PROTASPIDES OF UPPER CAMBRIAN APHELASPIS (PTYCHOPARIIDA, TRILOBITA) AND RELATED SPECIES WITH THEIR TAXONOMIC IMPLICATIONS

Abstract:  The ontogeny of Aphelaspis brachyphasis is illustrated and described on the basis of newly discovered silicified material from the McGill section, Nevada, USA. Protaspides of three other Aphelaspis species are redescribed. Of ptychopariide species for which protaspides have been documented, the protaspides of those previously considered to be closely related to Aphelaspis are illustrated herein. Protaspides of Aphelaspis are most similar to those of Olenus , supporting previous taxonomic suggestions that the Aphelaspidinae is closely related to the Olenidae and may be assigned to the Olenacea. The protaspides of Housia share few similarities with those of Aphelaspis , contradicting the hypothesis that these genera are placed together within the Pterocephaliidae.     

Biological Control of Culex pipiens pattens (Diptera, Culicidae) by the Release of Fish Muddy Loach, Misgurnus mizolepis in Natural Ponds, Korea

ABSTRACT An assessment on the biological control potential with the fish muddy loaches (Misgurnus mizolepis) was conducted against naturally bred Culex pipiens pollens larvae in four ponds (A, B, C and D) in Busan from July through September, 2001. Predation of the fish at 3 different release rates of 4,5, and 6 fish/m² resulted in mostly over 90% mosquito control from the first week after treatment through the end of the survey period for 11 weeks. There were no significant difference among the release rates of fish at the 5% level of probability. However, substantial controls of 43.0% and 25.9% were obtained from pond C during the 3rd and 7th weeks after the fish introduction, respectively. The results of those two weeks showed a lower biological control by the introduced larvivorous fishes. This might be due to the presence of heavy organic matters including aquatic weeds and/or severely polluted water from sewage in pond C. The aquatic weeds covered the pond's water surface which may have affected the deterioration of mosquito preying in favor of aquatic weeds. Also, the fishes were observed to avoid severely contaminated sewage water in some parts of ponds A and C where more mosquito larvae were found.     

Carbon isotopes as indicators of elephant diets and African environments

Stable carbon isotope ratios have been successfully used to assess modern animal diets and to reconstruct prehistoric diets of animals and humans (Vogel & van der Merwe, 1977; van der Merwe & Vogel, 1978; Burleigh & Brothwell, 1978; Vogel, 1978a; DeNiro & Epstein, 1978; Tieszen et al., 1979; Tieszen & Imbamba, 1980; Chisholm, Nelson & Schwarcz, 1982; Tauber, 1981). We have used ¹³C/¹²C ratio measurements of bone collagen to study the diets of African elephants in twelve wildlife refuges. These represent most of the habitats in which elephants live, including such diverse plant communities as primary rain forest, savanna woodland and desert. The δ¹³C values were found to have a simple linear relationship with tree density in most cases. When translated into relative amounts of dietary browse (C₃ plants) and graze (C₄ plants), the grass content is seen to be systematically under-represented, presumably due to inefficient metabolism. This does not affect the relationship between elephant diet and tree density, which has implications for the study of elephant-woodland interactions, and for reconstructions of past African environments.     

拟澳洲赤眼蜂生殖系统的研究

拟澳洲赤眼蜂(Trichogramma confusum)的体长约0.6mm,腹部长度约0.3mm.雌蜂生殖系统(包括卵巢、生殖腔、受精囊及三种附腺)位于腹部后端,约占腹腔的2/3.成熟的卵巢由两条多滋式的卵巢管组成.两条成熟卵巢的端段细长,扭卷成一条疏松索,基部膨大,内脏贮存大量卵粒.成对的侧输卵管较短,分别开口于生殖腔后方的两侧,中输卵管缺如.受精囊呈梨形,开口于生殖腔后方.雌性生殖系统三种附腺中,第一种附腺是成对的,呈锤状,分别连接于生殖腔前方两侧;第二种附腺,腺体呈球状,其前端以短曲的小管通进膨大的贮腺囊,贮腺囊端部成柄状的弯曲小管,连接于产卵管的基部开口处.第三种附腺的腺体呈棒状,前端为细长的小管,开口于第二种附腺贮腺囊的前端.雄性生殖系统由成对的睪丸,输精管、贮精囊、附腺及单一的射精管组成.蛹的早期到后期至成虫期睾丸的形态结构,各有不同变化.     

中国蝶类新种小志Ⅳ

本文记述国产眼蝶科(Satyridae)的一个新属Sinonympha与它的一个模式种Sinonympha amoena(新种),这一蝶类最早是笔者于1939年7月在我国四川省西北部的杂谷脑(理县)发见的。为欲较全面地了解它们在分类系统上的亲缘关系,又于1963年和1964年在原产地采集了大量的成虫标本,并于1965—1966年在北京饲养了它的幼期。 新华新眼蝶属Sinonympha新属 新属属征 新华新眼蝶属Sinonympha(新属)与Coenonympha Hbner(1819)较为近似,但是某些形态特征和生物学特性(包括幼期)则与Ypthima Hbner(1818),OeneisHbner(1819)以及Mycalesis Hbner(1818)等属的种类互有相似之处,现将本新属的主要特征列述于下:     

Wax Ester Production by the Marine Cryptomonad Chroomonas salina Grown Photoheterotrophically on Glycerol

SYNOPSIS. An age-autolyzed culture of Chroomonas salina , grown under cool-white light with glycerol, produced waxy lipid constituting about 44% of total matter harvested. This lipid was composed of 87% wax ester, 9% triglyceride, 3% polar lipid and 1% hydrocarbon. The major wax ester species were identified by total carbon number as C₂₆(28%), C₂₈(35%), C₃₀(15%). The main fatty acid components of the wax esters were 12:0 (39%), 14:0 (30%), 16:0 (14%), while the main alcohols were 14:0 (53%) and 16:0 (40%). The hydrocarbon fraction showed saturated paraffins ranging from C₁₇ to C₃₃, with odd-numbered chain components predominating. No polyunsaturated components were detected in the wax ester or hydrocarbon fractions. This is the first record of wax ester production by a cryptomonad or a marine phytoplankter.     

SELECTION, PREDICTION AND RESPONSE

1. The biometric approach to selection experiments has been outlined, and found to be rather deficient because it is based on excessively restrictive models which cannot take into account the complex architectures of quantitative traits as are being revealed today. 2. The nature of polygenes is discussed in detail from the theoretical point of view. In out breeding species, some form of the balanced polygenic complex is likely, showing polymorphism for the constituent genes. Although polymorphism is implicit in the argument, definitive evidence for poiymorphisms has only just appeared. 3. There is no evidence that polygenes differ from any other gene. 4. Several artificial selection experiments are described, in particular in Drosophila. By means of appropriate breeding techniques after obtaining responses to selection, genetic activity controlling quantitative traits can be located to chromosomes, and even specific loci found. Such few studies as have been carried out reveal, in general, the types of genetic architecture predicted on theoretical grounds. 5. Selection for behavioural traits is considered briefly and it appears that no new principles are needed, except that careful environmental control and objective measurement present problems. 6. The results of selection for quantitative traits in micro-organisms reveal similarities to results in higher organisms in the few cases where definitive work has been carried out. 7. Work on the simulation of models by computers has not greatly advanced selection experiment theory, mainly because, with few exceptions, linkage has been ignored. 8. The existing theory on which selection experiments are based is inadequate for several reasons. It cannot predict the rate of response to selection nor the ultimate limits to selection, the nature of correlated responses to selection, nor the nature of gene segregation underlying the observed variability. 9. Strains set up from single inseminated founder females from the same population of Drosophila have been shown to differ genetically for several quantitative traits. Therefore the base population is polymorphic for genes controlling these traits. This was exploited by carrying out directional selection on lines derived from those strains showing a high incidence of scutellar chaetae. This led to far more rapid responses to selection than lines derived from strains where the incidence of scutellar chaetae was lower. 10. Ultimately, one can envisage the selection experiment as it is known today being partly replaced by the manipulation of located genes controlling quantitative traits into certain combinations.     

Four New Species of Xenylla (Collembola: Hypogastruridae) from Korea

ABSTRACT Four new species of the collembolan genus Xenylla, X. convexopyga, X. longistriata, X. dotata and X. marina from Korea are described. X. convexopyga is characterized by an absence of the dorsal seta m₃ on Th. II-III. While the other three new species share similarities in dorsal chaetotaxic characters. However, they are dissimilar in the following respects: ventral chaetotaxy, body colour, presence or absence of inner teeth on unguis, the length proportion of abdominal segments and thoracic segments, arrangement of anal papillae and the general shape of apical bulb of fourth antennal segment. As a result of this study, a total of 25 species in 6 genera of Hypogastruridae have been recorded from the Korean Peninsula.