Dorsolateral Ciliary Folds in the Polychaete Foregut: Structure,Prevalence and Phylogenetic Significance

Abstract Ciliary folds form the dorsolateral walls of the foregut in numerous polychaetes. These feeding structures have not been recognized earlier. They are described here for 26 species in 16 families. The folds consist of ciliated cells, usually associated with gland cells, and have no intrinsic muscular system. Protraction of the dorsolateral folds to make contact with the substratum during uptake of food is mainly achieved by contractions of the musculature of the body wall in the anterior part of the body. These folds either occur alone or are associated with a ventral pharyngeal organ. Dorsolateral ciliated folds are structures originally adapted to microphagy. From the present study and the literature it is obvious that these structures are widespread among polychaetes of various taxa. This distribution and their similar structure suggest that dorsolateral folds are phylogenetically old structures which might already have been present in the stem species of polychaetes.     

Doubly uniparental inheritance of mitochondrial DNA in freshwater mussels: History and status of the European species

Doubly uniparental inheritance (DUI) is a mode of inheriting mitochondrial DNA that is distinct from strictly maternal inheritance. It has been described in nine and three families of marine and freshwater mussels, respectively, including the European margaritiferids and unionids. Among the 16 freshwater species of Unionida inhabiting Europe, DUI has been described in 9 species of dioecious mussels and was absent from a single hermaphroditic species and from secondary hermaphroditic specimens. The DUI freshwater mussels include two vastly genetically different mitochondrial genomes: maternal (F genome) and paternal (M genome), which coexist within the same specimen but in different tissues. The F genome is present in all female tissues and somatic male tissues. It is inherited in the typical, maternal, manner. Conversely, the M genome is located primarily in the male gonads and generative cells, and is inherited paternally. Dioecious Unionidae display unique characteristics that have been interrelated for over 200 million years: a high fidelity of the transmission of the F and M genomes in DUI and two paths of spermatogenesis–the typical path that produces sperm cells containing mitochondria with the F genome and the atypical path that produces sperm cells with the M genome. The mitogenomes of freshwater mussels display unique features that are not present in any other animal, that is, an additional, gender-specific gene and an elongated cox2 gene occurring exclusively in the M genome. These features mean that the mitochondria, in addition to their basic function of producing energy, also may take part in determining sex in these dioecious organisms.     

Ultrastructural studies of the cysticercoid of moniezia expansa (Anoplocephalidae) with special reference to the development of the cyst.

Cysticercoids of the sheep tapeworm Moniezia expansa have been grown in oribatid mites in the laboratory. Three species of mite became infected: Xenillus tegeocranus, Platynothrus peltifer and Euzetes globulus, the latter not previously recorded as a host of anoplocephalines. Cysticercoids aged 15 and 28 weeks were examined with the electron microscope. Four distinct types of cells were found in the 15-week cysticercoid. Subsequent cyst development involves a transformation from a cellular to a mainly fibrous structure. The fibres, arranged in three layers, resemble collagen fibres described elsewhere. The outer epidermis of the cyst is replaced by an amorphous, electron-dense outer coat whose nature is unknown. The inner part of the cyst becomes condensed to a myelin-like structure. The scolex develops features characteristic of the adult tapeworm.     

前寒武纪瓮安生物群具围卵腔结构的胚胎及其发育序列

通过对贵州瓮安新元古代陡山沱组瓮安微型球状化石SEM的观察,发现代表未分裂卵,和2、4、8、16不同分裂阶段的胚胎。这些未分裂的卵和处于不同发育阶段的胚胎化石不仅大小和卵壳表面装饰相同,而且它们均具明显的围卵腔和球形卵裂等特征,清楚表明这些卵和胚胎均为同一物种的产物。由于这些卵的表面装饰与现生某些甲壳类休眠卵极其相似,曾被解释为动物的休眠卵;当前不同卵裂阶段胚胎的发现表明它们不是休眠卵,而是处于发育过程的卵。围卵腔不仅是现生两侧对称动物早期胚胎的常见构造,而且具围卵腔构造的未分裂卵和不同卵裂阶段的胚胎化石在瓮安动物群也十分常见。除了以上具表面装饰胚胎化石的大量发现外,文中还报道围卵腔构造在表面光滑胚胎化石中的发现。这些具围卵腔结构的胚胎化石主要为两侧对称动物的胚胎。     

Brush-like cells within bronchial epithelia of chicken lung (Gallus gallus)

The secondary and primary (mesobronchus) bronchi of chicken lung are lined by a typical respiratory epithelium: pseudostratified columnar ciliated with goblet cells. Up to date, four constituting epithelial cell types have been identified: ciliated, mucosecretory, basal and endocrine cells. In this study a putative new epithelial cell type, the brush-like cell, is described. The avian brush-like cells have only been found in the bronchial epithelia but never in the gas-exchange areas. They are scattered among the other epithelial cells, mainly ciliated cells, and their number is extremely low. The characteristic morphological feature of these cells is an apical protruding cytoplasm with microvilli. This cell type is similar to that found in the lung of some mammalian and non-mammalian species. The functional role of these cells is not yet clear; they could carry out absorptive processes.     

Neoperla spio (Plecoptera): a species complex?

Abstract. Almost thirty Neoperla species have been described from Africa, but have subsequently been grouped together as one very variable species, Nspio (Newman), only one author publicly disagreeing. In this study new techniques have been used to test the hypothesis that only a single species of African perlid exists. Samples were collected from an area where three morphologically dissimilar forms were sympatric on a temporal and spatial basis. These are here considered to belong to three species of Neoperla as a result of differences in chorionic features of the egg (elucidated by the scanning electron microscope). Multivariate analysis and electrophoretic data support the conclusion that Nspio is a species complex. Sexes of the three species were associated on the basis of mating experiments, and ecological data pertaining to mating.     

Sacciform cells in the skin of teleost fish

The fine structure of sacciform gland cells of the epidermis is described in the number of species of teleost fish. In some of these the cell type had either not been found, or not recognized as such, before. Some histological and histochemical results are also reported. Despite considerable differences in the histochemistry and in the morphology of the sacciform cells over the range of species studied, some features of the fine structure are constant and can be used as diagnostic characters. The nucleus is peripheral, and there is a large membrane-limited lumen, into which the secretion is released from membrane-bounded vacuoles at the margin of the cytoplasm. It is probable that the secretion originates mainly in channels of endoplasmic reticulum which become swollen to form the vacuoles. Most sacciform cells open at the surface of the skin by an apical pore, but some have not been seen to open. The classification of the various unicellular glands of teleosts is discussed and it is concluded that attempts to categorise them by the nature of the secretion alone are unsatisfactory.     

Spore morphology and some other features of Goniomitrium Hook. & Wils. (Funariaceae)

Abstract

Goniomitrium enerve, G. acuminatum and G. africanum are distinguished mainly on costal features. There are some problems with the Australian species because of intergradation of characters but no name changes have been suggested and a key to species is provided. The spores of the three species, which are monolete and have a large reticulate ornamentation, are distinctive amongst moss spores and appear to be diagnostic for the genus.     

Ultrastructural studies on erythropoiesis in the avian thymus

Summary Thymus lobes from three species of birds, Quelea quelea, Passer domesticus and Sturnus vulgaris, have been examined ultrastructurally. The component cell types are compared with their counterparts in mammalian thymus glands, and found to be similar. Greater differences exist between small, intermediate and enlarged lobes of one species than exist between species. Developing erythroid cells are present in most enlarging and some enlarged glands. They appear to be developing at the expense of lymphoid cells in some birds. The origin of these cells is discussed. Cells that are possible candidates for the production of some thymic hormones are also described.Formerly: Houghton Poultry Research Station, Houghton, Huntingdon, Cambs     

Pollen morphology of the genus Cornukaempferia (Zingiberaceae) in Thailand

Cornukaempferia is a recently described genus of Zingiberaceae which only occurs in Thailand as a rare genus with limited geographical distribution. Only three species have been described so far, including a recently described new species, C. larsenii. These three species are morphologically very similar and additional data on other biological aspects are useful for the elucidation of their relationship. Pollen morphology of all three species of genus Cornukaempferia has been studied by light microscopy and scanning electron microscopy. The pollen grains are monad, spherical, inaperturate. The exine sculpture is echinate with psilate between the spines for C. aurantiflora and C. longipetiolata, or echinate with regulate between the spines for C. larsenii. This obser-vation helps support the taxonomic status of C. larsenii.     

An unusual species of spoon-wing lacewing (Neuroptera: Nemopteridae) from South Africa, with notes on its biology

Abstract. An unusual species of spoon-wing lacewing, Palmipenna aeoleoptera sp.n., is described from Namaqualand, South Africa. This small species is similar to its three congeners in general body morphology and genitalic features. Its hindwings, however, differ dramatically from known insect hindwing form. These conspicuously pigmented wings with their relatively huge surface area are hypothesized to have dual aerodynamic and semaphore functions when used by males in gliding flight during mate attraction.     

Cuticle micromorphology of leaves of Pinus (Pinaceae) in east and south-east Asia

Cuticle micromorphology of 21 species of Pinus in east and south-east Asia was studied with scanning electron microscopy and leaf morphology was described. Cuticle characters that can be distinguished by their size, shape, and surface texture, as well as by the number of subsidiary cells, the rows of epidermal cells within a stomatal band, the number of cells between stomata in stomatal rows, and the patterns of cuticular flanges are described in detail. Most of these characters have not been considered in sufficient detail previously. Some of the inner cuticular features, such as the texture of periclinal walls, the shape of the top of the anticlinal walls, the comparative size of the lateral and polar subsidiary cells, and the development of the groove near bristles, are diagnostic characters for subgenera. The agreement between cuticle characters and taxa is discussed. Cuticular characters were used to try to resolve the position of taxa that currently appear in different places in different classifications.     

Phylogenetic study of two truffles, Tuber formosanum and Tuber furfuraceum, identified from Taiwan

Truffles are one of the most valuable edible fungi and have drawn extensive research interests worldwide. In Taiwan, two species of truffle, Tuber formosanum and Tuber furfuraceum , have been identified and reported. Although the morphological features of these two truffles have been described, lack of molecular identification has led to difficulties with firmly establishing their relatedness to other truffles. In this study, we utilized the internal transcribed spacer (ITS) and β-tubulin gene sequences to generate the phylogenetic relationship of T. formosanum and T. furfuraceum with other taxonomic relatives. Our analysis revealed five/three major phylogenetic clades according to the 5.8S-ITS2/β-tubulin gene sequences and corroborated with their morphological characterization. Tuber formosanum highly resembles the Tuber indicum B complex, while T. furfuraceum is most similar to Tuber huidongense . Based on a molecular clock, we estimated that T. furfuraceum and T. formosanum would have diverged from their close relatives in mainland China between 10.2 and 4.1 Ma, respectively. Based on the results, we propose that these two Tuber species found in Taiwan might originate from the common ancestors with some truffle species in China. However, due to a long divergence time and geographical separation, they have evolved into indigenous species of Taiwan.     

A New Species of Coronilla (Loteae, Fabaceae) from Southeastern Spain: Evidence from Morphological and Molecular Data

Currently, there are nine species classified within the genus Coronilla (Loteae, Fabaceae); however, some populations discovered in the province of Almería, SE Spain, have features that are not present, as a whole, in the other known species. These plants are related to Coronilla juncea and C. minima, although several features of branches, leaves, flowers and seeds (zigzag branches; fleshy, deciduous leaves without hyaline margin; connate reddish stipules; very narrow seeds with fluted foveolae) are usually recognized as belonging to distinct species. To clarify the taxonomic status of these populations, morphological and genetic studies have been performed. The results obtained suggest that their separate classification is appropriate. Accordingly, a new species, Coronilla talaverae, whose currently recorded range is restricted to three populations in southeastern Spain is described here. Regarding its risk of extinction, the IUCN red list criteria have been followed to assess its category, proposing the status EN B1ab(i,ii,iii,v)+2ab(i,ii,iii,v). In addition, an identification key is provided for the species of the genus Coronilla.     

Characterization and identification of field ectomycorrhizae of Boletus edulis and Cistus ladanifer

Field ectomycorrhizae sampled under Boletus edulis and Cistus ladanifer have been characterized and described in detail based on standard morphological and anatomical characters. The described ectomycorrhiza has traits typical of Boletales: whitish with three differentiated plectenchymatous layers in the mantle in plan view forming ring-like structures and rhizomorphs with highly differentiated hyphae. The inflated, smooth cystidia-like clavate end cells on the surface of the rhizomorphs and their slightly twisted external hyphae are additional characterizing features. The Hartig net occupies 1 1/2 rows of cortical cells, partly reaching the endodermis. Not all hyphae have clamps. The identification of the fungal symbiont as B. edulis was confirmed by ITS rDNA sequence comparison between mycorrhizas and sporocarps. The singularity of this symbiotic association, as well as its ecological and practical implications, are discussed.     

Comparative leaf anatomy of Salix species and hybrids

Epidermal features, mesophyll differentiation and calcium oxalate characteristics of 19 species and 12 hybrids of Salix are described. The species and hybrids can be distinguished by the presence or absence of the following epidermal features: striated cuticle; stomata; covering trichomes; beaded anticlinal walls, and diosmin-like njstals. In or near marginal teeth, glandular trichomes are present in all cases. The leaf veins of all specimens examined have calcium oxalate prism sheaths and, with the exception of S. herbacea , cluster crystals in some cells of the mesophyll. Most sprcies studied in the subgenus Salix show: both adaxial and abaxial stomata; striated cuticle metopllyll of palisade cells, with little or no spongy mesophyll, but with a well-defined hypodermis, and absence of thick-walled, sinuous trichomes. Characteristic features of the subgenus Caprisalix are: abaxial stomata only; epidermal crystals; smooth cuticle; mesophyll diflerentiated into palisade cells and spongy mesophyll and without a hypodermis, and trichomes more numerous and varied than those of the subgenus Salix . Leaves of the two species of the subgenus Chaemelia examined and those of S. lapponum , have predominantly anomocytic stomata, whereas all the other leaves studied have predominantly paracytic stomata. The anatomical features described, in conjunction with the morphologiral characters, enable the species and hybrids of Salix studied to be autheenticated.     

Pronophiline butterflies (Satyridae) of the three Andean Cordilleras of Colombia

The 125 species of the satyrid butterfly tribe Pronophilini known from the three Andean Cordilleras of Colombia are listed, together with two species whose Colombian status is doubtful. The biological, ecological and biogeographical features of the tribe are described, using the listed species as examples. The features include restriction to moist conditions at high altitudes, endemism in the Cordilleras and in areas and on slopes within them, allopatric speciation and subspeciation, parapatric distributions of related species up the altitude gradients, intraspecific variation and polymorphism and apparent mimicry. The criteria used for classifying the taxa and assessing their relationships are discussed. Seventeen new species, three new subspecies and one new form are described. At the species level, 11 new synonymies are established, two synonymies are rejected, the status of 15 other taxa is revised, and 23 new combinations are made. At the generic level, two new synonymies are established, and one genus is resurrected.