Volatiles from feces of wild male house mice : Chemistry and effects on behavior and heart Rate.

Volatile compounds from the fecal pellets deposited by a house mouse could be used for the purpose of communication with conspecifics. Analysis of volatiles from fresh and aged pellets by gas chromatography-mass spectrometry showed that many compounds were present and that ketones, alcohols, and carboxylic acids were the most common. Introducing volatiles from the fecal pellets of strange males into the territory of a singly housed male altered the site at which the resident mouse deposited most of its feces, and introducing the fecal pellets of a male mouse into the environment where it encountered a conspecific improved its success in an encounter with a stranger. The combined volatiles from feces of strange males had a greater effect on the heart rate of a male mouse than the combined volatiles from its own feces. Several individual volatiles from the fecal pellets of strange males affected the heart rates of test animals, but individual animals responded differently to constituents with similar retention times.

Volatile compounds from excreta of laboratory mice (Mus musculus) : Preliminary examination of composition and effects on behavior.

Volatile components of all the excretory products deposited by house mice may contribute to their ability to identify their own territories. When mice were placed on a clean surface, they deposited feces, secretions discharged from the anus (anal secretion) and urine. Exposure to several clean surfaces in succession caused a decline in the number of fecal pellets and urine spots deposited and an increase in the number of anal smears. The volatile compounds emanating from feces and anal secretion appeared to be qualitatively and quantitatively different from those emanating from urine, but many compounds with short retention times appeared to be common to feces and anal secretion. Introducing volatiles from feces of strange males into the territory of a singly housed male altered the site at which the resident animal deposited its feces but had no effect on the site at which it urinated. Introducing the feces or the anal secretion of a male mouse into the environment where it encountered a strange conspecific appeared to improve its success in encounters with a conspecific. It was concluded that at least some of the volatile compounds that enable mice to distinguish their own territory from those of neighboring groups may be derived from feces and that many fecal volatiles may originate from the secretions of glands opening into the digestive tract.

Microflora and volatile fatty acids present in inguinal pouches of the wild rabbit,Oryctolagus cuniculus, in Australia.

Contents of inguinal pouches of the wild rabbit,Oryctolagus cuniculus, have been examined for the presence of microorganisms and volatile fatty acids. A total of 245 isolates were made from 167 samples taken from 75 rabbits, and microorganisms were obtained from 93% of individuals. The most common microorganism encountered wasStaphylococcus aureus, followed by the yeastCandida kruzei. Other organisms isolated wereBacillus subtilis,Escherichia coli, andStreptococcus faecalis. Quantitative analysis of volatile fatty acids in scrapings from pouches showed considerable variation between individuals. Of the acids identified, acetic acid and isovaleric acid were the most abundant. In a liquid medium containing one of these acids, the growth of microorganisms was only slightly affected. However, growth became inhibited when these fatty acids were used in combination.

The ovipositional response of the Australian sheep blowfly, Lucilia cuprina, to fleece-rot odours.

The ovipositional response of Lucilia cuprina flies to odours emanating from fleece-rot lesions of greasy wool in which Pseudomonas aeruginosa bacteria proliferated, was studied. Fractionation of the fleece-rot odours was carried out by bubbling the volatile components through hydrochloric acid and sodium hydroxide solutions to remove basic odours and acidic odours respectively. It was found that the acidic/neutral odours of fleece-rot wool, when perfused into wet, greasy wool stimulated L. cuprina to oviposit. On the other hand, the basic/neutral odours of fleece-rot wool were virtually unattractive to the gravid fly. Similarly, the acidic/neutral odours emanating from fleece-rot lesions of clean wool from which the non-fibre components, wax, suint and epithelial debris, had been removed by scouring, were found to be unattractive to the gravid fly in choice tests.

Effect of volatiles collected above fecal pellets on behavior of the rabbit,Oryctolagus cuniculus, tested in an experimental chamber : I. Total volatiles and some chemically prepared fractions.

The fecal pellets of rabbits,Oryctolagus cuniculus, are coated with secretion from the anal gland, the odor from which functions as a territorial marker. The total volatiles collected from above fecal pellets and three different fractions prepared by washing the volatiles through either distilled water, 1 M sodium hydroxide, or 1 M hydrochloric acid were tested for their effect on the territorial confidence of individual animals. Tests were based on the neutral pen paradigm used in previous studies but employed a specially designed test chamber, the internal odor environment of which could be fully controlled. In the four series of bioassays a total of 140 separate tests were performed and 64 adult male rabbits were used. The results showed that the presence of the total volatiles influences the outcome of territorial competitions in pairs of male rabbits in favor of the individual from which they were derived. They were comparable with those obtained in earlier studies when fecal pellets were presented in the test pen. The effects of the different washing reagents on the total odor are illustrated by gas chromatograms, and the components most likely to be removed by the different treatments are suggested. The volatiles remaining after passing through distilled water had less effect on the rabbit's behavior than the total odor. Since the washing process not only removed water-soluble compounds but also led to a reduction in the concentrations of water-insoluble components introduced into the test chamber, either of these factors could have been responsible for the weakened effect. Fractions of the odor obtained by washing with either sodium hydroxide or hydrochloric acid did not influence the results of the tests. This suggests that the essential components of the olfactory signal include both basic and acidic compounds.

Identification of some volatile compounds in the odor of fecal pellets of the rabbit,Oryctolagus cuniculus.

A study has been made of the volatile constituents in the vapors collected from fecal pellets of wild rabbits,Oryctolagus cuniculus. Measurements of changes in the heart rates of adult male rabbits exposed to the effluent of a gas chromatographic capillary column were used to indicate the presence of compounds which may be of behavioral significance. Combined with the use of high-resolution columns in gas chromatography and gas chromatography-mass spectrometry, this approach has implicated several classes of compounds, including volatile fatty acids and phenols, which in certain absolute or relative concentrations may be involved in the formation of signals of territorial importance.

Effect of volatiles collected above fecal pellets on behavior of the rabbit,Oryctolagus cuniculus, tested in an experimental chamber : II. Gas chromatographic fractionation of trapped volatiles.

Gas chromatographic techniques were used to trap and fractionate the volatile substances emanating from the fecal pellets of wild rabbits,Oryctolagus cuniculus, which incorporate the odor of the anal gland secretion. The volatiles were bubbled through water, trapped on Chromosorb 105, transferred to Silicone SF96 traps, passed through a GC capillary column, and retrapped on SF96. The behavioral effect of trapped and fractionated volatiles was determined in four series of bioassays involving 51 adult, male, wild-type rabbits in 112, ten-minute tests. The bioassay was based on the demonstration of territorial confidence by the rabbits under the influence of their own odor. In the bioassays of the unfractionated volatiles eluted from Chromosorb 105 and SF96 traps the animals were significantly more confident in the presence of the volatiles from their own fecal pellets. One of the two fractions of the total volatiles was ineffective while the effect of the other was less than that of the unfractionated odor. The results demonstrate that the gas chromatographic techniques can be used to manipulate complex mammalian odors with precision. Combined with a discriminative bioassay, this opens up the possibility of identifying the specific combinations of volatile substances involved in the formation of olfactory signals.

The establishment of a laboratory colony of Ixodes holocyclus.

A laboratory colony capable of producing annually 3000 female Ixodes holocyclus was maintained for 3 years. Guinea-pigs were used for larval feeding and bandicoots for nymphs and adults. The methods and equipment employed are described in detail.

Failure to demonstrate involvement of prostaglandins in the immune expulsion of Trichostrongylus colubriformis from the intestine of guinea pigs.

The intraduodenal injection of synthetic prostaglandins did not lead to the expulsion of Trichostrongylus colubriformis from the intestine of guinea pigs. Treatment of immune guinea pigs with aspirin and indomethacin failed to inhibit the expulsion of a challenge infection with this nematode. These results suggest that in this infection, unlike Nippostrongylus brasiliensis infection in the rat, prostaglandins do not play an important role in the immune expulsion of the parasite from the intestine.

Cuticular lipids of adults and puparia of the Australian sheep blowfly Lucilia cuprina (Wied.).

The presence of a strong contact component in the sex and ovipositing behavior of the sheep blowfly Lucilia cuprina Wied. prompted an investigation into the chemical composition of the cuticular wax of the adult male and female flies as well as that of the blowfly puparia. Thin-layer chromatography indicated that the lipids in all the waxes examined comprise hydrocarbons, nonglyceryl esters, triglycerides, free fatty acids, and hydroxy compounds, probably diglycerides and monoglycerides. Phospholipids were not detected. Straight-and branched-chain saturated compounds, the latter often pre-dominating, are present in the hydrocarbon, free fatty acid, and ester fractions. Unsaturated molecules were absent. The hydrocarbons resemble those of the cricket to some extent, but the absence of unsaturated compounds is in striking contrast to both the cricket and the cockroach. Pheromones may be present in the low molecular weight fatty acids obtained on brief extraction of the insects.