DOI: 10.2478/s11686-008-0016-9 © 2008 W. Stefañski Institute of Parasitology, PAS Acta Parasitologica, 2008, 53(2), 158–164; ISSN 1230-2821 Redescription of Decorataria decorata (Spirurida, Acuariidae) based on nematodes from Podiceps cristatus and P.grisegena (Aves, Podicipediformes) from Bulgaria Yasen Mutafchiev and Boyko B. Georgiev* Central Laboratory of General Ecology, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113 Sofia, Bulgaria Abstract Decorataria decorata (Cram, 1927) is redescribed on the basis of light-microscopy and SEM observations on specimens col- lected from the stomach of Podiceps cristatus and P. grisegena from Bulgaria. The SEM study revealed the presence of a pore- bearing field on each pseudolabium and a pair of spines (one dorsal and one ventral) situated between bases of the cordons. The deirids are spine-like and minute. The light-microscopy examination showed the presence of ornamentation situated under the dorsal surface of caudal alae. The occurrence of D. decorata in Bulgaria is a new geographical record. Keywords Nematoda, Decorataria decorata, morphology, Podiceps, Bulgaria Introduction female nematodes was collected on 21 January 1993 from the same host species and the same locality. One male and two The morphology of Decorataria decorata (Cram, 1927), a female nematodes were collected from one P.grisegena on 16 stomach parasite of grebes, has been known from several April 1985 in the vicinity of the village of Garvan (44°07´N, light-microscopy studies (Cram 1927, Baylis 1937, Sobolev 26°55´E), Silistra Region. The nematodes were preserved in 1943 cited after Skryabin et al. 1965, Baruš and Zajíèek 1967, 70% ethanol. For light-microscopy, specimens were cleared Borgarenko 1972, Okulewicz 1980, Smogorzhevskaya 1990). and examined as temporary mounts in glycerine. Specimens Though the importance of SEM observations for the taxono- used for SEM observations (2 males and 2 females from P. my of the subfamily Acuariinae was demonstrated by several cristatus) were transferred from 70% ethanol to 40% ethanol studies (e.g. Wong and Anderson 1982, 1987; Digiani 1999; (10 min), rinsed in 0.1 M cacodylate buffer, post-fixed in 1% Frantová 2002; Díaz et al. 2004, 2005; Mutafchiev and Ge- OsO4 for 2 h, dehydrated in an ethanol series and critical-point orgiev 2008), the fine morphology of this species has never dried with CO2 using a BAL-TEC CPD 030. Specimens were been described. In the course of a survey of the acuariid nema- coated with gold-palladium in sputter coater Polaron SC7640 todes from Bulgarian birds, we found specimens of D. deco- and examined using a LEO VP 1540 microscope at 10 kV. rata from two grebe species, Podiceps cristatus (L.) and P.gri- Metrical data are given as the range, with the mean in segena (Boddaert). Their examination by light microscopy parentheses. Measurements are in micrometres except when and SEM provided new data of the variability and, for the first otherwise stated. time, ultrastructural information on this species. The results of The following indices were used: cordon length/body this study are reported in the present article. length = ICL/BL; length of muscular oesophagus/length of glan- dular oesophagus = ImOE/gOE; length of oesophagus/body length = IOE/BL; length of caudal alae/body length = ICA/BL; Materials and methods length of left spicule/length of right spicule = ILSP/RSP; distance from vulva to posterior end/body length = IV/BL. A sample of 7 male and 7 female nematodes was found under Voucher specimens are deposited in the Parasitic Worms the lining of the gizzard of P. cristatus on 5 October 1984 at Collection of the Natural History Museum, London, Nos. Durankulak Lake (43°40´N, 28°33´E), Dobrich Region, Bul- 2008.4.8.11–14. The remaining specimens are in the hel- garian Black Sea coast. Another sample of 10 male and 4 minthological collection of the Central Laboratory of Gen- *Corresponding author: [email protected] Redescription of Decorataria decorata from Bulgaria 159 Œl¹ski eral Ecology, Bulgarian Academy of Sciences, Sofia (CLGE), pair of papillae and field of numerous small pores situated collection nos. N000.654 (from P.grisegena); N000.655 (from anteriorly to amphids (Figs 10–13). Cordons arise dorsally P. cristatus); N000.866 (from P. cristatus); N001.036, two and ventrally between pseudolabia, extending in longitudinal females from P. cristatus, SEM stub; N001.037, two males direction and anastomosing laterally about level of first and from P. cristatus, SEM stub. second fifth of glandular oesophagus (Figs 1, 2 and 14); cutic- ular plates increasing their width in posterior direction and reaching maximum size in posterior half of cordons; deep, Results almost closed longitudinal groove present on outer edge of cordons. Deirids very small, spine-like, about 3 long, situat- Decorataria decorata (Cram, 1927) Skryabin, Sobolev et ed close to posterior end of cordons (Fig. 17). Postdeirids Ivashkin, 1965 (Figs 1–20) small, c.2 in diameter (Fig. 18). Pair of spines situated dorsal- Syn.: Echinuria decorata Cram, 1927; Acuaria (Echinuria) decora- ly and ventrally between bases of cordons (Figs 12 and 13). ta (Cram, 1927) Baylis, 1937; Syncuaria (Decorataria) decorata (Cram, 1927) Sobolev in Skryabin, Shikhobalova et Sobolev, 1949 Transverse cuticular striations present, interrupted along lat- eral sides of body (Fig. 18). Buccal cavity elongate. Excretory Description (based on specimens from P. cristatus from Du- pore at border between middle and posterior thirds of cordons. rankulak): Medium-sized acuariid nematode. Anterior end Nerve ring surrounding narrow anterior portion of muscular with 2 triangular pseudolabia, each bearing single amphid, oesophagus. Phasmids subterminal. Figs 1–9. Decorataria decorata: 1. Anterior end, male, lateral view. 2. Anterior end, female, lateral view. 3. Posterior end, female, lateral view. 4. Posterior end, vagina vera, ventral view. 5. Posterior end, vagina vera, lateral view. 6. Posterior end, male, ventral view. 7. Left spicule, sinistral view. 8. Right spicule, dextral view. 9. Egg. Scale bars = 250 µm (1, 2, 3, 6); 100 µm (4, 5, 7, 8); 20 µm (9) 160 Zdzis³aw Yasen Mutafchiev and Boyko B. Georgiev Stanis³a Figs 10–16. Decorataria decorata, SEM: 10. Anterior end, female, lateral view; note the cephalic papillae (arrows) and the amphid (arrow- head). 11. Pore-bearing field and an amphid. 12. Anterior end, male, note the spine situated dorsally (or ventrally) between bases of cordons and the cephalic papillae (arrows). 13. Anterior end, female, apical view; note the spine situated dorsally (or ventrally) between bases of cor- dons (arrow) and amphids (arrowheads). 14. Posterior end of cordons. 15. Posterior end, male; note precloacal papillae (arrowheads). 16. Posterior end, female. Scale bars = 10 µm (10); 2 µm (11); 20 µm (12, 13); 50 µm (14, 15, 16) Male (n = 17, except otherwise stated): Body length culate caudal papillae, 4 precloacal and 5 postcloacal (Figs 6 7.3–12.9 mm (10.4 mm). Maximum width 129–330 (246), in and 15); first precloacal pair of papillae at some distance from posterior half of body. Tail 212–346 (262) long. Body width at group formed by second and third pairs; fourth pair situated level of cloaca 84–134 (118). Cordons 1,032–1,925 (1,595) at level of cloca, consisting of bigger papillae. Postcloacal long and 73–111 (99) wide. Deirids and excretory pore at pairs of pedunculate papillae not grouped. Sixth pair of post- 1,050–1,925 (1,614) and 376–677 (516, n = 16), respective- cloacal papillae sessile, smaller, situated between bases of last ly, from anterior end. Buccal cavity (measured from anterior pedunculate papillae. Left spicule 386–460 (420, n = 16) long body end) 224–344 (300) long and 16–25 (22) wide. Muscular and 21–31 (26, n = 16) wide; distal end of spicule acute (Fig. oesophagus 478–860 (718) long and 45–72 (62) wide. Glan- 7). Right spicule 183–249 (206) long and 41–52 (47) wide dular oesophagus 2,087–3,609 (3,022) long and 79–113 (103) (Fig. 8). ICL/BL 0.136–0.187 (0.154); ImOE/gOE 0.204– wide. Nerve ring at 241–358 (319) from anterior end. Cuticle 0.294 (0.238); IOE/BL 0.297–0.454 (0.362); ICA/BL 0.072– thickness 8–11. Distance between cuticular striations 4–6. 0.108 (0.087); ILSP/RSP 1.85–2.29 (2.05, n = 16). Caudal alae 726–1,149 (903) long, transverse ornamentation Female (n = 11, except otherwise stated): Body length distinct under their dorsal surface (Figs 19 and 20). Single 10.5–16.6 mm (13.2 mm). Maximum width 264–424 (346), in median sessile precloacal papilla present. Nine pairs of pedun- posterior third of body. Tail 179–255 (221) long. Body width Redescription of Decorataria decorata from Bulgaria 161 Roborzyñski rosbœŸæv fjad kadsææ¿æ Figs 17–20. Decorataria decorata: 17. Deirid (arrowhead) and cordon anastomosis, male, SEM. 18. Postdeirid; note cuticular striation, SEM. 19. Caudal ala (the rectangle shows the area presented in Fig. 20), dorsal view, DIC light-microscopy. 20. Ornamentation under dorsal surface of caudal alae, DIC light-microscopy. Scale bars = 10 µm (17); 3 µm (18); 50 µm (19); 20 µm (20) at anus 87–124 (102), at vulva 358–494 (411). Cordons Czech Republic, Poland, Lithuania, Estonia, Ukraine, Mol- 1,674–2,270 (1,983) long and 116–170 (138) wide. Deirids dova, Russia, Azerbaijan, Georgia, Kyrgyzstan, Tajikistan and and excretory pore at 1,694–2,270 (1,999) and 541–700 (628), Kazakhstan (for surveys of the host range and the geographi- respectively, from anterior end. Buccal cavity (measured from cal distribution, see Smogorzhevskaya 1990 and Storer 2000). anterior body end) 322–371 (353) long and 23–30 (28) wide. This is the first record of D.