Limnological studies on freshwater ponds of Hyderabad,India IV. The biocenose. Periodicity and species composition of unicellular and colonial phytoplankton in polluted and unpolluted environments

Periodicity and species composition of unicellular and colonial phytoplankton was investigated for two years in three freshwater polluted and unpolluted ponds of Hyderabad, India. Periodicity of various taxonomic groups such as Volvocales, Chlorococcales, Desmids, diatoms and blue-greens was found to be related with the fluctuations of the physicochemical parameters of the ecosystem. Factors like temperature, rainfall, nitrates, nitrites, total sulfides, silica, oxidizable organic matter and basic ratio (Na + K/Ca + Mg) were observed to play an important role in the periodicity of phytoplankton. Taxonomic analysis of the commonly occurring phytoplankton resulted in the identification of 138 species.     

An experimental study of some indigenous drugs with special reference to hydraulic permeability

The effect of commonly used indigenous drugs for hepatic disorders i.e. Tinospora cordifolia, (Guduchi/Amrita), Andrographis paniculata (Kalmegha), Picrorhiza kurroa (Kutki), Phyllantnus niruri (Bhoomyamalaki) and Berberis aristata (Daruharidra) was tested on the hydraulic permeability of water in the presence of bile salt through a transport cell model. The data on hydraulic permeability were calculated as t (time). JV = Lp x AP, where Lp = hydraulic conductivity and AP is the pressure difference. It was observed that the value of controlled hydraulic permeability (0.49 x 10(-8) M3 S(-1) N(-1)) decreased in the presence of indigenous drugs and bile salt. The results suggest that these drugs might have the cell membrane stabilizing property which may lead to prevention of the toxic effect of bile salts in various hepatic disorders.     

Blood pressure levels of Rellis (India) with special reference to variations with age

The paper presents a survey of arterial blood pressures measured in 193 adult males and females of Relli community, selected at random from Visakhapatnam City, Andhra Pradesh. Age shows more influence on the rise of systolic than diastolic blood pressure. Females show a higher rate of rise in both pressures with advancing age. The incidence of hypertension is also found to be higher in females than in males.     

The biogeography of species,with special reference to ferns

An important element of the biogeography of species is the geographic aspects of speciation. The geography of species has a role in the processes of speciation which have a reciprocal role in species geography. The homosporous ferns provide an especially favorable group for biogeographic studies because nearly all species have an equivalent capacity for dispersal and migration. Species ranges are based on the ecology of the environment, rather than on animal vectors of dispersal or pollination. However, with allowance for these differences, the processes of geographic speciation are basically the same in ferns and other vascular plants, although often on a broader geographic scale in the ferns. Speciation most frequently produces a new species with a small range, which can rapidly expand to occupy the geography of the environment to which the species is adapted. The members of a closely related speciesgroup retain their morphological and geographic relations for a relatively short time. With speciation, changes in distribution, and extinction, the original relations of the species and the biogeographical history of the group will be lost. High regional species diversity occurs in the wet mountainous regions of the tropics, where there is greatest ecological diversity and maximal opportunities for speciation and persistence.     

Molecular phylogeny of small brown algae,with special reference to the systematic position of Caepidium antarcticum (adenocystaceae,ectocarpales)

Nuclear ribosomal DNA (3′-SSU, ITS, 5′-LSU) and plastid-encoded (rbcL and Rubisco spacer) sequences were determined in Caepidium antarcticum and compared to homologous sequences of relatives from Ectocarpales, Scytothamnales, and other brown algae. Plastidial sequences confirmed a previous conclusions from nuclear ribosomal sequences that some taxa with stellate plastids (Asterocladon and relatives) form the closest outgroup to the Ectocarpales as yet identified. To reconcile nomenclature with the clades resolved in recent molecular studies, we propose a subdivision of the Ectocarpales in five families. Plastidial sequences support the recent proposal of Adenocystaceae, and all sequences suggest that Caepidium should be included in this family. As a further result, Geminocarpus was shown to belong to the same clade as Pylaiella and a number of other brown algae with an isomorphic life history and discoid plastids. We recognise this clade, whose correct name is Acinetosporaceae, as another family in the Ectocarpales. We also propose to unite a number of genetically related taxa, which were formely classified in different families, in an extended Chordariaceae. The remaining species of the Ectocarpales belong to Scytosiphonaceae and to Ectocarpaceae, the latter containing only Ectocarpus and Kuckuckia.     

Dynamics of some Western Australian ligneous formations with special reference to the invasion of exotic species

Invasion of natural vegetation in Australia by exotic species has become pronounced in the last 150 years of European settlement. Changes in the frequency and type of fire have been a major disturbance to the dynamics of natural vegetation, and this disturbance has allowed rapid spread of exotics, particularly in urban and semi-rural regions. Less obvious disturbances include changes in nutrient levels and hydrological regimes, which also allow exotic species to establish and spread, at the expense of native species. Permanent plots established in various vegetation types show a decline in diversity which is associated with an increase in invasion by exotic species. Possible management strategies, designed to maintain the natural vegetation, which can be postulated include control and change of fire regime, removal of exotic species before seed-set, and the active introduction of native plants adapted to disturbance.We gratefully acknowledge the assistance of R. Hume for cartography and Doreen Jones for typing. One of us (DJB) was in receipt of a Commonwealth of Australia postgraduate award during the course of this work.     

The Chromosomes of some octodontids with special reference to Octodontomys (Rodentia; Hystricomorpha)

The chromosomes of three species (Octodontomys gliroides, Octodon degus and Ctenomys talarum) of octodontid hystricomorph rodents are compared. — The diploid numbers are 38, 58 and 48 respectively. No polymorphic chromosomes were noted in the specimens available. The sex chromosomes are heteromorphic and pair end to end in meiosis. — The karyotypes are compared on the basis of the extreme specialisation of the habitat of the three species. The asymmetric karyotype of Octodontomys can be compared more readily with that of a Ctenomys ancestor than with that of its present-day relative, Octodon.     

A microscopical study of a marine species of Codosiga James-Clark (Choanofiagellata) with special reference to the ingestion of bacteria

Cells of Codosiga gracilis (Kent) de Saedeleer were grown in culture with two strains of bacteria and observed over a period of almost two years. Throughout the growth cycle, cell form varied with rounded motile individuals predominating during the first three days after subculture and stalked cells predominating in older cultures. Electron microscopy of sections revealed the presence of at least two flagellar bases and an elaborate microtubular system associated with the base of the single emergent flagellum. Capture and ingestion of bacteria has been observed using light microscopy, and electron microscopy of sections has demonstrated the relationship between the engulfing pseudopodium and adjacent collar tentacles.     

The drug aloes of commerce,with special reference to the cape species

The laxative property in the juice of aloe leaves has been recognized since ancient times. The Union of South Africa is the principal producer today, but 90% of American imports come from the Dutch West Indies— Aruba and Bonaire.     

An ecological study of three freshwater ponds of hyderabad-India IV. the phytoplankton (diatoms,euglenineae and myxophyceae)

Data on the ecology of Diatoms, Euglenineae and Myxophyceae in three freshwater ponds, differing in chemical composition and algal flora, situated in the vicinity of Hyderabad-India are presented. An attempt has been made to isolate various genera into groups, as their multiplication depended on particular ranges of a single chemical factor or set of factors. Several species could be separated into seasonal forms as they occur in particular periods of the year. Others could be grouped under indifferent forms as these are neither influenced by fluctuations in chemical factors nor by seasonal changes.     

An annotated list of the marine algae of Visakhapatnam (India)

In all, 80 species and varieties of marine algae are recorded from the intertidal region of the Visakhapatnam coast. Of these, 18 are new records for India and seven are first records for the east coast. Information on the localities of their occurrence and notes on the morphology and other features of taxonomic interest are given in the annotations.     

An ecological investigation of the Portneuf River, Idaho: a semiarid-land stream subjected to pollution

The Portneuf River (mean monthly discharge near mouth 1.4-15.4 m³/s) in southeastern Idaho, U.S.A., flows through an area of reduced precipitation (approx. 33 cm/year) and is dependent on underground aquifers and snowmelt runoff from the surrounding mountains for its water. The stream was examined at ten locations, distributed over its 156-km course, during the period 1967-1971. The Portneuf River is shown to have undergone a number of changes from its natural state as evidenced by alterations in water quality and the distribution of benthic invertebrates along the stream course. Of particular interest are changes brought about by the use of the stream for irrigation and by runoff from agricultural lands, factors whose effects are magnified by the semiarid conditions of the region and by poor soil-conservation practices. However, the stream also is affected by wastes from a sewage-treatment plant, phosphate-processing operations, and an assortment of scattered urban sources. Benthic invertebrates were collected during all four seasons by means of artificial substratum samplers and during summer and autumn by a qualitative dip-net technique. In general, the samplers were more effective in obtaining a representative picture ofthe fauna. However, neither procedure alone gave as much information as the combined results. The artificial substratum collections are not believed to be representative of the usual effects of stream devvatering by irrigation withdrawal in as much as the samplers provide refugia for the benthos during the periods of reduced habitat.     

Contribution to ITS phylogeny of the Brassicaceae, with special reference to some Asian taxa

Sequence data from the nuclear ribosomal internal transcribed spacer (ITS) region for 189 accessions representing 184 species in 121 genera of Brassicaceae were used to determine monophyly of tribes and genera, tribal boundaries, and component genera. Parsimony analysis and Bayesian inference suggest that the tribes Camelineae and Arabideae are polyphyletic and should be subdivided into smaller tribes. The study also supports the recent recognition of the new tribes Aphragmeae, Biscutelleae, Buniadeae, Calepineae, Conringieae, Dontostemoneae, Erysimeae, Malcolmieae, Megacarpaeeae, and Turritideae. The data argue for the placement of Borodinia in the tribe Boechereae, Litwinowia and Pseudoclausia in the Chorisporeae, Atelanthera and Streptoloma in the Euclidieae, and Megacarpaea and Pugionium in the Megacarpaeeae, and exclusion of Asperuginoides, Didymophysa, and Ptilotrichum from the Alysseae, Macropodium, Pseudoturritis, and Stevenia from the Arabideae, and Crucihimalaya, Irenepharsus, Pachycladon, and Turritis from the Camelineae. Finally, the findings support the expansion of Stevenia to include both Berteroella and Ptilotrichum, Sterigmostemum to include Oreoloma and one species of Anchonium, Crucihimalaya to include Transberingia and several species of Arabis, and Parrya to include Pseudoclausia. The data also suggest that Calymmatium and Olimarabidopsis may be congeneric.