Male Burmese pythons follow female scent trails and show sex‐specific behaviors

Animals communicate with potential mates using species‐specific signals, and pheromones are powerful sexual signals that modify conspecific behavior to facilitate mate location. Among the vertebrates, snakes are especially adept in mate searching via chemical trailing, which is particularly relevant given that many snake species are invasive outside their native ranges. Chemical signals used in mate choice are, thus, potentially valuable tools for management of invasive snake species. The Burmese python (Python bivittatus) is an invasive snake in the Florida Everglades where it is negatively impacting native fauna. In this study, we sought to: (i) determine if males can follow conspecific chemical trails in a Y‐maze; and (ii) describe the mate searching behaviors exhibited by males while trailing. All males consistently followed a single female scent trail in the maze, but when only a male scent trail was present they did not discriminate between the male and blank arms. Rate of tongue‐flicking, a proxy for chemosensory sampling, was also marginally higher when males were following female versus male scent trails. However, when both female and male scent trails were simultaneously present in the Y‐maze, males did not show a preference for the female arm, although the tongue‐flick rate was higher in the female‐only trial compared to female versus male. Analyses of multiple male behaviors individually and using an ethogram revealed that behaviors were more frequent and complex in the female‐only trials compared to male‐only trials. Additional behavioral trials are needed to determine if an effective pheromonal approach to Burmese python management is possible.     

Preference status does not indicate intrinsic quality differences in Drosophila pseudoobscura

The good genes hypothesis states that choosers prefer individuals of high intrinsic quality to individuals of lower intrinsic quality. Variation in longevity is thought to reflect, in part, intrinsic quality differences of individuals in addition to the costs of mating and reproduction. Here we report longevity variation of Drosophila pseudoobscura, a species in which previous experiments have demonstrated that individual mate preferences (pre-touching mate assessments) of females and males are associated with enhanced numbers of eclosed (adult) offspring and higher egg-to-adult survival (offspring viability). Using mate assessment arenas and protocols similar to those in a previous experiment that demonstrated fitness benefits to breeders and their offspring of mating with individuals they preferred, we tested the following predictions: (i) preferred discriminatees live longer than non-preferred discriminatees; (ii) males live longer than females; and (iii) virgins live longer than mated individuals. The experiment yielded 938 individuals for longevity analysis. Sex and mating status affected longevity: males lived longer than females, virgin females lived longer than mated females, but there were no differences in longevity for mated and virgin males. Non-preferred discriminatees of both sexes survived as long as preferred discriminatees, a result inconsistent with the prediction of the good genes hypothesis for mate preferences. To our knowledge, this is the first demonstration of the cost of reproduction for females in D. pseudoobscura and of longevity variation of preferred and non-preferred discriminatees.     

Cuticular hydrocarbons in two parapatric species of ants and their hybrid

Discrimination between nestmates and non‐nestmates in social insects is thought to rely on the pattern of cuticular hydrocarbons. We investigated the cuticular hydrocarbon profiles of 2 parapatric sibling ant species, Temnothorax nylanderi (Förster, 1850) and Temnothorax crassispinus (Karavaiev, 1926), and their hybrid. We found that although the profiles show considerable similarities, a discriminant analysis based on the relative peak areas of cuticular hydrocarbons separates the 3 taxa. The profiles of hybrids were not consistently intermediate between those of the paternal species, suggesting either non‐additive interactions among the parental biosynthetic pathways or systematic differences in environment‐derived odor cues.     

马·花杂交F1的鲜茸产量和繁殖方法及探讨

系统报道了48年来我国几个主要单位开展家养马鹿(♀)与梅花鹿(♂)杂交,即马.花杂交试验研究工作及其马.花杂交F154只290副茸的鲜茸产量和2只创记录者各锯龄的锯茸规格茸型和鲜茸产量、本交繁殖方法,并探讨了采用马鹿人工授精和同期发情等现代繁殖技术,大规模高效开展育成杂交,尤其清.双杂交和清.西杂交,乃至培育茸肉血兼用型鹿与该项最佳杂交组合的显效性,为养鹿业种鹿场、良繁体系、良繁基地和大型企业名牌鹿的产业化高效生产经营提供了新理念和科学依据。     

Sex differences in the influence of social context,salient social stimulation and amphetamine on ultrasonic vocalizations in prairie voles

Prairie voles (Microtus ochrogaster) are a socially monogamous rodent species and their cooperative behaviors require extensive communication between conspecifics. Rodents use ultrasonic vocalizations (USVs) to communicate and because a prairie vole breeder pair must engage in extensive cooperation for successful reproduction, auditory communication may be critical for this species. Therefore, we sought to characterize USVs in adult male and female prairie voles, and to determine how these calls are influenced by social context, salient social stimuli and the psychostimulant drug of abuse amphetamine (AMPH). Here, we characterize prairie vole USVs by showing the range of frequencies of prairie vole USVs, the proportion of various call types, how these call types compare between males and females, and how they are influenced by social stimulation and AMPH. AMPH caused a robust increase in the number of USVs in both males and females and there was a dramatic sex difference in the complexity of call structures of AMPH‐induced USVs, with males emitting more elaborate calls. Moreover, we show that novel (i.e. salient) social cues evoked differential increases in USVs across sex, with males showing a much more robust increase in USV production, both with respect to the frequency and complexity of USV production. Exposure to an estrous female in particular caused an extraordinary increase in USVs in male subjects. These data suggest that USVs may be a useful measure of social motivation in this species, including how social behaviors can be impacted by drugs of abuse.     

Survival and Antibody Response of Channel Catfish,Blue Catfish,and Channel Catfish Female × Blue Catfish Male Hybrids after Exposure to Edwardsiella ictaluri

Abstract

Juvenile Norris strain channel catfish Ictalurus punctatus, blue catfish I. furcatus, and Norris strain channel catfish female × blue catfish male hybrids were challenged with Edwardsiella ictaluri by bath immersion or intraperitoneal injection (high or low dose) in aquaria. Survival (%) after bath immersion was highest for blue catfish (89.5 ± 2.8), intermediate for hybrids (73.8 ± 6.7), and lowest for channel catfish (62.0 ± 4.2). Prechallenge antibody levels to E. ictaluri, measured by enzyme-linked immunosorbent assay, were negative (mean ± SE optical density [OD] = 0.010 ± 0.003). Postchallenge antibody response for blue catfish (OD = 0.132 ± 0.045) was significantly lower than that of channel catfish (OD = 0.350 ± 0.045), whereas the response of the channel × blue catfish F₁ hybrids (OD = 0.263 ± 0.051) was intermediate and not significantly different from either parental species. Intraperitoneal injections of E. ictaluri resulted in significant mortality only in channel catfish (88.3 ± 2.6% survival) and were sublethal to hybrid catfish and blue catfish with 100.0% and 99.3 ± 0.4% survival, respectively. Antibody responses after the injection challenge were significantly different among catfish groups and injection dose with no group × dose interaction. Antibody responses after the injection challenge were consistent with the immersion challenge, and means of high and low challenge doses were lowest in blue catfish (OD = 0.061 ± 0.014), intermediate in hybrids (OD = 0.187 ± 0.014), and highest in channel catfish (OD = 0.272 ± 0.014). For all fish groups combined, the high injection challenge dose resulted in higher antibody levels (OD = 0.206 ± 0.011) than low injection challenge dose (OD = 0.140 ± 0.012). Overall results indicate greater resistance to E. ictaluri and lower antibody response in blue catfish, and show the potential to identify molecular markers linked with disease resistance and introgression of resistance genes from blue catfish into channel catfish.     

Major histocompatibility complex and mate choice in the polygynous primate: the Sichuan snub‐nosed monkey (Rhinopithecus roxellana)

The highly polymorphic genes within the major histocompatibility complex (MHC) not only play a major role in immunity resistance, but also seem to provide hints for mate choice in some animal populations. In the present study we investigated MHC‐related mate choice in a small natural population (group size 40–55 individuals) of a polygynous primate, the Sichuan snub‐nosed monkey (Rhinopithecus roxellana). We found that there was no evidence either for MHC‐disassortative mating, or for females to mate with males based on MHC heterozygosity or specific alleles. Nevertheless, of the 11 alleles identified, we found that the frequencies of 2 alleles, Rhro‐DRB2 (P < 0.01) and Rhro‐DRB5 (P < 0.05) were higher in offspring than in their parents. These findings suggest that MHC‐DRB in this population of R. roxellana is unlikely to be associated with mating preferences. Limited female opportunities for mate choice are likely due, in part, to the harem breeding structure present in R. roxellana, and the relatively small number of resident adult males in our study band (N = 4–6). In addition, we suggest that differences in the frequency of particular alleles across generations may be linked to parasite resistance in a fluctuating environment; however, confirmation of this finding requires further study.     

三种鹅鸡草的生物系统学研究

通过对鹅观草属犬草组长芒鹅观草、缘毛鹅观和鹅观草３个种及春种间杂种的形态变异、染色体配对行为和繁育特性进行研究,探讨这３个种的亲缘关系。Ｆ１植株的外形趋于两亲本之间。在减数分裂过程中,亲本种染色体配对正常。杂种Ｆ１的染色体配对数较高,平均构型：Ｒ．ｐｅｎｄｕｌｉｎａ＊Ｒ．ｄｏｌｉｃｈａｔｈｅｒａ为０．５６１Ⅰ＋１３．７２Ⅱ;Ｒ．ｄｏｌｉｃｈａｔｈｅｒａ＊Ｒ．ｋａｍｏｊｉ为７．５８Ⅰ＋１３．５８Ⅱ＋     

Biology of Larks (Aves: Alaudidae) in the Central Namib Desert

1. The biology of six species of larks in the Namib Desert near Walvis Bay, South West Africa, was studied in 1964, 1965 and 1966.

2. All species reproduced following rainfall in summer and autumn months, with the appearance of green grass and abundant insects on which the birds fed.

3. The primarily insectivorous species, Certhilauda albofasciata, shows no seasonality in moulting and testicular development, and reproduces whenever local rainfall results in favourable feeding and nesting circumstances, while the primarily granivorous Spizoeorys starki and Eremopterix verticalis have markedly seasonal testicular and moulting cycles timed so that reproduction occurs only during the late summer and autumn months. Ammomanes grayi is intermediate in food habits and in timing of moulting and reproduction, and C. albescens and Mirafra naevia may also be intermediate in this respect.

4. S. starki and E. verticalis are the only larks that normally drink, but flocks of both species were observed that were independent of drinking water.

5. Larks avoid heat stress during daytime by keeping to the shade of stones, tufts of vegetation and mouths of rodent burrows; and nests are nearly always placed on the shady side of a stone' or tuft of grass.

6. It is suggested that larks may be successful desert occupants because they have not become highly specialized and therefore can tolerate rapidly and severely changing environ-mental conditions associated with drought and irregular rainfall.     

Major ascaroside pheromone component asc-C5 influences reproductive plasticity among isolates of the invasive species pinewood nematode

Pheromones are communication chemicals and regulatory signals used by animals and represent unique tools for organisms to mediate behaviors and make “decisions” to maximize their fitness. Phenotypic plasticity refers to the innate capacity of a species to tolerate a greater breadth of environmental conditions across which it adapts to improve its survival, reproduction, and fitness. The pinewood nematode, Bursaphelenchus xylophilus, an invasive nematode species, was accidentally introduced from North America into Japan, China, and Europe; however, few studies have investigated its pheromones and phenotypic plasticity as a natural model. Here, we demonstrated a novel phenomenon, in which nematodes under the condition of pheromone presence triggered increased reproduction in invasive strains (JP1, JP2, CN1, CN2, EU1, and EU2), while it simultaneously decreased reproduction in native strains (US1 and US2). The bidirectional effect on fecundity, mediated by presence/absence of pheromones, is henceforth termed pheromone-regulative reproductive plasticity (PRRP). We further found that synthetic ascaroside asc-C5 (ascr#9), the major pheromone component, plays a leading role in PRRP and identified 2 candidate receptor genes, Bxydaf-38 and Bxysrd-10, involved in perceiving asc-C5. These results suggest that plasticity of reproductive responses to pheromones in pinewood nematode may increase its fitness in novel environments following introduction. This opens up a new perspective for invasion biology and presents a novel strategy of invasion, suggesting that pheromones, in addition to their traditional roles in chemical signaling, can influence the reproductive phenotype among native and invasive isolates. In addition, this novel mechanism could broadly explain, through comparative studies of native and invasive populations of animals, a potential underlying factor behind of the success of other biological invasions.     

Life-table experiments with Helisoma duryi (Wetherby) and Biomphalaria Pfeifferi (Krauss) at constant temperatures

In an effort to find an ecological homologue that could be utilized as a biological control agent of the intermediate host species of economically important helminth parasites, age-specific life-table experiments with Helisoma duryi (Wetherby) ind Biomphalaria pfeifferi (Krauss) (intermediate host of Schistosoma mansoni) were carried out at a series of constant temperatures in a laboratory. The results showed that the lifespan and net reproduction rate of H. duryi were higher than those of B. pfeifferi over the whole range of temperatures investigated (18-35°C). The conclusion is reached that H. duryi should theoretically be capable of establishing viable populations in most of the habitats occupied by B. pfeifferi in South Africa.     

Rapid assessment of montane anuran communities in the Albertine Rift: Hyperolius castaneus Ahl, 1931 as an umbrella species for conservation

The species richness of seven montane anuran communities of the Albertine Rift was assessed with visual and acoustic transects. A total of 28 anuran species were detected. The highland anuran communities at (2000–2800 m) were dominated by up to nine Albertine Rift endemic species considered threatened by IUCN Red List criteria, whereas the community at lower elevation included mainly wide-ranging, least-concern species. Cluster analyses of the presence/absence data on the overall array of species indicated that Ahl’s reed frog (Hyperolius castaneus) is a suitable umbrella species for the highland Albertine Rift endemics. Hyperolius castaneus was always among the first species collected at each site, either by visual detection or by acoustic detection based on the characteristic advertisement and aggression calls which were emitted during the day and at night. The ease of its detection in the field makes this species an ideal candidate for rapid assessments of priority sites for conservation measures.     

Differentiating among horse (Equus caballus), donkey (Equus asinus) and their hybrids with combined analysis of nuclear and mitochondrial gene polymorphism

A novel and brief method of differentiating among horse (Equus caballus) and donkey (Equus asinus) and their hybrids (mule, E. asinus × E. caballus and hinny, E. caballus × E. asinus) with combined analysis of nuclear and mitochondrial gene polymorphism (CANMGP) was reported in the present report. A nuclear gene, protamine P1 gene of donkey was sequenced and compared with the known horse sequence from GenBank while a published equid mitochondrial gene, cytochrome b gene of donkey was compared with that of horse. In each of the two genes, a fixed nucleotide substitution within an exon that could be recognized by Dpn II restriction enzyme was found between the two species. Two pairs of primers were designed for amplifying the fragments within the two genes containing the informative nucleotide positions in 65 horses and 41 donkeys and 38 hybrids and conditions of polymerase chain reaction and restriction fragment length polymorphism (PCR‐RFLP) analysis were optimized. Horse, donkey and mule and hinny had their own specific cleavage patterns after the PCR‐RFLP analysis was performed, which made it very easy to identify them from each other. As multiplex PCR can be conducted with the two pairs of primers and only one restriction enzyme is involved in PCR‐RFLP analysis, the method described in the present study is a convenient way to identify horse and donkey and their hybrids. The idea involved in the method of CANMGP can be also used to differentiate other animal species or breeds and their hybrids.     

A description of the life stages of Echinoparyphium elegans (Trematoda: Echinostomatidae)

South Africa urgently requires a national strategic plan for the conservation of the country's biodiversity. The formulation of such a plan would be relatively easy if centres (hotspots) of richness, endemism and rarity were congruent, both within and among many different taxa, if these hotspots captured a large proportion of the total species, and if hotspots fell within existing reserves. The investigation of six vertebrate taxa (vizfreshwater fish, frogs, tortoises and terrapins, snakes, birds, and various mammal orders) at a national scale reveals that hotspots are not coincident within taxa. Centres of richness are concentrated in the north-eastern areas of the country, whereas endemism is concentrated in the south-west, and centres of rare and threatened {Red Data Book) species can be in either area. Paired comparisons among taxa reveal greatly varying proportional overlaps of species richness hotspots (0-72%). The proportion of total species falling in hotspots ranges from low (66% for fish) to high (92% for birds). Hotspots are thus not an efficient method of siting representative (ideal) reserves. In order to design a more representative reserve system to protect all vertebrate species, a complementarity algorithm was applied to all taxa separately, and then to all taxa combined. The combined analysis yielded more efficient results {66 reserves are required to represent all 1074 species at least once) than the separate analyses (97 reserves). Many of these representative reserves coincide with both hotspots and existing reserves, and over 85% of the hotspots of most taxa coincide with existing reserves, thus South Africa's vertebrate fauna could be more effectively protected with only moderate acquisition of new, well-sited reserves. A biome analysis reveals that these reserves will also have to incorporate areas of those biomes that are currently inadequately protected, viz grassland, Succulent Karoo and Nama-Karoo. The methods outlined in this paper should be applied to as many other taxa as possible, in order to aid the formulation of a national strategic plan for biodiversity conservation.     

First Report of Ovoviviparity in a Southern African Amphisbaenid,Monopeltis C. Capensis

The behaviour of breeding and non-breeding male maccoa ducks (Oxywa maccoa) was studied in South Africa. Individual ducks were observed continuously from sunrise to sunset in the wild, and all ritualized and non-ritualized behaviour was recorded. Diurnal time budgets of territorial and non-territorial males were translated into energy budgets, showing relative time and energy expenditures for resting, foraging, preening and bathing, territorial defence and courtship activities. A territorial male spent one-third of the daytime on active behaviour associated with reproduction. Territorial males averaged 297 displays per fifteen-hour day, or about one display every three minutes. Active defence of territory occupied 15 per cent of a male's time budget, adding an estimated 20 per cent to the energy a non-breeding male spent on self-maintenance. Active courtship of females occupied IS per cent of a male's time budget, adding 18 per cent to the energy a non-breeding male spent on self-maintenance. The increase in time spent on reproductive behaviour over that of a non-breeding male is achieved mainly through decrease of time allocated to resting in the budget of the non-breeder. Territorial males increased energy expenditure by a factor of 1,3, but devoted the same portion of time as non-breeders to actual feeding (21 per cent). Energy and time-saving strategies were associated with territorial defence and courtship, contributing towards optimization of time and energy budgeting.     

Management of Wild Ungulate Populations in Italy: Captive-Breeding,Hybridisation and Genetic Consequences of Translocations

Captive-reproduced stocks of some species of ungulates (Artiodactyla), and particularly the red deer (Cervus elaphus), fallow deer (Dama dama), roe deer (Capreolus capreolus) and the wildboar (Sus scrofa) are more or less extensively translocated in Italy, mainly for local reintroductions or restocking of exploited wild populations. However, captive breeding often involves the reproduction of non-indigenous individuals or the production of artificial hybrids. Consequently, translocations of captive-reproduced ungulates are of concern for the conservation of indigenous populations and gene pools. The impact of translocations should be evaluated within the background of the growing knowledge on population genetic and phylogeographic structure of ungulates. Molecular genetic markers are being used to map geographic genetic diversity, and reconstruct the phylogeographic history of natural populations (i.e., in the roe deer). Molecular makers are also used to detect the consequences of domestication and identify hybrids between wild and domesticated populations (i.e., in the wildboar), or to detect inter-specific hybridisation (i.e., between the red deer and wapiti). Hybridisation of wild and domestic pigs, and diffusion of hybrids in nature is widespread in Italy. Admixture of indigenous and non-indigenous roe deer stocks is also widespread. Therefore, conservation and management of indigenous ungulates calls for careful evaluation of captive-reproduced stocks.

     

Autochtonous infection of dogs and slugs with Angiostrongylus vasorum in Hungary

On the course of a helminthological survey of the dogs of Baranya County, Hungary Angiostrongylus vasorum infection was detected in two asymptomatic dogs. Identification of the parasite was based on morphology of the first-stage larvae (L1) isolated from droppings, and successful experimental infection with first stage larvae to laboratory reared Discus rotundatus and Lissachatina fulica snails, in order to exclude species of the family Filaroididae that have similar larvae to A. vasorum. While angiostrongylosis is widespread among foxes, this is the first report of A. vasorum infection in housedog in Hungary. In gardens, where infected dogs were being kept 91 specimens of 6 species of limacid and arionid slugs were collected of which 5 specimens of Arion lusitanicus were found to carry larvae of A. vasorum. Dogs usually do not ingest such large slugs willingly. Frogs are known to act as paratenic hosts in the life cycle of A. vasorum. Since one of the infected dogs harboured also infection with the intestinal trematode Alaria alata, of which frogs certainly play the role of the second intermediate host, therefore it is assumed that in this case the dog became infected with A. vasorum by eating frogs.     

Body Lengths and Temperatures of the Crabeater Seal

In arid or semi-arid areas of southern Africa, frogs are typically active nocturnally and seasonally. They may adopt a variety of strategies to conserve water during the day or during the unfavourable part of the year. Aquatic frogs (e.g. Xenopus, most species of Sana, Ptychadena and Phrynobatrachus) do not normally have a water conservation problem except when the water in or near which they are living dries up. Burrowing frogs (e.g. Bufo, Pyxicephalus, Tomoptema and Breviceps) are able to select microhabitats in the soil which reduce evaporative water loss. Burrowing may, in particular cases, be associated with the formation of a keratinized cocoon of stratum corneum which appears to offer a barrier to outward water movement. In arboreal frogs (Chiromantis xerampelina and Hyperolius spp.) the most interesting adaptations are found. Evidence is given in the case of HyperoUus nasutus for low evaporative water losses at the end of the dry season, when the frogs sit exposed to the sun and dry air, in flowers. During the rains when H. nasutus is in breeding aggregation the evaporative water losses are high. Chiromantis xerampelina is uricotelic and resistant to desiccation.

The three approaches which anurans have adopted in response to water conservation problems have their correlates in bladder size and function. hormonal regulation of water balance and the extent to which water loss can be tolerated. The potential that the southern African amphibian fauna offers for physiological research is emphasized.     

紫貂的饲养管理

紫貂是一种极其珍贵的毛皮动物 ,其饲养管理可分为成年紫貂的饲养管理和仔兽育成期的饲养管理 ,成年紫貂的饲养管理又分为繁殖期的饲养管理和非繁殖期的饲养管理。紫貂繁殖期的饲养管理的重点为 :1做好发情鉴定和及时配种工作 ;2对处于妊娠期、产仔和哺乳期母兽应提供全价饲料 ;3及时断乳 ;4做好卫生防疫工作。非繁殖期的饲养管理的重点为做好防寒保温和提高毛皮质量工作。仔兽育成期的饲养管理的重点为提供充足的全价饲料和做好卫生防疫工作。     

Percutaneous absorption between frog species: Variability in skin may influence delivery of therapeutics

Frogs have permeable skin, so transdermal delivery provides a practical alternative to traditional dosing routes. However, little is known about how frog skin permeability differs interspecifically, and there are different reported clinical outcomes following topical application of the same chemical in different frog species. This study collated in vitro absorption kinetic data previously reported for two frog species: the green tree frog (Litoria caerulea) and the cane toad (Rhinella marina), and used linear mixed-effects modelling to produce a model of absorption. Histology of skin samples from each species was performed to observe morphological differences that may affect absorption. Absorption kinetics differed significantly between species, with the logP of the applied chemical a better predictor of permeability than molecular weight. Application site also influenced permeability, with dorsal permeability consistently higher in cane toads. Ventral permeability was more consistent between species. Skin thickness differed between species and skin regions, and this may explain the differences in absorption kinetics. Guidelines for selecting chemicals and dosing site when treating frogs are presented. The permeability differences identified may explain the poor reproducibility reported in the treatment of disease across frog species, and reinforces the importance of considering interspecies differences when designing therapeutic treatments for frogs.