Ceratomyxa gracillima n. sp (Cnidaria: Myxosporea) provides evidence of panmixia and ceratomyxid radiation in the Amazon basin

Author(s)

Zatti, Suellen A. ^[1] ; Atkinson, Stephen D. ^[2] ; Maia, Antonio A. M. ^[3] ; Bartholomew, Jerri L. ^[2] ; Adriano, Edson A. ^{[1, 4]}

Affiliation

^[1] Univ Estadual Campinas, Inst Biol, Dept Anim Biol, BR-13083970 Campinas, SP - Brazil

^[2] Oregon State Univ, Dept Microbiol, Corvallis, OR 97331 - USA

^[3] Univ Sao Paulo, Fac Anim Sci & Food Engn, Dept Vet Med, Ave Duque de Caxias Norte 225, BR-13635900 Pirassununga, SP - Brazil

^[4] Univ Fed Sao Paulo, Dept Ecol & Evolutionary Biol, Rua Prof Arthur Riedel 275, BR-09972270 Diadema, SP - Brazil

• Document type: Journal article
• Source: Parasitology; v. 145, n. 9, p. 1137-1146, AUG 2018.
• Web of Science Citations: 4

Abstract

We describe a new freshwater myxosporean species Ceratomyxa gracillima n. sp. from the gall bladder of the Amazonian catfish Brachyplatystoma rousseauxii; the first myxozoan recorded in this host. The new Ceratomyxa was described on the basis of its host, myxospore morphometry, ssrDNA and internal transcribed spacer region (ITS-1) sequences. Infected fish were sampled from geographically distant localities: the Tapajos River, Para State, the Amazon River, Amapa State and the Solimoes River, Amazonas State. Immature and mature plasmodia were slender, tapered at both ends, and exhibited vermiform motility. The ribosomal sequences from parasite isolates from the three localities were identical, and distinct from all other Ceratomyxa sequences. No population-level genetic variation was observed, even in the typically more variable ITS-1 region. This absence of genetic variation in widely separated parasite samples suggests high gene flow as a result of panmixia in the parasite populations. Maximum likelihood and maximum parsimony analyses placed C. gracillima n. sp. sister to Ceratomyxa vermiformis in a subclade together with Ceratomyxa brasiliensis and Ceratomyxa amazonensis, all of which have Amazonian hosts. This subclade, together with other Ceratomyxa from freshwater hosts, formed an apparently early diverging lineage. The Amazonian freshwater Ceratomyxa species may represent a radiation that originated during marine incursions into the Amazon basin that introduced an ancestral lineage in the late Oligocene or early Miocene. (AU)

• FAPESP's process: 16/22047-7 - Myxosporean parasites of commercially important Perciformes fish (Cichlaspp. and Plagioscion spp.) in the Amazon Basin
• Grantee: Edson Aparecido Adriano
• Support Opportunities: Regular Research Grants
• 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