IDENTIFICATION
The most consistent feature of earthworms is that each species is different but a few characteristics are common to all species. To make an accurate identification of earthworms, it is necessary to use only mature specimens, as many of the superficial identifying characteristics do not emerge until maturity.
Reds (L. rubellus)
Of European origin, these are a good deep red in colour, with the clitellum commencing at segment 32 and ending at 34. The clitellum is raised and runs from belly edge to belly edge like a saddle. When mature they are about 75 mm long and when well fattened can grow to 5 to 7 mm in diameter. In soil, Reds will be found always in the top 150 mm.
Tigers (E. fetida)
Again European, these are a rusty colour with a distinct brownish tinge. Each segment is usually clearly defined by a yellow band; tigers are similar to the Red, in that their clitellum is raised and commences at segment 32, extending to and including segment 34, and they will fatten to a similar size. However, Tigers have an inbuilt defence mechanism: when they are threatened, e.g. if used as fishing bait, they exude a fetid, unpleasant-smelling yellow liquid. They therefore do not make good fishing bait.
They are often confused with a close relative, Eisenia andrei (also named E. fetida andrei) which is often called a crossbreed between the Reds and Tigers, but it is not. It is a separate species and in all other respects is the same as the Tiger. For this reason, I treat it as a Tiger and do not refer to it again.
Blues (P. excavatus)
I have to say that from my point of view there is still some confusion about the naming of the species referred to ‘Blues’. It was originally named Perionyx excavatus when I first discovered it in my beds in November 1991, and at that time, I clubbed it ‘Indian Blue’, because of its phosphorescence when mature.
Then a few months later, I was advised that in fact it was an Australian native Spenceriella sp. nov. I was advised at the time that the two are very similar in appearance and hence the error. Whatever the name, they are a valuable commercial worm, of that there is no doubt. Like Reds and Tigers, Blues are an import, but instead of Europe, their originating home stretches from the Himalayan mountains into the lowlands of Malaysia and now, Australia, as fair south at Maryborough.
I don’t know of any other which can tolerate such a wide range of temperature and environment. Personal observations I have made of the reproductive behaviour, bodily growth rate and size achieved seem to exceed those recorded by R. D. Kale, B. Bano and R. V. Krishnamoorthy (Potential of Perionyx excavatus for utilizing organic wastes’) in a 1982 investigation of P. excavatus. Kale’s findings and my own are contained in the following comparison.My observations can hardly be classed as reliable experiments but merely observations, What I did was not in any way as exhaustive as the monitored work of Kale.
Kale, in her recording of capsule production, consistently used two worms. I have never seen two Blues coupling. I confined one sexually mature worm, on its own, and found cocoons produced, Sperzeriella sp. nom, is known to be parthenogenetic and I can find no reference which suggests that this is the case for P. excavaius
Kale recorded a maximum body weight of 1.7 gm at 145 days, while I can show thousands of these worms weighing 2,5 gm and more at about the same age.
The difference between the two is not easily noticeable. According to Rob Blakemore (CSIRO)Spenceriella has bolo nvphridia, whereas P. excavates does not and, to find this, the two must be dissected. Their external physical appearance seems to be identical_ Clearly, it would be very difficult to deny that the two must be very closely related.
To me, the difference in the behaviour of the samples used in Kale’s experiments and mine is so substantial that I find it difficult to believe that pig manure stimulates them to the much higher rates of bodily growth and reproduction, yet the feed is the outstanding major difference in the comparison.
Blue worms come in four distinct colours at sexual maturity and add a fifth as they approach full body size. The anterior (from the snout to the clitellum) is a deep red/purple while the posterior (from the clitellum to the tail) is a brownish red, but with a cream to white belly. The clitellum, commencing at segment 7 or 8, is not raised and may even appear depressed. It is of a creamy colour. Once Blues reach a length of about 70 mm they begin to phosphoresce a deep bluelpurple on exposure to light. As the size increases, so does the degree of phosphoresence, so that at full size, which is about 150 mm contracted (and 200 mm stretched out), they fairly flash a regal purple. It is a beautiful colour_ They are extremely active on exposure and will whip into a U-shape, constantly reversing the position. When used as fishing bait, they flip and twist on the hook, so that it is by no means easy to get both ends attached, They whip about so vigorously that they can snap themselves in half.
P. excavatus has the characteristics of being both a wanderer and a climber, with a preference for very moist conditions. In Malaysia, it has been found even in the jungle treetops, thought be seeking refuge from wetter conditions during heavy rains. I certainly attest to its wandering habits as we have it spread through the garden but, at the same time, it also seems quite happy to stay in the worm beds where the most food and it breeds there like crazy.
I have found it to be a most versatile worm and I consider it to very valuable.
