Renicolidae infection in Manx shearwater (Puffinus puffinus): is parasitism implicated on renal lesions?

Renicolid digeneans are frequently observed in the renal tubules and ureters of seabirds, such Puffinus puffinus, a migratory species distributed along the Brazilian coast. However, few studies have focused on the relationship between renicolid infection and health status in P. puffinus. Thus, the aim of this study was to describe (i) renal and systemic alterations, (ii) the renicolids and (iii) the biological aspects associated with the presence of renicolids in P. puffinus. Gross and histological assays were performed in 93 P. puffinus stranded on the Paraná coast, southern Brazil, and renicolids were submitted to morphological and molecular assays. A high prevalence of renicolids in P. puffinus (71/93) was observed. In the kidney, the main microscopic findings were lymphocytic interstitial infiltrate, ductal ectasia and tubular necrosis. The renal lesions were significantly associated with the parasite infection. The morphological (n = 84) and molecular analyses (n = 2) confirmed the species as Renicola sloanei (100% and 95.9% of nucleotide identity with R. sloanei strains from P. puffinus and from Spheniscus demersus, respectively). In both parasitized and non-parasitized animals, cardiac and skeletal muscle degeneration and necrosis were the most frequent systemic changes. Therefore, the results suggest renicolids being a possible cause for the demonstrated renal alterations. A contribution of this parasite to a decreased health status of Puffinus puffinus along their migratory route is possible.

Molecular identification and histological aspects of Renicola sloanei (Digenea: Renicolidae) in Puffinus puffinus (Procellariiformes): a first record.

Renicolids are parasites that inhabit the renal tubules and ureters of molluscivorous and piscivorous birds. Puffinus puffinus is a migratory seabird that was identified as the definitive host of Renicola spp. Studies focusing on the renicolid species and the resulting renal lesions are valuable for their association with causes of stranding in seabirds. The aim of this study was to identify the renicolid trematodes and evaluate the histological findings in two P. puffinus stranded on the coast of Paraná state, Brazil. The parasites were evaluated by histologic, ultrastructural and molecular assays, while tissue changes were analyzed by histologic methods. The morphological and morphometrical characteristics of the parasites, along with polymerase chain reaction and sequencing assays (ribosomal and mitochondrial regions), identified the species as Renicola sloanei. The results also suggest that this helminth can be the adult form of Cercaria pythionike. The dilation of collecting ducts was the main histological finding in the kidneys. In conclusion, R. sloanei was identified, and for the first time, P. puffinus was described as a host of this digenean inducing mild renal changes.

Molecular identification and histological aspects of Renicola sloanei (Digenea: Renicolidae) in Puffinus puffinus (Procellariiformes): a first record / Identificação molecular e aspectos histológicos de Renicola sloanei (Digenea: Renicolidae) em Puffinus puffinus (Procellariiformes): primeiros registros

Abstract Renicolids are parasites that inhabit the renal tubules and ureters of molluscivorous and piscivorous birds. Puffinus puffinus is a migratory seabird that was identified as the definitive host of Renicola spp. Studies focusing on the renicolid species and the resulting renal lesions are valuable for their association with causes of stranding in seabirds. The aim of this study was to identify the renicolid trematodes and evaluate the histological findings in two P. puffinus stranded on the coast of Paraná state, Brazil. The parasites were evaluated by histologic, ultrastructural and molecular assays, while tissue changes were analyzed by histologic methods. The morphological and morphometrical characteristics of the parasites, along with polymerase chain reaction and sequencing assays (ribosomal and mitochondrial regions), identified the species as Renicola sloanei. The results also suggest that this helminth can be the adult form of Cercaria pythionike. The dilation of collecting ducts was the main histological finding in the kidneys. In conclusion, R. sloanei was identified, and for the first time, P. puffinus was described as a host of this digenean inducing mild renal changes.

Resumo Renicolídeos são parasitos que habitam túbulos renais e ureteres de aves que se alimentam de moluscos e peixes. Puffinus puffinus, ave marinha migratória, foi registrada como hospedeiro definitivo de Renicola spp. Estudos relacionados com as espécies de renicolídeos e as lesões renais resultantes são importantes para o entendimento das causas de óbito de aves marinhas. O objetivo deste estudo foi identificar os trematódeos renicolídeos e avaliar os achados histológicos em dois P. puffinus encalhados no litoral do Estado do Paraná, Brasil. Os parasitos foram avaliados por ensaios histológicos, ultraestruturais e moleculares, enquanto as alterações teciduais foram analisadas por métodos histológicos. As características morfológicas e morfométricas dos parasitos, juntamente com a reação em cadeia da polimerase e sequenciamento (regiões ribossomal e mitocondrial), identificaram a espécie como Renicola sloanei. Os resultados também sugerem que este helminto pode ser a forma adulta de Cercaria pythionike. A dilatação dos ductos coletores foi o principal achado histológico renal. Em conclusão, R. sloanei foi identificado, e pela primeira vez P. puffinus foi descrito como hospedeiro deste digenético induzindo alterações renais discretas.

Análise comparativa de duas formações vegetacionais e de seu ecótono, Miranda - MS / Comparative analysis of two vegetation types and its ecotone, Miranda - MS

O Pantanal é constituído por diferentes formações vegetacionais, entre elas o Paratudal e a Mata Ciliar. Este trabalho objetivou analisar comparativamente essas duas formações, e o ecótono entre elas, quanto à diversidade e similaridade. O estudo foi desenvolvido na região do Passo do Lontra, às margens do rio Miranda, MS. Foram estabelecidas cinco parcelas de 10 x 10m em cada área e nelas todos osindivíduos acima de 1m de altura foram contados e identificados. Foram registrados 913 indivíduos, distribuídos em 70 taxa, dos quais 60 foram identificados em nível de espécie. O índice de diversidade de Shannon (H’) foi 2,715 com equidade de Pielou (J’) de 0,806 no Paratudal; 3,010 e 0,835 na Mata Ciliar; e 2,739 e 0,797 no ecótono, respectivamente. Esses resultados demonstram maior diversidade na Mata Ciliar, como esperado, já que as condições do ambiente do Paratudal são mais seletivas. A similaridade florística entre o Paratudal e a Mata Ciliar, de acordo com o índice de Sorensen, foi de 0,2o que distingue ambos os ambientes. Portanto, este trabalho evidencia a distinção entre Mata Ciliar e Paratudal, bem como os valores intermediários do ecótono.

The Pantanal consists of different vegetation types, including the Paratudal, a monodominat floodablesavanna, and Riparian vegetation. This study aimed to analyze diversity and similarity in samples of these two vegetations, and its ecotone. The study was developed in the region of Passo do Lontra, at the Miranda river margins. Five plots 10 x 10m, were allocated in each area, where all individuals above 1m height were counted and identified. Nine hundred and thirteen individuals were registered, distributed in 70 taxa, of which 60 were identified in species level. The Shannon diversity index (H’) was 2.715 with Pielou Eveness (J’) of 0.806 in Paratudal, 3.010 and 0.835 in Riparian vegetation, and 2.739 and 0.797 in ecotone, respectively. These results show highest diversity in the Riparian vegetation, as expected, since the Paratudal’s ambient conditions are more restrictive. The floristic similarity between the Paratudal and the Riparian vegetation, according to the Sorensen index, was of 0.2, what distinguishboth environments. Therefore, this study evidences the distinction among Riparian vegetation and Paratudal, as well the existence of an intermediary values with ecotone.