New host and geographical records for Parafilaroides normani (Nematoda: Filaroididae) Dailey, 2009 in South American fur seal, Arctocephalus australis, from southern Brazil

Abstract

Lungworms are a common finding in seals and fur seals around the world. However, from existing records, the biogeographical distribution of filaroid helminths appears to be restricted, and these parasites are endemic in only certain areas and species, mainly in the Northern Hemisphere. The occurrence of infection in pinniped species in the Southern Hemisphere is scarce. The objective of this work is to verify the prevalence of lungworms in Arctocephalus australis in waters off the southern coast of Brazil. Twenty subadult specimens of A. australis found recently dead on the southern coast of Brazil were necropsied and their lungs were examined. Parasitic cysts were found in only one specimen (prevalence of 5%). The helminths were morphologically identified as Parafilaroides normani (Metastrongyloidea: Filaroididae). This helminth species has been reported in pinnipeds from Australia, New Zealand and South Africa. This is the first record of P. normani in A. australis and for the western South Atlantic, providing additional data regarding the biogeographic distribution of the parasite.

Molecular phylogeny of the Pseudaliidae (Nematoda) and the origin of associations between lungworms and marine mammals

“…is related to forms infecting carnivorans, most likely those from the sister group of pinnipeds, the Musteloidea (see Burgin et al, 2018 ; Hassanin et al, 2021 ). Furthermore, species of Parafilaroides seem to exhibit a protracted, likely basal association with their pinniped hosts; although they are apparently absent from walruses (Odobenidae), the 7 species described so far occur in a number of phocids and otariids from both Hemispheres ( Dailey, 2006 , 2009 ; Echenique et al, 2020 , and references therein). Anderson (1982 , 1988) postulated that the ancestral life-cycle in metastrongyloid nematodes was heteroxenous, with terrestrial invertebrates acting as intermediate hosts.…”

Helminths of South American fur seals (Arctocephalus australis) from the Subtropical Convergence Zone of the Southwestern Atlantic

“…All measurements were expressed in mean (µm) and were based on mature males and females for monoecious species and mature individuals for dioecious species. For morphological identification the keys of Delyamure (1969), Travassos et al (1969), Khalil et al (1994) and Anderson et al (2009), and the papers of Sardella et al (2005), and Fonseca et al (2019), were used.…”

First Report of Uncinaria hamiltoni in Orphan Eastern Mediterranean Monk Seal Pups in Greece and Its Clinical Significance

“…However, other nematodes within the same genus (Parafilaroides spp.) have been described within pinnipeds [47] indicating an extended geographical distribution of helminths. The evolutionary outcome of dispersal is that parasite distribution may depend on the host's dispersal dynamics [48] when dispersal is local (e.g., in large colonies as seen in pinnipeds).…”