The Nucleolar Chromosome in Hepatics. I.

Abstract

1. In six species of hepatics belonging to the Marchantiales and Acrogynae the large heteropycnotic chromosome found in addition to the sex chromosome or microchromosome is the nucleolar chromosome.

2. The sex chromosomes and microchromosomes in these species, and in four of the five species of which the nucleolar chromosomes have been described by other authors, are not nucleolar chromosomes. Riccardia pinguis (L.) Gray appears to stand alone in having a nucleolar orpnizer on the sex chromosome in addition to that on an autosome bearing a heteropycnotic trabant.

3. The large heteropycnotic sex chromosomes of certain species of Frullania belonging to the subgenus Galeiloba Steph. are not apparently homologous with the large heteropycnotic chromosome of Frullania africana Steph., belonging to the subgenus Chonanthelia Spr. This is not in accordance with the suggestion of Tatuno (1941) that all ' H-chromosomes' are phylogenetically homologous.

4. It is argued that the nucleolar chromosomes throughout the hepatics, with the exception of the sex chromosome of Riccardia pinguis, may be phylogenetically homologous.     

A contribution to the knowledge of epiphyllous bryophytes of Bioko Island (Equatorial Guinea), including additional remarks on non-epiphyllous species

Abstract

A collection of epiphyllous bryophytes from Bioko Island was investigated. It contained 57 epiphyllous bryophytes, comprising 55 hepatics and two mosses. Three taxa, Cololejeunea eustacei Pócs, Colura calderae Pócs and Lejeunea halei Robinson subsp. africana Pócs, are new to science. Cololejeunea papilliloba Steph. is new to Africa, five species of hepatics are new to West Africa, and an additional 31 species of hepatics are newly reported from Bioko Island. The second part of the paper deals with records of non-epiphyllous collections. Fourteen species are reported for the first time for Bioko Island. Actinodontium dusenii Broth. is made a synonym of Actinodontium streptopogoneum Broth. The following new combination is proposed: Wijkia rigidicaule (Müll.Hal. ex Broth.) Frank Müll., comb. nov. (Basionym: Acanthocladium rigidicaule Müll.Hal. ex Broth.).     

Biodiversity within urban areas: A case study on bryophytes of the city of Cologne (NRW,Germany)

In this study, the urban bryophyte flora of the city of Cologne (W. Germany) was studied. A total of 143 bryophyte taxa (17 hepatics and 126 mosses) were recorded within the metropolitan area of Cologne. Three species were newly recorded for North Rhine‐Westphalia: Hannediella heimii, Schistidium helveticum and Tortula schimperi. Thirteen species red‐listed in NRW were recorded, among them hardly endangered: Bryum intermedium and Syntrichia laevipila and extinction endangered: Syntrichia papillosa. The temperate biogeographic element prevails among Cologne bryophytes. According to frequency of recordance, only 11 species are widespread over the urban area of which three are hepatics.     

New species of the genus <Emphasis Type="Italic">Bathycongrus—B. parviporus</Emphasis> (Congridae,Anguilliformes)—from waters of Central Vietnam (Nha Trang and Van Phong Bays)

Bathycongrus parviporus sp. nova is described from specimens collected in the South China Sea, in the coastal waters of central Vietnam. By its characters (short snout, elongate-oval vomerine tooth patch with numerous small teeth of approximately the same size, slender relatively short tail, and residual leptocephalic pigmentation as a series of small melanophores just below lateral line in adults), the species belongs to the group of species of this genus represented by B. bleekeri, B. trimaculatus, and B. unimaculatus in the western part of the Pacific Ocean and B. dubius in the western Atlantic Ocean but differs in small infraorbital pores which are enlarged in all known species of the genus Bathycongrus. By the number of preanal pores, the new species is similar to B. bleekeri from Philippine waters but differs from it in a higher number of vertebrae (120–122), in more numerous rows of teeth on the premaxilloethmoid, in more number of branchiostegal rays (9–10), a shorter head, and in some other proportions of head and body. Topography of canals and pores of the cephalic seismosensory system of B. parviporus sp. nova is described. Morphometric and osteological characters for placing this species in the genus Bathycongrus are noted.     

Fissidens monguilloni Thér. in England

Abstract

The 1996 Chagos Expedition provided an opportunity to study the archipelago's bryophyte flora: 25 of the 55 islands were ecologically investigated, some in more detail than others, and lists and representative collections of mosses, hepatics and other cryptogamic plants were assembled for many of them. Although the islands have a low biodiversity for most of these groups, as would be expected in terms of their relatively young age, remoteness and small terrestrial surface areas, those organisms that are present are often found in abundance and play significant ecological roles. Where the status of taxa on islands has been determined, there appears to be a good correlation between bryophyte biodiversity and island size. Epiphytic bryophytes were not host specific and no epiphyllous species was observed. Biogeographic details are provided, where possible, for the 19 taxa recorded, of which four are new to the Indian Ocean and seven are new to the Chagos Archipelago. A new taxon, Cololejeunea planissima var. chagosensis Pócs var. nov. is described, and notes and illustrations of a probably new Lejeunea species are provided.     

Sporophytes of Rhodobryum laxe-limbatum (Ochi) Iwats. et Kop.

Abstract

A check-list of the bryophyte species of the Grand-Duchy of Luxembourg is given and briefly discussed. An appendix deals with infraspecific taxa. The total number of species is 517 (122 hepatics and 395 mosses); taking into account some acceptable infraspecific taxa, this small country has at least 538 different bryophytes.     

Review of the genusBembras Cuvier, 1829 (Scorpaeniformes: Bembridae) with description of three new species collected from Australia and Indonesia

The bembrid genusBembras Cuvier is reviewed. Five species,B. japonica Cuvier,B. adenensis Imamura & Knapp and three undescribed species, were assigned to the genus. Type species of the genus,Bembras japonica is redescribed on the basis of 36 specimens including the holotype, and three new species,B. macrolepis, B. longipinnis andB. megacephala, previously misidentified asB. japonicus, are also described on the basis of specimens collected from Australia and Indonesia.Bembras macrolepis differs from its congeners by having large body scales, a long pectoral fin with 17–19 rays and a dark blotch on slightly upper portion to middle of margin, 14–15 anal-fin rays, small head and orbit, and caudal fin with a broad vertical dark band near posterior margin.Bembras longipinnis is distinguished from other members of the genus by having a slightly long pectoral fin with 17–19 rays and lacking a small black blotch near tip of upper rays, caudal fin with a large dark spot most intense in lower lobe, 1–2 gill rakers on upper gill arch, 13–14 anal-fin rays, slightly elong ated head and small orbit.Bembras megacephala is characterized by the following combination of characters: caudal fin with several irregular narrow vertical dark bands, small orbit, pectoral fin with 19–20 rays and lacking a small black blotch near tip of upper rays, head elongate, 2–4 gill rakers on upper gill arch, 15 anal-fin rays and small body scales. A key separating the five species ofBembras is given.     

Comparative spermatogenesis in the Jungermanniales (Hepaticae) I. Observations on the structure of the young spermatids of Cephalozia lunulifolia and Chiloscyphus pallescens

Abstract

A comparative analysis of the young spermatids of Cephalozia and Chiloscyphus reveals the organisation of the Jungermannialian blepharoplast to be basically the same as in other hepatics and mosses. Common features include the four-layered multilayered structure, the spatulate, asymmetrical anterior portion of the spline, and the staggered subapical insertion of the basal bodies, each with proximal triplet extensions. The range of spline widths in the Jungermanniales appears to be as great as in other groups of bryophytes and of no major taxonomic significance, but the position of the spline aperture may be more variable in hepatics than mosses. The lengths of the basal bodies are intermediate between those from unrelated taxa in other orders of hepatics.

However, the data also suggest the Jungermannialian spermatids exhibit many taxonomic variations and novel features. Whereas the left-lateral expansion of the spline in Cephalozia is common to most other bryophytes, a right-lateral expansion is peculiar to Marsupella. Chiloscyphus manifests an intermediate condition: its spline is unequally bilateral, the left-lateral expansion wider than the right. Lateral extensions of the lamellar strip beyond the spline in Cephalozia, Chiloscyphus and Marsupella have been previously recorded only in Anthocerotae. A posterior notch on the right hand side of the lamellar strip in Marchantiales is absent in Chiloscyphus and Cephalozia and has not been observed in the Metzgeriales.     

Botryocladius gen.n.: a new transantarctic genus of orthocladiine midge (Diptera: Chironomidae)

A new genus of orthocladiine Chironomidae, Botryocladius (type species B. grapeth sp.n. from eastern Australia) is described and illustrated in all life history stages. All thirteen included species are described as new, six from eastern Australia (B. grapeth, B. brindabella, B. mdfrc, B. collessi, B. tasmania, B. australoalpinus), two from Western Australia (B. bibulmun and B. freemani), one from ephemeral streams in Australia (B. petrophilus) and four from Patagonian Argentina and Chile (B. edwardsi, B. glacialis, B. mapuche and B. tronador). All Australian species are known from at least pupal exuviae, most from adult males and several from larvae. In contrast, only B. edwardsi amongst Neotropical species is known from the adult male; all others are described from pupal exuviae. The immature stages are lotic in Australian permanent and temporary streams and Patagonian glacial streams and rivers, and lentic in Neotropical glacial-fed and Australian subalpine lakes. Botryocladius appears to belong with a grouping centred on two formally undescribed taxa from Australia. The genus evidently demonstrates a vicariant distribution with at least two sister-group relationships between South American and Australian taxa, providing a minimum dating for the clade of 38 Ma., with apparent absence from New Zealand indicating a maximum date of 80 Ma.     

Observations on the cytology of Bipes (Amphisbaenia) with special reference to its lampbrush chromosomes

The positions and general anatomical and histological characteristics of the gonads of Bipes biporus and B. canaliculatus are described. The amounts of DNA per haploid chromosome set have been measured in both species, the values being 1.83 and 2.0 pg for biporus and canaliculatus respectively. The karyotypes of both species are described on the basis of data from mitotic and meiotic metaphase chromosome sets and from lampbrush chromosomes. B. biporus has 10 macrochromosomes and 11 microchromosomes. B. canaliculatus has 11 macrochromosomes and 11 microchromosomes. The karyotypes of the two species differ distinctly with regard to the shapes of 3 of the macrochromosomes. Chiasma distribution is described for male meiosis in B. biporus. Studies of the lampbrush chromosomes of both species show the chiasma distribution in the female to be generally similar to that found in the male biporus. In B. canaliculatus, lampbrush chromosomes with maximally extended lateral loops are found in oocytes that are oblate spheroids measuring 0.7×1.0 mm along their short and long axes respectively, these being well before the start of the major phase of vitellogenesis. Smaller oocytes have more distinct chromomeres and shorter loops. Microchromosomes take the form of typical small lampbrush chromosomes in oocytes. There are at the most 1,000 chromomeres per haploid set of lampbrush chromosomes in B. canaliculatus. Chiasmata are described from lampbrush preparations in which the two half-bivalents are firmly attached to one another without evident association of their axes, indicating the possibility of chiasmate association between the DNA axes of lateral loops. There are remarkably few extrachromosomal nucleoli in Bipes oocytes, and its is suggested that this may indicate a level of ribosomal gene amplification that is much lower than that found in fish and Amphibia. The observations are particularly discussed in relation to current ideas concerning the structure and function of lampbrush chromosomes.     

A new species of Botryocladia from the West Indies

A very small species of Botryocladia (Rhodophyta-Rhodymeniales), notable for the spinose projections on the surface cells of the vesicles, is here described as B. spinulifera sp. nov. from the Bahamas and the American Virgin Islands.     

A Bryophyte Flora of Berkshire and Oxfordshire

Abstract

In temperate North American forests, collections were made of myxomycetes (plasmodial slime molds) for which bryophytes served as the primary substrate for fruiting. Most associations among the 52 myxomycete species and 55 bryophyte species, represented in these collections, appeared to be coincidental but two species of myxomycetes (Barbeyella minutissima and Lepidoderma tigrinum) were evidently bryophilous, preferring leafy hepatics on rotten coniferous logs. Bryophytes obviously provide exposed surfaces convenient for myxomycete sporulation. Whether bryophytes also sustain the feeding phases of the myxomycete life-cycle (swarm cells, myxamoebae, and plasmodia) is not yet known.     

Botrytis sinoallii: a new species of the grey mould pathogen on Allium crops in China

A study was conducted to identify Botrytis spp. isolated from bulb onion, green onions, garlic, and garlic chives grown in Hubei Province of China. Based on colony morphology and conidial characteristics, 367 strains of Botrytis spp. were identified as five distinct species, namely, B. cinerea, B. squamosa, B. porri, B. byssoidea, and an undescribed Botrytis species (Botrytis sp.), which accounted for 64.3, 29.9, 3.3, 0.3, and 2.2%, respectively. The previously undescribed species is herein described as a new species, B. sinoallii sp. nov., which is characterized by production of numerous small sclerotia on potato dextrose agar. Phylogenetic analysis using partial sequences of three nuclear genes (G3PDH, HSP60, and RPB2) showed that B. sinoallii forms a unique lineage, which is closely related to B. squamosa, a well-known species on Allium crops, but distantly related to the other species of Botrytis on Allium crops, including B. cinerea, B. porri, B. aclada, B. allii, B. byssoidea, B. globosa, and B. sphaerosperma. Results of inoculation tests showed that B. sinoallii is a newly identified agent that can cause leaf blight of green onion, garlic, and garlic chives. Potential impact of B. sinoallii on production of Allium crops in China is discussed.     

Community and species-performance patterns along an alpine poor-rich mire gradient

Abstract. Vegetation, water table depth and water chemistry of 16 peatlands in the southern Alps, Italy, were analysed in 115 sample plots. A poor-rich gradient could be detected along the first axis of a partial Detrended Canonical Correspondence Analysis. Both vegetation and hydrochemistry vary gradually along the gradient. Vascular plants have much broader niches along the gradient than bryophytes. Mosses (except Sphangnum) and hepatics have narrower niches than Sphagnum. The various species of Sphagnum segregate more clearly from each other along the moisture gradient than along the poor-rich one. The positions of species optima along the latter gradient largely reflect the ecological preferences of mire plants in peatlands with respect to nutrient status.     

Ordination of epiphytic bryophyte communities in a wet-temperate coniferous forest,South-Coastal British Columbia

Three coniferous tree species (Pseudotsuga menziesii, Tsuga heterophylla, and Thuja plicata) at Capilano Canyon, British Columbia, were studied for their epiphytic communities. Quantitative data were obtained for fourteen bryophyte species by sampling at heights of 0.5 m, 1 m and 2 m above ground level. Scapania bolanderi is an abundant and widely distributed species; Dicranum fuscescens, Bazzania denudata, Lepidozia reptans and Hypnum circinale are also common. An environmentally uniform study area was chosen to minimize the effects of factors other than bark and elevation on the distribution of epiphytes. In general, tree species are similar in terms of their epiphytic assemblages, but ordination methods using quantitative data exposed compositional variation that may be explained by differences in microclimate and bark-type. In this respect, the results point the way to further studies to examine epiphyte associations in closer detail, and to relate these associations to specific factors in the microenvironment.Nomenclature for vascular plants follows Hitchcock & Cronquist (1973); bryophyte nomenclature follows Schofield (1976) for mosses and Stotler & Crandall-Stotler (1977) for hepatics.We thank Dr. W. B. Schofield for aiding in bryophyte identification.     

Branched and swollen rhizoids in hepatics from montane rain forest in Peninsular Malaya

Abstract

Swollen and branched rhizoids are produced by flagellar axes in seven species of hepatics from montane rain forest. Rhizoid branching is associated with contact with the substratum whereas swollen tips contain abundant fungal hyphae.     

The bryophyte diaspore bank and its role after small-scale disturbance in a boreal forest

Abstract. The composition of the bryophyte diaspore bank in an old-growth Picea abies forest was studied before and after experimental disturbance of forest-floor patches. 40 species, both hepatics and mosses, emerged from spores, and probably also from gemmae and moss fragments, in greenhouse cultivations of soil samples. The three most abundant taxa were Pohlia nutans, Sphagnum spp. and Polytrichum commune/longisetum. Initially, the number of species from the diaspore bank in mineral soil, 9.9 species/sample, was higher than that in humus, 6.6. Four years after the disturbance took place, the reverse was found. Several species that are typical colonisers of disturbed soil were very common in the diaspore bank. By contrast, some of the most abundant forest floor species appeared to be absent. The diaspore bank of bryophytes appears to play a role similar to that of the seed bank in vascular plants: (1) it allows species to survive unfavourable periods (temporal dispersal); (2) it facilitates rapid colonisation after disturbance; (3) it influences the post-disturbance species composition and diversity. The results emphasise that the understanding of vegetation succession patterns is, to a large extent, dependent on quantitative data on the relative importance of spatial and temporal dispersal.     

Karyological studies on some Antarctic liverworts

Abstract

Chromosome counts are reported from five species of Antarctic hepatics belonging to five genera and four families. The chromosome numbers in the genera Herzogobryum (H. teres n = 9) and Paehyglossa (P. dissitifolia n = 9) are reported for the first time. The first chromosome count from Lophozia excisa, n = 27, is the highest reported from Lophozia. A diploid number, n = 18, is reported for the first time from Barbilophozia hateheri; a second count, n = 9, agrees with earlier reports. The commonest Antarctic liverwort Cephaloziella cf. exili[lora has n = 18 and this agrees with earlier reports for the genus.