Haemosporidian blood parasites of the Plasmodium genus are the causative agents of avian malaria in many parts of the world. Despite the great diversity of Brazilian avifauna, few studies have been conducted to examine the haemosporidians of wild birds found in the Brazilian Atlantic Forest, especially those kept in captivity. This study aimed to re-examine and further characterize the South American avian parasite Plasmodium paranucleophilum using a multidisciplinary approach. Blood samples were collected from 68 captive birds representing 15 species found in the Atlantic Forest of southeastern Brazil. Morphometric and morphological characterization was performed, in addition to PCR and sequencing of the mitochondrial cytochrome b gene and subsequent phylogenetic analysis. The overall prevalence of P. paranucleophilum infection in the study was 13.23% (n = 9), with a mean parasitemia of 0.58%. We observed the highest parasitemia of 3.88% in Rupornis magnirostris. In our phylogenetic analysis, P. paranucleophilum and P lasmodium nucleophilum formed distinct, highly supported clades, with a mean genetic divergence of 2.48%. This study provides new morphological and molecular data, expanding our knowledge of the haemosporidians of wild birds in Brazil and highlighting the need for further investigation. The true depth of diversity in Brazilian avian haemosporidians remains largely unknown, and given the enormous variety of vectors and avian species, there may be many more species of these blood parasites yet to be described.

RESUMO -Quatro vacas lactantes canuladas no rúmen, com 155 dias em lactação, foram dispostas em um quadrado latino 4 × 4 e alimentadas, duas vezes ao dia, com silagem de milho e concentrado (relação 55:45, base matéria seca), para se avaliarem os efeitos da monensina e do óleo de soja na dieta de vacas lactantes sobre a contagem de protozoários ciliados, além de estabelecer correlações entre os protozoários com alguns parâmetros da digestão e da fermentação ruminal. Os tratamentos consistiram da inclusão de 33 ppm de monensina sódica ou de 4% de óleo de soja na dieta, assim representados: dieta controle, sem óleo ou monensina -CT; dieta com monensina -MN; dieta com óleo -OL; combinação de 33 ppm de monensina e 4% de óleo de soja -OM. Verificou-se a ocorrência de 11 gêneros de ciliados, sendo Entodinium o predominante em todos os tratamentos. Não foi observada interação significativa óleo de soja × monensina sobre a contagem de protozoários e gêneros. Os gêneros Entodinium, Dasytricha, Eremoplastron e Isotricha foram reduzidos nas dietas com óleo, enquanto a monensina diminuiu a contagem de Dasytricha, Eremoplastron e Epidinium. O número total de protozoários e de ciliados celulolíticos foi reduzido pelos efeitos de óleo de soja e monensina, indicando efeito aditivo defaunatório quando combinados o óleo e a monensina. Os ciliados celulolíticos foram reduzidos pelo consumo de ácido linoléico e positivamente relacionados à digestibilidade ruminal da FDN e amônia ruminal. O número total de protozoários foi correlacionado à proporção de propionato no líquido ruminal, indicando que monensina e óleo de soja, pelo seu efeito defaunatório, podem reduzir a perda de metano no rúmen.Palavras-chave: bovinos, Ciliophora, lipídios, ionóforo, metano Effect of monensin and soybean oil on rumen ciliate protozoa and correlation between protozoa with ruminal fermentation and digestive parametersABSTRACT -Four lactating dairy cows with ruminal cannula and 155 DIM were allotted to a 4 × 4 Latin square and fed twice daily corn silage and concentrate (55:45, %DM) to evaluate the effect of monensin and soybean oil in the diet of lactating cows on the counting of ciliate protozoa beyond establishing correlations between number of protozoa with some parameters of digestion and ruminal fermentation. The treatments consisted of the inclusion of 33 ppm of sodium monensin or soybean oil at 4% DM, as following: control diet, without oil or monensin -CT; diet with monensin -MN; diet with soybean oil -OL; diet with the combination of 33 ppm of monensin and 4% of soybean oil -OM. Occurrence of 11 ciliate genera was observed, being Entodinium the predominant in all treatments. No significant soybean oil × monensin interaction was observed on protozoa number and genera. The genera Entodinium, Dasytricha, Eremoplastron and Isotricha reduced in the diets with oil, while monensin reduced the counting of Dasytricha, Eremoplastron and Epidinium. The total number of ciliate protozoa and cellulolytics protozoa was reduced by soybean oil and monensin effec...

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.

The 18S rDNA was used to infer oral ciliature patterns of evolution within the family Ophryoscolecidae, with the addition of five new sequences of ciliates from the genus Ostracodinium. Our data confirmed the monophyly of the subfamilies Entodiniinae and Ophryoscolecinae, but more analysis would be required for the definition of the status of the subfamily Diplodiniinae. The oral infraciliature patterns reflect evolutionary divergence in the family Ophryscolecidae, observing monophyly on Entodinium-type, Diplodinium-type, Ostracodinium-type, Epidinium-type, and Ophryoscolex-type. The ancestral infraciliature of Entodinium-type cannot be proven, however, the position of Entodinium-type showed closer of Diplodinium-type than Ophryoscolex-type, corroborating previous studies using morphological characters. The observed inconsistencies reflect the need to increase the number of 18S rDNA sequences to family Ophryoscolecidae and investigate the evolution of this group using other molecular markers.

The species composition, prevalence, and average relative abundance of rumen ciliates were analyzed in 16 Brazilian sheep. 28 species of ciliates were identified belonging to 3 families: Isotrichidae, Ophryoscolecidae, and Parentodiniidae. Among these ciliates, Entodinium alces, Metadinium esalqum, and M. rotundatum were found for the first time in sheep, and other 12 species for the first time in Brazilian sheep. Different morphotypes of parentodiniid ciliates were identified in 7 of the 16 sheep analyzed and this is the second report of this family in ruminants. The species Entodinium contractum was redescribed based on the new data on the general morphological features; for the first time, we described the oral infraciliature, which in this species is of the Entodinium-type. In this species, it is noteworthy that the prominent vestibular polybrachykinety can be used as an important identifying characteristic.

O objetivo deste trabalho foi registrar ocorrências de predação e canibalismo em protozoários ciliados no rúmen de ovinos. Foram analisadas amostras de conteúdo ruminal de cinco ovinos mestiços Santa Inês, fistulados no rúmen, mantidos em pastagem natural de caatinga, no município de Sertânia, Pernambuco. Foram obtidas seis amostras de conteúdo ruminal de cada ovino, totalizando 30 amostras, as quais foram fixadas em formalina 18,5% (v/v). De cada amostra foi retirada uma alíquota de 1 ml de conteúdo ruminal ao qual se adicionaram três gotas de solução de lugol para a coloração e identificação dos protozoários ciliados. Estas alíquotas foram analisadas utilizando-se lâminas e lamínulas, em campos determinados randomicamente. Constatou-se a ocorrência de interações do tipo predador-presa entre ciliados de Ophryoscolecidae Stein, 1859, onde Elytroplastron bubali (Dogiel, 1928) apresentou comportamento predatório sobre Enoploplastron triloricatum (Dogiel, 1925) e sobre outras espécies de Epidinium Crawley, 1923 e de Entodinium Stein, 1859. Foram ainda observados casos de canibalismo entre espécimes de E. bubali, o que consiste no primeiro registro deste tipo de interação nesta espécie. Registra-se, ainda, pela primeira vez a ocorrência de E. bubali no rúmen de ovinos no Brasil.

To date the genus Diploplastron comprised only one species of ophryoscolecid ciliate, Diploplastron affine, which is characterized by having two retractable ciliary zones in the anterior end of the body, two slender and juxtaposed skeletal plates on the right side, a rod shape macronucleus, and two contractile vacuoles. During study on the characterization of rumen ciliate community composition in Brazilian domestic sheep, we observed ciliates with atypical morphology but with diagnostic features of genus Diploplastron. This study describes Diploplastron dehorityi, a new species of ophryoscolecid ciliate, that differs from D. affine, primarily, in the morphology of skeletal plates, morphology of nuclear apparatus and body shape. In addition to the similarities between the new species and congener species, D. dehorityi has some morphological similarities to species of genus Eremoplastron.

The genus Metadinium includes ophryoscolecid ciliates, with two retractile ciliary zones in the anterior body portion, two broad skeletal plates, a lobed macronucleus and two contractile vacuoles. Species belonging to this genus were recorded in several geographical locations and in different host species. However, they were mostly described based on a single ciliatological technique, and until now, there is only one description of the infraciliary pattern in Metadinium ciliates (Metadinium medium). The present study performs the morphological and infraciliature characterization of four species belonging to Metadinium: M. esalqum, M. minorum, M. rotundatum and M. ypsilon; and presents taxonomic notes on the genus. The oral infraciliature in these four Metadinium species corresponds to the Diplodinium-type, pattern shared with genera Diplodinium, Diploplastron, Eudiplodinium, Eremoplastron and Polyplastron. A brief review conducted highlights the difficulty of delimiting Metadinium species due to the morphological similarity among them.