Ecological versus phylogenetic determinants of helminth parasite community richness

Abstract

SummaryWe examine patterns of community richness among intestinal parasitic helminth communities in fishes, herptiles, birds and mammals with respect to the comparative number of component species in a host population. We show that terrestrial hosts have, on average, fewer component species than aquatic hosts. We also show that the mean number of component species in aquatic hosts increases from fishes through herptiles to birds before declining slightly in mammals. For terrestrial hosts, the mean number of component species increases from herptiles, through birds, reaching a maximum in mammals. We conclude that: (i) habitat of the host is more important in determining community richness than is host phylogeny; (ii) the phenomenon of 'host capture' may be largely responsible for increased species richness in some host groups; (iii) aquatic birds harbour the richest intestinal helminth communities; and (iv) as we interpret them, our data refute the time hypothesis, which would predict that fishes as the oldest lifestyle should have the richest helminth communities.

Higher gregarine parasitism often in sibling species of host damselflies with smaller geographical distributions

“…This could lead to observations where the more widespread and locally abundant host species are less parasitized. Gregarine parasites are passively-transmitted, protozoan gut parasites of most invertebrates (Bush et al, 2001). For odonate hosts, gregarines are ingested as oocysts by the host and then migrate to the mid-gut where they develop (Åbro, 1974).…”

“…For odonate hosts, gregarines are ingested as oocysts by the host and then migrate to the mid-gut where they develop (Åbro, 1974). Once they reach sexual maturity, gregarines in the insect gut form gametocysts and are excreted by the host as oocysts (Bush et al, 2001). The prevalence of gregarines in odonates is on average 20%, although there is considerable variation (Corbet, 1999).…”

Metazoários parasitos de seis espécies de peixes do Reservatório de Lajes, Estado do Rio de Janeiro, Brasil

“…Os espécimes estudados mediram: A. bimaculatus 11,9 ± 1,8 (8,0 -16,0); A. fasciatus 13,8 ± 1,2 (11,0 -17,7); H. affinis 26,8 ± 3,0 (21,5 -34,5); H. malabaricus 43,2± 7,6 (16,0 -58,7); L. castaneus 33,2 ± 3,2 (28,0 -42,0) e T. striatulus 14,3 ± 1,1 (12,5 -17,0) A análise incluiu somente as espécies com prevalência maior que 10% (BUSH et al, 1990). O cálculo da freqüência de dominância e da dominância relativa (número de espécimes de uma espécie/número total de espécimes de todas as espécies de cada infracomunidade) foi feito seguindo a metodologia de Rohde et al (1995).…”

Seasonal variability of the composition and structure of parasite communities of red porgy, Pagrus pagrus (Perciformes: Sparidae) off Brazil

“…The identifi cation of the parasites follows Tavares and Luque (2006) for anisakid larvae, Cohen et al (2013) for Monogenea, Kohn et al (2007) for Digenea, and Santos et al (2008) for Acanthocephala and Luque et al (2013). The statistics analysis included only parasite species with prevalence higher than 10 % (Bush et al, 1990). In all comparisons, data were considered signifi cantly different when a bilateral obtained probability p < 0.05.…”