Evidence for Thermoregulation in the Tortoise Chersine Angulata

The results of experiments on Chersine angulata suggest that a mechanism exists for controlling rate of change of body temperature over the range 20-35°C. Active retardation of heat uptake close to the upper temperature is a prominent feature as measured by cloacal temperature. Unlike other reptiles so far studied, Chersine angulata, when alive, cools more rapidly than it heats up. Dead animals heat and cool at the same rate, and more rapidly than live animals. It is suggested that overheating is the critical factor in the thermal relations of the tortoise.     

Histopathological and behaviour effects of formaldehyde treatment in juvenile mullet,Mugil liza (Valenciennes)

Considerable losses may be related to diseases caused by parasites in aquaculture. Formaldehyde (37% gas dissolved in water) is an effective chemotherapeutic, widely used to control ectoparasites in fish. However, for many species of fish used in aquaculture, the control of external parasites and the deleterious effects of formaldehyde in short‐term baths are still uncertain. In order to clarify some gaps, 1 h‐prophylactic baths (67.5, 135, 270, 405 and 540 mg L^?1 formaldehyde in triplicate) were performed in juvenile mullet, Mugil liza (Valenciennes). Results showed that prophylactic baths of 135 mg L^?1 formaldehyde by 1 h did not cause death in tested mullets. At this concentration, histopathologies were mild and fish survival was high. However, fish exposed to increasing concentrations of formaldehyde presented severe histopathologies in the gills besides behavioural and morphological alterations. The histopathological and behavioural implications of formaldehyde use in aquaculture are discussed.     

Modulation of the response of rainbow trout (Oncorhynchus mykiss Walbaum) to confinement, by an ectoparasitic (Argulus foliaceus L.) infestation and cortisol feeding

The effects of a 21 day infestation with the ectoparasite Argulus foliaceus on the response of rainbow trout Oncorhynchus mykiss to an acute stressor (confinement) were investigated. Fish were divided into a control and two parasitized groups, with one parasitized group having received cortisol feeding 72 and 24 h before infection. Prior to confinement only control fish showed a significant increase in body mass and condition factor. Following 4 h confinement, plasma glucose levels in the normal- fed/infested group were significantly higher than in the controls, while the cortisol-fed/infested group had significantly lower plasma levels of adrenocorticotropic hormone (ACTH) and glucose. Both infested groups, but not controls, had higher plasma ACTH and cortisol levels 48 h after confinement when compared with their pre-confinement levels. Stressor-induced immunomodulation was more evident in the parasitized fish after confinement, as was concluded from decreased lysozyme activity, alternative complement activity and oxygen radical production either immediately after, or 48 h post 4 h confinement. Circulating lymphocyte numbers were significantly reduced in the control and normal-fed/infested fish. Results indicate that low ectoparasitic infestations can, for a prolonged period, lead to a stress experience with effects that impair the response to subsequent stressors. Such effects may be further confounded by a previous elevation of plasma cortisol levels.     

图木舒克地区春夏季羊体外寄生虫感染情况调查

为了解图木舒克地区羊群体外寄生虫的种类及感染情况,对采集到虫体进行形态学观察,鉴定出11种寄生虫,其中蜱7种、螨2种,虱2种,优势虫种为扇头蜱属的血红扇头蜱(Rhipicephalus sanguineus)、短小扇头蜱(R.turanicus)图兰扇头蜱(R.pumilio).根据感染情况的调查结果,提出预防性驱虫措...     

Zonation and habitat selection on a reclaimed coastal foredune

Geomorphic / floristic variables are useful as general habitat indicators on coastal foredunes. Variables used in this study were vegetation cover, plant community structure and sand movement. Three distinct zones, four habitats and six subhabitats were identified. Zonation and habitat selection appeared to be related to cover for two small mammal species. The arthropod orders were less susceptible to zonation and strict habitat selection, although some of the species showed selection. The normally unfavourable edaphic habitat, the transition dune, was the most populated, dominated by the marine isopods.     

Poultry Integrated Pest Management: Status and Future

Modern commercial poultry production under large companies is expanding worldwide with similar methods and housing, and the accompanying arthropod and rodent pest problems. The pests increase the cost of production and are factors in the spread of avian diseases. The biology, behavior and control of ectoparasites and premise pests are described in relation to the different housing and production practices for broiler breeders, turkey breeders, growout (broilers and turkeys), caged-layers, and pullets. Ectoparasites include Ornithonyssus fowl mites, Dermanyssus chicken mites, lice, bedbugs, fleas, and argasid fowl ticks. Premise pests include Alphitobius darkling beetles, Dermestes hide beetles, the house fly and several related filth fly species, calliphorid blow flies, moths, cockroaches, and rodents. Populations of these pests are largely determined by the housing, waste, and flock management practices. An integrated pest management (IPM) approach, tailored to the different production systems, is required for satisfactory poultry pest control. Biosecurity, preventing the introduction of pests and diseases into a facility, is critical. Poultry IPM, based on pest identification, pest population monitoring, and methods of cultural, biological, and chemical control, is elucidated. The structure of the sophisticated, highly integrated poultry industry provides a situation conducive to refinement and wider implementation of IPM.     

Preliminary investigation on rodent–ectoparasite associations in the highlands of Tigray,Northern Ethiopia: implications for potential zoonoses

We studied associations between rodents and their arthropod ectoparasites in crop fields and household compounds in the highlands of Tigray, Northern Ethiopia. Ectoparasite infestation indices, such as percent infestation, mean abundance, prevalence and host preferences, were calculated for each taxon. In total, 172 rodents from crop fields and 97 from household compounds were trapped. Rodent species and numbers trapped from the crop fields and household compounds were Mastomys awashensis (Lavrenchenko, Likhnova & Baskevich, 1998) (88 and 44), Arvicanthis dembeensis (Ruppel, 1842) (63 and 37) and Acomys sp. (21 and 16), respectively. A total of 558 insects and acarids (belonging to 11 taxa) were recovered from the rodents trapped in the crop fields, and 296 insects and acarid (belonging to 6 taxa) from the rodents trapped in the household compounds. Approximately 66% of the rodents trapped from the crop fields and 47% of those trapped from the household compounds were infested with ectoparasites. Laelaps sp. (64.9%) and Xenopsylla sp. (20.6%) comprised the highest proportion of the ectoparasites recovered in the crop fields, and the same ectoparasites, but in reverse order, comprised the highest proportions in the household compounds (Xenopsylla [50.3%] and Laelaps sp. [29%]). Our study revealed that crop fields and household compounds in the highlands share similar rodents and several ectoparasites. Furthermore, at least 1 of the rodent species and some of the ectoparasites identified in this study were reported to have posed medical and veterinary threats in other parts of Ethiopia and neighboring countries.     

Mechanism of resistance to synthetic pyrethroids in buffalo flies in south-east Queensland

Resistance to synthetic pyrethroids (SP) was first recorded in buffalo flies in Australia in 1980, associated with previous use of DDT and fenvalerate. By the 1990s, resistance was widespread. Resistance to SP in the related horn fly of the Americas is associated with kdr and super-kdr mutations in a gene encoding for a voltage-gated sodium channel. We describe 7-20-fold resistance to SP in buffalo flies from south-east Queensland, present evidence of flies that are heterozygous resistant at the kdr locus and show an increase in the frequency of the resistant allele 1 month after treatment of cattle with SP.