Trichodina ctenophorii N. Sp., a Novel Symbiont of Ctenophores of the Northern Coast of the Gulf of Mexico

ABSTRACT. Peritrich ciliates of the genus Trichodina are internal or external symbionts of invertebrate and vertebrate hosts. We describe here Trichodina ctenophorii n. sp., a symbiont of Mnemiopsis mccraydii and Beroë ovata (Phylum Ctenophora). The morphology of fixed and living specimens is revealed by silver impregnation, scanning electron microscopy, and differential interference microscopy. Distinguishing features of Trichodina ctenophorii include a denticular morphology composed of falcate, blunt-tipped blades, and long, straight thorns, with five pins per denticle. Trichodina ctenophorii is found only on the comb plates of these ctenophores. To the best of our knowledge, this is the first report of a trichodinid from the Gulf of Mexico and the first associated with ctenophores.     

不同组织来源透明质酸的分离纯化及其鉴定

以猪牛眼玻璃体、鸡冠、人脐带为原料,利用水浸提,乙醇沉淀的方法,提取透明质酸粗品,经ＤＥＡＥ－纤维素纯化,获得高纯度的透明质酸．经测定,其蛋白含量０．３８％～０．６３％,分子量７．９×１０~４～４．７×１０~５,收率０．６４％～２．４％,红外扫描图谱与文献报道一致     

ULTRASTRUCTURE OF VEGETATIVE ORGANIZATION AND CELL DIVISION IN THE UNICELLULAR RED ALGA DIXONIELLA GRISEA GEN. NOV. (RHODOPHYTA) AND A CONSIDERATION OF THE GENUS RHODELLA1

This study suggests that the genus Rhodella be restricted to that set of features currently observed only in Rhodella maculata Evans and Rhodella violacea (Korn-mann) Wehrmeyer, that a new genus Dixoniella be established to accommodate the unicellular red alga, Rhodella grisea (Geitler) Fresnel, Billard, Hindák et Pekár-ková, and that Rhodella cyanea Billard et Fresnel be further studied for probable reclassification. These conclusions are based on ultrastructural comparisons of Dixoniella grisea with published information on the genus Rhodella. The presence of thylakoids in the pyrenoid, a peripheral encircling thylakoid in the chloroplast, a dictyosome/nuclear envelope association, and the lack of a specialized pyrenoid/nucleus association in D. grisea separate this alga from the genus Rhodella. Cell division in D. grisea is not demonstrably different from that in Rhodella, although the unusually well-defined material of the presumptive microtubule organizing center (MTOC) made it possible to follow the development and behavior of the MTOC to a greater degree than in previously studied red algal cells. The surprising amount of conformity in cell division characters between D. grisea and the genus Rhodella prompted a comparison of cell division characteristics in all red algal unicells studied to date. All unicells show a remarkable degree of similarity except for differences in interzonal spindle length, dissimilarities in size of the nucleus-associated organelle (NAO), and the unusual NAO of Porphyridium purpureum (Bory) Drew et Ross.     

SEA ICE DIATOMS (BACILLARIOPHYCEAE) OF THE CANADIAN ARCTIC. I. THE GENUS STENONEIS1

Ice diatom assemblages in the Canadian Arctic are dominated by the Naviculaceae, a family which includes the genus Stenoneis Cleve. A taxonomic history of S. inconspicua var. baculus (Cleve) Cleve (including type material of Navicula baculus Cleve) is presented with morphological data including the first SEM views of the genus. Stenoneis inconspicua var. baculus was compared with S. obtuserostrata (Hustedt) comb. nov. (basionym: Navicula obtuserostrata Hustedt). In the SEM, external, short, flattened siliceous ridges were revealed beside the proximal parts of the raphe branches and central pores. This may be a significant taxonomic feature of the genus. Valves of S. inconspicua var. baculus ranged from 40–103 μm in length, 7–11 μm in width and had 17–20 striae in 10 μm, whereas valves of S. obtuserostrata were shorter (27–53 μm), narrower (6–7.5 μm) and more finely striated (24–30 in 10 μm). Both taxa have a circumpolar Arctic distribution.     

Process of comb division of reused nests in the Australian paper waspRopalidia plebeiana (Hymenoptera,Vespidae)

Summary InRopalidia plebeiana, combs made in the previous year are often reused by foundresses in the following spring and structurally divided into subnests by them. Close observations of the comb dividing process revealed that: 1) combs that had multiple brood areas (areas where cells had eggs) were frequently divided into subnests, while those with single brood areas were never divided; 2) groups of foundresses each occupied a particular brood area even before comb division started; and 3) frequency with which a foundress practiced comb cutting was independent of her social status or oviposition frequency. These observations suggest that the initial grouping of foundresses that colonize an old nest leads to subsequent comb division, rather than the major egg layers cutting combs to safeguard their oviposition territories from their rivals.     

A revision of the genus Cryptonemia (Halymeniaceae,Rhodophyta) in Bermuda,western Atlantic Ocean,including five new species and C. bermudensis (Collins & M. Howe) comb. nov.

Cryptonemia specimens collected in Bermuda over the past two decades were analysed using gene sequences encoding the large subunit of the nuclear ribosomal DNA and the large subunit of RuBisCO as genetic markers to elucidate their phylogenetic positions. They were additionally subjected to morphological assessment and compared with historical collections from the islands. Six species are presently found in the flora including C. bermudensis comb. nov., based on Halymenia bermudensis, and the following five new species: C. abyssalis, C. antricola, C. atrocostalis, C. lacunicola and C. perparva. Of the eight species known in the western Atlantic flora prior to this study, none is found in Bermuda. Specimens reported in the islands in the 1900s attributed to C. crenulata and C. luxurians are representative of the new species, C. antricola and C. atrocostalis, respectively.     

Meiotic analyses ofCucumis hybrids and an evolutionary evaluation of the genusCucumis (Cucurbitaceae)

Meiosis in seven interspecificCucumis hybrids has been analysed i.a. inC. metuliferus ×C. zeyheri, where the parents belong to different sections. In the triploid hybrids a remarkably high number of trivalents has been found. Additional data from literature on geographical distribution, cucurbitacins, flavonoid patterns, isozymes, C-banding, genome size, DNA amount and chloroplast DNA are used to discuss species relationships and evolution. The African cross-compatible group is divided into theMyriocarpus subgroup with the diploid speciesC. africanus, C. myriocarpus subsp.leptodermis and subsp.myriocarpus, and theAnguria subgroup withC. anguria, C. dipsaceus, C. ficifolius, C. prophetarum, C. zeyheri and all polyploids (exceptC. heptadactylus). It is argued that the Asian subg.Melo with x = 7 is derived from the African subg.Cucumis with x = 12; the latter contains all the polyploid species and has the most common basic chromosome number of theCucurbitaceae. This phylogenetic advance is interpreted with concepts of the quantum model of evolution.     

Dynamic phenotypic correlates of social status and mating effort in male and female red junglefowl,Gallus gallus

Despite widespread evidence that mating and intrasexual competition are costly, relatively little is known about how these costs dynamically change male and female phenotypes. Here, we test multiple hypotheses addressing this question in replicate flocks of red junglefowl (Gallus gallus). First, we test the interrelationships between social status, comb size (a fleshy ornament) and body mass at the onset of a mating trial. While comb size covaried positively with body mass across individuals of both sexes, comb size was positively related to social status in females but not in males. Second, we test for changes within individuals in body mass and comb size throughout the mating trial. Both body mass and comb size declined at the end of a trial in both sexes, suggesting that mating effort and exposure to the opposite sex are generally costly. Males lost more body mass if they (a) were socially subordinate, (b) were chased by other males or (c) mated frequently, indicating that subordinate status and mating are independently costly. Conversely, females lost more body mass if they were exposed to a higher frequency of coerced matings, suggesting costs associated with male sexual harassment and female resistance, although costs of mating per se could not be completely ruled out. Neither competitive nor mating interactions predicted comb size change in either sex. Collectively, these results support the notion that sex‐specific costs associated with social status and mating effort result in differential, sex‐specific dynamics of phenotypic change.     

Isolation and Identification of the Characteristic Sweet-aroma Compounds in Refinery Final Molasses

The characteristic sweet-aroma components in refinery final molasses were isolated by using a combination of sensory evaluation, column chromatography and gas chromatography, and were identified by infrared spectrometry, mass spectrometry and color reactions. Identified were ethyl n-hexanoate, ethyl phenylacetate, phenylacetic acid, n-butyl benzoate, isopropyl benzoate, l(+)-pantolactone, benzoic acid, o-toluic acid, m-toluic acid, β-phenylpropionic acid, succinic anhydride, maltol, isomaltol, and 2-methyl-5-hydroxy-6-ethyl-γ-pyrone.

The aroma of the mixture of these compounds and vanillin and vanillic acid was similar to that of refinery molasses by sensory evaluation. The results indicate that these compounds are important in producing of sweet molasses aroma.