First sign in Italy of Nematodirus roscidus, Apteragia quadrispiculata and Ostertagia drozdzi, found in Dama dama

The authors refer the first report in Italy of Nematodirus roscidus Railliet, 1911, Apteragia quadrispiculata Jansen, 1958 and Ostertagia drozdzi Jancev, 1977 from Dama dama. In fallow deer they found also: Trichostrongylus axei, Trichostrongylus colubriformis, Trichostrongylus vitrinus, Spiculopteragia asymmetrica, Skrjabinagia arctica, Oesophagostomum venulosum, Trichuris ovis. Trichostrongylus axei, Trichostrongylus colubriformis, Trichostrongylus vitrinus and Skrjabinagia arctica were not found before in Dama dama in Italy.     

In vitro development of Trichostrongylus axei, from infective larvae to young adults.

Advanced stages of Trichostrongylus axei were grown from exsheathed infective larvae in roller culture systems consisting of a complex cell-free medium, API-6, when used alone or supplemented for 8- or 21-day intervals with pepsin or reducing agents, or both. Young adult males and females were the most advanced stages attained. This stage was attained by days 18--21, when medium API-6 contained pepsin for 8 or 21 days, with or without reducing agents for the first 8 days; and by days 24--26, when medium API-6 was nonsupplemented. Trichostrongylus axei did not advance beyond early fourth stage or fourth molt when API-6 contained reducing agents for 8 or 21 days or reducing agents and pepsin for 21 days. The optimal culture system for development to young adults required medium API-6 supplemented with pepsin for 21 days and reducing agents for the first 8 days. This system produced maximal yields of less than 1% young adults in populations of about 100,000 T. axei by days 21--28.     

Interspecific interactions in naturally acquired nematode communities from sheep abomasum in relation to age of host and season in four areas of León (Spain).

The abomasa of naturally infected ewes (407) and lambs (190) from four areas of León were collected weekly over 2 years in the abattoir of León (north-west Spain). The major species and morphs found were Teladorsagia circumcincta and Trichostrongylus axei and to a lesser extent Marshallagia marshalli and Teladorsagia trifurcata. The putative interactions between species were assessed by Euclidian distances based on the results of multivariate analyses. The estimation of interaction was either based on mean intensities of worm burdens or on frequencies of nematode species within individual hosts. The areas, years, seasons and categories of sheep (ewes or lambs) did not influence the interaction estimates. These were not dependent upon the size of worm burden. The majority of interactions were positive. Slight negative interactions were found only with T. circumcincta-T. axei, T. circumcincta-M. marshalli and M. marshalli-T. axei. Positive interactions were recorded between the less frequent species.     

Examination of gastrointestinal helminth in livestock grazing in grassland of Bangladesh

To determine association of grassland with parasitic diseases of livestock in Bangladesh, the 'Tracer' animals (two cow calves and two goats) were released for a month in a grassland used for communal grazing of livestock near school premise in Kanthal, Trishal, Mymensingh, Bangladesh. After slaughtering of the tracer animals, their gastrointestinal tract examination revealed six species of nematode and one cestode. The nematode species were Haemonchus contortus, Trichostrongylus axei, Mecistocirrus digitatus, Oesophagostomum spp., Trichuris spp. and Bunostomum sp. The cestode was one of the genus Moniezia. With this preliminary study, grasslands are thought to be one of the main sources of gastrointestinal parasitic diseases of livestock in Bangladesh.     

Differences in the second internal transcribed spacer (ITS-2) of eight species of gastrointestinal nematodes of ruminants.

Genetic differences in the nucleotide sequence of the second internal transcribed spacers (ITS-2) among Trichostrongylus axei, Trichostrongylus colubriformis, Ostertagia ostertagi, Cooperia oncophora, Cooperia punctata, Nematodirus helvetianus, Nematodirus filicollis, and Haemonchus contortus are described. The ITS-2 sequences of the 8 species ranged between 230 and 241 base pairs in length. Sequence similarities between the different genera varied between 60% and 80%. Identities between the different species within a genus varied between 99% for C. oncophora and C. punctata, 95% for T. axei and T. colubriformis, and 89% for N. helvetianus and N. filicollis. The ITS-2 sequences proved to be useful for species differentiation. Except for the species of Cooperia (2.07% intraspecific variations for C. oncophora and 0.83% for C. punctata) the degree of intraspecific variations (N. filicollis 0.85%, T. colubriformis 1.26%, T. axei 1.27%, H. contortus 2.60%, O. ostertagi, and N. helvetianus no variation) was markedly lower than the interspecific variations allowing a reliable differentiation within the ITS-2 region between single species.     

Further observations on a focus of human trichostrongyliasis in the Viterbo resident

Human cases of trichostrongyliasis recorded in Italy in Viterbo city were determined by T. axei, T. capricola, T. colubriformis and T. vitrinus. The authors refer the results of the treatment with piperazine hydrate and a benzimidazole derivative.     

The occurrence of severe infections with Rhabditis axei in AIDS patients in Iran

During an investigation on strongyloidiasis in AIDS patients from Iran, direct smears of stools revealed many eggs and larvae of Rhabditis axei, which were subcultured to confirm identification.     

In vitro culture of Pelodera punctata Cobb and Rhabditella axei Cobbold (Rhabditida, Nematoda

A new method for the "in vitro" culture and maintenance of free-living coprophilous nematodes Rhabditella axei and Pelodera punctata is described. With this method the culture and maintenance of these nematodes is seen to be remarkably simple and therefore facilitate their use as "spy-organisms" to reveal "active" residues of nematocide substances in food.     

Microecological characterization of parasitic nematoda present in goats of arid zones of Venezuela

Goats from the Venezuelan northern arid zones were found infested by the following nematodes: Haemonchus contortus, Trichostrongylus axei, T. colubriformis, Cooperia curticei, Oesophagostomum columbianum, Skrjabinema ovis y Trichuris globulosa. The Shannon-Weaver index of diversity values oscillated between 0.045 and 1.73 bits (means = 1.16 +/- 0.24 bits). The maximum value of montly diversity ranged from 1 to 2.80 bits (means = 2.49 +/- 0.28 bits) and the equitability ranged from 0.045 to 0.67 (means = 0.44 +/- 0.09). Parasitic associations were found among 1) T. axei, T. colubriformis and H. contortus, 2) T. colubriformis, H. contortus and O. columbianum and 3) T. colubriformis, S. ovis and T. globulosa. The above results suggest that in months when the diversity index is close to the maximum value and the equitability index is near unity, wide spectrum antihelmintic treatment should be used for poly-parasitized animals.     

Host choice and fitness of anemonefish Amphiprion ocellaris (Perciformes: Pomacentridae) living with host anemones (Anthozoa: Actiniaria) in captive conditions

In this study, we investigated the host choice of naïve Amphiprion ocellaris, a specialist, at two different stages of development (newly settling juveniles and post-settlement juveniles). The fish were exposed to their natural and unnatural host species in the laboratory and their fitness was assessed in terms of activity and growth rate. Newly settling juveniles exhibited little host preference, while post-settlement juveniles immediately associated with their most common host in the wild. The analysis of fish activity confirmed that A. ocellaris is diurnal; they are most active in the morning, less at midday and barely move at night. The average travelling distance of juveniles was shorter in the groups living with their natural host, increasing in the groups living with an unnatural host and was highest in groups that did not become associated with any other unnatural host species. Post-settlement juveniles living with the natural host species grew better than those living with unnatural hosts or without anemone contact. These results suggest that the welfare of A. ocellaris in captivity will be optimized by keeping them with their natural anemone host species, although more generalist Amphiprion species may survive in association with other hosts.     

Distribution of nematode parasites of the digestive system in sheep (Ovis aries) and goats (Capra hircus) of the Piedmontese and Valdostano Alpine arc

A survey, carried out on gastro-intestinal nematodes of sheep and goats of Piemonte and of Valle d'Aosta (87 sheep and 12 goats) has shown the presence of the following species in sheep, Bunostomum trigonocephalum, Chabertia ovina, Cooperia curticei, Haemonchus contortus, Marshallagia marshalli, Nematodirus abnormalis, Nematodirus filicollis, Nematodirus helvetianus, Nematodirus spathiger, Oesophagostomum venulosum, Ostertagia circumcincta, Ostertagia lyrata, Ostertagia trifurcata, Skrjabinema ovis, Trichostrongylus axei, Trichostronglus colubriformis, Trichostronglus vitrinus, Trichuris ovis and Trichuris skrjabini; in goats, Bunostomum trigonocephalum, Chabertia ovina, Haemonchus contortus, Nematodirus filicollis, Nematodirus helvetianus, Oesophagostomum venulosum, Ostertagia circumcincta, Ostertagia ostertagi, Ostertagia trifurcata, Trichostrongylus axei, Trichostrongylus colubriformis and Trichostrongylus vitrinus. The percentage of each species in the two host is given in the text table.     

Efficacy of p-Toluoyl chloride phenylhydrazone against gastrointestinal helminths in ovines.

A new anthelmintic candidate, p-toluoyl chloride phenlylhydrazone, was administered to lambs in a paste formulation. The efficacy of this drug was determined at dose rates of 20, 30, 40, and 50 mg of active ingredient per kilogram of body weight. Helminths expelled by these dosages included Haemonchus contortus, Ostertagia circumcicta, Trichostrongylus colubriformis, T. axei, Nematodirus filicollis, Cooperia curticei, Strongyloides papillosus, Oesophagostomum columbianum, Bunostomum trigoncephalum, Chabertia ovina, Moniezia expansa, and M. benedeni.     

Qualitative and quantitative differences in cuticular hydrocarbons between laboratory and field colonies of Pogonomyrmex barbatus

Ants held in the laboratory and field ants of the species Pogonomyrmex barbatus have quantitative differences in their cuticular hydrocarbons and a qualitative difference in their methyl-branched hydrocarbons. Laboratory-held workers showed twice the hydrocarbon content as field ants. This difference was mainly due to higher amounts of straight-chain alkanes and methyl-branched alkanes in laboratory ants, whereas the proportion of the alkenes remained the same for both groups. In addition to the absence of some hydrocarbons in the field colonies, one of the methyl-branched hydrocarbons differed in amount and branching pattern between the two groups of ants. Whereas, notable peaks of 2-methylalkanes were identified in ants kept in the laboratory, these compounds could not be identified in ants living in their natural habitat. However, a trace amount of 4-methyltriacontane was found in lieu of the 2-methyltriacontane counterpart in field ants. Possible explanations for both qualitative and quantitative differences are discussed.     

Preliminary observations on the spawning conditions of the European amphioxus (Branchiostoma lanceolatum) in captivity

Members of the subphylum Cephalochordata, which include the genus Branchiostoma (i.e. amphioxus), represent the closest living invertebrate relatives of the vertebrates. To date, developmental studies have been carried out on three amphioxus species (the European Branchiostoma lanceolatum, the East Asian B. belcheri, and Floridian-Caribbean B. floridae). In most instances, adult animals have been collected from the field during their ripe season and allowed (or stimulated) to spawn in the laboratory. In any given year, dates of laboratory pawning have been limited by two factors. First, natural populations of these three most studied species of amphioxus are ripe, at most, for only a couple of months each year and, second, even when apparently ripe, animals spawn only at unpredictable intervals of every several days. This limited supply of living material hinders the development of amphioxus as a model system because this limitation makes it more difficult to work out protocols for new laboratory techniques. Therefore we are developing laboratory methods for increasing the number of amphioxus spawning dates per year. The present study found that a Mediterranean population of B. lanceolatum living near the Franco-Spanish border spawned naturally at the end of May and again at the end of June in 2003. Re-feeding experiments in the laboratory demonstrated that the gonads emptied at the end of May refilled with gametes by the end of June. We also found that animals with large gonads (both, obtained from the field and kept and fed at the laboratory during several weeks) could be induced to spawn in the laboratory out of phase with the field population if they were temperature shocked (spawning occurred 36 hours after a sustained increase in water temperature from 19 degrees C to 25 degrees C).     

Multiweek cell culture project for use in upper-level biology laboratories

This article describes a laboratory protocol for a multiweek project piloted in a new upper-level biology laboratory (BIO 426) using cell culture techniques. Human embryonic kidney-293 cells were used, and several culture media and supplements were identified for students to design their own experiments. Treatments included amino acids, EGF, caffeine, epinephrine, heavy metals, and FBS. Students researched primary literature to determine their experimental variables, made their own solutions, and treated their cells over a period of 2 wk. Before this, a sterile technique laboratory was developed to teach students how to work with the cells and minimize contamination. Students designed their experiments, mixed their solutions, seeded their cells, and treated them with their control and experimental media. Students had the choice of manipulating a number of variables, including incubation times, exposure to treatment media, and temperature. At the end of the experiment, students observed the effects of their treatment, harvested and dyed their cells, counted relative cell numbers in control and treatment flasks, and determined the ratio of living to dead cells using a hemocytometer. At the conclusion of the experiment, students presented their findings in a poster presentation. This laboratory can be expanded or adapted to include additional cell lines and treatments. The ability to design and implement their own experiments has been shown to increase student engagement in the biology-related laboratory activities as well as develop the critical thinking skills needed for independent research.     

The role of androgen receptors in regulating territorial aggression in male song sparrows

This paper examines the role that androgen receptors (ARs) play in modulating aggressive behavior in male song sparrows, Melospiza melodia morphna. Song sparrows are seasonally breeding, territorial birds that maintain year-round territories with male-female pair bonds formed during the spring breeding season. Plasma testosterone levels peak as territories are established and mates acquired. In late summer, testosterone levels fall and remain basal during the non-breeding season. We examined the role of ARs in regulating territorial aggression in captive song sparrows under short- and long-day conditions as well as just prior to, and at the start of the breading season in freely living birds using the nonsteroidal antiandrogen flutamide to block AR function. Birds were implanted with either empty or drug filled silastic implants for 18 to 42 days and then challenged with a novel male decoy to assess the individual birds level of male-male aggression. Freely living birds remained on their home territory and underwent a simulated territorial intrusion, whereas laboratory-held birds were assessed using a laboratory simulated territorial intrusion and remained in their home cage. Experimental treatment of male song sparrows decreased aggressive behavior during the pre-breeding life history substage (March-April) in freely living birds as well as in laboratory-held birds under long-day (16L:8D) conditions. During the early breeding substage (April-May) there was no measurable effect of flutamide treatment on aggressive behavior, nor was there a difference in behavior in the (8L:16D) laboratory birds. This demonstrates that ARs are an important component of the neuroendocrine control of aggressive behavior. Given that flutamide only affected aggression during the pre-breeding substage and in LD birds, the results suggest that AR dependent control of aggressive behavior changes as song sparrow life history states change.     

Phase transformation and chiasma frequency variation in locusts

Locusts exhibit two basic forms or phases, one characteristic of swarming populations, termed phase gregaria, and the other characteristic of low density populations, termed phase solitaria. It has been claimed by Nolte that locusts living at low density, both in the field and in the laboratory, have a reduced chiasma frequency compared with animals living at high density. A postulated gregarisation pheromone is held to be responsible for the stimulation of melanin biosynthesis in the swarming animals and an unknown metabolite in this pathway causes the increase in chiasma frequency, as well as other phenotypic changes associated with phase transformation. According to Nolte this represents a means of releasing stored genetic variation necessary for adaptation in the areas invaded by swarms. — This claim has been re-examined in laboratory stocks of Schistocerca gregaria using a methodology comparable to that of Nolte. No reduction in the chiasma frequency of isolated animals was observed in any of the experiments. The isolated animals did, however, develop a phenotype characteristic of phase solitaria in terms of their pigmentation and morphometrics.     

Fluoride plus aluminum: useful tools in laboratory investigations,but messengers of false information

Aluminofluoride complexes (AlF(x)) form spontaneously in aqueous solutions containing fluoride and traces of aluminum ions and appear to act as phosphate analogs. These complexes have become widely utilized in laboratory investigations of various guanine nucleotide-binding proteins. Reflecting on many laboratory studies, a new mechanism of fluoride and aluminum action on the cellular level is being suggested. The long-term synergistic effects of these ions in living environment and their hidden danger for human health are not yet fully recognized.     

Rank-dependent compromises between growth and predator protection in lizard dominance hierarchies

Juvenile Anolis aeneus lizards often live in dominance hierarchies, and in both the laboratory and field, rank was primarily determined by a juvenile's size relative to the others when it entered a hierarchy. Because juveniles entered hierarchies soon after hatching and left when they reached subadult sizes, most juveniles slowly rose in status during their sojourn in dominance hierarchies. In laboratory experiments, rank and growth rate were positively related when both food and perches were uniformly distributed. However, when perches were non-uniformly distributed, juveniles competed to live on those perch configurations which offered protection from predators. Under these conditions, growth was more weakly related to rank than in the uniform-habitat trials, and high-ranking juveniles living on the preferred (safe) perches had significantly lower growth rates than those living elsewhere. In contrast, low-ranking juveniles in non-uniform habitats experienced no such compromise between growth and safety, and those on the preferred perches tended to grow faster than those living elsewhere. Since most juveniles in the field seem to gradually rise from low to high rank, the behavioural strategies for optimizing growth and survival may change ontogenetically in this species.     

The occurrence and abundance of helminth parasites of the mountain hare Lepus timidus (L.) and the wild rabbit Oryctolagus cuniculus (L.) in Aberdeenshire, Scotland

Mountain hares were collected each month between April 1984 and March 1985 and their intestines examined for helminths. 26 rabbits were also collected between July and December 1984 and examined for gastro-intestinal helminths. Three nematode and two cestode species were found in the hares while only two nematode and one cestode species were found in the rabbits. Trichostrongylus retortaeformis was recorded from 88% of the 193 hares and 92% of the rabbits while comparable figures for Passalurus ambiguus were 0.5% and 54% and for Mosgovoyia pectinata 14% and 81%. Seasonal fluctuations were observed in the T. retortaeformis populations in the hare; numbers tended to be low during the winter months and high throughout the summer. Paranoplocephala wimerosa was reported for the first time from the British Isles and Trichostrongylus axei was recorded for the first time in the mountain hare.