Frequency of tail loss reflects variation in predation levels,predator efficiency,and the behaviour of three populations of brown anoles

We investigated two predictions regarding the incidence of tail regeneration in lizards for three populations of brown anoles exposed to varying predation levels from the same predator (cats). Firstly although inefficient predators are likely to increase the incidence of regenerated tails (i.e. lizards can escape through tail autotomy), highly efficient predators will kill and eat the lizard and thus leave no evidence of autotomy. At the site with no cats, only 4% of anoles demonstrated signs of tail regeneration. This value was not significantly different from the site where feral cats (i.e. ‘efficient’ predators that would capture prey to eat, as supported by behavioural observation) were present (7%). By contrast, 25% of anoles present at the site with pet cats (well‐fed domesticated cats that caught and played with anoles, i.e. were ‘inefficient’ predators) exhibited regenerated tails. Secondly, more obvious lizards are more susceptible to predation attempts. Supporting this hypothesis, our data indicate a higher incidence of regenerated tails (28%) was recorded amongst adult males (which are territorial, occupying exposed positions) compared to females and subadult males (17%) or juveniles (1%). In conclusion, the behaviour of both the predator and the lizard influences the frequency of regenerated tails in brown anoles. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 648–656.     

The experimental infection of pigs with different numbers of Taenia solium eggs: immune response and efficiency of establishment

Three of 4 pigs inoculated with 10 eggs of Taenia solium became infected. In those pigs infected with larger numbers of eggs, all became infected. Specific antibodies against the metacestodes were found in serum at day 30 postinoculation (PI) in animals that received 1,000 or more eggs and at day 60 in those that received 10 or 100 eggs. The concentration and diversity of antibodies increased up to the day of death in pigs that received 10,000 or 100,000 eggs. All pigs infected with 1,000 or more eggs developed antibodies, but only 40% and 75% of pigs that received 10 and 100 eggs, respectively, developed antibodies. Metacestodes were found in the muscles of 23 of the 27 infected animals. In 35.7% of the pigs that received 1,000 or more eggs, metacestodes were also found in the brain. Most of the metacestodes found in pigs infected with 10 or 100 eggs were caseous, whereas in pigs infected with 1,000 or more eggs the majority of metacestodes were vesicular. This study shows that the severity of T. solium infection and the possible regulation of the immune system-evasion mechanisms depend on the number of metacestodes that succeed in establishing themselves and remain vesicular.     

Saurian malaria in Kenya: epidemiological features of malarial infections in lizard populations of the West Pokot District

During investigations into the prevalence of malarial parasites among lizards in the West Pokot District in Kenya, 179 lizards comprising eight species were caught. Examination of the Giemsa-stained smears made from their blood showed that 34 lizards were infected with Plasmodium species. Fifteen lizards were infected with a single species of Plasmodium and 19 carried multiple infections, the maximum, in four lizards, was four species. There were 19 combinations of parasite infections. Seventeen Plasmodium species were identified, the commonest being P. icipeensis. Only two of the eight lizard species were infected: the skink Mabuya striata and the agamid Agama agama. Eight of the Plasmodium species infected both; another eight species infected M. striata only but three of these have been described from different lizard families elsewhere in Africa. P. robinsoni infected A. agama only, although it was first described from another lizard family in another part of Africa. The epidemiological significance of these results is discussed.     

Spermatophore production and spermatheca content in Tenebrio molitor infected with Hymenolepis diminuta

Male and female Tenebrio molitor act as intermediate hosts for metacestodes of the rat tapeworm, Hymenolepis diminuta. It is known that the bean-shaped accessory glands of infected males exhibit an extended growth period and are significantly larger than those from noninfected males by day 10 after emergence. We wished to determine whether more material is transferred from these glands into the spermatophores. Here we report that the protein content and trehalase activity of spermatophores produced by bean-shaped accessory glands from infected males is elevated. However, protein transferred to the female spermatheca during mating was not affected by the infection status of the male. No evidence of transfer of trehalase to the spermatheca was detected but spermatheca from virgin, infected females contained significantly greater trehalase activity than those from noninfected females.     

Acanthocephala in amphibians (Anura) and reptiles (Squamata) from Brazil and Paraguay with description of a new species

In a survey of 1,732 amphibians and reptiles collected across S?o Paulo Province, Brazil, and 7 provinces in Paraguay, 26 species were found infected with acanthocephalans. Of 1,510 anurans, 14 anurans, representing 11 species, were infected with cystacanths of Centrorhynchus spp. and 1 anuran with cystacanths of Oligacanthorhynchus sp. Of 107 lizards, 1 lizard was infected with cystacanths of Centrorhynchus sp. and 1 lizard with cystacanths of Oligacanthorhynchus sp. Acanthocephalus caspanensis was found in 3 anurans (3 species) and Acanthocephalus lutzi in 3 anurans (2 species) and 2 snakes (2 species). The systematic position of A. lutzi cannot be resolved using presently available morphological data. Acanthocephalus saopaulensis n. sp. was found in a single individual of Bufo ictericus. The new species can be differentiated from all its congeners except A. caspanensis in having a sigmoid-shaped male posterior end and from A. caspanensis in having a proboscis armature of 16 rows of 5-7 hooks rather than 18-19 rows of 6-7 hooks and larger eggs. The status of Acanthocephalus and Pseudoacanthocephalus continues to be problematic.     

Interspecific interactions tested: two species of malarial parasite in a West African lizard

Plasmodium giganteum and P. agamae, parasites of the rainbow lizard, Agama agama, in West Africa were studied to determine the nature of any interspecific interactions between the two malaria species. The plasmodia are distributed in A. agama throughout the mesic zone of Africa; P. agamae is sometimes found as a solitary malaria species in populations of the lizard, but P. gigateum has not been found alone. In 3170 lizards from Sierra Leone the prevalence of lizard malaria at 22 sites varied considerably (8–90% of lizards were infected), but the ratio of the two species was similar among sites (52–91% P. agamae). Larger lizards were more often infected. Mixed infections occurred 2–5 times more often than expected by chance. Parasite density within individual hosts, or parasitemia, was similar for each species when alone or in mixed infection. Natural infections followed in laboratory lizards stayed at constant levels for as long as 211 days. The two species use different classes of host cells (P. giganteum in immature cells and P. agamae in mature erythrocytes) and may have different periods of peak transmission. Analysis of the data does not support a neutral relationship between P. giganteum and P. agamae, nor ongoing competition for resources or heterologous immunity. The data best support facilitation in which P. agamae alters the host in a way that allows more successful establishment of P. giganteum.     

Hepatozoon kisrae n. sp. infecting the lizard Agama stellio is transmitted by the tick Hyalomma cf. aegyptium

Hepatozoon kisrae n. sp. was found infecting a starred lizard at a site in southeastern Samaria, Palestine. These lizards were also hosts to the ixodid tick Hyalomma cf. aegyptium, which was demonstrated to be the vector of this hemogregarine. Hepatozoon and tick infections occurred in lizards within a very restricted locality; at a second site, nearby, ticks occurred without Hepatozoon infection. Micro- and macromeronts occurred mainly in the lungs, while cyst-like merogonic stages, mainly dizoic, occurred in the liver. Mature intraerythrocytic gametocytes were stout and encapsulated. Development from oocysts to sporocysts took place in the tick hemocoel, and was examined by transmission electron microscopy. Lizards were successfully infected when fed on sporocyst-infected ticks or viscera of infected lizards. Ticks become infected when fed on infected lizards; sporogony was complete when the ticks reached adult stage, over 40 days after initial attachment.     

Metacestode-induced depression of the production of, and response to, sex pheromone in the intermediate host Tenebrio molitor

Hymenolepis diminuta infection of Tenebrio molitor is associated with an impairment of vitellogenesis and a reduction in host fecundity. In this communication the effect of infection upon an additional aspect of host reproduction, the initiation of mating behavior, has been examined. Copulatory release pheromone, extracted from control virgin females 6-7 days old, was shown to stimulate a positive mating response in 88% of 5- to 6-day-old control males; however, only a 56% response was elicited by pheromone from infected females. In addition, parasitization adversely effected male response to pheromone from control females. A significant (P less than 0.001) depression of copulatory response occurred in infected 6- to 7-day-old males (age of peak response) although this effect was not sustained in older beetles. The possibility that an endocrine interaction between metacestodes and host may mediate these effects is discussed in the light of our knowledge of the role of host juvenile hormone in controlling both pheromone production and vitellogenesis in T. molitor.     

Parietalectomy does not affect testicular growth in photoregulating lizards

The testicular response of male anoles maintained at a constant 32 degrees C was similar in both parietalectomized and sham-parietalectomized lizards exposed to either constant light (40 lux intensity) or to photic gradients (40-300 lux). The results support the hypothesis that the acceleration of gonadal growth in parietalectomized lizards noted by others depends on the ability of lizards to self-regulate exposure to thermal, but not photic, stimuli.     

Wolbachia感染对拟澳洲赤眼蜂寿命、生殖力和嗅觉反应的影响

研究了通过共享同一寄主卵,短管赤眼蜂Trichogramma pretiosum体内共生的Wolbachia被水平传递到拟澳洲赤眼蜂T. confusum体内后,Wolbachia对新宿主拟澳洲赤眼蜂的影响。结果表明： Wolbachia的侵染能使拟澳洲赤眼蜂进行不完全的产雌孤雌生殖,增加拟澳洲赤眼蜂子代雌性比例,但却导致了雌蜂寿命缩短和繁殖力降低的生理损失。Wolbachia感染的当代处女蜂及其建立的种群连续5代(F₁～F₅),其子代雌蜂百分率分别为79.17%、76.60%、68.66%、72.58%、68.15%和64.06%,基本上呈现出逐代降低的趋势,并越来越接近对照的63.85%。处女蜂及F₁～F₅代雌蜂的平均寿命分别为4.33、5.50、5.60、6.68、7.32和7.50天,而未感染交配雌蜂寿命为7.59 天;处女蜂及F₁～F₅代雌蜂平均产卵量分别为11.33、70.00、86.41、93.90、102.92和124.38粒/雌,除F₅代外,均显著低于未感染交配雌蜂的产卵量134.81粒/雌。用四臂嗅觉仪测定了Wolbachia新宿主拟澳洲赤眼蜂对寄主小菜蛾的嗅觉反应,结果表明Wolbachia的侵染具轻微干扰拟澳洲赤眼蜂嗅觉反应的负面影响。未感染Wolbachia的拟澳洲赤眼蜂及Wolbachia供体短管赤眼蜂对寄主小菜蛾具较强的嗅觉反应,其雌蜂在小菜蛾腹部鳞片正己烷提取液和小菜蛾卵表正己烷提取液处理区内滞留时间显著或极显著长于对照区。而感染Wolbachia的拟澳洲赤眼蜂F₂代和F₃代雌蜂,尽管在小菜蛾腹部鳞片正己烷提取液处理区内滞留时间比对照区长,但没有达到显著水平;其F₂代雌蜂在小菜蛾卵表正己烷提取液处理区内滞留时间与对照区相比,也没有达到显著水平。随Wolbachia在拟澳洲赤眼蜂种群中垂直感染代数的增加,拟澳洲赤眼蜂对寄主小菜蛾的嗅觉反应恢复正常,在Wolbachia感染后的 F₄～F₆代,雌蜂在两种提取液处理区内的滞留时间均显著或极显著长于对照区。     

Control of arthropod abundance by Anolis lizards on St. Eustatius (Neth. Antilles)

The two Anolis lizard species of St. Eustatius (Neth. Antilles) have large effects on the abundance of arthropods. Over a six-month period, we excluded Anolis lizards from three experimental areas and maintained three other areas with natural densities of lizards. Exclusion of anoles resulted in a two to three-fold increase in the abundance of arthropods on the forest floor (mainly Dipterans), and a twenty to thirty-fold increase in the abundance of three large web-building spiders. These abundant web-building spiders, in turn, caused approximately a 25% decrease in the abundance of insects between the forest floor and canopy. Exclusion of anoles had no observed effect on the degree of herbivory as assayed by the amount of leaf damage on two plant species.     

Annual testicular cycle of the lizard Anolis carolinensis: effects of pinealectomy and melatonin

The effects of pinealectomy and exogenous melatonin treatment on the reproductive system of male anoles were examined at several different times of year. In September pinealectomy of anoles exposed to either a stimulatory LD 14:10 light cycle or a nonstimulatory LD 10:14 light cycle induced significant testicular growth and development over that observed in sham-operated anoles. At a nonphotosensitive time of year (December) pinealectomy also had a significant progonadal effect but no effect of pinealectomy was seen in February-March. Daily melatonin injections given either in the morning or afternoon (or both) failed to block gonadal growth either (1) in sham-operated or pinealectomized anoles exposed to LD 14:10 in the fall or (2) in pinealectomized lizards exposed to LD 10:14 in the fall. Continuous melatonin administration via subcutaneous silastic implants blocked the progonadal effects of pinealectomy in the winter (December). The results show that pinealectomy can have significant progonadal effects; these effects are seasonal but can encompass phases of the annual testicular cycle which are either photoperiod-dependent or temperature-dependent; and melatonin may be a reproductively active factor involved.     

Schellackia occidentalis n.sp., a Blood-inhabiting Coccidian Found in Lizards in Southern California

SUMMARY. Schellackia occidentalis n. sp., is described from the following lizards from southern California: Sceloporus occidentalis becki, S. o. biseriatus , and Uta stansburiana hesperis. Evidence is presented to show that lizards become infected by ingestion of the lizard mite Geckobiella texana. The mite acts as a passive vector by swallowing infected erythrocytes. After ingestion of the mites carrying parasitized red cells, the lizard is infected by migration of the sporozoites into the lizard's intestinal epithelial cells. Schizogony and sporogony occur in the intestinal wall of the lizard. Sporozoites appear in the peripheral blood from 30 to 45 days after ingestion of infected mites. This is the first species of the genus Schellackia to be described in the Western Hemisphere.     

Experiments on dispersal: Short-term floatation of insular anoles,with a review of similar abilities in other terrestrial animals

Summary The floatation ability of a common Carribean insular lizard, Anolis sagrei, was tested under controlled conditions in a laboratory seawater wave tank. Short-term passive floatation abilities are extensive: all 39 animals survived 1 h, and 30% of those tested were still afloat by 24 h.The survival times for anoles in seawater are much greater than those reported in the literature for the 19 species of small mammals tested in freshwater; only mediumsized mammals have comparable abilities. Floatation, unaided by rafts, is a likely means of dispersal for anoles and perhaps other lizards between nearby islands such as in the Bahamas. The literature on observed overwater dispersal distances in non-volant animals is tabulated; data are rather scarce.     

Spatio-temporal distribution of aggressive and courting behaviors in the lizardGallotia galloti from Tenerife,the Canary Islands

The temporal and spatial distribution of various aggressive and courting behaviors of the lacertid lizardGallotia galloti was studied in Tenerife (the Canary Islands) for several days from April to June, by direct observations with binoculars from a hide situated near the study area. Aggressive behaviors were exhibited by the lizards throughout the whole recording period and were more frequently shown on sunny days or near the midday hours of cloudy days. The same occurred for courting behaviors, but these were less frequently seen in April and May. The spatial distribution of both kinds of behaviors for each lizard proved to be overlapped, thus confirming the non-territoriality of this lizard population.     

Host plant toxins and unpalatability of Neacoryphus bicrucis (Hemiptera: Lygaeidae)

Abstract. 1. Host plant choice of the seed bug, Neacoryphus bicrucis Say (Hemiritera, Lygaeidae), was evaluated in four different Georgia habitats. N. bicrucis utilized only species of Senecio as host plants at a granite outcrop and at old fields on the coastal plain, in the piedmont, and in the Blue Ridge Mountains.
2. In laboratory tests N. bicrucis is distasteful to the green anole lizard, Anolis carolinensis Voight. Only six of ninety field-collected bugs were eaten in palatability trials while eighty-four of the remaining ninety attacked bugs were rejected by lizards without apparent harm. However, the bugs were palatable to Fowler's toads, Bufo woodhousei fowleri Hinckley, which ate all thirty-six bugs offered to them.
3. N. bicrucis selectively sequesters pyrrolizidine alkaloids from Senecio spp. These may cause the insects' distastefulness to green anoles. In palatability trials, lizards ate all twenty insects reared on sunflower seeds, Helianthus annus, but rejected all twenty reared on Senecio smallii.     

An Analysis of Inter-Population Divergence in Visual Display Behavior of the Green Anole Lizard (Anolis carolinensis)

Variation in habitat structure can profoundly affect the evolution of visual displays in animals. We compared the field display behavior of two populations of the green anole lizard (Anolis carolinensis) in Southern Louisiana. These two populations occupy habitats varying markedly in structure (clumped vs. continuous), ecological setting (urban vs. natural) and the degree of male competition and predation. We filmed 56 large adult male lizards during the active spring reproductive period and detected substantial divergence in display behavior between populations. We found that (1) relative dewlap areas did not differ significantly between populations, (2) Tulane anoles spent about twice as much time displaying compared with Good Hope field anoles, although the average display duration did not differ significantly between populations, and (3) the two populations differed significantly in the relative frequency of display types: lizards from the Tulane population used a higher proportion of A and B display types, whereas Good Hope Field anoles used C displays more often. Finally, we detected differences in other aspects of display behavior (use of display modifiers, volley length distributions). We suggest that these display differences may result from differences in green anole male density (three times higher at Tulane), combined with habitat differences (clumped vs. continuous).     

Thyroxine affects behavioral thermoregulation but not growth rate among populations of the western fence lizard (Sceloporus occidentalis)

We investigated whether thyroxine influences hatchling growth rate of the western fence lizard (Sceloporus occidentalis) throught its effects on thermoregulatory behaviors. We reared control and thyroxine-injected hatchlings from three populations of S. occidentalis that differ in growth rate in a thermal gradient. We also measured the daily changes in body temperature and activity level (proportion of time spent out of retreat sites) of control and thyroxine-injected lizards. Previous studies have shown that within and among population differences in growth rate of the western fence lizard are correlated with the maintenance of high activity levels (proportion of time spent outside of retreat sites) and high body temperatures throughout the day. Growth rate was not influenced by injections of thyroxine. However, injections of thyroxine did elevate average daily body temperature and daily activity. Although administration of thyroxine uniformly increased the probability of activity throughout the day, it did not appear to alter the daily changes in activity. Previous studies have shown that the slower-growing hatchlings from northern populations exhibit a decline in activity during the later part of the thermal cycle, whereas the faster growing southern hatchlings maintain the same level of high activity throughout the thermal cycle. The decline in activity of northern populations was not prevented by thyroxine injection used in our current study. Northern lizards receiving exogenous thyroxine were still less active later in the day compared to early in the day, even though activity level throughout the day was elevated. Thus, the effects of thyroxine on temperature regulation observed in our study (general increase in activity level) appear to be unrelated to those aspects of temperature regulation (e.g., daily changes in behavioral thermoregulation) that are correlated with among population differences in growth rate. We also raised hatchlings in a cycling thermal regime (forced thermal cycle of 34°C:15°C, 12L:12D) where behavioral thermoregulation is not possible. The growth rate of lizards forced to cycle between 34°C:15°C on a daily basis was significantly lower than those lizards allowed to behaviorally thermoregulate, further underscoring the importance of the circadian pattern of thermoregulation for growth.Abbreviations GR growth rate - MR metabolic rate - SMR standard metabolic rate - SVL snout-vent length - T₄ thyroxine - T _b body temperature - T _e environmental temperature     

Microsatellite markers developed for a Swedish population of sand lizard (<Emphasis Type="Italic">Lacerta agilis</Emphasis>)

Populations of sand lizards (Lacerta agilis) are declining throughout its north-western range. Here we characterize fifteen new microsatellite markers developed specifically for parentage analysis in a small Swedish population of sand lizards. These loci were screened in the Asketunnan population and a much larger and genetically diverse Hungarian population, with heterozygosities ranging from (0.217–0.875) and (0.400–0.974), respectively. All loci were in Hardy-Weinberg Equilibrium in the Swedish population but eight loci had significant heterozygote deficiencies in the Hungarian population. Two loci were significantly linked in both populations. These microsatellite loci are likely to be applicable in research on other sand lizard populations throughout Europe. An erratum to this article can be found at     

Experimental infection of pigs and cattle with eggs of Asian Taenia saginata with special reference to its extrahepatic viscerotropism.

Asian Taenia saginata, tentatively called Taenia saginata taiwanensis, has been described to be infected in its metacestode stage only in the liver of intermediate host animals. Experimentally, however, we found that the metacestodes of the Asian Taenia saginata are also infected in other viscera than the liver of pigs (Landrace-Duroc-Hampshire) 4 days to 4 months postinoculation (PI). Viscerotropism of cysticercosis was apparent because a majority (70.7%) of the non-calcified cysticerci were found in the livers while a minority were found in extrahepatic organs such as the omentum (19.2%), lungs (8.1%) and serosa of colon (2.0%). When experimentally infected to cattle, Asian T. saginata cysticerci were also observed calcified in the livers. On the other hand, classical Taenia saginata metacestodes infected the muscles and viscera of the Holstein-Friesian cattle whereas no infection was observed in experimental pigs. Extrahepatic metacestodes of Asian T. saginata, which were obtained from an experimental pig were confirmed to be infective to a male volunteer. This extrahepatic viscerotropism of Asian T. saginata metacestodes in experimental pigs explains well the transmission modes of Asian T. saginata among people considering the eating habits.