Oviduct adenocarcinoma in some species of captive snakes

This article reports 5 cases of oviduct adenocarcinoma in adult captive snakes from Smithsonian's National Zoological Park. This neoplasm was found in 1 of each of the following species: emerald tree boa (Corallus caninus), Amazonian tree boa (Corallus enydris enydris), Burmese rock python (Python molurus bivittatus), Northern pine snake (Pituophis melanoleucus melanoleucus), and corn snake (Elaphe guttata). Grossly, tan to red firm masses were found within oviducts in 3 cases. In an additional 2 cases, the primary tumor was detected only histologically. Microscopically, neoplasms were papillary, and often extended transmurally. The neoplastic cells were polygonal and organized in acini or cords, with often abundant fibrovascular stroma. Hemorrhages and necrosis were present in all cases. Inflammation, myxomatous material, desmoplasia, and bacteria were often observed. Histologic evidence of metastasis was present in all cases. Solid metastases were seen in all animals except the Northern pine snake and involved several organs including the liver, lung, and heart. Emboli of neoplastic cells were observed in all animals but the Burmese rock python and corn snake.     

Environmental temperatures, physiology and behavior limit the range expansion of invasive Burmese pythons in southeastern USA

A well-established population of Burmese pythons resides in the Everglades of southern Florida. Prompted in part by a report that identified much of southern USA as suitable habitat for expansion or establishment of the Burmese python, we examined the plausibility of this snake to survive winters at sites north of the Everglades. We integrated daily low and high temperatures recorded from October to February from 2005-2011 at Homestead, Orlando and Gainesville, Florida; and Aiken, South Carolina, with minimum temperatures projected for python digestion (16 °C), activity (5 °C) and survival (0 °C). Mean low and high temperatures decreased northward from Homestead to Aiken and the number of days of freezing temperatures increased northward. Digestion was impaired or inhibited for 2 months in the Everglades and up to at least 5 months in Aiken, and activity was increasingly limited northward during these months. Reports of overwinter survivorship document that a single bout of low and freezing temperatures results in python death. The capacity for Burmese pythons to successfully overwinter in more temperate regions of the USA is seemingly prohibited because they lack the behaviors to seek refuge from, and the physiology to tolerate, cold temperatures. As tropical Southeast Asia is the source of the Everglades Burmese pythons, we predict it is unlikely that they will be able to successfully expand to or colonize more temperate areas of Florida and adjoining states due to their lack of behavioral and physiological traits to seek refuge from cold temperatures.     

Female scent mobilizes leukocytes to airways in BALB/c male mice

The scent of receptive females as a signal to reproduction stimulates male mice to olfactory search of a potential breeding partner. This searching behavior is coupled with infection risk due to bacterial contamination of the fecal and urine scent marks. We hypothesized that sniffing of female soiled bedding induced the migration of immuno‐competent cells into airways as a possible adaptation to breeding‐related infection. Using bronchoalveolar lavage in a study on mice, we found the number of leukocytes to be significantly higher in male mice that were provided new portions of soiled bedding daily from female cages, in comparison with male mice that were kept in isolation from female scent. The number of leukocytes in blood was equal in both groups. However, monocytes were fewer in number in male mice exposed to female scent than in male mice isolated from female mice. Scent‐induced migration of leukocytes was accompanied by typical behavioral (increased sniffing activity and aggressiveness) and morphological (increase preputial glands and seminal vesicles) responses to olfactory sexual stimulus.     

Ecological correlates of invasion impact for Burmese pythons in Florida

An invasive population of Burmese pythons (Python molurus bivittatus) is established across several thousand square kilometers of southern Florida and appears to have caused precipitous population declines among several species of native mammals. Why has this giant snake had such great success as an invasive species when many established reptiles have failed to spread? We scored the Burmese python for each of 15 literature-based attributes relative to predefined comparison groups from a diverse range of taxa and provide a review of the natural history and ecology of Burmese pythons relevant to each attribute. We focused on attributes linked to spread and magnitude of impacts rather than establishment success. Our results suggest that attributes related to body size and generalism appeared to be particularly applicable to the Burmese python's success in Florida. The attributes with the highest scores were: high reproductive potential, low vulnerability to predation, large adult body size, large offspring size and high dietary breadth. However, attributes of ectotherms in general and pythons in particular (including predatory mode, energetic efficiency and social interactions) might have also contributed to invasion success. Although establishment risk assessments are an important initial step in prevention of new establishments, evaluating species in terms of their potential for spreading widely and negatively impacting ecosystems might become part of the means by which resource managers prioritize control efforts in environments with large numbers of introduced species.     

Fertility control of Rattus nitidus using quinestrol: effects on reproductive organs and social behavior

Fertility control has been identified by studies in the laboratory and the field as a more appropriate and long‐term control strategy for rodent pests than lethal control. In this study, we investigated the effects of quinestrol on mass of reproductive organs and on social behaviors in female and male Himalayan field rats (Rattus nitidus). A total of 16 adult females and 16 adult males were randomly assigned to 4 groups. One male and one female group were fed rice with 0.005% quinestrol by weight for 7 days, and another 2 groups were fed rice only. After 7 days, rats were assigned to 10 min dyadic encounters between groups, and investigation, aggression, defense and attack latency were quantified. All animals were killed on day 10, and reproductive organs were dissected and weighed. Dyadic encounter data showed that there were obvious changes in social behaviors of quinestrol‐treated rats. Quinestrol significantly inhibited the investigative behavior of quinestrol‐treated males toward control females in Rattus nitidus, but seldom affected investigation between control males and quinestrol‐treated females. Aggression of control females toward quinestrol‐treated males was higher than that of quinestrol‐treated females, and defense of quinestrol‐treated males toward control females was more remarkable than that of control males. Quinestrol remarkably decreased wet masses of epididymis and spermotophore in males and ovaries in females, but had no effect on wet masses of testes and uteri after quinestrol treatment. These results indicate that the anti‐fertility effects of quinestrol on R. nitidus are attributed to not only suppressing reproductive organs but also impacting social behaviors associated with territory defense and mate choice.     

Plasma concentrations of chloramphenicol in snakes

Plasma chloramphenicol concentrations after a subcutaneous injection were studied in 87 snakes of 16 different species. The biological half-life of chloramphenicol varied from 3.3 hours in the indigo snake (Drymarchon corais couperi) to 22.1 hours in the midland water snake (Nerodia sipedon). A single dosage of 50 mg of chloramphenicol/kg of body weight produced plasma concentrations greater than 5 micrograms/ml for nearly 72 hours in 2 species of water snakes (Nerodia erythrogaster, Nerodia sipedon), for 24 hours in the Burmese python (Python molurus bivittatus), and for less than 12 hours in the gray rat snake, Indigo snake, and eastern king snake (Elaphe obsoleta spiloides, Drymarchon coraise couperi, and Lampropeltis getulus getulus). A dosage of 50 mg/kg administered to water snakes every 72 hours for 18 days maintained a minimum plasma concentration of chloramphenicol between 2 and 5 micrograms/ml.     

Vomeronasal organ lesion disrupts social odor recognition,behaviors and fitness in golden hamsters

Most studies support the viewpoint that the vomeronasal organ has a profound effect on conspecific odor recognition, scent marking and mating behavior in the golden hamster (Mesocricetus auratus). However, the role of the vomeronasal organ in social odor recognition, social interaction and fitness is not well understood. Therefore, we conducted a series of behavioral and physiological tests to examine the referred points in golden hamster. We found that male hamsters with vomeronasal organ lesion showed no preference between a predator odor (the anal gland secretion of the Siberian weasels (Mustela sibirica) and putative female pheromone components (myristic acid and palmitic acid), but were still able to discriminate between these 2 kinds of odors. In behavioral tests of anxiety, we found that vomeronasal organ removal causes female hamsters to spend much less time in center grids and to cross fewer center grids and males to make fewer crossings between light and dark boxes than sham‐operated controls. This indicates that a chronic vomeronasal organ lesion induced anxious responses in females. In aggressive behavioral tests, we found that a chronic vomeronasal organ lesion decreased agonistic behavior in female hamsters but not in males. The pup growth and litter size show no differences between the 2 groups. All together, our data suggested that vomeronasal organ ablation disrupted the olfactory recognition of social chemosignals in males, and induced anxiety‐like and aggressive behavior changes in females. However, a vomeronasal organ lesion did not affect the reproductive capacity and fitness of hamsters. Our studies may have important implications concerning the role of the vomeronasal organ in golden hamsters and also in rodents.     

Mate desertion in response to female promiscuity in the socially monogamous aardwolf Proteles cristatus

In most monogamous breeding systems males demonstrate a high degree of paternal care. With the significant costs of this parental investment, it is clearly in the interests of males to raise only their own offspring. It has therefore been predicted, but never observed in the field, that if the female of a monogamous male is promiscuous, he will desert her and attempt to breed with an alternative female. Here we report a case of such a mate desertion in the aardwolf Proteles cristatus. We suggest, however, that mate desertion should occur only rarely in response to female promiscuity. This is because a cuckolded male may still be raising some of his own offspring, and should desert only on the rare occasions when an alternative receptive female is exclusively available to himself.     

No evidence for avoidance of black rat scent by the presumably less competitive Natal multimammate mouse in a choice experiment

In Africa, indigenous multimammate mice (Mastomys natalensis) only appear to live commensally in houses when invasive black rats (Rattus rattus) are absent, yet little is known about the underlying mechanism. Avoidance through smell may cause the absence of M. natalensis from areas occupied by R. rattus, but this hypothesis has not yet been tested. We conducted a Y-maze choice experiment where 15 M. natalensis were offered a choice between corridors containing conspecific scent, R. rattus scent and a control scent. Residence time in the R. rattus corridor was greater than that in the control corridor but equal to that in the M. natalensis corridor, suggesting that multimammate mice do not actively avoid the scent of their invasive competitor.     

Reproductive strategies in males of the world's southernmost lizards

Reproductive and life history patterns in reptiles are tightly related to the environmental conditions, so male reproductive cycles have been historically characterized as continuous, for tropical lizards, or seasonal, for temperate lizards. However, males of Liolaemus and Phymaturus lizards (Liolaemidae), from cold temperate climates of high altitudes or latitudes in Argentina and Chile, have developed a variety of reproductive cycles to coordinate with the short female reproductive season and to deal with the low frequency of reproductive females in the population. Using gonadal histology and morphological analysis, we describe the male reproductive biology, fat storage and sexual dimorphism of the viviparous lizards Liolaemus sarmientoi and Liolaemus magellanicus that inhabit an austral grass steppe at 51°S, in the southern limit of the American continent. Males of L. sarmientoi and L. magellanicus are reproductively available during the entire activity season of approximately 5 months. In addition, males of both species exhibit greater body sizes than females in morphological variables relevant in sexual selection. Meanwhile, females of both species exhibit larger inter‐limb length than conspecific males, which suggests fecundity selection to increase space for a larger litter size. The continuous sperm production throughout the activity season allows these liolaemids to mate at any time when females ovulate, representing a selective advantage to deal with the short activity season and the adversities of the cold environment they inhabit.     

Social Scents in Hand-Reared Pronghorn (Antilocapra Americana)

Three male and one female pronghorn (Antilocapra americana) were taken in the wild when a few hours to three days old and were hand-raised. The development of their behaviour was studied with particular emphasis on their olfactory communication. Fifty hours of field observations confirmed most of the findings in the captive animals.

Four scents are important in the social life of the pronghorn: They originate with the paired subauricular and ischiadic glands, the single dorsal gland and the odour of urine. The subauricular and dorsal scents are produced by males only. Urine is an important component of the sniffing - pawing -urinating - defecation sequence of the males. The ontogeny of this sequence is described. An experiment with an artificial marking post demonstrated that the subauricular scent of a male one rank lower released the strongest response in other bucks. Preliminary gas chromatographic analysis of the subauricular scent has been carried out.     

缅甸蟒沙门氏菌的分离与鉴定

为探究缅甸蟒肺炎病因,本研究对海南文昌缅甸蟒养殖场的4条发病缅甸蟒进行了肺和心血组织的病原菌分离纯化、菌落及染色形态观察、生化、和16S rRNA分子鉴定,最后对各分离菌株进行了体外药敏实验。结果显示,全部分离株菌落及细胞形态特征一致,均为革兰氏阴性杆菌;糖醇发酵等生理生化特性与肠道沙门氏菌一致;根据16S rRNA基因的同源性比对,发现分离菌株与肠道沙门氏菌Salmonella enterica subsp.houtenae DSM 9221菌株同源性达到99%,可确定分离株全部为肠道沙门氏菌。通过23种抗菌药物的药物敏感性显示,所分离菌株对氟罗沙星等12种抗生素完全敏感。本研究结果表明海南文昌缅甸蟒肺炎病因为沙门氏菌感染,体外药敏实验可为该病的抗生素治疗提供使用参考。     

Investigation into the participation of male pheromones of Rhipicephalus evertsi evertsi during infestation

It was shown in this study that Rhipicephalus evertsi evertsi males emit pheromones in the preparasitic as well as in the parasitic phases. Conspecific unengorged male and female images exhibited a high response to water-soluble volatiles collected from unengorged males. A vigorous assembly of unfed female R. evertsi evertsi occurred on filter paper discs which had been in contact with either unfed or 5- and 9-day fed males. Progressively increasing percentages of conspecific unengorged males reacted to organic soluble volatiles obtained from 5- and 9-day fed males as well as to hexane washings of intact males which had fed for 9 days. It is concluded that R. evertsi evertsi males participate not only as pheromone receptive, but also as pheromone emitting, partners in the intraspecific communication of this tick species.     

Incidence of ovulation without coital stimuli in captive Japanese black bears (Ursus thibetanus japonicus) based on serum progesterone profiles

The purpose of this study was to ascertain whether or not Japanese black bears (Ursus thibetanus japonicus) are induced ovulators. The progesterone levels of female bears kept with a male and allowed to mate (n=2) and female bears allowed contact with a male through bars but not allowed to mate (n=6) during the mating season increased significantly in late October. Based on this result, the female bears were considered to have ovulated. Females isolated from males (n=3) were ovarioectomized after the mating season, and no corpora lutea were observed, indicating they had not ovulated. These findings suggest that Japanese black bears may be induced ovulators that ovulate with stimuli from males and without coitus at a high rate.     

波尔、萨能山羊与崇明白山羊杂交对繁殖性能和血清乳酸脱氢酶活性的影响

为了筛选与崇明白山羊杂交的优势组合,选用波尔山羊♂、萨能山羊♂、崇明白山羊♂各两头分别与20头崇明白山羊♀进行交配,研究不同组合对繁殖性能和血清乳酸脱氢酶(LDH)活性的影响。试验结果表明:①就繁殖性能而言,波尔山羊、萨能山羊与崇明白山羊杂交后,体现出一定的杂交优势。其中,波尔山羊的杂交效果比萨能山羊的杂交效果明显,每头母羊胎产羔2头,活羔1.71头,产羔率为200%,羔羊的断奶成活率平均为100%,产活羔数、产羔率、羔羊成活率、断奶活羔数均为三组中最高,是生产中较为理想的杂交父本。②三种成年公羊血清LDH活性由小到大的顺序是波尔、萨能、崇明,以崇明白山羊的活力为最高;在后代羔羊中,波尔与崇明杂交一代公羊的LDH活性高于萨能杂交一代公羊,也高于崇明羊自交后代,可辅助判断出波尔与崇明羊的杂交优势高于萨能羊,可能是较优杂交组合。     

雌性动情状态和雄性等级对布氏田鼠社会行为的影响

在雄性竞争条件下,不同动情雌性布氏田鼠与雄鼠之间行为观察表明:(1)雌鼠动情状态下,优势雄鼠的攻击、自我修饰行为以及交配频次与交配时间均显著高于从属雄鼠,并具有交配优先权;优先被动情雌性选择交配。而从属雄鼠则表现出更频繁的上跳(逃跑或亢奋)行为。(2)当雌鼠处于非动情状态下,雌鼠与优势雄鼠间的相互嗅问行为频次显著高于雌鼠与从属鼠;优势鼠对雌鼠和从属雄鼠的攻击行为频次均显著高于从属鼠对雌鼠和优势雄鼠的攻击;从属鼠也表现出频繁的上跳行为。(3)在与不同雌鼠动情状态下共栖时,从属雄鼠对动情雌鼠的攻击行为频次显著高于对非动情雌鼠;优势雄鼠和从属雄鼠,与非动情雌鼠的友好行为频次均高于雌鼠;与非动情状态雌鼠共栖,雄鼠之间的友好行为频次显著高于动情雌鼠状态。(4)雌鼠动情状态和雄鼠等级会影响雌雄鼠之间的相互行为,动情雌鼠优先与优势雄鼠交配。     

An optimized high quality male DNA extraction from spermatophores in open thelycum shrimp species

The crucial step of most of the current genetic studies is the extraction of DNA of sufficient quantity and quality. Several genomic DNA isolation methods have been described to successfully obtain male DNA from shrimp species. However, all current protocols require invasive handling methods with males for DNA isolation. Using Aristeus antennatus as a model we tested a reliable non‐invasive differential DNA extraction method to male DNA isolation from spermatophores attached to female thelycum. The present protocol provides high quality and quantity DNA for polymerase chain reaction amplification and male genotyping. This new approach could be useful to experimental shrimp culture to select sires with relevant genetic patterns for selective breeding programs. More importantly, it can be applied to identify the mating pairs and male structure in wild populations of species as A. antennatus, where males are often difficult to capture. Our method could be also valuable for biological studies on other spermatophore‐using species, such as myriapods, arachnids and insects.     

应用气味丰容减少圈养华南虎（Panthera tigris amoyensis）的刻板行为

2012年3～7月,对上海动物园2只雄性华南虎的刻板行为特征进行总结和分析,并开展同种其他个体的气味丰容,旨在减少圈养华南虎的刻板行为.华南虎的刻板行为主要出现在外展区4个区域,分别位于外展区的水池边、饲料投喂口、动物串门,室内笼舍.主要表现为重复性踱步,整体形状为“8”字形或者直线;华南虎的刻板行为主要发生于早晨（7：00～8：00）、傍晚（16：00～18：00）.气味丰容前后,华南虎的昼间行为的整体分配出现显著性差异（P＜0.05）,其中刻板行为的发生频率显著降低（P＜0.05）;活动行为的发生频率显著提升（P＜0.05）,标记行为显著增加（P＜0.05）;站立行为、卧息行为及睡眠行为减少,其他行为（如嗅闻和探索）增加,但均无显著差异（P＞0.05）.     

Differences in mating behavior lead to asymmetric mating interactions and consequential changes in sex ratio between an invasive and an indigenous whitefly

The invasive B whitefly and the indigenous ZHJ2 whitefly in China of the Bemisia tabaci complex represent two previously allopatric cryptic species. Laboratory experiments have shown that the invasive B can displace the indigenous ZHJ2. Here, we observed the mating behavior and mating interactions between B and ZHJ2 to elucidate the behavioral mechanisms underlying their competition. The 2 species are able to mate with each other, although at a significantly lower frequency than that between males and females within the same species. Heterospecifically-mated females produce only male progeny, indicating reproductive isolation. Heterospecific mating had only a marginal effect on reproduction of females in either species. Detailed observations on mating interactions between the 2 species showed that B had higher sexual activity than ZHJ2. B males were more likely to interrupt courtships initiated by rival males than ZHJ2 males. Compared with ZHJ2 males, B males were also more likely to successfully interrupt courtships initiated by rival heterospecific males than by males of the same species. In addition, B males guarded B females post-copulation, whereas ZHJ2 males did not. When the 2 species co-occurred, the behavioral differences and interactions between them resulted in an increased proportion of females produced in the offspring of B but reduced proportion of females in the progeny of ZHJ2. These asymmetric mating interactions might be an important mechanism underlying the displacement of ZHJ2 by B. Our study shows that reproductive interference might contribute to the competitive exclusion between closely related species during biological invasions.     

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.