller (mean total length 277.31mm, SD = 71.85mm, range 73–377mm, n = 36) than females (mean total length = 332.33mm, SD = 97.64mm, range 59–496mm, n = 53). Angulate tortoises had a mean total length of 155.17mm (SD = 33.89mm, range 59–194mm, n = 18). Males were larger (mean total length = 186mm, SD = 8.40mm, range 174–194mm, n = 5) than females (mean total length = 143.31mm, SD = 32.48mm, range 59–178mm, n = 13). The estimated population density for leopard tortoises was 0.85 tortoises ha−1 with an estimated biomass of 6.02kg −1. Angulate tortoise population density was estimated at 0.12 tortoises ha−1 with a mean biomass of 0.06kg ha−1. The possible consequences of this high density and biomass are discussed.  相似文献   

15.
In infrapopulations of helminth parasites, density-dependent effects, through some form of intra- and interspecific competition, play an important role in shaping and regulating the infrapopulations. The mechanisms responsible for these processes have often been observed in laboratory studies and rarely studied under natural conditions. Here, 24 natural infrapopulations (77-447 individuals) of the acanthocephalan Sclerocollum saudii Al-Jahdali, 2010 from the fish Siganus rivulatus consisted of cystacanths, newly excysted juveniles, immature and mature worms, distributed in a well-defined fundamental niche (anterior 60% of the intestine). Each of these stages exhibited a significantly different longitudinal distribution within this niche. In small infrapopulations, cystacanths and newly excysted juveniles were found in the sixth 10% of the intestine, immature worms in the fifth 10% and mature worms in the anterior 40% of the intestine. However, their proportions followed a clear ascending order in each infrapopulation, and the female-male ratios of both immature and mature worms were distinctly female-biased. In large infrapopulations, mature worms existed partially in the site of immature ones, where a differential mortality among immature females was constantly observed. However, the proportions of immature worms increased significantly and those of mature worms decreased significantly, the mean lengths of immature and mature females decreased dramatically and the female-male ratios were distinctly male-biased. The mean sizes of immature and mature males seemed stable through all infrapopulations. The distribution of mature males and females suggests intense male-male competition for access to females, and reveals that larger females are copulated prior to the smaller ones. The results are statistically significant and suggest that infrapopulation self-regulation is through density-dependent mechanisms, in which immature females may play a key role.  相似文献   

16.
Abstract: Relocations of gopher tortoises (Gopherus polyphemus) in Florida, USA, are frequently employed as mitigation tools when tortoises occupy land desired for development. Here we present information about retention and health of a relocated population of gopher tortoises 17 years after relocation. We combine our 17-year postrelocation data with earlier surveys 1 year and 2 years postrelocation to examine whether retention rates change over time. We also evaluate whether retention rates vary by age and gender. Of 74 gopher tortoises relocated in 1985, 31 were present in 2002. We found a 1-year retention rate of 42%, with retention rates of 100% each year thereafter, when we used the percentage of relocated individuals captured at each survey. We found a 1-year retention rate of 73%, a retention rate of 92% from year 1 to year 2, and an overall retention rate of 98.5% from year 2 through year 17, based on the assumption that all individuals present in later surveys were present in earlier surveys. We found no significant difference in retention rate over the 17-year period for adults and juveniles and for adult males and females. Relocated gopher tortoises showed natural growth patterns, indicating good health, but 35% of these gopher tortoises had ≥1 symptom of upper respiratory tract disease, a disease associated elsewhere with population declines of tortoises. Thus, retention rates of relocated gopher tortoises change over time, with relatively low retention during the first year postrelocation but nearly 100% retention in subsequent years. In general, our study shows that relocations can successfully lead to long-term retention of gopher tortoises, but we predict that without management (e.g., fire management and predator control) this relocated population is not viable.  相似文献   

17.
Santos  Cynthia  Bueno  Sérgio L. S. 《Hydrobiologia》2001,456(1-3):65-71
The nemerteans of the genus Carcinonemertes live in association with decapod crustaceans. Juveniles of Carcinonemertes carcinophila imminuta Humes, 1942 are found in the gills of their hosts. A total of 281 specimens (52 males and 229 females) of Callinectes danae Smith, 1869 and 373 (332 males and 41 females) of Callinectes ornatus Ordway, 1863 were inspected for the occurrence of Carcinonemertes carcinophila imminuta in their gills. The prevalence and mean intensity of infestation by these nemerteans with regard to sex, maturity, condition of adult female crabs (ovigerous or non ovigerous), size (carapace width) and molt stage of hosts were evaluated. A prevalence of infestation by Carcinonemertes carcinophila imminutaof 39.1% was found in the population of Callinectes danae; the mean intensity of infestation was 12.0±2.7, while intensity ranged from 1 to 268. In this host species, significant differences in prevalence were observed between males and females, juveniles and adults and ovigerous and non-ovigerous adult females. Prevalence of infestation did not differ significantly among crabs in different molt stages. Mean intensity did not differ significantly between males and females nor among crabs in different molt stages. Significant differences in mean intensity were observed between ovigerous and non-ovigerous adult females of Callinectes danae. A positive correlation was observed between prevalence of infestation and the carapace width of Callinectes danae females. The prevalence of infestation in Callinectes ornatus was 8.0%; the mean intensity of infestation was 2.7±0.4 while intensity ranged from 1 to 9. Prevalence and mean intensity of infestation did not differ significantly between males and females and juveniles and adults. Prevalence did not differ significantly among crabs in different molt stages. No correlation was observed between the prevalence of infestation and the carapace width of males and females of Callinectes ornatus.  相似文献   

18.
Increasingly, renewable energy comprises a larger share of global energy production. Across the western United States, public lands are being developed to support renewable energy production. Where there are conflicts with threatened or endangered species, translocation can be used in an attempt to mitigate negative effects. For the threatened Mojave desert tortoise (Gopherus agassizii), we sought to compare habitat- and space-use patterns between short-distance translocated, resident, and control groups. We tested for differences in home range size based on utilization distributions and used linear mixed-effects models to compare space-use intensity, while controlling for demographic and environmental variables. In addition, we examined mean movement distances as well as home range overlap between years and for male and female tortoises in each study group. During the first active season post-translocation, home range size was greater and space-use intensity was lower for translocated tortoises than resident and control groups. These patterns were not present in the second season. In both years, there was no difference in home range size or space-use intensity between control and resident groups. Translocation typically resulted in one active season of questing followed by a second active season characterized by space-use patterns that were indistinguishable from control tortoises. Across both years, the number of times a tortoise was found in a burrow was positively related to greater space-use intensity. Minimizing the time required for translocated tortoises to exhibit patterns similar to non-translocated individuals may have strong implications for conservation by reducing exposure to adverse environmental conditions and predation. With ongoing development, our results can be used to guide future efforts aimed at understanding how translocation strategies influence patterns of animal space use.  相似文献   

19.
We translocated 120 Agassiz's desert tortoises to 5 sites in Nevada and Utah to evaluate the effects of translocation on tortoise survivorship, reproduction, and habitat use. Translocation sites included several elevations, and extended to sites with vegetation assemblages not typically associated with desert tortoises in order to explore the possibility of moving animals to upper elevation areas. We measured survivorship, reproduction, and movements of translocated and resident animals at each site. Survivorship was not significantly different between translocated and resident animals within and among sites, and survivorship was greater overall during non-drought years. The number of eggs produced by tortoises was similar for translocated and resident females, but differed among sites. Animals translocated to atypical habitat generally moved until they reached vegetation communities more typical of desert tortoise habitat. Even within typical tortoise habitat, tortoises tended to move greater distances in the first year after translocation than did residents, but their movements in the second or third year after translocation were indistinguishable from those of resident tortoises. Our data show that tortoises translocated into typical Mojave desert scrub habitats perform well; however, the large first-year movements of translocated tortoises have important management implications. Projects that employ translocations must consider how much area will be needed to contain translocated tortoises and whether roads need fencing to prevent the loss of animals. © 2012 The Wildlife Society.  相似文献   

20.
Blood values of wild cetacean population are a valuable tool to drive proper management of threatened species. Reference intervals of 26 serum analytes were determined from 107 apparently healthy Amazon river dolphins (Inia geoffrensis) wild-caught in the Mamirauá Sustainable Development Reserve (3°3′S, 64°51′W), central Amazon, Brazil. No differences were detected between males and females or between pregnant and nonpregnant females. Calves had higher serum calcium than juveniles and adults, and alkaline phosphatase activity was higher in calves and juveniles than adults as a result of bone growth. Adults showed higher creatinine levels than juveniles due to higher body mass, and higher urea than calves. Positive correlation was found between body length and body weight with creatinine, urea, and alanine aminotransferase activity; whereas calcium and alkaline phosphatase and creatine kinase (CK) activities negatively correlated with these body parameters. Cardiac rate and respiratory frequency appear to have not correlated with any serum analyte, while stress level positively correlated with CK. Storage of frozen samples for 60 days at −80°C significantly altered 10 of the 19 analytes after one freeze–thaw cycle. Important differences were detected among age classes, stress level, and sample storage and should be taken into account before any clinical or physiological interpretations.  相似文献   

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