AGE DETERMINATION OF ARIANTA ARBUSTORUM (L.) (PULMONATA) BASED ON GROWTH BREAKS AND INNER LAYERS

The pulmonate snail Arianta arbustorum from the Swiss Alps wasaged using thin sections of the shell margins cut from markedindividuals. Shell layers at the apertural lip and growth breaksin the juvenile can give a reliable estimate of age. (Received 16 May 1986;     

The Effect of Salinity Changes Upon the Physiology of Eulittoral Green Macroalgae from Antarctica and Southern Chile: II INTRACELLULAR INORGANIC IONS AND ORGANIC COMPOUNDS

The effects of hypo- and hypersaline treatments ranging from7–68% on the intracellular inorganic ion and organic soluteconcentrations were determined in the eulittoral green macroalgaeUlothrix implexa, Ulothrix subflaccida, Enteromorpha bulbosa,Acrosiphonia arcta, and Ulva rigida from Antarctica and SouthernChile. The main inorganic cations were K⁺, Na⁺, and Mg²⁺ inall species. The major osmolyte in E. bulbosa, A. arcta, andU. rigida was K⁺ at increasing salinities. In both Ulothrixspecies, however, K⁺ levels declined during hypersaline stressand Na⁺ concentrations rose significantly. The main inorganicanions were Cl^-, SO²_4-, and PO³_4- in all algae, while E. bulbosaand U. rigida also contained NO⁺₃. A. arcta showed an extremelyhigh SO^2-₄ content. The organic solutes proline, sucrose, andß-dimethylsulphoniopropionate (DMSP) played an importantrole in osmotic acclimation. The occurrence of three organicosmolytes suggests an additional function of these solutes ascryoprotectants in the cold-water macroalgae investigated.     

Bio-Economics of Large-Scale Eradication of Feral Goats From Santiago Island,Galápagos

ABSTRACT Invasive mammals are premier drivers of extinction and ecosystem change, particularly on islands. In the 1960s, conservation practitioners started developing techniques to eradicate invasive mammal populations from islands. Larger and more biologically complex islands are being targeted for restoration worldwide. We conducted a feral goat (Capra hircus) eradication campaign on Santiago Island in the Galápagos archipelago, which was an unprecedented advance in the ability to reverse biodiversity impacts by invasive species. We removed >79,000 goats from Santiago Island (58,465 ha) in <4.5 years, at an approximate cost of US$6.1 million. An eradication ethic combined with a suite of techniques and technologies made eradication possible. A field-based Geographic Information System facilitated an adaptive management strategy, including adjustment and integration of hunting methods. Specialized ground hunting techniques with dogs removed most of the goat population. Aerial hunting by helicopter and Judas goat techniques were also critical. Mata Hari goats, sterilized female Judas goats induced into a long-term estrus, removed males from the remnant feral population at an elevated rate, which likely decreased the length and cost of the eradication campaign. The last 1,000 goats cost US$2.0 million to remove; we spent an additional US$467,064 on monitoring to confirm eradication. Aerial hunting is cost-effective even in countries where labor is inexpensive. Local sociopolitical environments and best practices emerging from large-scale, fast-paced eradications should drive future strategies. For nonnative ungulate eradications, island size is arguably no longer the limiting factor. Future challenges will involve removing invasive mammals from large inhabited islands while increasing cost-effectiveness of removing low-density populations and confirming eradication. Those challenges will require leveraging technology and applying theory from other disciplines, along with conservation practitioners working alongside sociologists and educators.     

On the role of body size for life-history evolution

1. Body size is a central element in current theories of life-history evolution. Models for optimal age at maturity are based on the assumptions that there is a trade-off between development time and adult size and that larger size provides a reproductive advantage.
2. The results of large, replicated experiments with the water strider Gerris buenoi (Heteroptera: Gerridae) contradict both these assumptions. Individual rearings under field conditions showed that there is a negative, not a positive, correlation between development time and adult size. The physiological basis of growth, with stretch-induced moulting, may provide a partial explanation for this correlation.
3. This study examined a number of fitness components for their correlations with female size: lifetime fecundity, reproductive life span, average volume per egg, total volume of eggs laid, and the proportion of eggs hatched. None of these traits was correlated with female size.
4. The data on water striders suggest an alternative scenario for life-history evolution, in which size is not an adaptive trait, but evolves as a correlated response to selection on other traits. This expands the range of possible models, and opens life-history theory to the debate about adaptation and optimality.     

Distribution of phlebotomine sandflies and the rate of their infection with Leishmania promastigotes in the Algarve, Portugal

Four species of sandflies: Phlebotomus (Larroussius) perniciosus Newstead, Sergentomyia minuta (Rondani), Phlebotomus (Paraphlebotomus) sergenti Parrot and Phlebotomus (Larroussius) ariasi Tonnoir, were collected, by aspiration and light traps, from three dog kennels and an area of high prevalence of human and canine visceral leishmaniasis in the Algarve, Portugal. Midgut infections with leishmanial promastigotes were observed only in P. perniciosus with a minimum infection rate of 5%. The engorgement, gravidity, population dynamics and sex ratios of the sandflies, and the temperature, source and altitude of collection sites were examined. Host preferences were noted for P. perniciosus.     

UPPER BARREMIAN (CRETACEOUS) HETEROCERATID AMMONITES FROM SOUTH AFRICA AND THE CAUCASUS AND THEIR -PALAEOBIOGEOGRAPHIC SIGNIFICANCE

Heleroceratid ammonites are abundant in the Upper Barremiansediments of Zululand, South Africa, and representatives ofthe genera Heteroceras, Colchidites and Paraimerites are describedbelow. This assemblage shows strong similarities to faunas knownfrom the Caucasus region of the USSR, a similarity that persistedinto the succeeding Aptian. This similarity presents somethingof a paradox, because the genera concerned are among the leasthydrodynamically streamlined of ammonites. Their distributionsuggests an open marine connection between the Mediterraneanparts of Tethys and the eastern coast of Africa, linked, inthe Barremian — early Aptian at least, to Patagonia. Theirwide distribution also supports the view that climatic gradientswerelow during the Barremian and that the climate was generallywarmer than at present. (Received 12 January 1983;     

Inactivation of Salmonellae on Chilled and Deep Frozen Broiler Carcasses by Irradiation

Chilled and deep-frozen broiler carcasses were examined for total counts of salmonellae using pooled samples taken from 76 batches each of five birds. By means of a most probable number technique (MPN) it was found that counts expressed/100 g of skin or /500 ml of thaw water varied between < 2 and 1400 with 90% being < 100. Irradiation of carcasses using a dose of 250 krad was found to be highly effective in destroying salmonellae whether the birds had been chilled or deep-frozen.     

New deep-sea Tardigrada (Arthrotardigrada,Halechiniscidae) from a manganese nodule area of the eastern South Pacific*

Three new Tardigrada species are described from a manganese nodule area of thc abyssal castern South Pacific. Moebjergarctus mangunis gen. et sp.n. is characterized by its segmcntcd ccphalic cirri, club-shaped and forward bent primary clavae, spherical secondary clavae, spines on legs I, 11, 111, small clavoid papillae on legs IV, long cirri E, and corkscrew-shaped digits with simple claws. Angursa capsula sp.n. is distinguished by the presence of secondary and tertiary clavac, occurring as elevated cuticular areas, club-shaped primary clavae, short lateral cirri, short median cirrus, spines on legs I and hcmisphcrical, capsulc-shaped papillae on legs IV. Angursa lingua sp.n. is characterized by the presence of secondary and tertiary clavae, occurring as elevated cuticular areas, balloon-shaped primary clavae, long lateral cirri, long median cirrus, spines on legs I, clavoid papillae on legs IV and weakly broadened distal parts of cirri E, resulting in tongue-shaped swellings. A simple key to the species of Angursa is presented.     

Changing Sink Demand Affects the Area but not the Specific Activity of Assimilate Sources in Cantaloupe (Cucumis meloL.)

To better understand source-sink interactions, this work focusedon the influence of fruit number on leaf area and photosyntheticactivity in cantaloupe. To this end, flowers were removed over2 years on two Charentais cultivars to obtain single-fruit plantsand plants with an unrestricted fruit load (which set two tofive fruits and constituted control plants). At the whole plantscale, net photosynthesis was reduced by about 30% under highfruit load. At the leaf scale, a submodel of stomatal conductancewas fitted to the data and was included in a rectangular hyperbolamodel of leaf photosynthesis. Maximum leaf net photosynthesisaveraged 14.83 µmol CO₂m^-2s^-1at 1000 µmol quantam^-2s^-1. Light use efficiency was not affected by fruit loadand equalled 0.040 mol CO₂mol^-1quanta. Leaf area of plants withunrestricted fruit load decreased after 24 days from pollination,while the leaf area of single-fruit plants was still increasing.The decrease was due to production of fewer new leaves per day,whereas the number of senescent leaves and the size of individualleaves were not affected by the treatment. Under high fruitload, cultivar Galoubet developed a larger projected leaf areathan cultivar Talma. Thus it is concluded that: (1) large cantaloupefruits may divert a large amount of assimilates away from, andgrow at the expense of, the canopy; and (2) photosynthesis ofthe canopy was lowered because leaf area was reduced whereasphotosynthetic rate of leaves was not altered.Copyright 1998Annals of Botany Company. Cucumis meloL., fruit load, source-sink interactions, leaf photosynthesis, canopy photosynthesis, leaf area, SLA, source strength.