The helminth parasites of the badger (Meles meles) in Cornwall

The helminth parasites of 118 badgers from Cornwall are recorded. Nematode infestations are common. The five species found are Capillaria? erinacei, Molineus patens, Uncinaria stenocephala, Aelurostrongylus falciformis and Strongyloides sp. Cestode infestations appear to be rare, the species recorded being Mesocestoides lineatus and Dilepis undula. Similarly only a single trematode, Ityogonimus lorum, is recorded.     

Honeybees and the nectar of Echium plantagineum L. in southeastern Australia

An account is given of the flower of Echium plantagineum in south-eastern Australia, including stages and timing of flowering, behaviour of raindrops in the flower and aspects of floral microclimate. The concentration of nectar solutes varied with time and site, with means varying from 2 to 62% (as g sucrose/100 g solution). There was a significant negative correlation between nectar solute concentration and ambient relative humidity: the drier the air, the more concentrated the nectar. Rates of nectar secretion per flower varied with the bagging method, with long-term bagging reducing net secretion rates, possibly because of re-absorption. Rates varied with time, day and site, with a temporal pattern of change suggesting a link between rates of photosynthesis and secretion. Maximum nectar secretion rates in short-term bagging experiments were ca. 300 μg sugar/flower/hr (equivalent to > 2 mglflower/24 hr). Secretion rate was correlated with flower density. As flower density increased, secretion rate per flower decreased; rate of sugar production per unit area increased relatively more slowly than flower density. E. plantagineum could produce > 500 mg sugar/m²/day. Honeybees foraged on E. plantagineum only at ambient air temperatures above ca. 17°C unless irradiance exceeded ca. 750 W m^-2. Foragers collected nectar or pollen alone, or both, with the type of visit significantly correlated with nectar solute concentration. Below 35% (as g sucrose/100 g solution) most bees took pollen only; above 40%, most took nectar. Mean standing crop of nectar was generally < 100 μg/flower when most bees were taking nectar, but could exceed 1000 μg/flower when bees were absent or foraging mainly for pollen. Honeybees did not always remove all nectar from flowers they probed. Reabsorption of residual nectar may augment the following day's secretion.     

Hormones, Reproductive Behavior, and Speciation

A research plan is outlined which combines two ordinarily separatelines of investigation, namely, the reciprocal interaction betweenhormones and behavior and the role of behavior in the evolutionand maintenance of species, bringing both to bear on outstandingquestions in behavioral and evolutionary biology. This integrativeapproach to animal behavior, which spans three levelsµphysiology,behavior, and evolutionµshould not only yield answersto specific questions within each level of analysis, but, bytaking into account the adaptive value of each in nature, alsodemonstrate interrelationships between the leve.     

Anatomy and Systematics of Some Polycystididae (Turbellaria, Kalyptorhynchia) from the Pacific and S. Atlantic

Paraustrorhynchus gen.n., P. pacificus sp.n. (California), Antiboreorhynchus novzelae sp.n. (New Zealand) and Gyratrix proaviformis sp.n. (Oregon) are described as new taxa. Additional notes are given on Gyratrix hermaphroditus Ehrbg. (new localities on the N. American Pacific coast), Scanorhynchus forcipatus Karling (new locality in California), Paraustrorhynchus elixus (Marcus) comb.n. and Alcha evelinae Marcus (new localities in California). The taxonomy of the genera and species is discussed. Viewpoints are presented on evolutionary trends and homologous atrial organs in the family Polycystididae.     

Transmission of louping ill virus between infected and uninfected ticks co-feeding on mountain hares

Abstract. Most of the data on oral infection of ticks by louping ill virus have been obtained from experiments in which animals were infected by syringe inoculation with infectious material. Using infected ticks to mimic the natural situation, we have demonstrated that louping ill (LI) virus transmission can occur from infected to uninfected Ixodes acinus feeding in close proximity on mountain hares (Lepus timidus). Under these conditions the hares developed either low or undetectable viraemias. Highest prevalence of LI virus infection was observed in recipient nymphs which had fed to repletion between days 3 and 7 post-attachment of virus-infected adults; following engorgement, 56% of nymphs acquired virus. These results demonstrate the efficient transmission of LI virus between co-feeding ticks on naive mountain hares. However, when ticks were allowed to co-feed on virus-immune hares a significant reduction in the frequency of infection was observed. Neither red deer (Cervus elaphus) nor New Zealand White rabbits supported transmission of LI virus. The significance of virus transmission between cofeeding ticks on LI virus epidemiology is discussed.     

Benthic Biological Studies of the Southwest Florida Shelf

Between 1980 and 1987, the U.S. Department of the Interior fundeda series of benthic studies of the continental shelf off southwesternFlorida. The goal was to gather environmental information inorder to make decisions about offshore oil leasing. One major study element was habitat mapping. Fourteen transectswere surveyed geophysically (side scan sonar, subbottom profiler)and visually (underwater video and still cameras), and the resultswere compiled in atlases showing the distribution of substratumtypes and visually distinct benthic communities. Rock outcropswere rarely seen and usually of low relief (<1 m), but patchesof reef-associated sessile epifauna such as sponges, hard corals,gorgonians, ascidians, and bryozoans occupied 31% of the seafloorsurveyed. Most of the sessile epifauna were seen on hard bottomcovered by a thin sand veneer, or on biogenic rubble layers(shell rubble, coralline algal nodules). A second major study element was benthic station sampling. Fifty-fivestations were sampled from two to twelve times each, and over1,500 species of epibiota and over 1,100 species of macroinfaunawere identified. The species composition of both hard- and softbottomcommunities varied primarily in relation to water depth.     

Growth Response of Axenic Entamoeba histolytica to Hydrogen, Carbon Dioxide, and Oxygen *,†

Entamoeba histolytica required CO₂ for growth in axenic culture while growth was inhibited by H₂. The organism was tolerant to 5% O₂ in the gas phase and it was able to detoxify products of O₂ reduction in the medium. The ameba did not require a negative oxidation-reduction potential for axenic growth. However, little or no free O₂ was present in media exposed to 5% O₂ in the gas phase. Growth was improved by adding yeast extract to the medium.