A Phylogeny of Life-cycle Patterns of the Digenea

Jc, Pearson

doi:10.1016/s0065-308x(08)60174-8

Cited by 70 publications

(46 citation statements)

References 111 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…According to Brooks et al (1989), Pearson (1972) "... stressed the importance of the mutual exclusion of rediae and daughter sporocysts to understanding the evolution of diverse digenean developmental programs". What Pearson in fact said was that "Redia and daughter sporocyst appear to be mutually exclusive...", which is scarcely a statement on their evolution.…”

Section: Sporocystmentioning

confidence: 99%

“…Given the trend toward smaller and more numerous cercariae in three-host life-cycles (Pearson, 1972;fig. 5, p. 167), a trend that combines foetalization (smaller body, less well-developed excretory system) and specialisation (penetration glands, oral sucker temporarily modified into a boring organ), then the cercarial excretory system may be arrested at an early stage that does not indicate the future adult condition.…”

Section: Cercarialmentioning

confidence: 99%

“…3 here). Given the clearly multiple origin of second intermediate hosts and hence of the metacercaria [three times in Brooks' cladogram; below 81 in echinostomes and psilostomes (Pearson, 1972;Ginetsinskaya, 1988), above 82 in hemiurids, accacoeliids (Bray & Gibson, 1977, p. 55) and syncoeliids (Gibson & Bray, 1977, p. 230), and above 106 in gymnophallids (cf. Burnellus with feUodistomes and with the closely related gymnophallids) and brachylaimids (cf.…”

Section: In Brooksmentioning

confidence: 99%

See 2 more Smart Citations

On the position of the digenean family Heronimidae: an inquiry into a cladistic classification of the Digenea

Pearson

1992

Syst Parasitol

View full text Add to dashboard Cite

Brooks, O'Grady & Glen (1985b) placed the seemingly aberrant and highly derived family Heronimidae at the base of their cladogram of the Digenea. In the absence of arguments for the composition and polarity of the putative homologous series on which their cladogram is based, it was found necessary to consider in detail almost all of their character series. In the course of my analysis I (1) argue that the oral sucker is singular to the Digenea, and that the oral sucker is not synapomorphic nor the ventral sucker symplesiomorphic for the Digenea, but that early digeneans lacked both suckers, (2) reiterate that the amphistomate condition is secondary and has arisen more than once, and that the embryology of the excretory system proves it to be secondary in all cases, (3) offer support for Cable's view that the cercarial stylet is not of single origin, and (4) restate the argument that paramphistomes, microscaphidiids, and gyliauchenids have not an oral sucker but a pharynx. Brooks, Bandoni, Macdonald & O'Grady (1989) stated that the bifurcate gut is unambiguously a synapomorph of the Digenea, on the basis of their cladistic demonstration that Rugogaster with a bifurcate gut is a sister group to the rest of the Aspidobothria, which in turn is a sister group to the Digenea. Testing this in a new cladogram of the Aspidobothria constructed from Brooks et al. 's (1989) 15 characters (corrected, especially those of the ventral sucker, for which a new phylogeny is advanced), supplemented by an additional 23 characters, reveals Rugogaster as the derived form it appeared to be and aspidogastrids, with a single caecum, as sister group to the rest of the Aspidobothria.A new analysis of the characters produced an increase in homoplasy from 18% to 37%, showed 97 out of 212 characters invalid as used, these two resulting in a decrease in resolution from 82% to 32%, and resulted in changes in polarity in 20 of the 65 putative homologous series listed by Brooks et al. (1985b).The Heronimidae cannot be at the base of their cladogram as it has not three but 13 apomorphs, which is more than have the next three groups, the paramphistomiforms, echinostomatiforms and haploporiforms.Comparison of the Heronimidae with the Bivesiculidae in the light of 48 defensible plesiomorphs shows that the Bivesiculidae, which have 39 of the 48 characters, are more plesiomorphic than the Heronimidae, which have only 23.In conclusion, what remains of the data-base is insufficient to support their cladogram and classification. Better data from the flukes themselves are necessary for a sound cladistic analysis. 82 J.C. Pearson

show abstract

Section: Sporocystmentioning

confidence: 99%

Section: Cercarialmentioning

confidence: 99%

Section: In Brooksmentioning

confidence: 99%

See 1 more Smart Citation

On the position of the digenean family Heronimidae: an inquiry into a cladistic classification of the Digenea

Pearson

1992

Syst Parasitol

View full text Add to dashboard Cite

show abstract

“…Phylogeny above the family level in the Digenea, however, is arguably the most controversial area in helminth systematics (Pearson, 1972(Pearson, , 1992Clark, 1974;Cable, 1974;Brooks et al, 1985, Brooks, 1989Gibson, 1987). A key problem is the paucity and widespread evolutionary convergence of characters from morphology and life-cycles.…”

Section: Introductionmentioning

confidence: 99%

Utility of the D1 domain of nuclear 28S rRNA for phylogenetic inference in the Digenea

et al. 1993

View full text Add to dashboard Cite

The relatively variable D1 domain near the 5' end of the 28S ribosomal RNA gene (large subunit rRNA) has been sequenced for 12 species of digenean trematodes. Phylogenetic relationships among these species and Schistosoma mansoni (previously published sequence) were investigated with maximum parsimony and distance methods. A DNA sequence from the tapeworm (Cestoda) Hymenolepis diminuta was used for outgroup comparison. In all analyses, several clusters of taxa appeared repeatedly: (1) four fasciolids;(2) three didymozoids with a hemiurid; and (3) two lepocreadiids with a gyliauchenid. Bootstrap resampiing of the data revealed that the first two clusters were well supported. In contrast there was less support for the cluster containing the lepocreadiids and gyliauchenid. We conclude that the D1 domain is too variable for phylogenetic inference among distantly related families, but it is well suited to phylogenetic inference within and among closely related families in the Digenea.

show abstract

“…He thus interpreted these con cretions to be a carbonate. Concretions (corpuscles) have been reported as occurring in the osmoregulatory system of many adult aspidobothrians, and Pearson (1972) has observed that the presence of excretory corpuscles in the osmoregula tory bladders of digenean cercariae tends to accompany primitive two-host life cycles. The significance of Pearson's 19 72 observation when applied to aspidobothrians cannot be assessed at this time.…”

Section: Cotylocidium Of Cotylaspis Insignis (Figures 25 26)mentioning

confidence: 99%

Biology of aspidobothrian trematodes

Fredericksen

View full text Add to dashboard Cite

A Phylogeny of Life-cycle Patterns of the Digenea

Cited by 70 publications

References 111 publications

On the position of the digenean family Heronimidae: an inquiry into a cladistic classification of the Digenea

On the position of the digenean family Heronimidae: an inquiry into a cladistic classification of the Digenea

Utility of the D1 domain of nuclear 28S rRNA for phylogenetic inference in the Digenea

Biology of aspidobothrian trematodes

Contact Info

Product

Resources

About