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Catalogue of Invertebrate Collection deposited in the Department of Zoology, the University Museum, the University of Tokyo. Phylum Annelida (Classes Polychaeta and Myzostomida): A catalogue of Akira Izuka’s type and non-type polychaete collection in the University Museum, the University of Tokyo

Eijiroh Nishi1) and Katsuhiko Tanaka2)

1)Faculty of Education and Human Sciences, Yokohama National University, Tokiwadai, Hodogaya, Yokohama 240-8501, Japan
2)Global Oceanographic Data Center, JAMSTEC, 224-3 Toyohara, Nago, Okinawa 905-2172, Japan

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A set of polychaete specimens, collected and studied by Professor Akira Izuka from 1880s to 1910s (Meiji to Taisho Era), was discovered in The University Museum, The University of Tokyo,Japan. A total of 157 lots, including 71 species from 26 families, were found in the collection. Twenty-seven lots were judged as the type material of the following species: Panthalis mitsukurii Izuka, 1904; Nereis ijimai Izuka, 1912; Nereis dyamusi Izuka, 1912; Nereis japonica Izuka, 1907; Ceratocephale osawai Izuka, 1903; Aphrodite watasei Izuka, 1912; Glycera hasidatensis Izuka, 1912; G. chirori Izuka, 1912; G. onomichiensis Izuka, 1912; Hemipodus yenouraensis Izuka, 1912; Goniada japonica Izuka, 1912; Coelobranchus papillosus Izuka, 1912; Marphysa iwamushi Izuka, 1907; Diopatra sugokai Izuka, 1907; Polygordius ijimai Izuka, 1904. Here we provide a catalogue of the Izuka’s collection with related bibliographical, geographical, and taxonomic information. Four lots of Myzoostomida are also included in the sample.


Taxonomy is dependent upon access to literature, specimens, and data. Unfortunately, few collections have inventories that provide detailed information on the taxonomic, geographical and temporal distribution of their holdings. This condition forces taxonomists to spend significant time and resources travelling the world, and visiting various collections in search of additional material that would help validate their conclusions (Speers and Edwards, 2008). Cataloging forgotten old collections/specimens, particularly those including type material, and allowing an open access to the information will reduce the costs associated with of taxonomist’s determining the material location and obtaining access to this material, and may facilitate taxonomic and related research.

The polychaete collection of Professor Akira Izuka, the first polychaete taxonomist, accumulated from 1884 to 1919 (Meiji to Taisho Era) is housed in the University Museum, the University of Tokyo (abbreviated as UMUTZ-Ann-Pc). The collection consists of 157 jars in total, 116 of which are classified into 71 taxa, 89 lots are identifide into 43 species. The remaining 41 lots are not identified to the genus level because some samples are in a poor state of preservation or completely dried out, and others lack labels at all or the label information is missing. Those specimens were collected from 1884 to 1919, mostly off the Japanese coasts from Hokkaido to Okinawa, and some from foreign countries, such as Russia (Sakhalin Island, Baltic Sea) and Martha’s Vineyard, U.S.A. Some labels in the jars have collector’s name as “ A. Izuka” or “飯塚“(Fig. 1B-D, G).

Professor Akira Izuka was born in Gunma Prefecture on 16 June, 1868. He graduated in 1897 from and then worked as an associate professor (1900-1905) at the College of Science, Tokyo Imperial University (= currently the University of Tokyo). After being awarded the Doctor of Science degree in 1910 based on his intensive study of polychaetes, he worked as a professor of Gakushuin University(1910-1930)and as the director of the National Science Museum (1930-1938). Professor A. Izuka died on 10 December, 1938 (Mukai, 1985). He was the first Japanese polychaete researcher, because before his studies, the only paper on polychaete biology published by a Japanese researcher was that of Oka (1895). Professor Izuka’sstudies of taxonomy and life history of errant polychaetes from 1880s to 1910s (late Meiji to Taisho era) were summarized in a large monograph (Izuka, 1912). Before this monograph was published, 74 errant species had been known from Japan (Grube,1870; Marenzeller, 1879; McIntosh Challenger Report: Moore, 1903; Moore and Bush 1904; Izuka, 1912). He added 50 newly recorded species, including 32 new species, in his monograph (Izuka, 1912). Although Izuka (1912) might have overlooked some papers (e. g.,Marenzeller 1884, 1902a, b), and, for example, the description of Coelobranchus papillosus Izuka, 1912 was done without seeing Marenzeller’s description of the same species, some species have been considered to be valid up to now.

The Professor A. Izuka’s collection has not been re-examined after his death and was overlooked for a long time until Imajima (1972) had noted the Izuka’s material (see below). Professor A. Izuka’s contributions to the polychaete biology have been published in Zoological Magazine (= currently Zoological Science), Annotationes Zoologicae Japoneses, The Journal of College of Science,Tokyo Imperial University. He also contributed to a wide area of zoology, e.g., general zoology (1899a, b, c), bioluminescence (1897a), reproduction (1904b, 1906, 1930), local fauna (1896a, b, 1897b, 1919a, 1915, 1927), and introduction of alienspecies (1898, 1904d, e, 1908d,1910b, c, 1912a, 1913). We summarize his contribution to the polychaete biology in the references, including his famous books on Zoology and Developmental Biology (Izuka, 1906, 1907, 1931). His contributions to ornithology and other areas of science are not considered here.

The Professor A. Izuka’s collection is important because it contains a large number of type specimens of the Japanese polychaete species belonging to e.g., families Nereididae, Glyceridae and Acoetidae (=Polyodontidae). The non-type specimens also have both taxonomical and historical importance, especially for our knowledge of the original distributions of certain species in Japan. Because large areas of recent Japanese coasts are re-claimed and access to many places is restricted, we cannot collect useful material in some coastal and offshore areas. Additionally, recently many alien polychaetes were found in the Japanese waters (Nishi & Tanaka, 2009). The knowledge of the species distribution in older era is very important when we decide whether a certain species is a Japanese native species or an invader. For example, the Izuka’s collection contained a colony of a tubicolous invasive serpulid Hydroides elegans (Haswell), the oldest record of this species collected as fouling organisms in 1907 (=Meiji 41) on the hull of the battleship “Iki”.

In his review of Nereidae, Imajima (1972: 46) was the first to note a part of the Izuka’s collection when he cited the material of Tylorrhynchus heterochaetus (Quatrefages, 1865) as “A. Izuka coll.” (Sumida River, Tokyo, X-1910, (3). A. Izuka coll.). Miura (1986: 269) found the Izuka’s collection and shortly noted that “some of the type specimens studied by Izuka are now deposited at the University Museum, the University of Tokyo”. The first author (E.N.) also found some Izuka’s specimens and reported a scaleworm Panthalis mitsukurii Izuka (Nishi, 1996). Nishi had informed M. Sato about the presence of some Izuka’s Nereididae specimens (Sato and Nakashima, 2003). Some specimens had been studied by H. Paxton, M. Boeggeman, and R. Barnich through E. Nishi during 2000 to 2005 (Paxton,1998: Boggemann, 2002, 2005).

Among the Professor A. Izuka’ specimens, some myzostomid specimens were found. The Myzostomes had belongedto the the Class Polychaete, but recently this unique parasitic taxon has been considered to be a member of Class Myzostomida (e.g., Grygier, 2000, Bleidorn et al., 2007, Lanterbec et al., 2009). Here we treat it as the Class Myzostomida.

During our examination of the specimens deposited at of the University Museum, the University of Tokyo from 1995 to 2005, and continuous to 2010, we discovered 157 lots of the Izuka’s polychaete collection, 26 families and 71 species, including type material of fifteen species. Unfortunately, the types of other species could not be found, possibly because they were discarded or destroyed by the Great Kanto Earthquake of 1923. We present here the catalogue of the Professor A. Izuka’s collection with the current status of each specimen and the related bibliographical, geographical and taxonomic information. Some specimens have been dried out or damaged, and some lots have useless labels or no label at all. However, we deposited and catalogued all available specimens for further taxonomic research. The current paper is a first attempt to catalogue classic Japanese polychaete collections. Out of 38 species described by Professor A. Izuka, we report specimens (marked with asterisk) of 15 species clearly judged as types.

Material examined

All specimens have been stored in glass bottles. Alcohol remained in some bottles (noted as wet - good), but it completely evaporated in others, making the specimens dried out.

The scientific names were determined by us based on examination of specimen’s external morphologies and by reference to the label data. Some specimens were studied and identified by other scientists who are noted in the remarks.

The list was compiled according to the recent system WoRMS (World Register of Marine Species) database found at http://www.marinespecies.org/aphia.php. For each specimen or lot, the scientific name and collecting information are provided in the following order: 1, current name (as identified by us); 2, reference to the original description (=reference) in type specimens; 3, registration number of UMUTZ-Ann-Pc; 4, type status; 5, collecting locality; 6, collecting date; 7, collector(s) name; 8, number of specimens in the jar; 9, original label data (if it is written by Japanese, English translation and original Japanese are noted; if we cannot identify the written word(s), it is expressed as ○); 10, specimen condition as good (wet), dried, rotten or dissolved (wet); 11, remarks; 12, reference(s). When the lot had no label, collecting locality, collecting date, collector’s name, label data, remarks and references were omitted. But when specimens were identified or information was obtained from the literature, remarks and references were added. Some scanned labels are shown in Figures 1(B-J) and 2.

Decisions about type series

Many type specimens were discovered in the marine organism collections of UMUTZ. Among the materials, some specimens of Porifera were labeled as “types” (Ogawa et al., 2010) and others have not been labelled as “type” or “holotype”. In the Sipunculidan specimens of UMUTZ, there are no designation of “type” and “holotype” in labels, and instead, some jars contained labels where species names were followed by “n. sp.” written by the author of the original description (Nishikawa and Ueshima, 2006). When the label information was consistent with the original descriptions, the specimens in such jars were regarded as name-bearing types (Nishikawa and Ueshima, 2006). In the polychaete materials deposited in UMUTZ, some jars had labels with the species name followed by “n. sp”, possibly hand-written in pencil by Professor A. Izuka. Those hand-written signature (e.g., Fig. 1C) were thought to be same as one appeared in Izuka (1931: Fig. 1A) - Izuka Developmental Zoology, Hakubunkan, Tokyo.

Digitization and databasing

The information of Professor A. Izuka’s specimens catalogued in the present study was compiled in a Microsoft Exel format and submitted to the University Museum, the University of Tokyo, to facilitate online publication from the database < /DDoubutu/TDoubutu.php>.


Professor A. Izuka’s material contains 15 type specimens, and based on this material, validity and synonymies will be studied in the future. Some species of this type series have been already studied (Boggemann, 2002; Nishi, 1996; Sato and Nakashima, 2003), and some work on Nereididae samples is currently beingdone by Dr. Sato, M. (Sato et al. 2006). Because some jars had no labels, it was impossible to determine the collection data from those samples. We will continue studying these materials based on the literature.

An interesting finding in these samples is the oldest records of them, especially those of Hydroides elegans (Haswell, 1883) collected from the hull of the battleship "Iki". Hydroides elegans (Haswell, 1883) is probably the most widespread harbour-fouling serpulid in tropical and subtropical areas in both Old and New World (ten Hove, 2003) and one of the most famous alien fouling species in worm waters world-wide (e.g., NIMPIS, 2002, Pettengill et al. 2007, Masterson, 2007, Read, 2009). Although it is very difficult to reconstruct its center of origin, ten Hove (2003) hypotheszed that the Australian origin the most likely because the natural occurrence of the species on certain sea-weeds and the depth in 20 m at the time of its discovery in 1883 (Allen, 1953). And it had been introduced in harbours from the natural populations within Australia, then further in Meditteranean etc. In Mediterranean harbours, the oldest record of H. elegans is at Naples goes back to 1888 (Zibrowius, 1992). In Japan and adjacent waters, the oldest record was at Seto, Wakayama in 1928 (Nishi & Tanaka, 2008), and now at an unknown localities in 1908 (this study). Taxonomy of this species was studied by Bastida-Zavala & ten Hove (2003) and it is proposed as a model organism for biofouling research by Nedved & Hadfield (2009). Hydroides elegans has relatively limited larval dispersal, but its wide distribution in the Atlantic, Pacific, and Indian Oceans and in the Mediterranean Sea has been achieved by regular and consistent transport of adults and larvae on the hulls and in the ballast water of ships, respectively (Pettengill et al., 2007). This species was possibly widely distributed in Japanese and adjacent waters even in Meiji era around 100 years ago, thus, fouling was an effective strategy of extending its distribution range.

World Register of Marine Organisms (WoRMS) lists many Japanese polychaetes. Based on the WoRMS database and recent taxonomic papers, the following 16 species described by Professor A. Izuka are valid:

1) Notophyllum sagamianum Izuka, 1912 (WoRMS)

2) Glycera onomichiensis Izuka, 1912 (WoRMS)

3) Aphrodita watasei Izuka, 1912 (WoRMS)

4) Diopatra sugokai Izuka, 1907 (WoRMS)

5) Notopygos mitsukurii Izuka, 1910 (WoRMS)

6) Polygordius ijimai Izuka (1903), accepted as the original name (Rota & Carchini, 1999)

7) Panthalis mitsukurii Izuka, 1904, accepted as Eupolyodontes mitsukurii (Izuka, 1904), however, Fiege & Barnich (1998) have recorded as synonym of E. gulo.

8) Panthalis jogasimae Izuka, 1912 accepted as Acoetes jogasimae (Izuka, 1912) (WoRMS)

9) Harmothoe holothuricola Izuka, 1912 (valid?)

10) Harmothoe yendoi Izuka, 1912 (WoRMS)

11) Harmothoe sinagawaensis Izuka, 1912 - accepted as Arctonoella sinagawaensis (Izuka, 1912) (Buzhinskaja, 1967)

12) Tomopteris (Johnstonella) pacifica (Izuka, 1914) accepted as Tomopteris pacifica Izuka, 1914 (WoRMS)

13) Nereis japonica Izuka, 1908 accepted as Hediste japonica (Izuka, 1908) (Sato and Nakashima, 2003)

14) Nereis ijimai Izuka, 1912 accepted as Nectoneanthes ijimai (Izuka, 1912) (WoRMS)

15) Ceratocephale osawai Izuka, 1903 is accepted as Tylorrhnchus osawai (Izuka, 1903) in Sato et al. (2006)

16) Polynoe microsetosa Izuka, 1912 - Lepidasthenia microsetosa (Izuka, 1912) as Showapolynoe microsetosa (Izuka, 1912) – Imajima (1997).

And following twelve species described by Professor A. Izuka are not valid:

1) Lepidasthenia longissima (Izuka, 1912) accepted as Lepidasthenia izukai Imajima & Hartman, 1964 - non-valid? - Fauvel (1936)

2) Glycera chirori Izuka, 1912 is a synonym of G. nicobarica Grube, 1868 (Boggemann, 2002)

3) Glycera hasidatensis Izuka, 1912 is a synonym of G. macintoshi Grube, 1877 (Boggemann, 2002)

4) Glycera misakiensis Izuka, 1912 is a synonym of G. pacifica Kinberg, 1865 (Boggemann, 2002) or accepted as G. americana Leidy, 1855 (WoRMS)

5) Nereis ezoensis Izuka, 1912 accepted as Nereis vexillosa Grube, 1851 (WoRMS)

6) Nereis dyamusi Izuka, 1912 accepted as Alitta virens (M. Sars, 1835) (WoRMS)

7) Nereis ezoensis Izuka, 1912 accepted as Nereis vexillosa Grube, 1851 (WoRMS)

8) Nereis shishidoi Izuka, 1912 accepted as Cheilonereis cyclurus (Harrington, 1897) (WoRMS)

9) Marphysa iwamushi Izuka, 1907 accepted as Marphysa sanguinea (Montagu, 1815) (WoRMS)

10) Eunice flavopicta Izuka, 1912 accepted as Eunice aphroditois (Pallas, 1788) (WoRMS)

11) Vanadis grandis Izuka, 1914 accepted as Vanadis longissima (Levinsen, 1885) (WoRMS)

12) Callizona japonica Izuka, 1914 accepted as Rhynchonereella gracilis Costa, 1864 (WoRMS)

In general, there are three patterns of taxonomic works involving re-examination of types and older important material. The first is concentrated on taxa (genera, family, etc.) (e.g., Boggemann, 2002), the second examines the material studied by a particular researcher (e.g., Loi, 1980 on material of J. Percy Moore and Hartman, 1949 on material of Kinberg), and the third one deals with the material deposited in a particular museum or institution (e.g., Fiege & Wehe, 2004; Solis-Weiss et al., 2004; Nishi & Kupriyanova, 2011). This work is the first study of the second type among Japanese annelids studies. As a result of this work on Izuka’s materials, older samples collected by other Japanese researchers such as Okuda Shiro, Kitamori Rhonosuke, Takahashi Keizo and T. Fujiwara will become the focus of attention. The material studied by Prof. Okuda Shiro material has been deposited in Hokkaido University (T. Kato, pers. comm.). Nishi et al. (2007) unsuccessfully searched for Kitamori’s lost samples, particularly those of Pilargiidae Sigambra and related specimens, so his samples may be lost. There is also no information on materials of K. Takahashi and T. Fujiwara.


We would like to thank M. Aizawa, A. Sakamoto, and R. Ueshima for giving us the chance to study the old samples of UMUT. We also thank E. Kupriyanova for linguistic corrections and assistance in editing the manuscript, M. Sato, T. Kato, T. Miura, R. Barnich, M. Boggemann, and H. Paxton for their help in identifyng the specimens and giving us useful information on the samples. This work is partly suppoted by KAKENHI (No. 225101).

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