Jenna Moore curates one of the world's largest collections of annelid worms

The annelid collection is one of the most important in the world. Why is it so important for science and environmental issues?

Our collection is one of the oldest in Germany—it contains material collected in the early 19th century and has steadily grown since then. We have the second largest type collection of annelids in the world, with over 3600 type specimen lots in the collection. Type specimens are the original references for species. So they are extremely important for our knowledge of biodiversity.

What are some special objects in the earthworm collection?

We have an astonishing number of earthworm type specimens, thanks to the first curator of the collection, Johann Wilhelm Michaelsen, who was one of the most historically significant earthworm taxonomists. These types include 13 specimens from the Hamburg area alone. We have representatives of some spectacularly large earthworm species from the Andes, Papua New Guinea, and Romania, and our earthworm collection is unusually comprehensive in terms of geographic representation.

Why are worms so important for the ecosystem?

Annelids play many ecological roles in the environments in which they live. Most famously, earthworms are key decomposers, breaking down organic material and improving soil through their burrowing activities. Some marine worms play a similar role by burrowing into the sediment. Burrowing worms loosen up soil or sediment that would otherwise be compacted and transport nutrients and oxygen into deeper layers, allowing plant roots and other animals to penetrate more easily. Earthworms are therefore critical to agriculture and food production for humans. Marine annelids have even more diverse functional roles in the oceans, as predators, prey, filter-feeders, scavengers, parasites, and hosts and live in every habitat from shallow reefs to the deep sea, including in the water column and hydrothermal vents. .

How were researchers able to support the theory of continental drift using the earthworms in the LIB collection?

The annelid collection’s first curator, Johann Wilhelm Michaelsen, who worked at the museum from 1894 to 1937,was interested in biogeography and studied to the global distribution of earthworm species using the extensive collection. Because earthworms cannot move very far during their lifetimes, his observation that earthworm species in, for example, Africa and South America, were more closely related to one another than to those in northern continents was incorporated into Alfred Wegener’s theory of continental drift.

How does your work help us to better understand the environment?

My research focuses on characterizing marine annelid biodiversity through describing new species, and reconstructing their evolution with genetic methods. I am particularly interested in how worm bodies “work” from a functional perspective. Part of characterizing biodiversity is understanding how species are distributed across the world’s oceans. If we can develop an understanding of how many species there actually are, where they occur, and what environmental factors drive their distributions, we create a basis for understanding biodiversity change.

In marine animals with swimming larvae, it used to be assumed that there are few barriers in the oceans and the species were broadly distributed. With genetics, we are learning more and more that many species have more restricted geographic distributions, and this means lots of unrecognized biodiversity.

Which regions do the annelids in the LIB collection come from?

The collection includes earthworms, leeches, as well as marine annelids from all over the world. Marine worms in particular are extremely diverse – some have jaws, spines, or scales, are parasitic, or swim freely. The diversity of body plans in annelids is enormous, especially in the sea.

Our collection reflects this diversity and is unusually comprehensive. We have specimens of the largest annelid—the marine “sand striker” worm which reaches up to 5 m in length. We also have many unusual groups represented, including pelagic species, such as Tomopteris, which are difficult to collect and are not often found in collections. We have representatives of almost all families of marine annelids, and as I said, one of the largest type collections in the world.

While our collection has a global scope, there is a particular focus on the southern hemisphere. Species from Australia, South America, and southern Africa are particularly well represented in the earliest collections, and many specimens from Antarctica were added in the mid- to late 20th century by former curators Gesa Hartmann-Schröder and Angelika Brandt.

Are you observing the effects of climate change?

Most of the observations on how climate change influences worm distributions has been done with terrestrial species like earthworms, but there have also been some studies showing this in the marine realm. The major problem with marine invertebrates in general is that they are under-studied, so we don’t even know how many species there are, let alone much about their distributions or ecology. In contrast,  we already know a lot about birds, so it's immediately noticeable when one is in the wrong place. With worms, we often lack basic knowledge such as species identification or distribution. That's why it's so important to establish a foundation of biodiversity knowledge first which then allows us to identify changes and what drives them.

So worm research is not a mass phenomenon?

No, it's a very small research community, especially if you consider that there are more than 17,000 species known and many more to discover. When it comes to marine worms, between 100-200 researchers from around the world meet every three years at the big conference, showing how small the community is. In Germany, there are comparatively many scientists who study worms, which creates fantastic opportunities for collaborations.

What fascinates you most about annelids?

Annelids are one of few segmented groups, the others being arthropods and chordates. Their segmentation lends a lot of flexibility for different kinds of body plan specialization, like we see in crustaceans, for example. The annelid research field is particularly exciting now, because much of what we thought we knew about their evolution was completely overturned by genomic data about 15 years ago. So it’s an extremely exciting time to reconsider how annelids have evolved and study their morphological evolution.

Do you have a favorite species?

My favourite worm is called Chaetopterus, a highly morphologically specialised species which filter-feeds using a mucus net and has specialised segments for this particular kind of feeding. The family Chaetopteridae, to which they belong, is my main taxonomic specialization.l.  In terms of sheer admiration, I am a big fan of fish leeches – they can be very colorful and beautiful, and to me are pretty cute.

And a favorite object?

One of my favourite specimens in our collection is a paratype specimen of a giant earthworm from Ecuador—Martiodrilus ischuros. An LIB colleague's brother helped collect the specimens used in its description when he was a child, but its official description only mentioned the research team. The story is a fascinating coincidence, but also raises important issues concerning provenance and recognition. We want to better understand our collection’s history and especially how we can make biodiversity discovery, characterization, and data more equitable, fair, and open as part of the global network of research museums.

To the video interview as part of the special exhibition:

“People Make Museums - Focus on Research”