[mcv]

  > Some 300 prehistoric worms were analysed - and two ‘were shown to contain viable nematodes’.

This sounds like 300 non-nematode worms were examined, and two of them contained viable nematodes as parasites. Is that correct? Because everything else in the article sounds like the nematodes are the worms, rather than were in the worms.

It's a tiny detail, but it's bugging me.

[flashman]

Yes, poor article, it's not 300 worms but 300 permafrost samples, of which two contained an unspecified number of viable nematodes :https://link.springer.com/content/pdf/10.1134%2FS00124966180...

> We analyzed more than 300 samples of permafrost deposits of different ages and origins, buried soils and fossil rodent burrows. Two samples were shown to contain viable nematodes.

[pmiller2]

It does say “They are both believed to be female,” so, unless it’s a translation error, it’s referring to 2 worms, not 2 samples.

[pvaldes]

I understand that those are Roundworms, not tardigrades. If they start to feed inmediately I understand also that aren't a parasitic species. There are a lot of species living freely in the soil.

Why the article was published just now (the samples were taken in 2015) is a most interesting question. Probably related with the current rush to explore the martian ice pole to find life. The siberian experts would add a invaluable experience in how to attack this drill problem avoiding contamination of the sample, and taking a undisturbed core-layers of ice to date it and understand the past climate of mars.

[pvaldes]

Hum, It seems that they belong to genus Plectus. This genus have some deep-dwelling species of free-living roundworms. At least eight species of Plectus are well adapted to live in very cold and dry ecosystems from Antarctica also.

[10cxyy]

What is worrying me is that nematodes are supposed to be killed by shock frosting fish for 24h.

I thought shock frosting meant -18°C.

[pvaldes]

Anisakis is a totally different animal, adapted to live in a stable and warm place inside a bigger animal.