A reader wrote to us recently to report that he saw a huge earthworm (in his words, a “HUGE earthworm”) high in the Sierra Nevada Mountains of eastern California. The large earthworm came out after a light rain and made its way under the tent our reader was sleeping in. He was wondering if it was native to this region of the California, or if it was “someone’s escaped fish bait” (lots of people fish for trout in this region), and he wanted to know if we could identify the exact species of earthworm he found. What might this enormous earthworm be?
The reader did not submit a picture along with his question, so we don’t know exactly what it looks like, nor are we sure of its precise size. It is quite large – indeed, it is “HUGE” – but this means different things to different people. In any case, it must be abnormally large or else the reader probably wouldn’t have bothered to report his finding to us.
Identifying distinct species of any sort of worm, larva, or insect is extremely difficult. The differences between species can be minuscule, and there are often an enormous number of species to compare. The situation with earthworms is a case in point, as there are thousands of different types of earthworms that would be largely indistinguishable to most people.
That said, we have actually written about huge earthworms before, discussing earthworm sizes and how long certain earthworms can get. Thus, we have some familiarity with earthworm species, and it seems that our reader might have found a Lumbricus terrestris, which is a common species that is spread around the globe. These earthworms routinely grow to over a foot (or more than 30 centimeters) in length, and some can grow to be considerably longer. They are native to Europe, but have spread over much of the globe, including the United States. (The story of how earthworms came to the U.S. from Europe is quite interesting.) Thus, ultimately speaking, these earthworms are not really native to the Sierra Nevada Mountains, but they could have been there for hundreds of years, and thus our reader needn’t assume the specific earthworm he found was brought in by a fisherman.
That our reader found a Lumbricus terrestris is of course just speculation. We didn’t see an image of the worm, and even if we did it would be hard to tell what species it is by merely looking at a picture. However, Lumbricus terrestris earthworms are, as noted, quite common and can become quite huge, so it is the most promising suggestion we can offer given what we know.
All About Worms is always free, always reader-supported. Your tips via CashApp, Venmo, or Paypal are appreciated! Receipts will come from ISIPP Publishing.