New myxosporeans parasitizing Phractocephalus hemioliopterus from Brazil: morphology, ultrastructure and SSU-rDNA sequencing

Author(s)

Naldoni, Juliana ^[1] ; Maia, Antonio A. M. ^[2] ; Correa, Lincoln L. ^[3] ; da Silva, Marcia R. M. ^[2] ; Adriano, Edson A. ^{[1, 4]}

Affiliation

^[1] Univ Fed Sao Paulo UNIFESP, Dept Ecol & Biol Evolut, Rua Prof Artur Riedel, 275, Jardim Eldorado, BR-09972270 Diadema, SP - Brazil

^[2] Univ Sao Paulo, Fac Zootecnia & Engn Alimentos, Dept Med Vet, Rua Duque Caxias Norte 225, BR-13635900 Pirassununga, SP - Brazil

^[3] Univ Fed Oeste UFOPA, Inst Ciencias & Tecnol Aguas, Travessa Prof Antonio Carvalho Fatima, BR-68040470 Santarem, PA - Brazil

^[4] Univ Estadual Campinas UNICAMP, Dept Biol Anim, Rua Monteiro Lobato 255, BR-13083970 Campinas, SP - Brazil

• Document type: Journal article
• Source: DISEASES OF AQUATIC ORGANISMS; v. 128, n. 1, p. 37-49, MAR 22 2018.
• Web of Science Citations: 5

Abstract

Myxozoans are a diverse group of parasitic cnidarians, with some species recognized as serious pathogens to their hosts. The present study describes 2 new myxobolid species (Myxobolus figueirae sp. nov. and Henneguya santarenensis sp. nov.) infecting skin and gill filaments of the Amazonian pimelodid fish Phractocephalus hemioliopterus, based on ultrastructural, histology and phylogenetic analysis. The fish were caught in the Amazon River, Para, Brazil. The plasmodial development of M. figueirae sp. nov. was in the dermis and those of H. santarenensis sp. nov. were of the intralamellar type. For both species, the plasmodia were surrounded by a connective tissue layer, but there was no inflammatory infiltrate. For M. figueirae sp. nov., mature spores were ovoid measuring 9.1 to 10 (9.5 +/- 0.3) mu m in length, 5.8 to 6.9 (6.4 +/- 0.3) mu m in width and 4.4 to 4.5 (4.5 +/- 0.1) mu m in thickness. Two polar capsules were elongated and of unequal size. For H. santarenensis sp. nov., mature spores were ellipsoidal in the frontal view, measuring 26.3 to 36.1 (31.9 +/- 3) mu m in total length, 9.6 to 11.9 (10.8 +/- 0.5) mu m in body length, 3.7 to 4.9 (4.3 +/- 0.3) mu m in width and 16.6 to 25.6 (21 +/- 3.1) mu m in caudal process. The polar capsules were elongated and of equal size. Phylogenetic analysis, based on partial small subunit ribosomal DNA (SSU rDNA) sequences and using the closest myxozoan sequences to each one of the species studied here based on previous GenBank data, showed M. figueirae sp. nov. and H. santarenensis sp. nov. clustering in distinct lineages. While H. santarenensis sp. nov. clustered in a well-supported subclade composed of Henneguya species that infect gills of South American pimelodid hosts, M. figueirae sp. nov. clustered in a weakly supported subclade containing parasite species of bryconid hosts. (AU)

• FAPESP's process: 14/22700-7 - Systematic and host-parasite relationship of myxosporean parasites of Pimelodidae family fish in the Amazon Basin
• Grantee: Juliana Naldoni
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/21374-6 - Systematics and host-parasite interaction of parasites of the phylum Myxozoa in fishes economically important in Amazon Basin
• Grantee: Edson Aparecido Adriano
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants