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 (, Acuariidae) based on 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 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 , 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; (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 . 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. decorata from Bulgaria. Accord- Muscular oesophagus 655–917 (800) long and 63–93 (76) ing to Smogorzhevskaya (1990), the records from hosts dif- wide. Glandular oesophagus 2,822–3,843 (3,414) long and ferent from grebes, i.e. Pluvialis apricaria (L.) (Charadrii- 107–152 (125) wide. Nerve ring at 349–402 (376) from ante- formes), Aythya fuligula (L.) and Anas platyrhynchos (L.) rior end. Cuticle thickness 8–9; distance between cuticular (Anseriformes), are doubtful. Therefore, this species ought to striations 5–7. Vulva at 358–494 (411) from posterior end; be regarded as a grebe specialist (Storer 2000). vulva protruding (Figs 3–5 and 16). Uterus monodelphic. The generic allocation of D. decorata is controversial. Vagina vera short, anteriorly directed (Figs 4 and 5). Vagina Chabaud (1975) and Wong et al. (1986) considered Decora- uterina long, with well-developed circular musculature in taria Sobolev in Skryabin, Shikhobalova and Sobolev (1949) walls. Uterus usually beginning with turn into posterior direc- (with type species D. decorata) as a synonym of Syncuaria tion (Fig. 3). Eggs oval, 32–34 × 19–21 (33 × 20, n = 20), con- Gil’bert, 1927. This taxonomic arrangement was followed by taining fully-developed embryo (Fig. 9). ICL/BL 0.118–0.177 Digiani (1999) and Zhang et al. (2003). However, Smogor- (0.153); ImOE/gOE 0.207–0.264 (0.235); IOE/BL 0.272– zhevskaya (1990) validated Decorataria on the basis of the 0.361 (0.323); IV/BL 0.025–0.039 (0.032). differences of the width of cordons, the size of the deirids and The specimens from P. grisegena have identical qualita- the degree of the lateral alae development. In the present tive characters with the above-described nematodes from study, we accept the opinion of Smogorzhevskaya (1990) as P. cristatus. For comparison of the metrical data, see Table I. justified and recognise Decorataria as valid on the basis of (1) its wide, not recurrent cordons, (2) small and spine-like dei- rids and (3) the lack of lateral alae. Currently, this in- Discussion cludes D. decorata and D. diacantha (Peter, 1961); the prob- able allocation of another similar species, Syncuaria plegadisi Cram (1927) described Decorataria decorata from Podiceps Digiani, 1999, in this genus requires further studies. auritus (L.) from the vicinity of Washington, DC, USA. The The specimens from Bulgaria have lesser body dimen- subsequent records of this species were mostly from grebes: sions in comparison with data from the original description Tachybaptus ruficollis (Pallas), Podiceps grisegena, P. nigri- (Table I). However, the size and morphology of the cordons, collis Brehm, P. cristatus and Aechmophorus occidentalis the number and position of the caudal papillae of males, the (Lawrence); its distribution is Holarctic: USA, Great Britain, size and the shape of the spicules and the shape of the female 162 Yasen Mutafchiev and Boyko B. Georgiev n = 2 n = 1 Bulgaria Present study Present n = 11 n = 17 Bulgaria P. cristatus P. grisegena 7.3–12.9 (10.4) 9.5 358–494 (411) 335–340 322–371 (353) 303–335 386–460 (420)183–249 (206) 411 190 264–424 (346)179–255 (221) 300–313 182–184 665–917 (800) 631–675 224–344 (300) 340 478–860 (718) 688 129–330 (246)212–346 (262) 268 225 1,674–2,270 (1,983) 1,387–1,561 1,032–1,925 (1,595) 1,401 – – (1990) Ukraine 7.2–16.0 10.5–16.6 (13.2) 10.7–10.9 300–500 250–400 360–430 179–200 160–320 168–240 530–810 220–350 500–700 180–280 200–220 6.0–10.0 2,000–3,200 2,822–3,843 (3,414) 3,055–3,360 1,900–2,400 2,087–3,609 (3,022) 3,436 n = 7 n = 5 (1980) Poland 410–480 300–360 380–440 190–230 200–240 340–400 660–730 260–340 620–760 240–330 250–270 Okulewicz Smogorzhevskaya T. ruficollis – 385 220 n = 4 n = 2 (1972) 385–401 440–550 132–176 198–220 297–350 770–900 630–700 330–370 Tajikistan P. cristatus P. cristatus, P. grisegena 1,650–2,640 2,010–2,310 998–2,040 1,485–1,520 1,050–1,630 860–1,490 , – – – (1967) 434–569 358–546 428–546 214–235 284–320 356–489 729–890 350–395 418–810 320–409 15.1–19.6 12.8–13.8 15.7–17.5 13.0–16.4 10.3–10.5 10.5–13.7 3,560–4,450 2,600–3,700 3,370–3,460 3,560–4,620 2,930–3,100 2,750–3,650 P. nigricollis , Tachybaptus ruficollis Tachybaptus – – – – – – – – – – – n = 6 n = 6 Baylis Baruš and Zajíèek Borgarenko (1937) 9.5–12.5 120–260 from various hosts and localities – – 457 207 199 315 316 714 300 340 14.0 Cram 1,900 1,100–1,650 1,850–2,400 3,400 (1927) 350–448 360–450 332–398 714–830 DC, USA England Czech Republic 15.0–17.5 11.5–13.5 1,900–2,700 1,150–1,350 2,510–3,320 Podiceps auritus P. cristatus P. cristatus D. decorata Metrical data of end, distance Vulva from posterior Vulva length Cordons, length Female Tail, length Tail, length Buccal cavity, Muscular oesophagus, length Glandular oesophagus, 3,200–3,800 Maximum body width Body length (mm) Left spicule, length Right spicule, length length Cordons, length length Muscular oesophagus, length Glandular oesophagus, Maximum body width length Tail, Buccal cavity, Male Body length (mm) Locality Table I. Table Source Host Redescription of Decorataria decorata from Bulgaria 163

posterior end correspond well with the original description kistana. Trudy Instituta Zoologii i Parazitologii AN Tadzhik- (Cram 1927). On the basis of these comparisons, we identify skoy SSR. Donish, Dushanbe, 39–47 (In Russian). our nematodes as D. decorata. Chabaud A.G. 1975. Keys to the genera of the order Spirurida. Part 2. Spiruroidea, Habronematoidea and Acuarioidea. In: (Eds. The metrical data of specimens from Bulgaria fit in the R.C. Anderson, A.G. Chabaud and A.G. Willmott) CIH keys to known range of morphological variation of this species. We the nematode parasites of vertebrates, No. 3. Commonwealth also did not detect substantial differences in the metrical data Agricultural Bureaux, Farnham Royal, Bucks, 58 pp. of the specimens from the two hosts studied from Bulgaria Cram E.B. 1927. parasites of the nematode suborder Stron- (Table I). gylata, Ascaridata, and Spirurata. US National Museum Bul- Our SEM study revealed the presence of a pore-bearing letin, 140, 1–465. Díaz J.I., Cremonte F., Navone G.T. 2004. First record of the acuari- field on each pseudolabium (Fig. 11) in both males and fe- oid nematode Paracuaria adunca from South America, with males that had not been reported previously. We confirmed the new morphological details and discussion of cordons. presence of spines situated between bases of the cordons (Figs Comparative Parasitology, 71, 238–242. DOI: 10.1654/4110. 12 and 13); these were illustrated (but not mentioned) in two Díaz J.I., Cremonte F., Navone G.T., Laurenti S. 2005. Adults and descriptions based on light-microscopy studies (Baruš and larvae of Skrjabinocerca canutus n. sp. (Nematoda: Acuari- Zajíèek 1967, Borgarenko 1972); none of the remaining idae) from Calidris canutus rufa (Aves: Scolopacidae) on the descriptions (Cram 1927, Baylis 1937, Okulewicz 1980, Smo- southern Southwest Atlantic coast of South America. Sys- tematic Parasitology, 60, 113–123. DOI: 10.1007/s11230- gorzhevskaya 1990) mentioned or illustrated these structures. 004-1379-4. Similar spines with the same position have been reported in Digiani M.C. 1999. First report of the genus Syncuaria (Nematoda: the descriptions of Decorataria diacantha (see Petter 1961, Acuariidae) in Argentina, with description of a new species. Digiani 1999) and Syncuaria plegadisi (see Digiani 1999), Folia Parasitologica, 46, 139–144. both parasitic in threskiornithid birds. The minute deirids of Frantová D. 2002. On the morphology and surface ultrastructure of D. decorata (Fig. 17) are also similar to those of D. diacan- some parasitic nematodes (Nematoda) of birds (Aves). Acta Societatis Zoologicae Bohemoslovenicae, 66, 85–97. tha and S. plegadisi (see Digiani 1999). In addition, we de- Mutafchiev Y., Georgiev B.B. 2008. A new acuariid nematode, scribe for the first time the postdeirids of D. decorata (Fig. 18, Syncuaria mackoi n. sp. (Spirurida), from Ciconia nigra (L.) SEM observations), which are not distinct by light-micros- (Ciconiiformes: Ciconiidae) in Europe. Systematic Parasitol- copy in our material), and the ornamentation situated under ogy, 70, 71–79. DOI: 10.1007/s11230-008-9138-6. the dorsal surface of the caudal alae (Figs 19 and 20, light- Okulewicz A. 1980. Wystêpowanie nicienia Decorataria decorata microscopy observations). Baruš et al. (1978) mentioned (Cram, 1927) Skrjabin, Sobolew et Iwaschkin, 1965 u per- kozka – Podiceps ruficollis (Pall., 1764) i perkoza dwu- transverse striation of caudal alae; however, their illustration czubego – Podiceps cristatus (L., 1758) w Polsce. Wiado- shows the presence of striation on the cuticular surface (cor- moœci Parazytologiczne, 16, 731–733. responding to that discernable in Fig. 15) rather than the orna- Petter A.-J. 1961. Un nouvel acuariide, Syncuaria diacantha, n. sp. mentation under the dorsal surface of alae (Figs 19 and 20). parasite de la spatule: Ajaja ajaja (L.). Annales de Parasit- ologie Humaine et Comparée, 36, 764–769. Acknowledgements. The light-microscopy facilities used were pro- Skryabin K.I., Shikhobalova N.P, Sobolev A.A. 1949. Spirurata and vided by the BioCore Project (leader Dr V. Peneva) with the financial Filariata. Opredelitel’ paraziticheskikh nematod. Volume 1. support of the National Science Fund, Ministry of Education and Izd. Akademii Nauk SSSR, Moscow-Leningrad, 519 pp. (In Science of the Republic of Bulgaria. SEM observations were carried Russian). out using facilities of the Museum für Naturkunde der Humboldt- Skryabin K.I., Sobolev A.A., Ivashkin V.M. 1965. Spirurata of Universität zu Berlin in the course of a research visit of the senior and Man and the Diseases Caused by Them. author granted by Synthesys DE-TAF-3124 (EC FP6) and kindly Spirurata. Part 3. Acuarioidea. In: (Ed. K.I. Skryabin) Osnovy hosted by Dr B. Neuhaus. Mrs G. Drescher of the same museum pro- Nematologii. Vol. 14. Izd. Nauka, Moscow, 572 pp. (In Rus- vided valuable assistance with the preparation of specimens for SEM sian). studies. Mrs E.A. Harris (Natural History Museum, London) helped Smogorzhevskaya L.A. 1990. Nematodes. Part 3. Acuarioidea. In: with some important literature. (Ed. V.P. Sharpilo) Fauna Ukrainy. Vol. 32. Naukova dumka, Kiev, 188 pp. (In Russian). Storer R.W. 2000. The metazoan parasite fauna of grebes (Aves: References Podicipediformes) and its relationship to the birds’ biology. Miscellaneous Publications Museum of Zoology, University Baruš V., Zajíèek D. 1967. Parasitic nematodes of birds of the order of Michigan, 188, 1–90. Colymbiformes in Czechoslovakia. Folia Parasitologica, 14, Wong P.L., Anderson R.C. 1982. The transmission and development 73–85. of Cosmocephalus obvelatus (Nematoda: Acuarioidea) of Baruš V., Sergeeva T.P., Sonin M.D., Ryzhikov K.M. 1978. Hel- gulls (Laridae). Canadian Journal of Zoology, 60, 1426– minths of fish-eating birds of the Palaearctic Region. 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(Accepted March 28, 2008)