Methods for Taxonomic Studies of Rumen Ciliates (Alveolata: Ciliophora): A Brief Review

Abstract

This review presents the principal methods used in taxonomic studies of rumen ciliates: live observation, Lugol staining, fixation and staining with methyl-green formalin saline (MFS) solution, protargol staining, silver carbonate impregnation, scanning electron microscopy and molecular techniques. Mastering these techniques is essential for successful research on the taxonomy of rumen ciliates. No single technique reveals all of the characteristics required for a complete description of a rumen ciliate; therefore, it is necessary to combine the use of these techniques as appropriate to the rumen ciliate group under study. Tables are provided to summarize: 1) morphological methods more appropriate for revealing morphological structures of interest, 2) morphological methods indicated for each group of rumen ciliates, and 3) main primers used for PCR amplification of the 18S rDNA of rumen ciliates.

Phylogenetic Analyses Support Validity of Genus Eodinium (Ciliophora, Entodiniomorphida, Ophryoscolecidae)

“…The identification of D. anisacanthum and E. posterovesiculatum morphotypes was acquired after morphometric analyses of 20 Lugol stained (Cedrola et al. ; D'Agosto and Carneiro ) specimens of each morphotype (Cedrola et al. unpubl.…”

“…For the morphological analyses, the rumen content (20 cm 3 ) was fixed in 18.5% formalin (Dehority ), while for the molecular analyses, in 100% ethanol (Cedrola et al. ). Eodinium posterovesiculatum morphotypes and D. anisacanthum morphotypes identifications were based on the redescriptions (Ito and Imai ; Kofoid and Christenson ; Kofoid and MacLennan ), instead of the original descriptions as more taxonomic details are provided.…”

What is your diagnosis? Nasal discharge from a sheep

“…2,3 However, differentiation of ciliate species by cytologic evaluation alone can be difficult; ultrastructural or genetic analysis is recommended for definitive identification. 3,4 Diagnostically, protozoa may be observed normally in oral secretions from ruminants due to rumination. Additionally, a mixed collection of ruminal bacteria (eg, gram-positive rods, gram-negative rods, and grampositive cocci) can normally be found in oral secretions.…”

Apparent digestibility and rumen protozoal profile of sheep fed cassava wastewater

“…At the end of the experiment, the animals were slaughtered after a fasting period of 14 h. Then, samples of the rumen contents were obtained from the center of the rumen mass. Each sample consisted of 50 mL of rumen contents fixed in 18.5% formaldehyde (v/v) (CEDROLA et al, 2015). Protozoa were identified and quantified using a Sedgewick-Rafter chamber (OGIMOTO & IMAI, 1981;CEDROLA et al, 2015).…”

“…Each sample consisted of 50 mL of rumen contents fixed in 18.5% formaldehyde (v/v) (CEDROLA et al, 2015). Protozoa were identified and quantified using a Sedgewick-Rafter chamber (OGIMOTO & IMAI, 1981;CEDROLA et al, 2015). An Olympus BX-51 light microscope (Olympus, Tokyo, Japan), equipped with an Olympus Evolt E-330 digital camera and Image-Pro Plus 6.0 imaging software (Media Cybernetics, São Paulo, Brazil), was used to take photomicrographs of the ciliates.…”