Research Article
Research Article
Lost and found – Fritz Müller´s type material of Glossiphonia verrucata (Fr. Müller, 1844) (Hirudinida, Glossiphoniidae) with notes on the leech fauna of lake Tegel in Berlin (Germany)
expand article infoUwe Jueg, Peter Michalik§
‡ Unaffiliated, Ludwigslust, Germany
§ Universität Greifswald, Greifswald, Germany
Open Access


In 1844, the famous German biologist Fritz Müller published his dissertation about the leech fauna of lakes in Berlin. This study not only addressed the occurrence of leeches in the different lakes, but also contains the description of a new species - Glossiphonia verrrucata (Fr. Müller, 1844). Unfortunately, he never mentioned how many specimens he found and where he deposited the material of his dissertation research. Thus, it came as a surprise that the material appeared in the small leech collection of the Zoological Museum of the University of Greifswald. Here, we provide an overview of the material focusing especially on the four syntypes of G. verrucata. Since this is a rarely found species, we further explored historical material from the type locality, Lake Tegel, held in other museums. Our survey revealed that the material collected by Müller is the only one known to date from the species-rich Lake Tegel, which is inhabited by 14 species of freshwater leeches.

Key Words

Hirudinida , Lake Tegel, freshwater leeches, ZIMG, Glossiphonia verrucata


The collection of leeches (Hirudinea) of the Zoological Institute and Museum of the University of Greifswald (ZIMG) is considerably small (only 66 specimens), but with 31 taxa the most diverse public collection of leeches in the state Mecklenburg-Vorpommern (Jueg 2015). Nearly all specimens were collected in the 19th century and are in good conditions considering their age. This collection contains the oldest conserved leeches for the state (1834, coll. Creplin), including seven first records and some other non-palearctic species, which are rarely represented in German natural history collections.

As revealed by Jueg (2015), it also contains four specimens of Glossiphonia verrrucata collected in lake Tegel in Berlin. Unfortunately, the specimen label does not have a collecting date, but it is noted that these specimens were collected and determined by Johann Friedrich Theodor Müller (1822–1897) better known as Fritz Müller – the famous German naturalist who emigrated 1852 to Blumenau (Brazil). Müller is a well-known early advocate of Darwinism (e.g. Müller 1864) and extensively corresponded with Charles Darwin and also other influential biologists of the 19th century (e.g. Ernst Haeckel). He published nearly 250 articles on life history, morphology, systematics and evolution of plants and animals. The Müllerian mimicry was named after him based on his ground-breaking contributions to the theory of insect mimicry. The life and scientific achievements of this remarkable biologist are summarized in Möller (1915–21) and West (2003, 2016).

Fritz Müller studied mathematics and natural sciences in Berlin finishing 1844 with a dissertation thesis on leeches in the area of Berlin including the redescription of Clepsine tessulata (synonym of Theromyzon tessulatum (O.F. Müller, 1774)) and Clepsine marginata (synonym of Hemiclepsis marginata (O.F. Müller, 1774)) as well as the description of the new species Clepsine verrucata (=Glossiphonia verrucata (Fr. Müller, 1844)). According to Jueg (2015), the Museum of Natural History in Berlin (MfN) does not possess any material from Müller´s work on leeches. Furthermore, Müller did not mention where his material was deposited (see Müller 1844) indicating that the material in the collection of the ZIMG could be indeed the type material of Fritz Müller (Jueg 2015). Here, we investigate this collection further by providing an overview of the collection Fr. Müller, revising the type material of Glossiphonia verrucata as well as presenting an overview of other historical records from Lake Tegel, which is the type locality of this rare species.

Figure 1.

A: The naturalist Fritz Müller in his typical appearance. B: Live specimen of Glossiphonia verrucata collected in the Krakower Lake (Germany) in 2017.

Figure 2.

The type specimens of Glossophonia verrucata in dorsal and ventral view.

Material and methods

The specimens are kept in 80% ethanol and were examined using a MBC-10 stereomicroscope. Images were taken with the BK PLUS Lab system (Dun Inc.) using a Canon 65 mm macro lens mounted on a Canon 5D Mark II camera. Image stacks were captured with Adobe Lightroom and processed using Zerene Stacker under PMax value. Obtained extended focus images were edited using Adobe Photoshop CS 6. All measurements are given in millimeters.


The leech collection of Fritz Müller at the ZIMG

Among the oldest specimens of the leech collection at the ZIMG are the ones from Fritz Müller, which likely was the basis of his dissertation research. Since the Museum of Natural History in Berlin does not have any material from Müller, the following specimens seem to be the only ones left from the leech collection of Fritz Müller:

Alboglossiphonia heteroclita (Linnaeus, 1761)

Berlin, Date?, leg. & det. Fr. Müller (det. as Glossiphonia heteroclita), rev. U. Jueg, ZIMG II/16225 (7 specimens)

Alboglossiphonia hyalina (O. F. Müller, 1774)

Berlin, 1840, leg. & det. Fr. Müller (det. as Glossiphonia heteroclita var. hyalina), rev. U. Jueg, ZIMG II/16224 (11 specimens)

Alboglossiphoniahyalina” (n. sp.?)

Berlin, Date?, leg. Fr. Müller (det. as Glossiphonia heteroclita), det. U. Jueg, ZIMG II/16225 (8 specimens)

These white specimens are regularly papillated and likely represent a new species, but after the commonly accepted taxonomy we assign these specimens to Alboglossiphonia hyalina for now.

Glossiphonia complanata (Linnaeus, 1758)

Mecklenburg-Vorpommern, Greifswald, 1847/1849, leg. & det. Fr. Müller, rev. U. Jueg, ZIMG II/16219a (5 specimens)

Glossiphonia verrucata (Fr. Müller, 1844)

Berlin, Tegeler See, Date?, in 1865 appearance in the catalogue of the ZIMG, leg. & det. Fr. Müller (labelled as Boreobdella verrucata), rev. U. Jueg, ZIMG II/16226 (4 specimens, type material, but not labelled as such)

Hemiclepsis marginata (O. F. Müller, 1774)

Berlin, Date?, leg. & det. Fr. Müller, rev. U. Jueg, ZIMG II/16222 (8 specimens)

Theromyzon tessulatum (O. F. Müller, 1774)

Berlin, Tegeler See, 1847, leg. & det. Fr. Müller (det. as Protoclepsis tessulata), rev. U. Jueg, ZIMG II/16233 (2 specimens)

Unfortunately, Müller did not provide very detailed locality information, but seven taxa of the Glossiphoniidae are present in the collection of Müller and thus correspond to his dissertation thesis (he assigned all species to the genus Clepsine): Hemiclepsis marginata, Theromyzon tessulatum, Glossiphonia verrucata, Glossiphonia complanata, Alboglossiphonia hyalina, Alboglossiphonia heteroclita and Helobdella stagnalis. Based on the descriptions in his thesis, Müller (1844) collected in several lakes, ponds and rivers in Berlin (e.g. Plötzensee, Grunewaldsee, Spree) and mentioned that G. verrucata was very rare and only present in Lake Tegel.

The type material of Glossiphonia verrucata

During his revision of the leech material in the natural history collections of Mecklenburg-Vorpommern, Jueg (2015) discovered five historic specimens of Glossiphonia verrucata (all labelled as Boreobdella verrucata) in the collection of the ZIMG. One specimen was collected by Julius Münter in 1857 in Tribsow (Eastern Pomerania, now Poland; ZIMG II/4287) and four specimens were collected by Fritz Müller in the Lake Tegel in Berlin (Original label: Boreobdella verrucata, E lacu Tegliano, Fr. Müller, Acc. Cat. II Nr. 16226). Unfortunately, no collection date was provided, but it was registered in the ZIMG collection catalogue in 1865 explaining the considerable difference between the catalogue numbers of these specimens. Based on the these syntypes, we erected a lectotype (ZIMG II/16226a) and three paralectotypes (ZIMG II/16226b-d).

The four specimen collected by Müller are in good conditions considering its age of over 170 years. They seemed to be immediately fixed in ethanol, which resulted in a strong contraction of the body. Thus, some characters are not or only hardly visible (e.g. sucker and head region). Paralectotype 3 (ZIMG II/16226d) has also a slightly twisted body and all specimens show some deformation in the middle region of the body. In a living stage the animals likely had a body length of 20 to 30 mm. The species characteristics are visible, but vary among the specimens. The color was not retained in the specimens. The typical papillation with an arrangement on the three annulae of each segment is clearly visible. The typical arrangement and number of the eyes can be seen in one specimen – the reduction to four eyes was already pointed out by Müller (1844). The typical margin of the body is clearly visible in three specimens. Based on all visible characters, which are summarized in Table 1, all specimen can be clearly assigned to G. verrucata.

Table 1.

Characteristics of the type specimens of Glossiphonia verrucata.

Lectotype Paralectotype 1 Paralectotype 2 Paralectotype 3
Length 16.0 15.0 14.0 12.0
Mean width of theurosome 5.5 5.0 4.8 ?
Max. width of the trachelosoms 11.2 9.3 11.2 9.2
Height of theurosome 3.2 2.5 1.7 ?
Height of the trachelosome 4.2 3.9 4.4 2.9
Length of anterior sucker 0.7 0.6 deformed very contracted
Width of anterior sucker 1.3 1.0 deformed very contracted
Length of posterior sucker 2.8 2.8 deformed 2.4
Width of posterior sucker 2.8 2.9 deformed 2.4
Colour, dorsal unicoloured light-brown – beige unicoloured light-brown – beige unicoloured light-brown – beige unicoloured light-brown – beige
paramedian stripes lightly outlined
Colour, ventral unicoloured light-brown – beige unicoloured light-brown – beige unicoloured light-brown – beige unicoloured light-brown – beige
Papilla present in typical arrangement present in typical arrangement not prominent, but clear to see light present in typical arrangement
Margin of the body irregular serrated irregular serrated smooth slight serrated
Head slightly bulbous slightly bulbous clearly bulbous not bulbous
Eyes 4 visible 4 visible 6 visible, in typical arrangement not visible
Others middle body strong squeezed, especially dorsal middle body strong squeezed, especially dorsal particularly squeezed, before posterior sucker slightly tear down middle body strong squeezed, especially dorsal

Historic material of Hirudinida from Lake Tegel

In order to underline the findings of Fritz Müller, we surveyed two further collections (Museum of Natural History in Berlin and Center of Natural History in Hamburg), which host historic material from Lake Tegel. In total, we found 14 species representing 5 families (Table 2) – a remarkable diversity of taxa. The lake contains nearly all common species typical for lakes of this size including Erpobdella monostriata, which is characteristic for such habitat. Hirudo medicinalis might be not a common element of Lake Tegel, as many smaller lakes are in close relations with Lake Tegel and likely the source for the appearance of this species. Glossiphonia verrucata was only found by Fritz Müller as we did not find another individual in the other collections neither it was not reported again from Lake Tegel. Of interest was the material of G. complanata as some specimen showed a similar papillation as in G. verrucata (MfN Nr. 2879-Q and CeNak Nr. V 12404), which could have led to an incorrect determination. However, the arrangement of the papillae was not as typical as in G. verrucata and the color, which would help to clearly assign the specimen to one or the other species, was not retain. Considering the variable morphology of G. complanata we did not further investigate these specimens and future studies using molecular markers should address the delimitation of this species.

Table 2.

Historical records from Lake Tegel in Berlin.

Species Fr. Müller (1844) Collections
Greifswald Berlin Hamburg
1840–1847 1886–1904 1930
Family: Glossiphoniidae
Alboglossiphonia hyalina (O. F. Müller, 1774) X X ?
Glossiphonia complanata (Linnaeus, 1758) X (cf.) X X
Glossiphonia verrucata (Fr. Müller, 1844) X X
Helobdella stagnalis (Linnaeus, 1758) X (cf.) X
Hemiclepsis marginata (O. F. Müller, 1774) X X ? X
Theromyzon tessulatum (O. F. Müller, 1774) X X X
Family: Piscicolidae
Piscicola geometra (Linnaeus, 1758) X
Piscicola pojmanskae Bielecki, 1994 X
Piscicola sp. X
Family: Hirudinidae
Hirudo medicinalis Linnaeus, 1758 (X)
Family: Haemopidae
Haemopis sanguisuga (Linnaeus, 1758) X
Family: Erpobdellidae
Erpobdella octoculata (Linnaeus, 1758) X X
Erpobdella testacea (Savigny, 1820) X
Erpobdella monostriata (Lindenfeld & Pietruszynski, 1890) X
Species total: 14 4 (6?) 2 (4?) 11 3
Table 3.

Records from Lake Tegel present in the zoological collection of the CeNak Hamburg (revised by Jueg) and the Museum of Natural History in Berlin (MfN, partly determined and revised by Jueg).

Species Original label Coll.-Nr. Locality Date leg. det. Comments
Coll. MfN, Berlin
Glossiphonia complanata Glossiphonia complanata 1408 Tegel-See 1887 Weltner Johansson
Theromyzon tessulatum Theromyzon tessulatum 1409 Tegel ? Weltner Johansson
Erpobdella octoculata Herpobdella atomaria octoculata 1411 Tegelsee ? Weltner Johansson
Erpobdella octoculata Hirudinea spec. 2877-Q Tegel-See, an der Unterseite von Brettstücken 25.04.1894 Weltner Jueg
Helobdella stagnalis
Hirudo medicinalis Hirudo medicinalis 2878-Q Tegel-See, Vorland, an einem auf dem Boden liegendem Stück Holz 26.04.1904 Weltner Weltner
Glossiphonia complanata Hirudinea spec. 2879-Q Tegel-See 27.03.1894 Weltner Jueg few specimens with „verrucata-like“ papillation
Erpobdella monostriata Hirudinea spec. 2880-Q Tegel-See 27.03.1894 Weltner Jueg
Erpobdella testacea
Haemopis sanguisuga Haemopis sanguisuga 2881-Q Tegel-See 27.03.1894 Weltner Weltner
Erpobdella octoculata Hirudinea spec. 2982-Q Tegel 00.05.1898 Weltner Jueg
Theromyzon tessulatum Theromyzon tessulatum 3527-Q Tegel 05.06.1887 Weltner Weltner
Piscicola pojmanskae Piscicola geometra 5131 Tegeler See 29.05.1891 Weltner Bielecki
Piscicola geometra 5131 Jueg
Piscicola sp. n. 5131 Bielecki
Erpobdella octoculata Herpobdella octoculata 5143 Tegel ? Weltner Johansson
Erpobdella octoculata Herpobdella vulgaris 9814 Tegel 00.12.1886 Collin Collin
Piscicola geometra Piscicola geometra 11213 Tegel-See, an der Unterseite von Brettstücken 25.04.1894 Weltner Bielecki
Coll. CeNak. Hamburg
Glossiphonia complanata Clepsine complanata V 12404 Tegeler See bei Berlin ? Quelle Augener inventory 1935; with „verrucata-like“ papillation
Hemiclepsis marginata Hemiclepsis marginata V 11067 Tegeler See, Berlin ? Qualle Augener inventory 1930
Erpobdella octoculata Nephelis octoculata V 11068 Tegeler See ? Qualle Augener inventory 1930


The original description of Glossiphonia verrucata can be found in the dissertation thesis „Hirudinibus circa Berolinum hucusque observatis” of Fritz Müller, but without any remark on the number of collected individuals and also on the fate of the material on which the description is based on (Müller 1844). Thus, it was rather surprising to find a considerable amount of his material in the collection of the ZIMG and that no material is present in the collection of the MfN (Hartwich 1986, Jueg 2015). The reason why the material of Müller is deposited in Greifswald is unclear, but he likely deposited all his dissertation material in the museum during his time in Greifswald where he studied medicine from 1845 to 1849. Moreover, Fritz Müller was already in contact with the founder and director of the Zoological Museum Greifswald, Christian Friedrich Hornschuch (1793-1850), during his dissertation work as he explicitly mentioned Hornschuch in the acknowledgements (Müller 1844).

The main distribution of Glossiphonia verrucata is restricted to the northern Palearctic (Jueg 2013). In Central Europe this species is extremely rare with the exception of the population reported from the river Danube where it was found from Bavaria to Hungary (Nesemann 1997, Nesemann and Neubert 1999). Since 1844, Lake Tegel is often cited as locality for this species (e.g. Johansson 1929, Autrum 1936, Herter 1968, Jueg 2013), but it was not found again since Müller´s study, which is also expressed clearly by Autrum (1936). Considering that G. verrucata is only rarely found (e.g. Jueg 2013), we safely assume that the material in the ZIMG is indeed the type material of this species. Thus, it is also negligible that the label of the type material was written later-on (likely with the entry in the catalogue in 1865). Regarding the occurrence of G. verrucata in Lake Tegel it is of interest, that Kalbe found one specimen in August 1961 around 25 km south of Lake Tegel in the “Jungfernsee” near Potsdam (Kalbe 1965). Both lakes are connected by the river Havel and Kalbe extensively worked in this area studying nearly 3.000 freshwater leeches. Thus, it can be concluded that G. verrucata is extremely rare in this area, but likely present in lakes connected by the Havel which should be addressed in future studies.


We are grateful to Henk Menkhorst (Krimpen aan den Ijssel, Rotterdam, Netherlands) for the translation of the dissertation of Fritz Müller. We further thank Birger Neuhaus (Museum für Naturkunde Berlin), Andreas Schmidt-Rhaesa and Helma Roggenbuck (both CeNak Hamburg, Germany) for provided access to the historical material of leeches in their collections. We thank Clemens Grosser and an anonymous reviewer for providing helpful comments on this manuscript.


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