There are actually three species of worms that could possibly be included in the worms you order for your worm bin.
They do not interbreed, but other than that they can basically be treated as all the same. They do have their differences, but for the beginner
it is not worth worrying about. Just go with Red Wigglers. (The information here is mainly from Wikipedia, also from my own understanding)
E. Fetida (Red Wigglers) is the species scientists usually cite, so for serious studies I suppose they must do the examination necessary to
tell them apart. Eisenia andrei is slightly darker in color with less pronounced stripes (but is often called the "tiger
worm"), but in practice it is quite difficult to tell them apart.
Here is a great photo at Gardenweb.com's
forums (scroll down).
L. rubellus is a little easier to identify, as it is iridescent dorsally
(along the back) and has a yellowish ventral (bottom) side; its common name is "Red Earthworm".
The other species that are widely used for vermicomposting are the "European Nightcrawler" and the "African Nightcrawler". The
African worms are used in the tropics, and the European ones in Europe. Hey that actually makes sense.
All composting worms are in the same Family
Kingdom: Animalia
- Animals
Phylum: Annelida
- Segmented Worms
- annelus="little ring"
Class: Clitellata
- Collared Worms
- clitellum ~ "collar": The cocoon-producing feature, a swelling about one-third of the way down the Earthworm. Only present on adult specimens
Sub-Class: Oligochaeta
- Terrestial and Freshwater Worms
- These worms usually have few setae (chaetae) or "bristles", and lack a parapodia, unlike polychaeta.
Order: Haplotaxida
- One of Two Orders under Sub-Class Oligochaeta
- 4 pairs of setae per segment
Family: Lumbricidae
- A Family of 42 Genera and over 670 (sub-)species
- Taxonomic Characteristics are highly technical
- See page 37 of this 77-Page List cited by Wikipedia Lumbricidae List, 505 KB pdf
Eisenia Fetida
"Red Wiggler" or "Compost Worm"
Genus: Eisenia
- Note the existence of a brown algae of the same (Botanical nomenclature) genus name!
- Taxonomic Characteristics are highly technical
Species: E. fetida (or foetida)
- One of 33 Species of the Genera Eisenia
- Its specific name arises because, when roughly handled, it exudes a pungent liquid.
- External Structures of Eisenia fetida: Eisenia fetida length 35-130mm (generally >70mm);
diameter 3-5mm; segments 80-120; first dorsal pore between segments 4/5 (sometimes 5/6);
clitellum over segments 24,25, 26-32; tubercula pubertatis on segments 28-30; seminal
vesicles, four pairs on in 9-12; spermathecae, two pairs in 9/10 and 10/11.
("Earthworms of Ontario" by John Reynolds, via http://www.happydranch.com/10.html)
Eisenia Andrei
"Tiger worm" or "Compost Worm"
Genus: Eisenia
- Note the existence of a brown algae of the same (Botanical nomenclature) genus name!
- Taxonomic Characteristics are highly technical
Species: E. andreii
- One of 33 Species of the Genera Eisenia
- Close relative of E. fetida
Lumbricus rubellus
"Red Earthworm"
Genus: Lumbricus
- Taxonomic Characteristics are highly technical
Species: L. rubellus
- One of 13 Species of the Genera Lubricus
- Usually reddish brown or reddish violet, iridescent dorsally, and pale yellow ventrally.
- They are usually about 25–105 mm in length, and have around 95-120 segments.
Eisenia hortensis
"European Nightcrawler"
Genus: Eisenia
- Note the existence of a brown algae of the same (Botanical nomenclature) genus name!
- Taxonomic Characteristics are highly technical
Species: E. hortensis
- One of 33 Species of the Genera Eisenia
- Mainly greyish, with a pinkish color on the front end of the body. The tip of the tail is cream or pale yellow.
Mycobacterium vaccae
"Soil Germ"
Kingdom: Bacteria
- Unicellular, prokaryote microorganisms
Phylum: Actinobacteria
- Gram-positive bacteria with high G+C ratio.
Order: Actinomycetales
- Very diverse order, contains a variety of subdivisions as well as yet unclassified isolates
- Some genera are very difficult to classify because of a highly niche-dependent phenotype.
Suborder: Corynebacterineae
- includes most of the acid-fast bacteria
Family: Mycobacteriaceae
- Single-genus family
Genus: Mycobacterium
- includes pathogens known to cause serious diseases in mammals, including tuberculosis and leprosy
- Yikes! Right? But that's what makes this species so interesting
Species: M. vaccae
- Nonpathogenic species of the Mycobacteriaceae family of bacteria that lives naturally in soil.
- Its name is derived from the Latin word, vacca (cow) as the first described strain was isolated from cow dung in Austria.
- Research areas being pursued with regard to killed Mycobacterium vaccae vaccine include immunotherapy for allergic asthma, cancer, depression, leprosy, psoriasis, dermatitis, eczema and tuberculosis
- See this Wikipedia article on Mycobacterium vaccae
- And this The Sunday Times article referring to health and happiness
- Leading Wellsphre.com to suggest that Mycobacterium vaccae is your friend
- I do not know if this critter is common in worm bins, but why wouldn't it be? I'm just saying . . .
Taxonomy, Phylogeny and Cladistics
Taxonomy
Recent advances in DNA sequencing computers have allowed Worm Scientists to take another look at the "Tree of Life",
which comes down to us from decades and centuries of work by dedicated scientists. "Taxonomy" is the activity of
giving names to things. Simplifying greatly, it can be said that the above represents the "Traditional Taxonomic
Classification" of the particular species we are most interested in for vermipractice.
Phylogeny
Scientists pursue the truth. They (generally) do not claim to ever have completed the job, and certainly the "Tree
of Life" still awaits further discovery. "Phylogeny" is the "True" Tree of Life - the one fully correct and complete
hierarchial structure by which every living thing is related to every other life-form. So Scientists do not "do"
Phylogeny: it is not an activity, but a fact, or set of facts, which we seek to discover. The goal is to determine
where evolution branched off in every case where a new and persistent phylum, class, family, genus, species, etc. developed.
Cladistics
So we have our Taxonomy, which resulted from a determined effort to describe a Tree of Life, yet we continue
to seek to discover
the one, true Tree of Life, the Phylogeny of Earth's life-forms. With the revolutionary capability to rapidly sequence DNA,
we find ourselves at the remarkable point in history where we can more or less directly read the answer from the back
of the book. With enough empirical evidence and confidence in the experimental and analytical methodology, our confidence
in our description of the Phylogeny can reach unprecedented heights. It's a great time to be be a Scientist!
Enter Cladistics, also known as Phylogenetic Systematics: finding objective genetic similarities and differences between taxa, to be
used as the basis for constructing the Phylogeny. If I may editorialize a bit, it would appear that the revolution this technology
causes in some cases is less than welcome to some scientists; also the "cladists" seem to want to start with a clean slate in many
cases, which must make it harder for those who think the old system has merit.
Earthworms and the Tree of Life
As it turns out, Cladistics calls for a very major change in the Annelid Phylum. The mud-dwelling echiuran spoon worms and
the gutless, deep-sea pogonophoran tube worms are both unsegmented, so they have long been given their own phylums. But
phylogenetic analyses of DNA sequences from the nuclear gene elongation factor-1alpha says they are in fact Annelids. The difference
is that the DNA says that these worms evolved from segmented worms, and then lost their segmentation over time. The traditional
taxonomy is based on their ancestors not having ever acquired segmentation.
What does all this mean to Vermipractice?
Oh, not a lot, I suppose. It also turns out - if my research conclusions are accurate enough - that by the time you get down
to the Order Haplotaxida, the Taxonomy is looking very solid when tested by Cladistics. In other words, for now at least, the
above scientific descriptions hold. The revolutionary findings are way up at the Phylum level, and the Clitellata Class is
not being challenged as far as I can tell. Just remember that it could change, and that, if you are interested, there is much
science to be done in the service of vermipractice.
So why do I even mention Lumbricus rubellus? Because discussions persist on the web about them co-mingling and possibly
interbreeding with Red Wigglers. For starters, everything I read and know tells me that they cannot interbreed - they have
been separated by Genus, so that's what the scientists think. There appears to be no reason why they couldn't live together,
however. The two genera are shown as closely related, and we have ample evidence that L. rubellus is not only good at vermicomposting,
but looks like and acts a lot like Eisenia foetida.
Still, this site is about Red Wigglers and other than on this page, I do not want to distract my reader and complicate things by
accounting for any differences between worm species. The same goes for both
European and African Nightcrawlers, but people do not have any
difficulty telling them apart from E. foetida or L. rubellus.
References and articles
Wikipedia
Animals Index
WormQuiz
wormdigest
U Michigan
