Anguillula aceti; Print; The free-living nematode Panagrellus redivivus (common names include vinegar eel; vinegar eelworm; vinegar nematode; paste worm; starch worm; sour paste nematode; sour paste eelworm; beer felt nematode; and beer mat nematode); is a tiny nematode that can be found living in beer mats; insect frass; slime from tree wounds; wheat paste; and mother of vinegar. Their environment makes them exceptionally tolerant of variation in acidity and alkalinity and they may be able to tolerate a wider range than any other nematode species; being able to survive from pH 1.6 to 11. One of thirteen currently recognized species of Panagrellus; P. redivivus is about 50 祄 in diameter and just over 1 mm in length; barely visible to the naked eye. Subsisting on yeast; it is easily cultured at home on a substrate of flour paste or porridge inoculated with dry yeast. Females reach maturity in about three days and deliver live young rather than eggs; as most nematodes produce.