Panagrellus redivivus

The free-living nematode Panagrellus redivivus (sour paste nematode,^[2] or beer mat nematode from its occurrence in constantly moist felt beer mats),^[1] is known to many aquarium enthusiasts and fish keepers as the microworm. It is a tiny roundworm used as the first food for larger kinds of newly-hatched fish, such as larval common carp.^[3] The microworm is widely used in aquaculture as food for a variety of fish and crustacean species.

Panagrellus redivivus
Observation of Panagrellus redivivus on a Zeiss microscope stage
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Nematoda
Class:	Secernentea
Order:	Tylenchida
Family:	Panagrolaimidae
Genus:	Panagrellus
Species:	P. redivivus
Binomial name
Panagrellus redivivus (Linnaeus, 1767)
Synonyms[1]
Chaos redivivum Linnaeus, 1767 Vibrio anguillula Müller, 1773 Vibrio glutinis Müller, 1783 Anguillula glutinis (Müller, 1783) Müller, 1786 Anguillula rediviva Müller, 1786 Rhabditis glutinis (Müller, 1783) Dujardin, 1845 Turbatrix rediviva (Müller, 1783) Peters, 1927 Turbator silusiae (de Man, 1913) Peters, 1927 Turbator redivivus (Linnaeus, 1767) Peters, 1927 Panagrellus leucocephalus (Steiner, 1936) Goodey 1945 Panagrellus redivivus (Linnaeus, 1767) Goodey, 1945 Neocephalobus leucocephalus Steiner, 1936 Cephalobus parasiticus Sandground, 1939 Turbator leucocephalus (Steiner, 1936) Goodey, 1945 Panagrellus silusiae (de Man, 1913) Goodey, 1945

One of thirteen currently recognized species of Panagrellus, P. redivivus is about 50 μm 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^[4] or porridge inoculated with dry yeast.^[5] Females reach maturity in about three days and deliver live young rather than eggs, as most nematodes produce.

The microworm has been used in genetic analysis studies, but not nearly as universally as its relative, Caenorhabditis elegans.

In Vietnamese cuisine, it is common to use lactic fermented yeast rice (cơm mẻ), which contains microworm (con mẻ), to make dishes sour.^[6]

References

1. Ferris H. (2009). "The beer mat nematode, Panagrellus redivivus: A study of the connectedness of scientific discovery" (PDF). J. Nematode Morphol. Syst. 12 (1): 19–25. Archived (PDF) from the original on 2021-09-25. Retrieved 2023-09-27.
2. Stock, S., and Nadler, N. 2006. "Morphological and molecular characterization of Panagrellus spp. (Cephalobina: Panagrolaimidae): taxonomic status and phylogenetic relationships". Nematology, 8(6), 921-938.
3. Schlechtriem, C.; M. Ricci; U. Focken; K. Becker (2004). "The suitability of the free-living nematode Panagrellus redivivus as live food for first-feeding fish larvae". Journal of Applied Ichthyology. 20 (3): 161. doi:10.1111/j.1439-0426.2004.00542.x.
4. Linnaeus identified the species in library or book paste.
5. "Worm Culture Information". Archived from the original on 2014-01-09. Retrieved 2014-01-09.
6. (in Vietnamese)"Cơm mẻ - Vị chua từ những chắt chiu". 2020-05-16. Archived from the original on 2021-08-01. Retrieved 2023-09-27.

Further reading

• Kovaleva, E.S.; et al. (2003). "Panagrellus redivivus as a molecular model for cyst nematodes". Journal of Nematology. 35 (3): 348.
• Sautter J.; Kaiser H.; Focken U.; Becker K. (2007). "Panagrellus redivivus (Linné) as a live food organism in the early rearing of the catfish Synodontis petricola (Matthes)". Aquaculture Research. 38 (6): 653–659. doi:10.1111/j.1365-2109.2007.01714.x.
• Batchelder, E., "Panagrellus redivivus" at Unity College Nematodes Archived 2019-10-04 at the Wayback Machine

External links

• Photos