''Lumbricus rubellus'' is a species of

earthworm An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. ...

that is related to '' Lumbricus terrestris''. It is usually reddish brown or reddish violet, iridescent dorsally, and pale yellow ventrally. They are usually about to in length, with around 95–120 segments. Their native distribution was mainland Europe and the British Isles, but they have currently spread worldwide in suitable habitats.

Size and appearance

''Lumbricus rubellus'', or the "red earthworm", ranges from to in length and has smooth, reddish, semi-transparent, flexible skin segmented into circular sections. Each segment contains four pairs of setae, or bristles, and the total number of segments per matured organism ranges from 95–105.Edwards, C.A., and Lofty J.R. (1972). ''Biology of earthworms''. Halsted Press, New York, NY. The segmentation of ''Lumbricus rubellus'' identifies the organism as a member of Phylum Annelida, while the enlarged segments towards the anterior of the organism called 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 ...

denotes membership to Class Clitellata. Members of this class are also defined by having permanent

gonads A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces ...

Habitat

''Lumbricus rubellus'' naturally lives in soils high in organic matter, preferably dung and feces. The worms require loose soil to burrow in and soil moist enough for gas exchange.Wallwork, J.A. (1983). ''Earthworm biology''. Edward Arnold Publishers Ltd., London, England. Further requirements include such abiotic factors as pH and temperature. Various abiotic factors are significant to ''Lumbricus rubellus''. pH is of particular importance; a range of 5.5 to 8.7 is acceptable with a preference for neutral soils.Reynolds, J.W., and Dindal, D.L. (1977). ''The earthworms (Lumbiridea and Sparganophilidea) of Ontario''. The Hunter Rose Company, Toronto, Ontario. Temperature is also significant, with implications for growth, respiration, metabolism and reproduction amongst other things. An ideal temperature is 51 degrees Fahrenheit (10.6 degrees Celsius). A further abiotic factor is moisture, which is important for respiration. A similar species, ''Millsonia anomala'', was most active at 10–17% moisture content. The substratum for ''Lumbricus rubellus'' is related to the species food sources and pH and moisture requirements. Dung is the species p