Effect of coal rank on the composition of organic matter (Short Communication)

Supono, Hudaidah S. 2018. Short Communication: The diversity of epipelic diatoms as an indicator of shrimp pondenvironmental quality in Lampung Province, Indonesia. Biodiversitas 19: 1220-1226. Epipelic diatoms live by attaching to sediment.Their existence is strongly affected by water and sediment quality. The purpose of this research was to analyze the structure ofepipelic diatom populations on the bottom of shrimp ponds and to determine the correlation between epipelic diatom diversityand the quality of water and of pond bottom sediment. This exploratory research was conducted on twelve shrimp ponds during thewater preparation period (pre-stocking). Data were collected to analyze the correlation between water and sediment qualities. The resultsshowed that Nitzschia and Pleurosigma were the dominant epipelic diatoms in the shrimp ponds. Epipelic diatom diversity in shrimpponds was affected by water quality parameters (namely total alkalinity, organic matter and nitrate) as well as sediment qualityparameters (namely cation exchange capacity, clay content and organic matter content).

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SHORT COMMUNICATION: Variation in soil total organic matter content and total nitrogen associated with microrelief

Canadian Journal of Soil Science ◽

10.4141/cjss95-068 ◽

1995 ◽

Vol 75 (4) ◽

pp. 471-473

Author(s):

C. Chang

Keyword(s):

Organic Matter ◽

Total Nitrogen ◽

Short Communication ◽

Organic Matter Content ◽

Matter Content ◽

Total Organic Matter ◽

Clay Loam Soil ◽

Plot Area ◽

Loam Soil

In a 140 × 50-m plot area on a Dark Brown Chernozemic clay loam soil subdivided into two subplots by direction of slope, total nitrogen (TN) and total organic matter (TOM) were significantly correlated with elevation after accounting for direction of slope. This finding, in an area that is not a closed hydrological basin and appears relatively flat, suggests aspect deserves consideration in the layout and sampling of experiments which include characterization of TN and TOM. Key words: Elevation, organic matter, total nitrogen

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Ultrastructure of primary spermatocyte in fish (Tilapia: Oreochromis niloticus): The synaptonemal complex

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143067 ◽

1986 ◽

Vol 44 ◽

pp. 288-289

Author(s):

T. Guha ◽

A. Q. Siddiqui ◽

P. F. Prentis

Keyword(s):

Fine Structure ◽

Electron Microscope ◽

Synaptonemal Complex ◽

Oreochromis Niloticus ◽

Short Communication ◽

Primary Spermatocyte ◽

Mitotic Division ◽

Meiotic Cell ◽

Electron Microscope Level ◽

Homologous Chromosomes

The Primary Spermatocytes represent a stage in spermatogenesis when the first meiotic cell division occurs. They are derived from Spermatogonium or Stem cell through mitotic division. At the zygotene phase of meiotic prophase the Synaptonemal complex appears in these cells in the space between the paired homologous chromosomes. Spermatogenesis and sperm structure in fish have been studied at the electron microscope level in a few species? However, no work has yet been reported on ultrastructure of tilapia, O. niloticus, spermatozoa and spermatogenetic process. In this short communication we are reporting the Ultrastructure of Primary Spermatocytes in tilapia, O. niloticus, and the fine structure of synaptonemal complexes seen in the spermatocyte nuclei.

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