Endohelminths in Cichla piquiti (Perciformes, Cichlidae) from the Paraná river, São Paulo state, Brazil / Endohelmintos de Cichla piquiti (Perciformes, Cichlidae) procedentes do rio Paraná, estado de São Paulo, Brasil

Fifty specimens of Cichla piquiti were collected from the Paraná River downstream of the Ilha Solteira Hydroelectric Power Station in Brazil and surveyed for endohelminth parasites. All fish were parasitised by at least one helminth species (overall prevalence [P] = 100%). Eight parasite taxa were present: the nematode Procamallanus (Procamallanus) peraccuratus in the intestines; third-stage larvae of the anisakids Contracaecum sp. and Hysterothylacium sp. in the visceral cavity, mesentery and serosa of the stomach and intestines and on the liver and spleen; the trematodes Austrodiplostomum compactum in the eye (metacercariae) and Genarchella genarchella in the stomach; and the cestodes Proteocephalus macrophallus, Proteocephalus microscopicus, and Sciadocephalus megalodiscus in the intestines. Hysterothylacium sp. larvae (P = 86%) and P. microscopicus (P = 74%) were the most prevalent parasites. Anisakids were more prevalent and abundant in the dry season. A negative correlation between the abundances of Hysterothylacium sp. and P. microscopicus was observed, suggesting a competitive/antagonistic relationship between these parasites. Cichla piquiti represents a new host for four parasite species. These new records significantly increase the list of parasites of C. piquiti, contributing to the knowledge of the host-parasite relationship and the geographical distribution of these helminths.

Cinquenta espécimes de Cichla piquiti foram colhidos do Rio Paraná, a jusante da Usina Hidrelétrica de Ilha Solteira, Brasil, na pesquisa de endohelmintos. Todos os peixes estavam parasitados por, pelo menos, uma espécie de helminto (prevalência total [P] = 100%). Foram encontrados oito taxa de parasitas: os nematóides Procamallanus (Procamallanus) peraccuratus no intestino; larvas de terceiro estádio dos anisaquídeos Contracaecum sp. e Hysterothylacium sp. na cavidade abdominal, mesentério e serosa do estômago e do intestino, e sobre o fígado e baço; metacercárias do trematódeo Austrodiplostomum compactum no olho e um indivíduo adulto de Genarchella genarchella no estômago; os cestóides Proteocephalus macrophallus, Proteocephalus microscopicus e Sciadocephalus megalodiscus no intestino. Larvas de Hysterothylacium sp. (P = 86%) e P. microscopicus (P = 74%) foram os parasitas mais prevalentes. Anisaquídeos apresentaram maior prevalência e abundância no período seco. Foi observada uma correlação negativa entre as abundâncias de Hysterothylacium sp. e P. microscopicus, sugerindo uma relação de antagonismo/competição entre esses parasitas. Cichla piquiti é descrito como novo hospedeiro para quatro espécies de parasitas. Estes novos registros aumentam significativamente a lista de parasitas de C. piquiti, contribuindo para o conhecimento da relação parasito-hospedeiro e distribuição geográfica desses helmintos.

Morphological study of the small intestine of moura pigs (Sus scrofa - Lineaus, 1758) during fetal development

The morphology of the small intestine of 39 fetuses and 13 neonates of Brazilian Moura pigs (Sus scrofa) was studied. Fetuses were collected on the 30th, 58th and 86th day of fetal life. The entire small intestine was removed and divided into proximal and distal regions (30th day), and into duodenum, proximal jejunum, distal jejunum and ileum on the 58th and 86th days and in neonates. On the 30th day, the small intestine was small and fragile and there was no visible delimitation among the three segments. The length and diameter of the intestine increased significantly (p<0.001) from 58 days of gestation to parturition. The length of the small intestine, duodenum, jejunum and ileum increased 2.5, 1.2, 2.6 and 3.0 fold, respectively, whereas the diameter increased 2.7, 2.4, 2.7 and 3.0 fold from 58 days of gestation to parturition. On the 30th day, the immature small intestine consisted of mesenchyme and stratified columnar epithelium. On the 58th day, the mucosa, muscularis circular, muscularis longitudinal and serosa were observed in the three segments of small intestine and there were no crypts in the distal jejunum and ileum. Goblet cells were common in the duodenum and rare in the jejunum and ileum. Brünner`s glands were observed in the submucosa. In 86-day fetuses, the presence of incipient myoblasts indicated that the muscularis mucosae was in formation. Crypts were observed in the three segments of the small intestine. In neonates, the muscularis mucosae was present and Brünner`s gland were more frequent. Peyer`s patches were observed in the ileum. These results show that the temporal development of the small intestine of Moura pigs is similar to that of modern breeds. However, macroscopic findings indicate that Moura fetuses have a longer small intestine and heavier body weight at birth than modern breeds.