''Enchytraeus buchholzi'', Grindal worms, (described by

František Vejdovsky František () is a masculine given name of Czech origin. It is a cognate of Francis, Francisco, François, and Franz. People with the name include: *Frank Daniel (František Daniel) (1926–1996), Czech film director, producer, and screenwriter *F ...

in 1879) are

enchytraeid Enchytraeidae is a family of microdrile oligochaeta, oligochaetes. They resemble small earthworms and include both terrestrial species known as potworms that live in highly organic Ecoregion#Terrestrial, terrestrial environments, as well as some ...

oligochaete Oligochaeta () is a subclass of animals in the phylum Annelida, which is made up of many types of aquatic and terrestrial worms, including all of the various earthworms. Specifically, oligochaetes comprise the terrestrial megadrile earthworms ...

worms. They are found in temperate meadows and disturbed roadside verges. The scientific name probably covers a group of morphologically indistinguishable species, which would complicate their use as test species in substitution for '' E. albidus'', a species commonly cultivated in the laboratory for toxicity tests, according to

OECD The Organisation for Economic Co-operation and Development (OECD; french: Organisation de coopération et de développement économiques, ''OCDE'') is an intergovernmental organisation with 38 member countries, founded in 1961 to stimulate e ...

.''OECD Guidelines for the Testing of Chemicals'' 220, adopted 13 April 2004 For aquarists "Grindal worms" are treated as smaller relatives of whiteworms, but usually only grow to about 10 mm and thus are an ideal size for most small freshwater fish, both adults and larger fry. Mrs. Morten Grindal, of Sweden, who was prominent in the development of culturing techniques for whiteworms, was apparently the first aquarist to isolate this smaller species. Grindal worms can be cultured exactly as whiteworms but are a much more adaptable species and have a greater tolerance for warmer temperatures. Maturity has been reported to occur around 16 days at 20 °C, the

clitellum The clitellum is a thickened glandular and non-segmented section of the body wall near the head in earthworms and leeches, that secretes a viscid sac in which eggs are stored. It is located near the anterior end of the body, between the fourteent ...

forming when the worms are about 3~4 mm. The generation period ( cocoon to cocoon) is about a month at 20 °C.

Uses

''Enchytraeus buchholzi''/Grindal worms are cultured by aquarists as a fish food, often on a bed of ground coconut shells, or

coir Coir (), also called coconut fibre, is a natural fibre extracted from the outer husk of coconut and used in products such as floor mats, doormats, brushes, and mattresses. Coir is the fibrous material found between the hard, internal shell ...

, with oatmeal. They are used for conditioning tropical fish before spawning, or for young fast-growing fish. In laboratory testing, ''Enchytraeus buchholzi'' were kept in an incubator at 15 ± 2 °C. Water loss and food were replenished if necessary during the test period. After 21 days the offspring and the surviving adults were counted. For two moisture levels (5% and 20% water content) the segment number of the surviving adults was counted. From 20% up to 40% water content Enchytraeus buchholzi showed no significant difference in reproduction. Below 20% and above 40%, the number of offspring was reduced. No juveniles were found at 5% water content, although adult survival was equal to higher moisture levels. Reproduction was decreased at 30% water content compared to 25% and 35% water content. Low soil moisture inhibited not only reproduction, but had also a negative effect on the growth of the parent generation.

References

{{Taxonbar, from=Q3053776 Enchytraeidae Animals described in 1879