Q10 measures of metabolic performance and critical swimming speed in King George whiting Sillaginodes punctatus

This study examined thermally driven changes in swimming performance and aerobic metabolism (Q₁₀ and aerobic scope of activity) of adult King George whiting Sillaginodes punctatus to the coldest (16° C) and the warmest (26° C) temperature encountered by this species. Compensation of aerobic scope, higher maximal swimming speeds and a maintained capacity to repay oxygen debt indicate that this species is capable of thermal acclimation to conditions expected under global warming.     

An interview with Dr. George C. Prendergast

Cell Cycle congratulates Dr. George C. Prendergast for his recent appointment as the Editor-in-Chief of Cancer Research (AACR). Dr. Prendergast, president and CEO of the Lankenau Institute for Medical Research in Wynnewood, PA, assumed the new post on January 1, 2010.     

Hybridisation between South polar skua (Catharacta maccormicki) and Brown skua (C. antarctica lonnbergi) in the Antarctic Peninsula region

Hybridisation between South polar skua (C. maccormicki) and Brown skua (C. antarctica lonnbergi) in the area of the Antarctic Peninsula is known at least since the beginning of the last century but no survey has been done so far. This paper reviews information on the species composition of skua colonies of more than 10 pairs in the Antarctic Peninsula region, and the incidence of mixed pairs. Morphometrics, population size and breeding success were examined in detail at King George Island. The northward distribution of South polar skuas extended to King George Island (62°11′ S 59°00′ W), with a small outlying population on Signy Island (60°45′ S 45°36′ W), whereas Brown skuas did not breed further south than Anvers Island archipelago (64°46′ S 64°03′ W). The proportion of mixed pairs was highest at the northern end of the ∼500-km-wide hybrid zone. Body size distribution of sympatric skuas from King George Island is clearly bimodal but overlaps considerably and hybrids cannot be identified. Skua population sizes at Potter Peninsula/King George Island remained stable between 1994 and 2004. Numbers of mixed breeding pairs fluctuated more strongly than those of pure species pairs. Breeding success of Brown skuas varied the least.     

Thermal sensitivity of isolated-perfused hearts from the ground squirrels,citellus tereticaudus and Citellus tridecemlineatus

Summary Perfused hearts of C. tereticaudus cease to beat at an average T _A slightly below 5.7±0.7° C, whereas perfused hearts of C. tridecemlineatus stop at a T _A slightly below –0.7±0.9° C. Although both species are approximately the same size and both can hibernate, the desert inhabiting C. tereticaudus has a smaller heart which beats slower, consistent with its lower metabolism, than the plains inhabiting C. tridecemlineatus. It is suggested that ecological factors were more important than taxonomic characteristics in the development of these specific features of hibernators adaptive for different habitats.This study was supported by a Public Health Service Grant GM 15889 from the National Institutes of Health. The invaluable technical assistance of Mrs. Denelda Baldock and Mrs. Rosa Wang is gratefully acknowledged. I am indebted to Mr. George Batik for the art work.     

Geographical variation in rotifers associated with Microcystis blooms

Lake George, Uganda, lies on the equator and shows little variation in temperature or in the dominance of Microcystis in the phytoplankton. The dominant planktonic rotifers in Lake George are compared to those found in lakes in other parts of the world, ranging from tropical and subtropical lakes with semi-permanent blooms of Microcystis to temperate localities with summer blooms or less regular blooms at multiannual intervals. A modified Sorensen Similarity Index is used to show a latitudinal gradient in the rotifers associated with Microcystis.     

ANNUAL GERMINATION WINFOW IN OOSPORES OF NITELLA FURCATA (CHAROPHYCEAE)1

Oospores of Nitella furcata subsp. megacarpa (Allen emend. Wood) were collected from an oospore bank in the sediments of Lake George, New York. Incubated at constant temperatures, all or nearly all of the oospores germinated when exposed to a brief pulse of red light when the annual window of germinability was open. The window seems related to the annual cycle of sediment temperatures. It is open in spring and closes wit the onset of a secondary dormacncy in the summer. Oospores in storage follow a parallel path if held at 18°C, a summer equivalent temperature; the window remains open indefinitely if the oospores are held at 4°C. Attention is drawn to the similarity if the cyclic window of germinability in seeds of summer annuals and oospores of N. furcata.     

The lichen genus <Emphasis Type="Italic">Umbilicaria</Emphasis> from the neighbourhood of Admiralty Bay (King George Island,maritime Antarctic), with a proposed new key to all Antarctic taxa

This paper documents the occurrence of the genus Umbilicaria in the neighbourhood of Admiralty Bay on King George Island in the maritime Antarctic. Nine species are reported from the area surveyed, with Umbilicaria kappeni being reported from King George Island for the first time. The occurrence of U. aprina, U. cristata and U. umbilicarioides on the island is confirmed and that of U. aprina is its first documented record from the maritime Antarctic. Fertile specimens of U. umbilicarioides are recorded for the first time from Antarctica. The area around Admiralty Bay seems to be one of the Antarctic regions with the highest diversity of Umbilicaria species. The diagnostic characters and distribution of each species are discussed. An updated key for identification of all the Antarctic species of the genus is provided.     

Properties, relationships and transmission of a strain of raspberry ringspot virus infecting raspberry cultivars immune to the common Scottish strain*

Plants of Lloyd George and Seedling M raspberry (Rubus idaeus L.) were found in eastern Scotland infected with raspberry ringspot (RRV), a virus to which these varieties were previously considered immune. Most RRV isolates from affected plants caused milder symptoms in herbaceous test plants than did the type isolates of the common Scottish and English strains. In graft-transmission tests the Lloyd George strain of RRV infected all the raspberry cultivars tested, including those immune to the common Scottish strain. No consistent differences were found between isolates of the two strains in in vitro properties or serological behaviour. Both strains were transmitted in seed of Stellaria media and in soil containing Longidorus elongatus. Possible reasons why the new strain is uncommon in Scotland are discussed.     

The inheritance of accessory buds inRubus idaeus L.

In the red raspberry cultivar Lloyd George, accessory (secondary) bud formation is controlled by two complementary genesBd ₁ andBd ₂, whose expression is markedly influenced by homozygosity, minor genes, and environment.     

Host range, properties and purification of raspberry bushy dwarf virus

Raspberry bushy dwarf virus (RBDV) was found in all plants of Lloyd George raspberry with bushy dwarf disease and occurred occasionally in plants of some other cultivars. It was transmitted by inoculation of sap to fifty-five other species in twelve families of flowering plants and infected most of them symptomlessly. It caused systemic symptoms in some species of Amaranthaceae, Chenopodiaceae and Cucurbitaceae, and necrotic local lesions in some Leguminosae. It did not induce bushy dwarf disease when returned to Lloyd George raspberry. Chenopodium quinoa was used for propagating the virus and Vigna cylindrica for local lesion assay. In C. quinoa sap, RBDV lost infectivity when diluted 10^-4, heated for 10 min at 65 °C or stored for 4 days at 22 °C. Preparations made by twice precipitating the virus at pH 4·8 and resuspending it at pH 7·0, followed by ultracentrifugation and exclusion chromatography in columns of 2 % agarose beads, contained isometric particles about 33 nm in diameter, which sedimented as two components, with sedimentation coefficients of 111 and 116S. Only a few particles, all of them disrupted, were seen in preparations mounted in phosphotungstate, but the particles were well preserved in uranyl formate provided that they were first dispersed in a saxlt such as MgCl₂ instead of distilled water. Many particles were oval in outline as though distorted during drying. No serological relationship was detected between RBDV and twenty-four other isometric viruses nor between RBDV and the filamentous virus apple chlorotic leafspot, to which it was previously thought to be related. An isolate of loganberry degeneration virus was serologically indistinguishable from RBDV.     

Eco Days at Marion

Wendy Saul with Alan R. Newman Science Fare: An Illustrated Guide and Catalog of Toys, Books and Activities for Kids New York: Harper &; Row, 1986 295 pp. $27.95 hardcover, $14.95 paper. Reviewed by Lloyd Wolfinbarger, Jr.

George D. Zuidema, ed., and Leon Schlossberg, illus. The Johns Hopkins Atlas of Human Functional Anatomy, 3d ed. Baltimore, Md.: The Johns Hopkins University Press, 1986 125 pp. $25 hardcover, $14.95 paper. Reviewed by Lloyd Wolfinbarger, Jr.

Alvin Silverstein and Virginia B. Silverstein The Story of Your Hand New York: G. P. Putnam's Sons, 1985 76 pp. $9.99 hardcover (library binding). Reviewed by Robert W. Boenig.

Langdon Winner The Whale and the Reactor: A Search for Limits in an Age of High Technology Chicago: The University of Chicago Press, 1986 178 pp. $17.50 hardcover. Reviewed by George G. Mallinson.

British Museum Dinosaurs and Their Living Relatives, 2nd edition New York: Cambridge University Press, 1986 72 pp. $24.95 hardcover. Reviewed by George R. Zug.     

Modern distribution of diatoms in sediments from the George V Coast, Antarctica

Currently, little information exists concerning high frequency climate change in the Antarctic, data that are essential to gaining a more complete understanding of global climate change. Sediments from the George V Coast continental margin potentially contain a high resolution record of the late Holocene. The relatively high rate of sedimentation ( 3 mm/year) and the presence of laminated intervals which contain undisturbed sequences make these sediments valuable for future downcore work. In order to utilize diatom assemblages as proxies of paleoclimatic and paleoceanographic parameters, a preliminary study of the surface sediment distribution of diatoms from the George V Coast continental margin was completed. Nitzschia curta (Van Heurck) Hasle and Nitzschia kerguelensis (O'Meara) Hasle present great potential for tracking the Holocene retreat of ice across the continental shelf of this region. Concentrations of N. curta, an “ice-related” form, decreases in an offshore direction, whereas N. kerguelensis, an “oceanic” species associated with circumpolar flow, displays an increase in sediments offshore. The genus Thalassiosira Cleve displays a clear association with areas of open water primary production, as has been noted in others parts of the Antarctic. Downcore variability in relative abundance of this genus will be useful in understanding the history of sea ice versus open water production on the George V Coast shelf. In contrast, the distribution of Chaetoceros Ehrenberg resting spores appears to be more complex, but may be related to the position of the stationary ice edge associated with the annual minimal extent of sea ice. Finally, an understanding of the downcore variability of Thalassiothrix antarctica Schimper ex Karsten, a species which is very abundant in the laminated sections of the sediment cores, will have to rely on studies of its distribution in other areas of the Antarctic, as it is sparsely distributed along the George V Coast today.     

The chloroplast pigments of some green and yellow-green algae

Pigment analysis carried out by thin-layer chromatography confirms that Chlorocloster engadinensis Vischer, C. solani George and Nephrodiella brevis Vischer are all green algae (Chlorophyceae) and not yellow-green algae (Xanthophyceae) as has been suggested. The pigments of Coccomyxa elongata Jaag, C. simplex (Pringsheim) Mainx and Pyrobotrys stellata Korshikov are also typical of green algae. The pigments of Pleurochloris commutata Pascher, P. magna Boye Petersen, Polyedriella helvetica Vischer et Pascher, Mischococcus sphaerocephalus Vischer and Tribonema aequale Pascher, are different to those of the green algae in accordance with their being classified as yellow-green algae. However, a detailed comparison of the pigments of Pleurochloris and Tribonema suggests that whilst both contain chlorophyll, α, β-carotene and esterified vaucheriaxanthin, the major xanthophyll in Pleurochloris corresponds to violaxanthin and not to antheraxanthin as in Tribonema.     

Saccharomycomorpha psychra n. g., n. sp., a Novel Member of Glissmonadida (Cercozoa) Isolated from Arctic and Antarctica

A novel genus and species within the order Glissmonadida (Cercozoa, Rhizaria), Saccharomycomorpha psychra n. g., n. sp., is described from lichen in the Ny-Ålesund region (High Arctic) and moss in the Fildes peninsula of King George Island (Maritime Antarctica). Cells were spherical and did not appear to present flagella in organic-rich Potato Dextrose Agar medium where they were able to feed osmotrophically. Molecular phylogenetic analyses based on 18S rRNA gene sequence demonstrated that Saccharomycomorpha psychra belong to “clade T” within the order Glissmonadida (Cercozoa, Rhizaria). All three investigated strains could grow at 4 °C and had an optimum growth temperature of 12 °C, 20 °C, and 20 °C, while a maximum growth temperature of 20 °C, 20 °C, and 25 °C, respectively. In conclusion, we established the phenotypic identity of “clade T,” which until now was exclusively detected by environmental sequences, and erect a new family Saccharomycomorphidae for “clade T.” Nomenclatural, morphological and ecological aspects of this novel species are discussed.     

The ecology and production of copepods, particularly Thermocyclops hyalinus, in the tropical Lake George, Uganda

(1) Total copepod numbers per litre in Lake George, Uganda, vary slightly during the course of a year. Numbers increase during the dry seasons June-August and January-February, and decrease during the rains. This variation is more marked in the mid-lake area, where copepod numbers are higher, but the change in numbers is not more than two-fold. By comparison with populations in temperate regions the population in Lake George is stable in size and shows little seasonal variation. (2) The carnivorous cyclopoid Mesocyclops leuckarti forms only 4–21 %, by num-bers, of the total copepod population and does not occur in numbers large enough to be analysed profitably. (3) The bulk of the population is the much smaller Thermoeyclops hyalinus and analysis of this population into the main development stages of its life history shows an almost constant age structure over the lake as a whole, throughout the year. (4) The development time of the eggs, as determined previously (Burgis, 1970), is 1–5 days. This, plus mean development-times of 6 and 11 days for nauplii and copepodites respectively, has been used to determine the daily rate of recruitment from each stage of the life history to the next. The recruitment from nauplii to copepodites and from copepodites to adults are very similar and almost constant. Recruitment from eggs to nauplii is. however, mueh greater, and it thus appears that the major loss to the population is at this eariy stage in the life history. This may well be due to predation by the larvae of Chaohorus. (5) Using this recruitment rate from eggs to nauplii, the potential turnover time of population numbers was calculated to have a mean value of 4–2 days for the lake as a whole. This is similar to maximum summer turnover times found by authors such as Hall (1964) for Daphnia populations in temperate waters. (6) The biomass of individuals at various stages in their life history was deter-mined as carbon, and application of these determinations to the numerical counts was used to calculate the standing-crop biomass in the lake. With a constant population of stable age-structure it is possible to estimate the daily biomass production from the turnover time of numbers. For the population of Thermocyelops hyalinus in Lake George this gives a mean figure of 211 μg C/I/day during 1969–70. (7) Instantaneous birth rates and instantaneous rates of change in population numbers (b and r) have also been calculated for the population of Thermocyclops. The values of r show some variation at one centre site, fluctuating around zero, but when calculated for lake mean figures r is hardly different from zero throughout the year. The values of b also show fluctuations when calculated for one site but when calculated for lake mean figures show no more than two-fold variations, being higher at the beginning of the two rainy seasons. The values of b are not as high as those attained during the summer in some temperate Daplmia populations such as those described by Wright (1965). The values of ZJ tend to be higher inshore than in mid-lake areas of the lake. (8) The instantaneous mortality rate r/has been calculated from b-r. With such very small values of r, d is always very similar to b. Most, if not all, recruitment to the population is counterbalanced by loss, probably predation. (9) At one inshore site the population was analysed and counted in detailed cate-gories, over a period of 10 days. This allowed a more accurate estimation of the standing-crop biomass and thus of production. A mean value of 103 μg C/l/day was obtained for these samples. (10) The mean daily level of production, c. 211 μg C/l/day, o(Thermocyclops hyalinus in Lake George, is among the higher values of zooplankton production available for comparison most of which are from temperate regions of the world. The fact that it is applicable throughout the year gives an annual value of 77g C/m³/year which is probably high.     

Stable isotopes prove shell growth bands in the Antarctic bivalve Laternula elliptica to be formed annually

Growth marks in calcareous shells or skeleton parts of benthic invertebrates are often assumed to be formed annually and hence are used for ageing purposes. For some Antarctic species this assumption has been validated by tagging experiments or direct monitoring of growth throughout the year. Here we use the record of stable isotope ratios (δ¹⁸O and δ¹³C) deposited in shell carbonate of Laternula elliptica from King George Island to demonstrate that shell growth bands are formed annually in this species. Received: 16 July 1995 / Accepted: 27 October 1996     

Life history,population dynamics and production of Pontoporeia hoyi (Crustacea,Amphipoda) in relation to the trophic gradient of Lake George,New York

The life history characteristics, population dynamics and production of Pontoporeia hoyi in Lake George, New York, were studied from May 1981 through October 1982. P. hoyi, in terms of both density and standing crop, is the most prevalent member of the deep water macrobenthos of Lake George. It reproduces in the winter, with young being released in the late winter-early spring. At the southernmost study site, young released in the spring grew to 6–7 mm in length and bred during their first winter. At the remaining sites, P. hoyi required two years to complete its life cycle. This difference in life history characteristics can be related to food availability and temperature differences. The open waters of the south end of Lake George are not only more productive but are also more closely associated with the littoral zone, providing a wealth of bacteria-rich detritus for benthic deposit feeders. The greater food availability in the south basin of Lake George is reflected in significantly larger brood sizes and smaller size at maturity for P. hoyi populations from the south end of the lake.The southernmost study site has significantly greater P. hoyi density and standing crop than all other sites. The cohort of the year dominated density and standing crop at the southern site while the cohort of the previous year dominated standing crop at the other sites. Peak abundance ranged from 600 · m^–2 at the north site to 2 900 · m^–2 at the south site. Cohort production ranged from 2g · m^–2 at the north site to 15g · m^–2 at the south site.     

Phytoplankton biomass and distribution in a shallow eutrophic lake (Lake George,Uganda)

Summary Lake George, a shallow lake in western Uganda, supports a permanent and dense crop of phytoplankton, and may be regarded as eutrophic although the ambient concentrations of inorganic nitrogen and phosphorus are low. The figures for the annual nutrient loadings (Viner and Smith, 1973) would suggest, however, a eutrophic lake when analysed on the scheme of eutrophication proposed by Vollenweider (1968).The horizontal distribution of chlorophyll a shows a concentric pattern, with the maximum values occurring towards the center. This horizontal variation is thought to reflect water movements, and a general pattern of water flow is proposed.The majority of the species show no seasonal variation but populations of both Anabaena and Melosira show annual variations. These two species also have a horizontal distribution pattern which is the reverse of other species. This pattern is used to support the proposed movements of water.Phytoplankton generation times are discussed in relation to the diurnal cycle occurring in Lake George.     

Book reviews

The Art of Primitive Peoples. J. T. Hooper and C. A. Burland. (168 pp., 68 pls. The Fountain Press, 46–47 Chancery Lane, London W.C.2. 1953. Cloth bound 42/—).

The God of the Witches. Margaret A. Murray. (2nd ed. Faber & Faber, London 1952).

Magic Books from Mexico. C. A. Burland. (31 pp., 16 colour pls. King Penguin Books, Harmondsworth, Middlesex, England 1953. Bound 4/6 d).

Outline of South American Cultures. George P. Murdock. (Behavior Science Outlines, Vol. II, Human Relations Files, New Haven 1951. Price: $ 2.50).

Kunst im Reiche der Inca. Heinrich Ubbelohde Doering. (66 pp., 240 pls., 4 colour pls., one map. Verlag Ernst Wasmuth, Tübingen 1952. Cloth bound DM. 42).

Tiahuanacu, Atacama und Araukaner. Walter Ruben. (262 pp., 70 ill., 3 maps. Otto Harrassowitz Verlag, Leipzig 1952. Paper wrapper DM 15.80, bound DM 17.20).

Kunapipi. Ronald M. Berndt. (223 pp. Melbourne 1951), and Djanggawul. (230 pp. London 1952).     

CULTURE AND BIOCHEMICAL ANALYSIS OF A TEA ALGAL PATHOGEN,CEPHALEUROS PARASITICUS1

To assess the current situation regarding the incidence of red rust disease in tea plants, an extensive survey was conducted in southern Indian tea plantations covering different tea cultivars and agroclimatic zones. The results indicated that the incidence of disease was more severe in tea seedlings than clones in all the agroclimatic zones. On the other hand, a simple, reliable, and reproducible technique was standardized for culturing Cephaleuros parasiticus G. Karst. isolated from infected tea leaves. Ten isolates were obtained, of which two were screened based on growth rate and culture characters for further studies. Ten culture media were tested for the culturing of C. parasiticus in which Trebouxia and Bristol media were the best followed by George, Go algal, and tea leaf extract media. Variations between isolates (Valparai C. parasiticus field number 27 [VCP27], Munnar C. parasiticus field number 11 [MCP11], and University of Texas culture number 2412 [UTEX2412]) of C. parasiticus were studied based on the growth pattern, protein expression profile, and cellular constituents in the filaments. The quantitative estimation of cellular constituents showed that there was no significant difference in these constituents among isolates. The detection of amino acids in the filaments of C. parasiticus isolates showed 16 free forms and 11 bound forms. Amino acids in bound form were higher in all the isolates than in free form of amino acids. The three isolates of C. parasiticus were closely related, with bands lying between the molecular weight of 116 and 35 kDa.