Corresponding author: Milcho Todorov (
Academic editor: Anne Thessen
The ultra-structure of the shell and the morphometric variability of soil inhabiting testate amoeba
The genus
The material for the present study (an aggregate sample of about 500 g) was collected in October 2013 from the organic horizon (litter, twigs and woody material) of rainforests at the Maromizaha Protected Area (Madagascar). This Protected Area is located in Central Madagascar, east of the capital Antananarivo and south of the village Anevoka, on the eastern slopes of the Central Highlands (18°57'S, 48°27'E, 950 m a.s.l.). At the laboratory, the material was dried for one day in a thermostat at 60˚C. Then was soaked and mixed in chlorinated tap water for about ten minutes, after which was filtered through a sieve with 500 μm mesh to remove large organic and mineral particles. The resulting filtrate was allowed to precipitate for two hours, the sediment was removed and the shells that floated on the surface were collected for examination. The study was carried out 12 hours after the flotation, when the gas bubbles inside the shells completely disappeared and the structure of the shells was well visible. All filtrate was examined in a petri dish at 100X magnification with Stereomicroscope “STEMI” Citoval-2 (Carl Zeiss Jena). A total of 81 individuals of
Remaining six specimens were studied by scanning electron microscope (SEM). They were extracted using a glass micropipette, washed several times in distilled water, and then individual shells were positioned with a single-hair brush onto a small drop of Araldite on a previously cleaned standard aluminium stub and air-dried. The shells were coated evenly with gold in a vacuum coating unit. The photomicrographs were obtained using a JEOL JSM-5510, operating at 10 kV.
The biometric description was made according to
The shell is yellowish or light brown, circular in oral and dorsal views, and hemispherical in lateral view (Figs
The basic morphometric characters of 75 individuals from the Maromizaha Protected Area in Madagascar were measured and the results are given in Table
Analysis of the size frequency distribution of the main characters indicates that
Until present, data on the ultramorphology and biometry of
Biometrical characteristic of the species, based on relatively rich material, was made. In addition to the diameter of the shell, six other shell characters were described biometrically for the first time. Our data for the shell diameter (Mean ± SD) fully corresponds to those given by
Surprisingly, our study showed that the population of
Another interesting feature observed in our SEM studies of
In respect to the biogeography of
We are grateful to Prof. B. Georgiev for providing the material used as a basis for this work. We thank the referees and editors for some useful suggestions, which helped to improve this paper.
Light micrographs of
Ventral view of specimen with three teeth, showing oval internal opening at the bottom of the apertural tube (white arrow) and dark coloured organic frame at the base of the tube (black arrow)
Ventral view of specimen with four teeth
Lateral view of the specimen from Fig. 1a, showing invagination of the apertural tube
Lateral view of the specimen from Fig. 1b, showing invagination of the apertural tube
Scanning electron micrographs of
Ventral view of specimen with three teeth
Ventral view of other specimen with three teeth
Ventral view of specimen with four teeth
Dorsal view, showing rough dorsal surface of the shell
Lateral view, showing rough dorsal and smooth apertural surface of the shell
Lateral view, showing rough dorsal and smooth apertural surface of the shell
Scanning electron micrographs of
View of aperture to show the smooth teeth and internal opening with collar (arrowed) on the bottom of the apertural tube
Details of organic cement with single and different sized pores
Dorsal view, showing rough dorsal surface of the shell
Lateral view of fractured shell, showing deep apertural invagination and its rough surface
Lateral view of farctured shell, showing deep apertural invagination and its rough surface
Fractured edge of the shell illustrating the shell structure with smooth outer thin layer of organic cement (large black arrow), intermediate layer of porous and fibrous organic cement (small white arrows) with incorporated mineral particles (small black arrow) and inner thick layer of organic cement (large white arrow)
Variability of the shell characters in
Diameter of shell, depth of shell, diameter at the base of apertural tube
Depth of apertural tube, large axis of internal opening, small axis of internal opening, length of teeth
Size frequency distribution of the main shell characters in
Biometrical characterization of
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175.8 | 175.0 | 7.30 | 0.84 | 4.15 | 159 | 190 | 75 |
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128.1 | 129.0 | 4.60 | 0.70 | 3.59 | 118 | 138 | 43 |
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59.8 | 60.0 | 3.19 | 0.37 | 5.32 | 54 | 67 | 75 |
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50.0 | 50.0 | 1.69 | 0.26 | 3.37 | 47 | 55 | 43 |
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37.1 | 38.0 | 3.41 | 0.41 | 9.20 | 27 | 43 | 69 |
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29.2 | 30.0 | 2.67 | 0.32 | 9.13 | 23 | 36 | 69 |
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16.2 | 16.0 | 1.97 | 0.23 | 12.12 | 12 | 23 | 75 |
Lamtopyxis callistoma
Biometry_Stattistica
File: oo_31598.STA