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1.
C.R. Brown 《African Zoology》2013,48(4):166-172
Oxygen consumption of individual long-fingered bats, Miniopterus schreibersii, was measured at air temperatures (Tr) between 2 and 42°C and that of clusters of four and six bats between 5 and 30°C. BMR of individuals was estimated to be 2.29 ml O2 g 1 h-1 between 34 and about 38°C. M. schreibersii showed two different responses to Ta, either maintaining body temperature (Tb) by increasing metabolic rate, or allowing Tb to fall close to ambient temperature and conserving energy (torpor). Euthermic clusters of four and six bats had lower rates of mass-specific oxygen consumption and lower thermal conductances than individuals at equivalent temperatures and torpid clusters maintained a greater temperature differential between Tb and Ta. Lowest rates of metabolism were measured for euthermic bats at air temperatures higher than those available to them in their natural roost in summer, so typical roost temperatures result in metabolic rates that are about 2 4–3.1 times estimated BMR. Roost temperatures of M. schreibersii in South Africa are substantially higher in winter than are generally accepted as being suitable for hibernation but these do not substantially affect torpid metabolic rates, which are low and independent of ambient temperature below 22°C. Clearly at least some species of insectivorous bats are capable of hibernating at temperatures generally considered to be too warm for this activity.  相似文献   

2.
A. Haim 《African Zoology》2013,48(1):67-70
Heat production measured as oxygen consumption (VO2 and heat dissipation calculated as the means of the overall thermal conductance were studied in a South African diurnal murid Lemniscomys griselda. This species maintains its body temperature (Tb) well at around 36,5 ± 1,0 °C over ambient temperatures (Ta) ranging between 5 and 34 °C. The thermoneutral zone lies between T a = 30-34 °C. When exposed to temperatures below the low critical point L. griselda at rest conforms to Newton's law of cooling. Non-shivering thermo- genesis (NST) was studied as a response to an injection of noradrenaline (sc). Following the administration of 1,5 mg noradrenaline per kg body mass to an anaesthetized animal, an increase of 329% in VO2 was recorded. The distribution pattern of L. griselda in comparison with that of Rhabdomys pumilio, the more common diurnal murid species in South Africa, is discussed.  相似文献   

3.
The increased rate of human-driven change is a major threat to biodiversity. Although there is sufficient evidence to suggest that species notably alter their ranges, facilitation of such movement for larger vertebrate species often places burdens on management agencies. Oribi antelope (Ourebia ourebi ourebi) in South Africa continue to experience dramatic decreases in range and numbers. Animals have and continue to be translocated for conservation, but also aesthetic and financial reasons. Initial translocations were done in the absence of any thought or understanding of genetic structure, while for the past two decades a conservative best-practice approach was adopted, but in the absence of any specific genetic information. Here, we use two mitochondrial and one nuclear fragment to report the phylogeographic structure in oribi antelope across South Africa. Our data indicate that the South African subspecies is distinct from other subspecies to the north, confirming that oribi in South Africa should be managed as a distinct conservation unit. Across the South African range, high genetic diversity is present with some evidence for genetic structure (phylogenetic trees and haplotype networks). However, there is no spatial component to the diversity (non-significant p-values in AMOVA analyses), possibly because of historic translocations. We evaluate translocation approaches currently in place, and make specific and general recommendations for future conservation management based on an improved understanding of population genetic diversity and genetic structure.  相似文献   

4.
Digestion rates were determined for natural prey items offered to each of seven species of sea anemones found at Wooley’s Pool in False Bay and to the single species (Bunodactis reynaudi) recorded at Biouberg on the Atlantic coast of the south-western Cape, South Africa.This was done by examining prey items removed from the coelenterons at regular intervals after feeding and assessing their degree of digestion according to a predetermined scale. There was considerable variation in the gut retention times between different anemone species offered the same prey types, with Actinia equina consistently showing the shortest gut retention times (12 h for amphipods, 15 h for pelecypods and 23 h for isopods). Of the various prey categories tested, amphipods tended to be the most rapidly digested group, while molluscs and echinoderms usually remained in the coelenteron the longest. Mean gut retention times in B. reynaudi, the only species found both in False Bay (17°C) and on the cold west coast (12°C) were markedly longer (72 vs 60 h and 43 vs 30 h for pelecypods and gastropods respectively) at the lower temperature.  相似文献   

5.
An exotic fresh-water gastropod recently discovered in South Africa is identified as Aplexa (Stenophysa) marmorata (Physidae) and is considered conspecific with a population known from West Africa since at least 1911 and a single record from Mozambique dating from 1886. It is speculated that these introductions could have occurred via the Portuguese slave trade during the 16th and 17th centuries. A key to A. marmorata, another introduced physid Physa acuta and the indigenous, sinistral genus Bulinus is presented.  相似文献   

6.
Reptiles are one of the fastest growing sectors in the United States pet industry. Reptile‐associated salmonellosis (RAS) continues to be an important public health problem, especially among children. We investigated an outbreak of human Salmonella infections resulting from serotypes Cotham and Kisarawe, predominately occurring among children. An outbreak of illnesses was identified in persons with exposure to pet bearded dragon lizards. Human and animal health officials, in cooperation with the pet industry, conducted epidemiologic, traceback and laboratory investigations. Onsite sampling was conducted at two US breeding facilities, one foreign breeding facility, and a large pet retail chain. A total of 166 patients in 36 states were identified with illness onset dates from 02/2012–06/2014. The median patient age was 3 years (range, <1–79 years), 57% were aged ≤5 years, and 37% were aged ≤1 year. Forty‐four patients (37%) were hospitalized, predominantly children. Sampling at breeding facilities and a national pet store chain resulted in isolation of outbreak serotypes at each facility; isolation proportions ranged from 2%–24% of samples collected at each facility.Epidemiologic, microbiologic and traceback evidence linked an outbreak of uncommon Salmonella serotypes to contact with pet bearded dragons. The high proportion of infants involved in this outbreak highlights the need to educate owners about the risk of RAS in children and the potential for household contamination by pet reptiles or their habitats. Strategies should be developed to improve breeding practices, biosecurity and monitoring protocols to reduce Salmonella in the pet reptile trade.  相似文献   

7.
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8.
Campylobacter causes acute gastroenteritis in people worldwide and is frequently isolated from food, animals and the environment. The disease is predominately food‐borne but many routes of transmission and sources of infection have been described, including contact with pets. The prevalence of Campylobacter spp. in dogs and cats varies widely, and data on New Zealand pets are limited. This study aimed to investigate the prevalence of Campylobacter spp. in dogs, cats and retail raw meat pet food products in New Zealand and to characterize Campylobacter jejuni isolates using multilocus sequence typing (MLST). Ninety dogs and 110 cats examined at the Massey University Veterinary Teaching Hospital for elective procedures, and fifty locally purchased retail raw meat pet diets were sampled. Two culture protocols combining Bolton broth enrichment and mCCDA and CAT agars in a microaerobic atmosphere at 42°C and 37°C with species identification using PCR were performed. The prevalence of Campylobacter spp., C. jejuni, Campylobacter upsaliensis and Campylobacter helveticus was 36%, 13%, 23% and 1% in dogs and 16%, 5%, 5% and 7% in cats, respectively. One dog had Campylobacter lari confirmed, and three dogs and one cat had multiple Campylobacter spp. detected. Significantly more animals tested positive using CAT than mCCDA agar (P < 0.001). Being neutered, vaccinated for Bordetella bronchiseptica, fed dry diets and brought in for neutering were protective factors for dogs, whereas attendance for dental treatment was a risk factor for cats. Campylobacter spp. were isolated from 28%, C. jejuni 22%, C. lari 6% and Campylobacter coli 6% of food samples. Six isolates positive by Campylobacter genus PCR were identified as Arcobacter butzleri. Poultry meat was more likely to be positive than non‐poultry meat (P = 0.006). Of the 13 C. jejuni pet isolates with full MLST profiles, eight were of different sequence types (ST) and all nine food isolates were of different STs.  相似文献   

9.
We screened 78 native and 94 exotic turtles from natural ponds and 39 exotic pet turtles for presence of Salmonella, resulting with infection rates of 6.61%, 6.4%, and 5.1%, respectively. Concurrent shedding of multiple serotypes of the bacteria was only detected in one pet turtle. Eleven isolates were obtained in free-living turtles, including serotypes commonly found in reptiles and also the serotype Typhimurium, which is commonly related to human infections. In pet turtles, the five serotypes isolated were different to those isolated in free-living turtles and had been reported to cause reptile-associated salmonellosis in humans. These results confirm the risk of transmission of Salmonella from free-living and pet turtles to humans, demanding the necessity of regulation of pet turtle trade in Europe.  相似文献   

10.
The diversity of Cryptosporidium at species, subtype family and subtype level in diarrhoeic children was investigated in four provinces in South Africa. A total of 442 stool samples from children <5 years of age were collected under a large rotavirus surveillance programme and analysed by Ziehl–Neelsen acid‐fast staining. Fifty‐four (12.2%) were positive for Cryptosporidium, of which 25 were genotyped by polymerase chain reaction (PCR)–restriction fragment length polymorphism (RFLP) and DNA sequence analyses of the 18S rRNA gene. The majority of genotyped specimens were identified as C. hominis (76%), and a high genetic diversity was found with five different C. hominis subtype families (Ia, Ib, Id, Ie and If). Cryptosporidium parvum was found in 20% of the isolates, and three subtype families were identified (IIc, IIe and IIb), with subtype family IIc being the most common. One specimen was identified as C. meleagridis of the subtype family IIId. These results are in accordance with findings from other developing countries and report for the first time the presence in South Africa of C. meleagridis, various subtypes of C. parvum and the subtype family Ie of C. hominis. The results suggest that C. hominis and anthroponotic C. parvum subtypes are the major cause of cryptosporidiosis in South Africa. Further molecular studies are needed to better understand the epidemiology and public health importance of Cryptosporidium in humans in South Africa.  相似文献   

11.
The spatial genetic structure of a species, and whether distinct genetic lineages are present, is strongly influenced by their biology and habitat requirements. Given habitat specificity and low vagility, many herpetofaunal species are reservoirs for high levels of cryptic diversity; chameleons are a case in hand. The common flap-necked chameleon Chamaeleo dilepis has a large range that spans much of sub-Saharan Africa. Within South Africa, the species is largely confined to the north-eastern and central areas of the country, and occurs from the coastal forests in southern KwaZulu-Natal westwards into Namibia. Their large range, together with anecdotal evidence that there is considerable morphological and phenotypic diversity across the range, suggests a questionable taxonomy with possible cryptic lineages. The aims of the present study were to investigate whether C. dilepis is genetically structured across parts of its South African range, and whether this species (as it currently stands) might include cryptic lineages. To this end, 72 C. dilepis individuals sampled from four localities across South Africa (Gauteng, n = 2; KwaZulu-Natal, n = 2) were sequenced for two mitochondrial markers (ND4 and 16S). The phylogenetic results suggest that C. dilepis is indeed spatially structured. In addition, the large sequence divergence values between groups strongly suggests the presence of cryptic lineages and, pending the inclusion of more data from a larger geographic range, the group may be in need of a taxonomic revision.  相似文献   

12.
In order to elucidate the taxonomic status of the melanistic, girdled lizard, Cordylus cordylus niger, occurring in the Cape Peninsula and the Saldanha Bay area, South Africa, character variation among populations of the C. cordylus complex in the section of the Cape Province south of 32°3C latitude and west of 19°30' longitude was analysed. Variation for 92 external morphological characters at 54 localities was determined. Distinct patterns of interlocality variation were observed in only eight characters, but interestingly, these patterns were concordant in all eight cases. The observed patterns are interpreted as indicating that three phenotypic forms of the nominate species occur in the south-western Cape, namely a coastal melanistic form (= C. c. niger), occurring in insular and peninsular situations along the coast; a montane melanistic form occurring at relatively high altitudes along the western section of the Cape Fold Mountains; and the typical form (= C. c. cordylus), occurring commonly along the coastal lowlands, but also further inland at some places.  相似文献   

13.
Populations of Hippopotamus amphibius have declined throughout Africa in recent years, and are expected to decline further. An understanding of the population genetics of individual populations of hippos is necessary for effective management. To that end, we sequenced a portion of the mitochondrial DNA (mtDNA) control region or D-loop from 37 H. amphibius, from six herds in the central region of Kruger National Park (KNP), Republic of South Africa. We amplified a 453 bp segment by PCR, and identified 21 polymorphic sites and seven haplotypes. All of these haplotypes are private alleles, not found in other populations of hippos from southern Africa. Overall nucleotide diversity (π) was 0.01739, and haplotype diversity (hd) was 0.8273, within the range observed in other parts of Africa. Mismatch analysis conformed more closely to a model of constant population size than either rapid demographic or spatial expansion. An analysis of molecular variance demonstrated no significant differentiation among herds, and Mantel tests showed no significant relationship between geographic and genetic distance among herds separated by up to 47 km (measured as Euclidean [x,y] distance) or 77 km (measured along rivers). Over this range, the population appears to be a single panmictic unit. A test of the hypothesis that calves are more likely to share a mtDNA haplotype with an adult female in the same herd than an adult female from a different herd was not significant.  相似文献   

14.
Development and reproduction of neotenic Polystoma australis were investigated in natural anuran Kassina and Semnodactylus hosts in South Africa. Newly established parasites attached mainly inside the left branchial chamber. They then migrated so that parasites older than eight days occurred almost exclusively in the right branchial chamber. Mortality was high and continuous. In young worms age could be readily determined from haptoral structure. At 23°C the developing reproductive system was discernible at seven days. Egg production started at 16 days and could be maintained at constant rates of around 10-20 eggs/ parasite/day for up to 40 days. No crowding effect influencing parasite development or reproduction could be established. These developmental standards could be used to measure the success of parasites subjected to experimental conditions.  相似文献   

15.
The African Penguin (Spheniscus demersus) has suffered population declines and is listed in the IUCN Red List as Endangered. The species is endemic to the coast of southern Africa, and breeding colonies are distributed on the south-western coast of Africa. Currently, African Penguins are being kept in zoo and aquarium facilities throughout South Africa. In this study, molecular genetic data based on 12 microsatellite markers from 1 119 African Penguin samples from four facilities were generated in order to determine the level of genetic variation, population structure and differentiation, and effective population size to assist in the development of an effective captive management plan. Expected heterozygosity ranged from 0.57 to 0.62, and allelic richness from 4.2 to 5.1. However, based on differences between first- and second-generation captive birds, we conclude that the ex situ population is at risk of losing genetic variability in the future and management programmes should include exchange of birds between captive facilities in order to induce gene flow and increase effective population size. Adding individuals from in situ populations should also be considered in the future in cases where these birds cannot be rehabilitated. Molecular genetic analyses of wild penguin populations should be carried out for comparison, and to ascertain to what degree ‘in situ genetic diversity’ is represented among ex situ populations. With regular resampling and analyses, the extent of the effect of processes such as genetic drift on diversity in the ex situ penguin populations will become evident.  相似文献   

16.
《African Zoology》2013,48(1):92-98
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17.
While most human Salmonella infections result from exposure to contaminated foods, an estimated 11% of all Salmonella infections are attributed to animal exposures, including both direct animal handling and indirect exposures such as cleaning cages and handling contaminated pet food. This report describes the epidemiologic, environmental and laboratory investigations conducted in the United States as part of the response to an international outbreak of tetracycline‐resistant Salmonella enterica serotype I 4,[5],12:i:‐ infections with over 500 illnesses occurring from 2008 to 2010. This investigation found that illness due to the outbreak strain was significantly associated with exposure to pet reptiles and frozen feeder rodents used as food for pet reptiles. Salmonella isolates indistinguishable from the outbreak strain were isolated from a frozen feeder mice‐fed reptile owned by a case patient, as well as from frozen feeder mice and environmental samples collected from a rodent producing facility (Company A). An international voluntary recall of all Company A produced frozen feeder animals sold between May 2009 and July 2010 occurred. Only 13% of cases in our investigation were aware of the association between Salmonella infection and mice or rats. Consumers, the pet industry, healthcare providers and veterinarians need to be aware of the potential health risk posed by feeder rodents, whether live or frozen. Frozen feeder rodent producers, suppliers and distributors should follow the animal food labelling requirements as described in 21 CFR §501.5, and all packages of frozen feeder rodents should include safe handling instructions. Persons should wash their hands thoroughly with soap and water after handling live or frozen feeder rodents, as well as reptiles or anything in the area where the animals live. Continued opportunities exist for public health officials, the pet industry, veterinarians and consumers to work together to prevent salmonellosis associated with pet food, pets and other animals.  相似文献   

18.
Fish eggs, thought to be those of the liparid fish, Careproctus griseldea, were found In the gill chambers of several specimens of the stone crab, Lithodes tropicalls, caught In deep-water (-600 m) oil the South West African/Namibian coast (-24°46/S/13°28'E). The size class and quantity of crabs involved in this symbiotic relationship are discussed and some observations are made as to the diameter, number and maturity of the fish eggs removed from the crabs.  相似文献   

19.
The northwestern part of KwaZulu-Natal (KZN) in South Africa is suitable for sheep farming as well as crop production. However, there are some constraints to animal production due to the low quality of natural vegetation during winter. Alternative winter feeding strategies have been suggested from research conducted in similar vegetation types in other parts of South Africa. Grazing maize is a potential alternative fodder source but its low crude protein might be a limitation to acceptable livestock production. This preliminary study investigated the potential of inter-cropping maize with high protein content crops for providing sheep with fodder of acceptable quality during winter in northwestern KZN.

Raphanus sativus (Japanese radish), Ornithopus sativus (serradella) and Vicia dasycarpa (grazing vetch) showed promising results in terms of dry matter yield and nutritional value. The production of Pennisetum glaucum (babala) and Avena sativa (oats) was relatively high. However, the nutritional value of both these species was marginal. Glycine max (soybeans) and Lablab purpureus (dolichos) showed good and above required nutritional properties, but dry matter yield was low.  相似文献   

20.
Though important, CO2 effluxes from non-agricultural ecosystems are poorly characterised. Given that thicket vegetation is prevalent in Eastern Cape, South Africa, we monitored soil CO2 effluxes from an intact thicket, degraded thicket (DT) and grassland (G) over 10 months, as affected by temperature, moisture and penetration resistance (PR). High soil moisture (16%) reduced PR (4?kg cm?2), which raised winter effluxes (1.2 µmol m?2 s?1), while low moisture (2%) resulted in hard dry soil (14?kg cm?2) that suppressed spring effluxes (0.2 µmol m?2 s?1). There was good interaction between PR and moisture (r = ?0.53), with seasonal effluxes increasing with increasing moisture (r = 0.9, p = 0.0001) and decreasing PR (r = ?0.66, p = 0.02). Temperature effects were significant under unlimited moisture supply. Thus high summer temperature (40 °C) gave lower effluxes in DT and G (<1 µmol m?2 s?1) due to limited moisture (<10%), whereas high autumn temperature (48 °C) and good moisture (16%) accelerated CO2 emissions (averaging 2 µmol m?2 s?1) from all covers. Although semi-arid ecosystems are limited by low moisture and sandy soils, they contribute to CO2 emissions under high moisture and increasing temperature. Keywords: Eastern Cape, grassland, soil carbon dioxide effluxes, soil organic carbon, thicket  相似文献   

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