Behavioral responses of prejuvenile red hake,Urophycis chuss,to experimental thermoclines

Synopsis Prejuvenile red hake, Urophycis chuss, that had reached the developmental interval where they normally descend from the planktonic to the benthic environment, were tested for their responses to experimental thermoclines. Laboratory thermoclines were created that simulated natural field conditions of late summer/ early fall (20°C at the surface and 10°C at the bottom). Prejuveniles did not descend immediately through the thermocline; rather, they remained in the water column at temperatures above 15°C. Results indicated that fish in the sea that do eventually reach the bottom despite the presence of a thermocline, must undergo an acclimation period while descending through the thermocline. The timing of prejuvenile descent may depend on a variety of factors including optimal growth conditions, susceptibility to predation, and competition for resources.     

Cross-reactivity of monoclonal antibodies against phytochrome from Zea and Avena

The cross-reactivity of diverse monoclonal antibodies against phytochrome from Zea and Avena was tested by enzyme-linked immunosorbentassay (ELISA) and by immunoblotting. About 40 antibodies were selected by means of nondenatured phytochrome; all of them reacted with sodium dodecyl sulfate denatured homologous antigen on immunoblots. The epitopes for 14 antibodies (4 raised against Avena and 10 against Zea phytochrome) were localized in 6 regions of the phytochrome molecule by means of Western blot analysis of proteolytic fragments of known localization. Results of studies on the inhibition of antibody binding by other antibodies were largely compatible with these latter findings. Except in a few cases, inhibition occurred when antibodies were located on the same or a closely adjacent region. As demonstrated by 16 species, cross-reactivity with phytochromes from other Poaceae was high. Greater losses in cross-reactivity were observed only with antibodies recognizing an epitope in the vicinity of the carboxyl terminus of 118-kg · mol^-1 phytochrome. Cross-reactivity with phytochrome from dicotyledons was restricted to a few antibodies. However, phytochrome(s) from plants illuminated for 24 h or more could be detected. One of the antibodies that recognized phytochrome from dicotyledons was also found to recognize phytochrome or a protein of 120–125 kg·mol^-1 from several ferns, a liverwort and mosses. This antibody (Z-3B1), which was localized within a 23.5-kg·mol^-1 section of Avena phytochrome (Grimm et al., 1986, Z. Naturforsch. 41c, 993), seems to be the first antibody raised against phytochrome from a monocotyledon with such a wide range of reactivity. Even though epitopes were recognized on different phytochromes, the strength of antibody binding indicated that these epitopes are not necessarily wholly identical.Abbreviations ELISA enzyme-linked immunosorbent assay - McAb monoclonal antibody - PBS phosphate-buffered saline - Pfr (Pr) far-red-absorbing (red-absorbing) form of phytochrome - SDS-PAGE sodium dodecyl sulfate-polyacrylamide gel electrophoresis     

Testing for non-randomness in sizes and habitats of West Indian lizards: choice of species pool affects conclusions from null models

Summary Several null models are proposed for testing whether size or habitat differences in West IndianAnolis lizards are greater than expected by chance. The models differ primarily in choice of the pool from which species are sampled to form random communities. Regardless of choice of pool, size differences in the Lesser Antilles are greater than null models predict; the pool using species on the known source (Puerto Rico) gives a greater variance in ratios but about the same mean ratio (for males), or a greater mean ratio (for females), compared with the pool composed of species on the islands being tested (the Stronget al., 1979, Galápagos procedure). On satellite islands of the Greater Antilles, sizes do not differ more than expected from null models. Pools composed of mainland-source species give null communities with more small or more large ratios than those composed of island species, depending upon whether four-species islands are included or excluded, respectively. Colwell and Winkler's unmodified Narcissus hypothesis is contradicted by these results in procedures where species not likely to be able to occur on small islands are included in the species pool. Using the most biologically reasonable, but not other, choices of source pool, species on satellite islands of the Greater Antilles differ more in structural habitat then expected by chance. In contrast to some of the results on size, here mainland-source pools are more likely to produce a statistically significant difference between real and random communities, as predicted by the Narcissus hypothesis. However, exclusion of structural habitat categories not found on satellite islands is necessary to achieve this significance.     

Changing attitudes to nature conservation: the ornithological perspective

Early conservation centred on legislation to prevent species declines. It now includes habitat conseivation, through the establishment of reserves and land management practices in the wider countryside. This need for a broader approach is increasingly acknowledged and presents great opportunities.
Bird enthusiasts, for obvious reasons, have been in the forefront of conservation. This interest continues nationally and internationally.     

Emergence of flies from overwintering populations of cabbage root fly pupae

ABSTRACT.

• 1 Once pupal diapause had been terminated, over-wintering cabbage root fly (Delia radicum (L.)) pupae from Wellesbourne required a further 14 days at 20°C for most of the flies to emerge.
• 2 There were considerable variations in the rates of fly emergence from thirteen populations of cabbage root fly pupae collected between latitudes 50° 42′ and 54° 59′ in England and Wales. These thirteen populations could be grouped into early-, intermediate- and late-emerging types. In the early-emerging type, flies emerged within 14 days at 20°C whereas in the late-emerging type emergence was protracted and was completed only after 100 days at 20°C in one population from Halsall, Lancashire. In the intermediateemerging type, approximately two-thirds of the flies emerged within 14 days at 20° C, the remainder taking considerably longer.
• 3 The intermediate-emerging types could be just mixtures of the early- and late-emerging types.
• 4 Subjecting pupae to diapause-breaking temperatures (4°C) for up to 1 year failed to shorten the time to subsequent fly emergence in any of the populations.
• 5 Populations of early, intermediate- and late-emerging fies could be selected from a parental population, heterogeneous with respect to emergence, within one generation.
• 6 The type of emergence that occurred in a locality was not correlated with latitude.
• 7 Any models developed for forecasting the most appropriate time to apply insecticide in a locality will have to include information about the emergence pattern of the fly population in that locality.

     

Biosystematics of the Muellerianella complex (Homoptera, Delphacidae): host-plants, habitats and phenology

Abstract. 1. Ecological differences between closely related species and forms of the planthopper genus MueIlerianella (Delphacidae) were studied.
2. In the field M.brevipennis and M.faimairei are restricted to Deschampsia cespitosa and Holcus lanahis/H.mollis . respectively. M.extrusa is mainly found on Molinia caerulea , but has also been recorded from other grass-species. Triploid all-female forms which reproduce by gynogenesis usually live on Holcus together with M.fairmairei . Other gynogenetic populations were found on Bromus ramosus, Deschampsia flexuosa and Calamagrostis canescens .
3. Breeding experiments showed that the diploid species cannot be maintained on each other's host-plants, but accept other grass-species.
4. Due to overlapping habitat requirements of the host-plants, ecological isolation between the Muellerianella species is incomplete.
5. M.extrusa lives in bogs, moors and forests on poor acid soil. M.brevipennis is found in forests, carr, fens and in extensively managed grasslands. M.faimairei and associated triploid forms occur mainly in grasslands and other man-made habitats. The habitats of all three species are usually wet.
6. In most parts of Europe M.brevipennis and M.extrusa are monovoltine and M.fairmairei is mostly bi-or polyvoltine.     

Torf-, pollen- und vegetationsanalytische Befunde zum Relikt vorkommen der Waldkiefer (Pinus sylvestris) in der Westfälischen Bucht

Mit der klima- und sukzessionsbedingten Zurückdrängung der Kiefer nach Osten schrumpfte ihr Areal in der Westfälischen Bucht auf eine Anzahl inselartiger Moorstandorte zusammen. Bei diesem Prozeß zeigen die einzelnen Moore eine unterschiedliche Refugialdauer, die in drei Perioden unterteilt werden kann:

• 1 . Moore, in derem Bereich bereits um die Wende Boreal/Atlantikum ein Erlöschen der Kiefernbestände erfolgt.
• 2 . Moore die durchgehend bis Ende des Subboreals als Refugialstandorte dienen.
• 3 . Moorbereich mit einer kontinuierlichen Refugialdauer über 8000 Jahre, bis in die historische Neuzeit hinein.

Der letztgenannte Typ, der die Bodenständigkeit der Kiefer nachweist, wurde auf Grund von pollenanalytischen und moorstratigraphischen Untersuchungen einer fossilen Torfschicht unter der Heppeldüne im Ostmünsterland festgestellt. Die Großreste des Torfes aus historischer Zeit zeigen eine ähnliche floristische Zusammensetzung wie die rezenten Kiefern-Birkenmoore des Ostmünsterlandes, die pflanzensoziologisch als eine kiefernreiche subatlantische Rasse des Betuletum pubescentis eingestuft werden können.     

Did the first insects live in water or in air?

We evaluate the arguments and evidence for a terrestrial vs an aquatic origin for the Insecta. The evidence falls into three categories: (1) evidence that does not support one view more than the other; (2) speculative evidence, which should carry little weight; and (3) evidence that does support one view more than the other. Category 1 includes evidence from locomotory and osmoregulatory systems; plausible functions have been proposed for 'protowings' in both aquatic and terrestrial environments, while locomotory and osmoregulatory mechanisms of insects shed little light on their origins. Fossils, phylogenetic speculation, gill structure and life histories fall into category 2, in which, although speculative, the evidence favours a terrestrial origin. The earliest fossil hexapods were apparently terrestrial and unequivocally aquatic hexapods do not appear until 60–70 million years later, while sister-group relationships point to a terrestrial life style from at least the Hexapoda-Myriapoda stem group. The great variation in gill structure, even within orders, suggests convergence, and the more or less completely aquatic life histories are better interpreted as steps towards independence from land, rather than signs of an aquatic origin. Category 3 includes evidence from the tracheal system. In order to have evolved in water, a tracheal system must have first invaginated, then connected with the body wall for gas exchange with the water, and thirdly connected with the internal organs. It is difficult to envisage functions for the first two stages; on the other hand, the system could have readily evolved on land by invagination of respiratory surfaces, and then have been modified to effect gas exchange in water via gills.     

天花粉蛋白等五种核糖体失活蛋白的5′－AMP－磷酸酯酶活性

用ＨＰＬＣ和薄层层析等方法,分析了不同反应时间天花粉蛋白（ＴＣＳ）和５＇－ＡＭＰ的反应产物成分,结果显示在０．５ｈ内生成腺嘌呤核苷,随着反应时间的增加,同时有腺嘌呤核苷和腺嘌呤生成,４８ｈ后则反应产物主要是腺嘌呤,α－苦瓜子蛋白、肥皂草蛋白、丝瓜素毒蛋白和多花白树毒蛋白等单链核糖体失活蛋白也有类似结果,紫外差光谱研究结果也表明ＴＣＳ与５＇－ＡＭＰ相互作用显示出明显的时间过程,提示单链核糖体失活蛋白除了Ｎ－糖苷酶活性外,还具有５＇－ＡＭＰ磷酸酯酶活性．