Evolution of parasitism in candirus

[Silurus]

Fernández, L & SA Schaefer, in press. Relationships among the Neotropical Candirus (Trichomycteridae, Siluriformes) and the evolution of parasitism based on analysis of mitochondrial and nuclear gene sequences. Molecular Phylogenetics and Evolution DOI:10.1016/j.ympev.2009.02.016.

Abstract

Phylogenetic relationships among the trichomycterid catfishes are investigated for the first time using molecular sequence data. Data derived from mitochondrial and nuclear DNA sequences for representatives of 17 genera were analyzed to test previous hypotheses of relationships among trichomycterid subfamilies, the monophyly of the subfamily Stegophilinae, and the monophyly and relationships among the genera of parasitic members of the family. We analyzed 2,325 aligned base-pairs from mitochondrial 12S, 16S, ND4 (tRNAHis tRNASer), and the nuclear histone H3 gene for representatives of 10 of 12 stegophiline and 3 of 4 vandelliine genera, plus 10 outgroup taxa selected to represent the range of subfamilial diversity. Maximum parsimony and likelihood approaches resolved a monophyletic semiparasitic Stegophilinae as the sister-group of the obligate hematophagous Vandelliinae. At the level of subfamilies, the pattern of relationships of the parasitic members among the remainder of the family is fully congruent with the most recent hypothesis of relationships for trichomycterids based exclusively on morphological data. Within stegophilines, our results differ from multiple previous morphological studies in recovery of (1) Haemomaster and Ochmacanthus as sister-taxa, (2) the morphologically plesiomorphic Pareidon microps nested within a relatively distal part of the tree topology, (3) Apomatoceros as sister to Henonemus, rather than to the morphologically similar Megalocentor. These result indicate that parasitism arose once and was unreversed within the Trichomycteridae. Survey of diet and feeding morphology among trichomycterids suggests that the semiparasitic lifestyle of the members of the Stegophilinae was retained in the enigmatic Pareiodon microps, despite reversal to the generalized trichomycterid condition of the associated morphological specializations found in all other stegophilines. These results further support the reconstruction of semiparasitism, rather than blood feeding, for the shared common ancestor of the parasitic Trichomycteridae.

[worton[pl]]

Great! At last something about this very interesting creature.
Is a pdf available?

Regards.

[Silurus]

It's available as an accepted manuscript for now, which means it has not been typeset (you get something like a Word document). If you wait a bit, something more like the final product will be available.

[Silurus]

This is now published in Molecular Phylogenetics and Evolution 52: 416–423.

[sidguppy]

Survey of diet and feeding morphology among trichomycterids suggests that the semiparasitic lifestyle of the members of the Stegophilinae was retained in the enigmatic Pareiodon microps

good thing to know, I've kep Ochmacanthus and it was a little devil for his tankmates....no Pareiodon for me then!

adding a slime and scale feeder to the tank, especially such a large one, won't be a good plan.
I was thinking of getting some interesting fish HERE

HH wrote

Available reports seem to indicate that they're not.

answering my question about parasitism in Pareiodon.
but if this report has found out that they are lepidophage, guess that clears things.

[worton[pl]]

Hey,

service not available due to a mainetance etc etc etc ;)

I hope I'm not too late ;)

Thanks for an info Silurus.

Regards.