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  • Author: A. Chaudhary x
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Abstract

The objective of this investigation is to study the influence of thermal radiation and radiation absorption parameter on a mixed convection flow over a continuously moving porous vertical plate under the action of transverse applied magnetic field taking into account the induced magnetic field with convective boundary. Under certain assumptions, the solutions for the velocity field, temperature distribution and induced magnetic field are obtained. The influences of various parameters on the velocity, temperature fields and on induced magnetic fields are studied graphically. It is also found that the dimensionless Prandtl number, Grashof number, Schmidt number and magnetic parameter have an appreciable influence on the independent variables.

Summary

Three species of digenetic trematodes are redescribed based on specimens collected from the intestine of freshwater fishes of Hastinapur and Meerut (U.P.), India: Allocreadium handiai () (Allocreadioidea: Allocreadiidae) from Mystus tengara (Hamilton, 1822) (Siluri-formes: Bagridae), Genarchopsis goppo (Hemiuroidea: Derogenidae) and Phyllodistomum chauhani (Plagiorchioidea: Gorgoderidae) from Channa punctata (Bloch, 1793) (Perciformes: Channidae). The three species were subjected to morphological, morphometric and molecular analyses. The morphological study revealed that A. handiai, G. goppo and P. chauhani can be distinguished by their congeners on the basis of their morphology. Partial nucleotide sequences of the 28S ribosomal RNA gene were obtained from the three trematode species and deposited in the GenBank. A phylogenetic reconstruction based on the 28S rRNA gene placed the three studied species within their respective families and their validity is discussed. For the first time molecular data of newly collected material of these species from India were used for confirmation of their validity and to assess their phylogenetic relationships.

Summary

A new nematode species, Heliconema monopteri n. sp. (Physalopteridae), is described from the stomach and intestine of the freshwater fish Monopterus cuchia (Hamilton) (Synbranchidae) in Bijnor district, Uttar Pradesh, India. It is mainly characterized by the lengths of spicules (468 – 510 µm and 186 – 225 µm), the postequatorial vulva without elevated lips, the presence of pseudolabial lateroterminal depressions and by the number and arrangement of caudal papillae. This is the first representative of the genus reported from a synbranchiform fish. Another new congeneric species, Heliconema pisodonophidis n. sp. is established based on a re-examination of nematodes previously reported as H. longissimum (Ortlepp, 1922) from Pisodonophis boro (Hamilton) (Ophichthidae) in Thailand; ovoviviparity in this species is a unique feature among all physalopterids. Heliconema hamiltonii Bilqees et Khanum, 1970 is designated as a species dubia and the nematodes previously reported as H. longissimum from Mastacembelus armatus (Lacépède) in India are considered to belong to H. kherai Gupta et Duggal, 1989. A key to species of Heliconema Travassos, 1919 is provided.

Summary

The phylogenetic relationships of the nematode species Thelandros scleratus (Oxyurida: Pharyn-godonidae) and Physalopteroides dactyluris (Spirurida: Physalopteridae) were analyzed using the ribosomal 18S rRNAand the mitochondrial cytochrome C oxidase subunit genes. The nematodes were recovered from Brook's house gecko, Hemidactylus brooki (Reptilia: Gekkonidae) from Hast-inapur, Meerut (U.P.), India. The results demonstrated that T. scleratus shows 100% similarity with another sequence available from the same species and a close relationship (98-99%) with species of Parapharyngodon in both 18S rRNAand cox 1 regions. Regarding the nematode Physalopteroides. analysis showed a close phylogenetic relationship between P. dactyluris and several species of Phy-saloptera. This is the first sequence of 18S available for any species of the genus Physalopteroides

Summary

Two species of digenetic trematodes of the genus Pleurogenoides viz., P. cyanophlycti and P. euphlycti have been described from India. Information regarding the molecular data of various species of the genus Pleurogenoides Travassos, 1921 is virtually lacking. This study addresses the application of molecular markers to validate the phylogenetic position of P. cyanophlycti and P. euphlycti. In the present study, two species P. cyanophlycti and P. euphlycti were collected between January 2016 to October 2017, infecting the freshwater frogs inhabiting the Western Ghats, India. In the present study, the two species were identifi ed morphologically and by PCR amplification of the 28S ribosomal RNA gene. Phylogenetic tree results clearly demonstrate that both P. cyanophlycti and P. euphlycti belongs to the family Pleurogenidae . Based on these results, we presented and discussed the phylogenetic relationships of P. cyanophlycti and P. euphlycti within family Pleurogenidae from India. Phylogenetic analyses showed that P. cyanophlycti and P. euphlycti cluster according to their vertebrate host and revealed an important congruence between the phylogenetic trees of Pleurogenoides and of their vertebrate hosts. P. cyanophlycti and P. euphlycti clearly constitute a separate, sister branch with other species of the genera, Pleurogenoides, Pleurogenes (=Candidotrema), Prosotocus and Brandesia. The present study firstly provides important information about the molecular study and phylogenetic analysis of P. cyanophlycti and P. euphlycti. This study will also serve as a baseline for Pleurogenoides species identifi cation for further studies.

Summary

Two species of Thaparocleidus Jain (1952a) were found harboring W. attu from the Ganga River at two localities, Meerut and Farrukhabad, Uttar Pradesh, India, during the period of 2013-2015. Morphology and morphometric study of specimens identified as Thaparocleidus gomtius (Jain, 1952a) Lim, 1996 and T. sudhakari (Gusev, 1976) Lim, 1996. Molecular analyses using the 18S rRNA gene confirmed the validity of T. gomtius and T. sudhakari and demonstrated that both the species clustered with other Thaparocleidus species from different geographical regions. We aim at reassessing the taxonomy and establishing the phylogenetic relationships among these two redescribed species with other representatives of the genus Thaparocleidus.

Summary

The nematode, Procamallanus spiculogubernaculus Agarwal, 1958 was found from the Stinging catfish, Heteropneustes fossilis (Bloch, 1794) from Ghazipur, Delhi, India. Morphological characterization, including scanning electron microscope observation supplemented with DNA sequences is provided. Specimens recently found are characterized by the presence of an unlined buccal capsule having a small basal ring, esophagus muscular and glandular, vulva position is slightly post-equatorial, tail conical, long, and ending in three digit-like processes, phasmids present at about mid-length and cloaca located at the posterior end. In this study the species P. spiculogubernaculus is validated on the basis of molecular data after 47 years from its original description. In the scanning electron microscope examination, the topology of mouth and sensory pits in anterior portion, while the phasmids and digit like processes in posterior portion is clearly observed. Molecular data of the 18S ribosomal RNA and mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were analyzed. Molecular phylogenetic analyses supported the validity of Procamallanus spiculogubernaculus and confirmed the paraphyletic status of the members of Procamallanus, Spirocamallanus, Camallanus and Paracamallanus. Taxonomic status of members of the family Camallanidae are briefly discussed along with the results of the systematic evaluation of P. spiculogubernaculus based on molecular data.

Abstract

This paper presents a study of a hydromagnetic free convection flow of an electrically conducting micropolar fluid past a vertical plate through a porous medium with a heat source, taking into account the homogeneous chemical reaction of first order. A uniform magnetic field has also been considered in the study which acts perpendicular to the porous surface of the above plate. The analysis has been done by assuming varying permeability of the medium and the Rosseland approximation has been used to describe the radiative heat flux in the energy equation. Numerical results are presented graphically in the form of velocity, micro- rotation, concentration and temperature profiles, the skin-friction coefficient, the couple stress coefficient, the rate of heat and mass transfers at the wall for different material parameters. The study clearly demonstrates how a chemical reaction influences the above parameters under given conditions

Abstract

Morphological Redescription and Molecular Characterization of Dactylogyrus labei (Monogenea, Dactylogyridae) from Catla catla: a New Host Record in India. Chiary, H. R., Chaudhary, A., Singh, H. S. - Dactylogyrus labei Musselius et Gusev, 1976 (atypical form) specimens were collected from host Catla catla from the river Brahmaputra, Guwahati, Assam, India. The Dactylogyrus samples were examined by morphological and molecular methods. This parasite was originally described from Labeo rohita from fish farm Kalyani, West Bengal, India, but the morphological study of sclerotized parts showed the existence of D. labei on Catla catla. This is the first record of D. labei from Catla catla in India.

Abstract

The present study describes the molecular characterization of the monogenea Dactylogyroides tripathii (Tripathi, 1959) Gussev, 1973 infecting the gill filaments of fish, Puntius ticto from River Brahmaputra, Guwahati, Assam, India. This study shows the D. tripathii species identification resulted from the use of molecular data, particularly the 28S rDNA gene. We compared the 28S partial rDNA sequence of D. tripathii with same gene region of the other species of monogeneans available in GenBank. With this comparison, we determined that the sequence had a similarity with one available species of the genus Dactylogyroides Gussev, 1963 i. e., D. longicirrus and also with the species of Dactylogyrus from which this genus was distinguished.