Papers by Zéphyrin Fokam
The paper demonstrates the influence of physico-chemical parameters on the distribution of endoco... more The paper demonstrates the influence of physico-chemical parameters on the distribution of endocommensal ciliates through the gut of the earthworm Alma emini. We measured physico-chemical parameters of the intestinal liquid extracted with the vacuum aspiration technique and concomitantly recorded biological parameter (species abundance). Furthermore, correlation analysis between physico-chemical parameters and biological parameter was performed in different compartments. In the foregut, among the eleven species of Astomatia recorded, correlation was significant between Metaracoelophrya intermedia, Coelophrya roquei and Water Content (WC = 46.94 ± 7.77%). In the midgut, among the nine species of Hysterocinetidae recorded, a significant correlation was observed between Metaptychostomum ebebdae, Ptychostomum macrostomum and Electric Conductivity (EC = 84.55 ± 12.94 µS/ cm). In the same compartment, a significant correlation was also observed between Ptychostomum macrostomum and Total Dissolved Substance (TDS = 16.20 ± 3.46%). In the hindgut, eight species of Astomatia were found, among which significant correlation was obtained between Coelophrya roquei and Hydrogen potential (pH = 7.35 ± 0.16). In the same compartment, taking into account the eleven species of Hysterocinetidae recorded, a significant correlation was also obtained between Ptychostomum macrostomum and pH; Ptychostomum commune and WC (28.84 ± 3.97%). These results suggest that each part of the digestive tract of A. emini can be
The morphology and ciliature of four Nyctotherus species (Nyctotherus orthostomatus n. sp., Nycto... more The morphology and ciliature of four Nyctotherus species (Nyctotherus orthostomatus n. sp., Nyctotherus ndoumeleleensis n. sp., Nyctotherus ngassami n. sp. and Nyctotherus atunibaensis n. sp.), isolated from the mid and hindgut of a Megascolecidae annelid of the genus Eupolytoreutus from the northwest region of Cameroon, were investigated using living observation (methylene blue) and silver impregnation methods (Fernandez-Galiano, 1994). Nyctotherus orthostomatus n. sp. is recognized by a pear-shaped body (128-152 × 95-104 µm); a conspicuous buccal apparatus with the peristome and the infundibulum perpendicular to each other; about 41-46 somatic kineties covering each side of the cell; one transversally elongated massive macronucleus located in the anterior third of the cell, surmounted by a very small spherical micronucleus. Nyctotherus ndoumeleleensis n. sp. is distinguished by the combination of the following characters: ovoid body (151-163 × 87-92 µm) with rounded poles; about 52-68 somatic kineties uniformly covering the cell body; an anterior, transversal and trapezoidal macronucleus carrying laterally a small micronucleus (2-3.5 µm in diameter). Nyctotherus ngassami n. sp. can be distinguished from its congeners by the following set of features: size about 153-269 × 102-148 µm; body ovoid, with 64-86 ciliary rows covering its surface; a small and globular micronucleus hidden by a transversal macronucleus located slightly above the equatorial part of the cell. Nyctotherus atunibaensis n. sp. is characterized by size about 145-253 × 95-162 µm, ovoid cell body, 108-122 somatic kineties, · 63 Protistology a transversal and arc-shaped macronucleus hiding a small micronucleus. In the present study, new locality (northwest region of Cameroon) and new species of the genus Nyctotherus are explored.
Earthworms of the genus Alma nilotica belonging to the family Glossoscolecidae, lodges an abundan... more Earthworms of the genus Alma nilotica belonging to the family Glossoscolecidae, lodges an abundant fauna of astomatous ciliates in its digestive tract. Each species is located in a well-defined portion of the gut and the reasons for this stratification still remain unclear. In order to assess the influence of physico-chemicals parameters of the soil on the distribution of one of these astomatous ciliates (Paracoelophrya polymorphus Fokam, 2012) along the digestive tract of Alma nilotica, a study was carried out from April to September 2013 in Bambui on the banks of Fansaah river. The volumic density (VD) of worms (number /dm 3 soil) was examined. A total of 60 worms were used for the counting of ciliates. The observation of Paracoelophrya polymorphus was done after staining with methylene blue. Twelve physico-chemicals parameters of the soil from the site of collection of worms were analyzed. The degree of binding between the VD of worms, the abundance of ciliates and physico-chemicals parameters was performed for different portions of the digestive tract. VD of the earthworms shows a positive and significant correlation with the Cation Exchange Capacity CEC (r = 0.771; P < 0, 05) and with Mg (r = 0.886; P < 0, 01). Paracoelophrya polymorphus is located in the foregut and midgut of its host but, its preferential zone is the foregut. In the foregut, a negative and significant correlation was found between available phosphorus (P) and P. polymorphus abundance (r =-0,943; P < 0, 01). In the midgut, a positive and significant correlation was obtained between the Cation Exchange capacity (CEC) (r = 0.754; P < 0, 05), magnesium (r = 0.812; P < 0, 05), calcium (r = 0.754; P < 0, 05) and P. polymorphus abundance. These chemical parameters influence directly the density of the earthworms and indirectly the stratification of P. polymorphus.
Prosicuophora cyclostomatus n. sp. and Nyctotheroides bambuiensis n. sp. are two new ciliate spec... more Prosicuophora cyclostomatus n. sp. and Nyctotheroides bambuiensis n. sp. are two new ciliate species isolated from the rectums of Bufo regularis collected in the vicinity of Bambili and Bambui. The morphological characteristics of these Protozoa are described and their relation to similar species is discussed.
International Journal of Biosciences (IJB)
International Journal of Biological and Chemical Sciences
Studies on five new species of hysterocinetian ciliates, endocommensal within a terrestrial oligo... more Studies on five new species of hysterocinetian ciliates, endocommensal within a terrestrial oligochaete from the genus Alma (Cameroon), reveal the existence of three distinct types of cytoskeletal topography within their adhesive apparatus. In the first topographical type, four superimposed antagonistic strata of skeletal fibres that correspond to the arrangement observed in the genus Ptychostomum, Stein 1860 are found. The second topographical type is characterized by the existence of an unorganized field of fibrillar structures forming a single dense mass in the central part of the sucker. For this, a new genus is created: Ptychostomoides, Nana, Fokam, Ntoungwa et al. n. g. The third type present in the genus Proptychostomoides, Nana, Fokam, Ntoungwa et al. n. g. differs from the latter by the existence of a bare patch within the central region of the adhesive apparatus. This new evidence of morphological diversification within the Hysterocinetidae supports a new approach to the systematics of this group.
innspub.net, Apr 29, 2015
Today, rice has become one of the most consumed cereals in Africa in general and Cameroon in part... more Today, rice has become one of the most consumed cereals in Africa in general and Cameroon in particular. The low domestic production imposes a strong import that accentuates the country's trade imbalance. To reduce this issue of external dependency, the national government is encouraging domestic production. However, producer’s efforts are inhibited by various constraints among which the pest attacks in general and in particular the stem borers. Data collection was based on sampling and incubation of white rice panicles in an experimental plots set up at Nkolbisson, Yaoundé. The susceptibility of rice varieties to different pest species was evaluated by comparing the frequency of pest species on their infested panicles. Among the NERICA rice lines, NERICA 3 had the greatest percentage of attacks panicles that was 41.96 % while NERICA 9 and 13 had the less percentage of attacks panicles that was 14.29 % for both of them. A total of three pest species were identified from the pani...
The intestinal liquid of A. emini was extracted using the vacuum aspiration technique, followed b... more The intestinal liquid of A. emini was extracted using the vacuum aspiration technique, followed by measurement of ion concentrations and concomitantly recorded species abundance. Nitrate (NO 3-) concentration decreased from the foregut to the hindgut. Nitrites (NO 2-), ammoniums (NH 4 +) and orthophosphates (PO 4 3-) reached their greatest levels in the midgut. Furthermore, correlation analyses between ion contents and ciliate abundance in different compartments were performed. In the foregut, a positive and significant correlation was found between the abundance of the Paracoelophrya ebebdensis and PO 4 3-. In the midgut, a positive and significant correlation was observed between the number of the ciliates Dicoelophrya mediovacuolata; Coelophrya roquei; Coelophrya ovales; Ptychostomum commune and NO 2-; Almophrya mediovacuolata and NH 4 +. In this same compartment, a positive and significant correlation was also observed between the abundance of Ptychostomum prolixus and NO 2-. In the hindgut, a positive and significant correlation was found between the values of PO 4 3-and Ptychostomum variabilis abundance. These results suggest that each portion of the digestive tract of A. emini can be considered as a set of natural micro-habitat in which a large number of ions generate ecological niches suitable for the Survival of a specific group of ciliate species.
Morphology and infraciliature of two new earthworm ciliates, Hoplitophrya polymorphus sp. nov. an... more Morphology and infraciliature of two new earthworm ciliates, Hoplitophrya polymorphus sp. nov. and Anoplophrya simplex sp. nov. Abstract Morphological and infraciliature studies carried out using pyridinated ammoniacal silver carbonate and the 4',6-diamidi-no-2-phenylindole (DAPI) staining techniques, led to the identification of two new species of ciliates pertaining to the subclass Astomatia. The first species, Hoplitophrya polymorphus sp. nov., displays two main cellular forms: the elongated form (150–247 μm long and 40–87 μm width) and the stocky form (140–170 μm long and 70–98 μm width). The macro-nucleus is generally skinny in the elongated forms and ribbon-shaped in the stocky forms. The common feature of the two cellular shapes uniting them in the same species is the identical structure of their skeletal apparatus, a V-shaped element located in an apical depression and bearing skeletal fibres on its ventral face. The second species, Anoplophrya simplex sp. nov., is totally deprived of skeletal apparatus. The cell shape is fusiform and dorsoventrally flattened (105–180 μm long and 65–125 μm width). Six to 12 pulsatile vacuoles form two rows arranged symmetrically on either side of the ma-cronucleus. These two newly identified species highlight the extremely rich diversity of ciliates inhabiting the digestive tract of tropical earthworms.
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Papers by Zéphyrin Fokam