Biodiversity in helminths and nematodes as a field of study: an overview

Abstract

Despite their potential negative effects, parasites may be used as targets for biological conservation and studies on the evolutionary and ecological impact of parasitism. These purposes serve to increase our knowledge on the species diversity of parasites. In the present paper we try to precisely define the composite zoological group currently designated as 'helminths' and to address the question of how many known species there are in the different clades of parasitic worms, as compared with the other major groups described in the Animalia. The relationships between helminthology and nematology are discussed. Finally, the question of how to improve the organisation of research in these different fields of study is briefly considered. The Nematoda seems to be the group which needs the greatest effort in the future. This supposes that specialists in nematode taxonomy are numerous enough to maintain a substantial effort. The necessary taxonomical effort is weakened by the distribution of the fields of study between helminthology and nematology, something which is inadequate from a zoological, as well as from a logical, point of view. The study of nematode zoology would certainly improve if nematology could emerge as an undivided speciality. One of the prior goals in such a unified field of study would be an exhaustive inventory of the nominal living species. A cooperative effort will also be needed to found the basis of a general classification of the phylum Nematoda. Finally, a clarification and a standardisation of the terminology is also needed.

Checklist of helminths from lizards and amphisbaenians (Reptilia, Squamata) of South America

“…Helminths are high diverse in vertebrates, but the species richness are poorly known (182,183). For example, less than a half of nematode species are believed to be currently described (148).…”

Diversidade de helmintos intestinais em mamíferos silvestres e domésticos na Caatinga do Parque Nacional Serra da Capivara, Sudeste do Piauí, Brasil

“…O agrupamento de C. thous e grandes felinos, com base na composição das suas faunas helmintológicas, em apenas um único grupo isolado entre as nove espécies de hospedeiros analisados, reforça a hipótese de que a composição de parasitos está fortemente ligada à especificidade dos helmintos com seus hospedeiros (HUGOT et al, 2001;BROOKS;MCLENAN, 1993) e também relacionada à dieta dos hospedeiros (WOOD, 2006). Reflete, portanto, os processos coevolutivos encontrados entre as ordens e famílias de hospedeiros e parasitos (BROOKS; GLEN, 1982).…”

The complete mitochondrial genome of Toxascaris leonina: Comparison with other closely related species and phylogenetic implications

“…Many nematodes are parasites of humans, animals and plants (Anderson, 2000), and cause significant diseases (Albonico et al, 1999;Hugot et al, 2001) and major socio-economic impact on a global scale (Cantacessi et al, 2012;McCarthy and Moore, 2000). Toxascaris leonina (Family Ascarididae) is a common parasitic nematode of dogs and cats, the adults of which live in their gastrointestinal tract (Okulewicz et al, 2002).…”