Folia Fac. Sci. Nat. Univ. Masaryk. Brun., Biol. 110 (2007): 53-65 Newsletter on Enchytraeidae No. 10: Proceedings of the 7 th International Symposium on Enchytraeidae; May 25-28, 2006, Brno, Czech Republic Edited by J. SCHLAGHAMERSKÝ Fridericia brunensis sp. n. (Clitellata: Enchytraeidae) – a new European enchytraeid species similar to F. monochaeta Rota, 1995 JI ŘÍ SCHLAGHAMERSKÝ Masaryk University, Faculty of Science, Department of Botany and Zoology, Kotlá řská 2, 611 37 Brno, Czech Republic; e-mail: [email protected] ABSTRACT Fridericia brunensis sp. n. (Clitellata: Enchytraeidae), a species similar to F. monochaeta Rota, 1995 with single dorso-lateral chaetae in most postclitellar segments, preclitellar chylus cells, large seminal vesicle, large sperm funnels, and fused spermathecal ampullae is described based on material from a municipal forest of the city of Brno, Czech Republic. In comparison to its co-geners the species seems very tolerant to acidic and dry conditions. Additional records from Hungary and Germany are discussed. Keywords: Enchytraeidae, Fridericia, taxonomy, species description INTRODUCTION The newly described species was found during an ecological study of enchytraeids conducted in a municipal forest of the city of Brno (Czech Republic) in 2003-2004 (ŠÍDOVÁ & SCHLAGHAMERSKÝ, 2007). It was originally listed as F. cf. monochaeta due to its similarity with the recently described Fridericia monochaeta Rota, 1995 (SCHLAGHAMERSKÝ, 2007; ŠÍDOVÁ & SCHLAGHAMERSKÝ, 2007). As some characters differed from F. monochaeta , additional specimens were investigated later to clarify the taxonomic status of the Brno population. In a discussion with Prof. Klara Dózsa- 54 JI ŘÍ SCHLAGHAMERSKÝ Farkas, Dr. Rüdiger M. Schmelz and Dipl.-Biol. Ulfert Graefe following the presentation of a preliminary view on the taxonomic status of this population during the International Symposium on Enchytraeidae in 2006 (SCHLAGHAMERSKÝ, 2006) it became clear that this was indeed a species not yet described and apparently of a wider distribution, at least within Central Europe. The species seems also interesting from the ecological point of view as the localities at Brno are characterised by a dry and acidic soil; at the more extreme of the study sites it was found as one of only two to three enchytraeid species present (ŠÍDOVÁ & SCHLAGHAMERSKÝ, 2007; SCHLAGHAMERSKÝ & ŠÍDOVÁ, 2007). In general, Fridericia species are considered to avoid soils of such acidity (GRAEFE & SCHMELZ, 1999). MATERIAL AND METHODS Study sites The species was found in each of four circular plots (177 m 2 each) that were investigated in a municipal forest of the City of Brno (South Moravia, Czech Republic) situated on the north-west to east-facing slopes south-west of the city quarter Jundrov at an altitude of about 310 m a.s.l. Two plots in close vicinity (49°12'18"N, 16°32'41"E) were within the Holedná Game Preserve and two in the forest adjacent to this enclosure (49°12'11"N, 16°32'48"E; 49°12'16"N, 16°33'3"E). Each pair of plots represented one coniferous (spruce, pine, larch) and one mixed forest stand (with pine, beech, oak and black locust). The farthest distance between plots was ca. 400 m. The soil was illimerized podsol, the soil texture class silt loam, the humus form moder (to mor in the coniferous stands) and soil pH ranged between 3.9 and 4.7 in H 2O and 3.1 and 3.9 in KCl, respectively (range of mean values for each plot is given; the O L/F litter layer of 3 cm height and the underlaying organic and anorganic soil layers to an approximate depth of 12 cm were measured separately; for more detailed soil characteristics see ŠÍDOVÁ & SCHLAGHAMERSKÝ, 2007). Mean annual rainfall in the area is 550 mm and mean annual temperature 8 °C (ČERMÁK, 2003), these values indicate a wetter and colder climate than elsewhere within the city boundaries. Sampling and investigation of specimens During the above-mentioned ecological study based on monthly sampling from Dec. 2003 to Dec. 2004 (some preliminary samples were already taken in Nov. 2003) in all four circular plots (6 soil cores per plot), 1833 specimens of F. brunensis sp. n. were identified (as F. cf. monochaeta ). This included many juvenile specimens or those with immature sexual organs (identification was possible due to the characteristic chaetal formula and the low number of Fridericia species present) and the individual specimens were investigated with various intensity. Additional samplings (mostly in one plot only) on Nov. 4, 2005, March 20 Fridericia brunensis sp. n. – a new European enchytraeid species similar to F. monochaeta 55 and May 3, 2006 and Jan. 17, 2007 yielded altogether 135 specimens, 51 of which were subadults with more or less well-developed sexual organs and 16 adults with well-developed sexual organs, including seminal vesicle and clitellum, and mostly also with a yolky egg. All specimens were collected using a cylindrical soil corer of 17 cm 2 surface area and subsequent modified O’Connor wet funnel extraction (12 hours of cold extraction followed by heating of soil samples in 2003-2004; 48 hours of cold extraction without subsequent heating in case of the additional samples taken in 2005-2007). Extracted specimens were stored in Petri dishes with tap water at 5-8 °C prior to identification alive under the microscope. All specimens were investigated alive, all those collected since autumn 2005 using an Olympus BX 51 compound microscope with a magnification of up to 400x (optionally using Nomarski interference contrast). Relevant characters were recorded by digital microscopic photographs, free-hand drawings and notes taken. Four specimens were fixed in hot Bouin’s fluid, stained with paracarmine, and reinvestigated as whole mounts in Canada balsam (SCHMELZ, 2003). These have been deposited at the Natural History Museum (Dept. of Zoology) of the National Museum in Prague. In the following description, “viv” and “fix” refer to observations on living and preserved material, respectively. RESULTS Fridericia brunensis sp. n. Holotype: P6E2996; mature specimen, stained and whole-mounted. Type locality: Czech Republic, Brno-Jundrov, Holedná Game Preserve (49°12’N, 16°32’E); mixed forest, leg. Ji ří Schlaghamerský, 2007. Paratypes: P6E2996 (as holotype); three mature specimens, stained and whole-mounted. Same locality as above, leg. Ji ří Schlaghamerský, 2007. Material examined: 16 adult and 51 subadult specimens were investigated alive in detail, 4 of the adult specimens were whole-mounted and present the type series. Etymology: Brunensis is the Latin adjective of Bruna, the historic Latin name of Brno (Czech) or Brünn (German), the place from which the species is described and the author’s place of birth. Description: Medium-sized Fridericia species, length ca. 10 (7-12) mm (viv), diameter 0.25-0.3 mm at XII (viv), segment number 39-50. Chaetae: Formula (0, 1), 2 – (2), 1 : 2, (1) – 2 (1); laterally from XIV-XVII (mostly XIV or XV) to rear end only one chaeta; maximum length of chaetae 40 µm; often floating packages of chaetae in segments VIII-X. 56 JI ŘÍ SCHLAGHAMERSKÝ Epidermal gland cells present in three to five transverse rows, greyish, not conspicuous (observed in anterior segments). Body wall rather thin (ca. 20 µm). Brain (cerebral ganglion) elongate, ca. 90 µm long and 55 µm wide (fix), sides parallel, anteriorly rounded, posteriorly slightly rounded to truncate. Pharyngeal (“septal”) glands: Three mid-dorsally united pairs in IV-VI (Fig. 1 A). Oesophageal appendages (“peptonephridia”) unbranched, not coiled, with large lumen (particularly in proximal part), rather short - reaching up to VI (Fig. 2). Spermatheca : Ectal duct rather long (ca. 250 µm; width: 16 µm, somewhat wider close to ampulla - viv), with very small, sessile gland at its ectal orifice (Figs 1 A, 1 B, 2); ampulla (including “ental duct”) cylindrical, elongate, ca . 140 µm long and 50 µm wide (viv), with two large, bean-shaped diverticula (ca. 60 µm long and 25 µm wide); ampullae proximally broadly fused at about half their length, with common opening into oesophagus dorsally (Fig. 3). Coelomocytes (Fig. 1 C): Coelomo-mucocytes elipsoid, without refractile vesicles, “type a” (MÖLLER, 1971), ca. 25 µm long; coelomo-lenticytes small (ca. 7 µm). Nephridia (Fig. 1 D): Five pairs in preclitellar segments (VI/VII-X/XI). Alimentary channel with chylus cells in IX-XI (Fig. 4), occupying 1-2 segments, mostly including X; ventral gut endothelium in several posterior segments inflated (XXXV-XL). Dorsal blood vessel rising in XIV-XVI, most often in XV (Fig. 4). Clitellum usually girdle-shaped but in some specimens with very few gland cells ventrally. Seminal vesicle not always present, when present mostly very large (reaching across 2-3 segments), filled with red-brown spermatozoa (Fig. 4). Spermatozoa ca. 400 µm long (viv); heads ca. 140 µm long (viv), reddish brown to iridescent green to black. Sperm funnel large (about 1.3x as long as body width in XII), ca. 350 µm long and 80 µm wide (length : width ≈ 4 : 1), collar slightly narrower than funnel body (Figs 1 E, 5). Vas deferens 7 µm wide (viv). Male copulatory organ small (ca. 100 µm long and 50 µm wide - viv), bursal slit bent (concavity oriented laterally) with short transverse branches (Fig. 1 F). Subneural glands absent but a field of inflated cutaneous cells (somewhat similar to an area glareosa) present mid-ventrally in XIII, located medially behind ventral chaetal bundles (Fig. 6). One mature, yolky egg at a time. Differential diagnosis: The character combination of (1) a chaetal formula with single chaetae dorso-laterally on most postclitellar segments except the very first ones (XIII, XIV, rarely as far as XVI) and (2) proximally fused spermathecal ampullae, is shared only by two valid species of the genus known at present, i.e. F. connata Bretscher, 1902 and F.