Tubificid oligochaetes are common and frequently dominant in freshwater benthic habitats. They are so tolerant to water pollution that they are often used as biological indicators. Faunistic studies of Korean freshwater oligochaetes have been actively conducted recently. The most well studied oligochaete family in Korea is the tubificids following the naidids. Nine species of tubificids have been reported so far. Nevertheless, many species of tubificids still remain to be discovered in Korea. In this study, we added four species of tubificid oligochaetes to the Korean fauna, including
Many species of Oligochaeta occur in a variety of freshwater environments such as puddles, rice paddies, reservoirs, brooks, rivers, and streams. About 1,700 species are known (Caramelo and Martínez-Ansemil, 2012). Oligochaetes are small-sized worms, ranging from 1 mm to a few centimeters in length. Tubificids are a dominant group found in freshwater benthic habitats among aquatic oligochaetes, and consequently bear ecological importance. Their bodies are red, and their reproductive organs are well-developed during maturity. When alive, their head is in the bottom sediment, usually gregarious in habitat and most commonly found in soft sediments covered with organic matter (Schenková and Helešic, 2006). Oligochaetes serve as an important source of food for fish and other aquatic animals as well as decomposers. Some oligochaetes have been used to monitor water pollution in rivers and streams (Lin and Yo, 2008). As a result of recent faunistic studies (Park et al., 2013a, 2013b), nine species of tubificids have been described in Korea, including
Specimens were collected from March−May 2013 from Gyochon-ri, Mokcheon-eup, Dongnam-gu, Cheonan-si, Chungcheongnam- do; Sinseong-ri, Hansan-myeon, Seocheon-gun, Chungcheongnam-do; Siljeon-ri, Hacheong-myeon, Geojesi, Gyeongsangnam-do, Korea. Aquatic oligochate samples were collected using a hand shovel at the edge of a stream covered with fine sand or sediment rich in organic material. In the laboratory, the samples were sorted under a stereomicroscope while the organisms were alive. They were fixed in 5% formaldehyde or 70% ethanol solutions, and the specimens were stained in alcoholic paracamine and mounted whole in Canada balsam following the protocol of Erséus (1994). Identification and measurements were performed using slide-mounted specimens. Figures and pictures were made with a BX41 research microscope (Olympus, Tokyo, Japan) attached to a 650D digital camera (Canon, Tokyo, Japan). Measurements were made with an eyepiece micrometer or by pictures taken and analyzed with InnerViewTM- i series image analyzing software (Innerview Co. Ltd., Seongnam, Korea). The figures were drawn with a microscope drawing tube. These mounted collections are stored in the Lab of Ecology Genetic (LEG), Department of Science Education, Ewha Womans University. Other materials, preserved in 70% ethanol, were submitted to the National Institute of Biological Resources (NIBR) of the Republic of Korea.
Phylum AnnelidaClass ClitellataOrder HaplotaxidaSuborder TubificinaFamily Tubificidae Vejdovský, 1884Genus Limnodrilus Claparède, 1862
1. Thick walled cuticular architomy and sheaths cylindrical, usually much longer than broad, surrounded by spiral muscles ∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙22. Penial sheath thin-walled, 50-80 times wider than sheath width ∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙L. claparedeianus Penial sheaths up to 7 times longer than broad, mwith hood reflected back over shaft unless forced forward ∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙L. profundicola* Length of penial sheath 4 times wider than sheath width ∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙L. udekemianus
* Species of present study.
Tubifex profundicola Verrill, 1871: 451.Tubifex profundicola Verrill. Smith, 1874: 699.vcLimnodrilus alpestris Eisen, 1879: 10.Limnodrilus monticola Eisen, 1879: 18.Limnodrilus alpestris Eisen, Vejdovsky, 1884: 45; Eisen, 1886: 896, Pl. II, fig. 11a-h; PI. XVII, fig. 11i-k; PI. XIX, fig. 18; Beddard, 1895: 254; Rybka, 1898: 390; Michaelsen, 1900: 44; 1914: 16, PI. V, fig. 5; Galloway, 1911: 315.Limodrilus monticola Eisen, Vejdovsky, 1884: 45; Eisen, 1886: 896, Pl. XI, fig. 10a-h; Beddard, 1895: 254; Michaelsen, 1900: 46; Galloway, 1911: 315.Clitellio (Limodrilus) alpestris (Eisen). Vaillant, 1890: 428.Clitellio (Limodrilus) monticola (Eisen). Vaillant, 1890: 427.Linmodrilus helceticus Piguet, 1913: 134, figs. 8-10.Limnodrilus helveticus Piguet. Piguet and Bretsher, 1913: 79, fig. 19b; Hrabě, 1954: 306; Juget, 1957: 3; 1958: 90, fig. 14a, b; Malevitch, 1957: 82; Sokolskaya, 1958: 310; 1961a: 56; 1961b: 85; Brinkhurst and Kennedy, 1962: 185; Moszynska, 1962: 27; Brinkhurst, 1963: 38, fig. 24a-e, 41, fig. 12g.Limnodrilus profundicola (Verrill). Brinkhurst, 1965: 130, fig. 4k-m.
Tubifex heuscheri Bretscher, 1900: 11, PI. I, figs. 1-4.Tubifex heuscheri Bretscher. Bretscher, 1905: 664; Piguet, 1906: 391; 1913: 127, fig. 4a, b.Ilyodrilus heuscheri (Bretscher). Piguet, 1913: 127; Stammer, 1932: 578; Jaroschenko, 1948: 57; Hrabě, 1950: 280; Juget, 1958: 89, fig. 141; Cekanovskaya, 1962: 260, fig. 159.Tubifex (Ilyodrilus) heuscheri Bretscher. Piguet and Bretscher, 1913: 69, figs. 14a, 7b.Ilyodrilus orientalis Cernosvitov, 1938: 545, figs. 16-23.Ilyodrilus orientalis Cernosvitov. Hrabě, 1950: 279.Euilyodrilus orientalis (Cernosvitov). Brinkhurst, 1963: 51.Euilyodrilus orientalis (Bretscher). Brinkhurst and Kennedy, 1962: 184; Brinkhurst, 1963: 49, fig. 34.
Prostomium short conical and separated by a distinct furrow. Ventral chaetae in II, 2-4 per bundle, with upper tooth straight, longer than the lower (Fig. 2A, B). Hair chaeta 1-2 per bundle, with pectinate chaetae, with relatively long and straight teeth and several slightly shorter intermediate denticles (Fig. 2C, D). Spermathecal chaetae mostly with narrow, hollow-tipped with parallel edges of the distal grooved portion, and with hooked distal end (Fig. 2E). Chloragogen cells from II onwards.
1. Prostates attached to anterior face of upright atria with broad apically and narrow gradually towards the penial bulbs, vasa deferentia frequently very long ∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙2 2. Chaeta bundle containing all chaeta types, muscular penial bulb present ∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙T. tubifex Chaetae are comparatively straight and thin in both anterior and posterior crotchets, penial with truncated conical, thick-walled. ∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙T. blanchardi*
* Species of present study.
Tubifex tubifex f. Blanhardi Vejdovsky, 1891
Ventral chaetae in II, 5-6 per bundle, with slightly longer upper tooth in anterior segments (Fig. 3A). Hair chaetae absent. Clitellum is muff-shaped and extends from mid segment X to the end of segment XII. Sexual organs in XI. Vasa deferentia coiled ducts, thin-walled inside, thick-walled outside (Fig. 3B). Penial with truncated conical, thick-walled inside with glandular cells (Fig. 3C).
Tubifex templetoni Southern, 1909: 140, Pl. VIII, fig. 6a-e; Friend, 1912: 292; Lastockin, 1927: 67; Brinkhurst, 1962: 326, fig. 1n; 1963: 23; 1965: 124, fig. 2e-g; Cekanovskaya, 1962: 275; Hrabě, 1962: 308; Kennedy, 1964: 228.Tubifex templetoni var typical Brinkhurst, 1963: 37, fig. 9d.Tubifex templetoni var walshi Brinkhurst, 1963: 42, fig. 9c; 1966: 736, fig. 1j-1.Ilyodrilus temletoni (Southern). Hrabě, 1966: 61, figs. 9-20.
[Fig. 4.] Ilyodrilus templetoni (Southern, 1909). A, Ventral chaeta II; B, Ventral chaeta III; C, Ventral chaeta V; D, Reproductive organs (a, vasa deferentia; b, prostate; c, penial sheath; d, atrium); E, Head plate of penial sheaths. Scale bars: A-C, E=1 μm, D=5 μm.
Ventral chaetae with the upper tooth slightly longer and thinner than the recurved lower tooth with no intermediate tooth, 2−5 per bundle (Fig. 4A−C). Vasa deferentia as long as the atrium. Chitinous penial sheath long, conical in their expanded proximal end in X, disto-lateral opening (Fig. 4D, E). Penial chaetae absent, no spermatozeugmata.