Descriptions of Wardula Bartolii N. Sp.(Digenea: Mesometridae) and Three Newly Recorded Accidental Parasites of Boops Boops L.(Sparidae) In the NE Atlantic

Systematic Parasitology (2006) 63:99–109 DOI 10.1007/s11230-005-9003-9 Ó Springer 2006 Descriptions of Wardula bartolii n. sp. (Digenea: Mesometridae) and three newly recorded accidental parasites of Boops boops L. (Sparidae) in the NE Atlantic ´ ´ Ana Perez-del Olmo,*, David I. Gibson, Mercedes Fernandez, Oscar Sanisidro, Juan Antonio Raga & Aneta Kostadinova Marine Zoology Unit, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, PO Box 22 085, 46071, Valencia, Spain 2 Department of Zoology, Natural History Museum, London, SW7 5BD, UK 3 Central Laboratory of General Ecology, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113, Sofia, Bulgaria Accepted for publication 15th 4, 2005 1 Abstract Four species of digeneans parasitic in the bogue Boops boops from the Spanish coast of the NE Atlantic are described. All are new records for this host, but one species is new and the other three are considered to be accidental parasites. Wardula bartolii n. sp. (Mesometridae) is distinguished from its two congeners on the basis of a range of morphometrical features, such as the post-ovarian extent of the uterus, the relative length of the attachment organ, the position of the pharynx and vitelline fields, and the absence of anterior caecal diverticula. The other three species are Lecithaster confusus Odhner, 1905, Aponurus laguncula Looss, 1907 (Lecithasteridae) and Accacladium serpentulum Odhner, 1928) (Accacoeliidae). Introduction The parasite fauna of the bogue (‘boga’) Boops boops L. is relatively well known in the Mediterranean, where large samples of fish have been studied and contrasted to the NE Atlantic situation (Renaud et al., 1980; Anato et al., 1991). In a study of the biodiversity and geographical variations of parasite communities in B. boops along the Spanish coasts of the NE Atlantic, we found four digenean species not previously reported from this host, including a species from the mesometrid genus Wardula, which we believe is new to science. This paper describes W. bartolii n. sp., the lecithasterids Lecithaster confusus Odhner, 1905 and Aponurus laguncula Looss, 1907, and the accacoeliid Accacladium serpentulum Odhner, 1928, recovered from B. boops off the Atlantic coast of Spain. *Author for correspondence (E-mail: ana.perez-olmo@uv.es) Materials and methods A total of 120 B. boops from three localities (off Malpica and Vigo, Galicia, and off Ondarroa, Basque Country) on the Spanish NE Atlantic coast was collected and examined during 2001 and 2004. Worms were recovered from fresh or, in the cases of Accacladium serpentulum and a few specimens of Wardula bartolii n. sp. collected from off Vigo and Ondarroa, from frozen fish, fixed in cold 70% alcohol, stained with iron acetocarmine (Georgiev et al., 1986), dehydrated through an alcohol series, cleared in dimethyl phthalate and examined as permanent mounts in Canada balsam. Measurements are taken from illustrations, made using a drawing apparatus. All measurements are presented in micrometres. Type-material and voucher specimens are deposited in the Natural History Museum (BMNH), London. 100 Family Mesometridae Poche, 1926 Genus Wardula Poche, 1926 Wardula bartolii n. sp. Material studied Specimens from Boops boops L. (type-host). Rectum. NE Atlantic coasts of Spain: off Malpica, Galicia (type-locality) (12.v.2004; prevalence 23.3%; mean intensity 12.3); Vigo, Galicia (18.v.2001; prevalence 3.3%; intensity 1.0); and Ondarroa, Basque Country (6.vi.2001; prevalence 3.3%; intensity 1.0). Type-material: Holotype BMNH 2005.4.18.1; paratypes BMNH 2005.4.18.2-13, 2005.4.18.14-15. Etymology: We name the new species for Professor ´ Pierre Bartoli, Centre d’Oceanologie de Marseille, in recognition of his major contribution to the morphology, taxonomy, life-history studies and evolution of the Mesometridae. Description (Figures 1, 2) Based on 16 whole-mounted adult specimens; metrical data in Table 1. Body elongate, fusiform, with rounded extremities and maximum width in posterior third of body. Anterior part of body slightly narrower than, and delineated from, remainder of body by shallow constriction (Figure 1), somewhat leaf-like and concave ventrally (concavity referred to as ‘attachment organ’ by Bartoli & Gibson, 1989). Tegument armed with very fine spines, observed in only few specimens as they are readily lost in fixed material. Numerous eye-spot pigment granules dispersed in parenchyma of prepharyngeal region. Small pre-oral lobe, clearly seen in lateral view, present in most specimens. Oral sucker ventrally subterminal, subspherical, with buccal ridges furnished with blunt sclerotised denticles which appear to form 1 or 2 transverse arches in ventral view (Figure 2A,B). Ventral sucker absent. Prepharynx very long (30–38% of body length), narrow, with thin wall, difficult to see. Pharynx (‘oesophageal bulb’) subconical, with wide lumen, enlarged to form bulb posteriorly (Figure 2C); inner wall sclerotised, transparent, linked to prepharynx through relatively thick projection forming tulip-like structure at junction between pharynx and prepharynx; this structure consists of 6 pieces whose lateral margins merge at mid-level of pharynx (Figure 2C); outer layers of pharyngeal wall comprised of fine circular muscle fibres covering layer of inner longitudinal muscles with rugged appearance. Two groups of small gland-cells surround anterior and posterior extremities of pharynx (Figure 2C). Oesophagus absent. Intestinal caeca 2, relatively narrow but swollen posteriorly in most specimens, end blindly close to anterior margin of anterior testis; anteriorly oriented diverticula absent. Testes 2, round to transversely-oval, tandem to somewhat oblique, contiguous in posterior quarter of body. Cirrus-sac absent. Long, tubular, convoluted seminal vesicle free in parenchyma, difficult to distinguish, extends from about level of intestinal bifurcation to about anterior third of attachment organ. Pars prostatica indistinct; prostatic sac (terminology of Bartoli & Gibson, 1989) absent. Ejaculatory duct difficult to distinguish. Genital pore mid-ventral, at level of posterior margin of oral sucker. Ovary entire, transversely elongate-oval, contiguous with posterior testis or separated from it by loop of uterus. Mehlis’ gland similar in size to ovary, contiguous with and dorsal to posterodorsal to ovary. Uterine seminal receptacle present just anterior to testes. Uterus forms small loop ventral or slightly posterior to ovary and fills intercaecal region of body between level of anterior testis and pharynx. Metraterm not observed. Vitellarium in 2 lateral fields of relatively small number (see Table 1) of large follicles; fields mostly ventral to caeca and extend between anterior testis and level some distance posterior to pharynx (Figure 1A). Eggs numerous, operculate, large and rather elongate. Excretory system reticular (Figure 1B). Excretory pore wide, dorso-subterminal. Remarks The material described above belongs to the Mesometridae Poche, 1926 because of the absence of a ventral sucker and cirrus-sac, the presence of an accessory attachment organ and the reticulate excretory system (see Bartoli & Gibson, 1989). It shows affinity to the Wardulinae Paggi & Orecchia, 1964 with respect to the structure and distribution of vitellarium and the position of the testes (see Paggi & Orecchia, 1964; Bartoli & Gibson, 1989). 101 Figure 1. Wardula bartolii n. sp. ex Boops boops. A. Holotype, ventral view, anterior end twisted to one side partly obscuring ‘attachment organ’; B. Terminal regions of male (left) and female ducts illustrated separately (uterus usually obscured by male duct); C. Excretory system. Scale-bar: A,C, 500 lm. The worms from our collection exhibit similarities with both known species of Wardula, i.e. W. capitellata (Rudolphi, 1819) and W. sarguicola Bartoli & Gibson, 1989, but in different combinations of features. They resemble W. sarguicola in body dimensions and the slight extension of the uterus 102 Figure 2. Wardula bartolii n. sp. ex Boops boops. A. Oral sucker, lateral view; B. Oral sucker, ventral view; C. Pharynx. Scale-bars: A,B, 200 lm; C, 100 lm. posterior to the ovary. However, the body of W. bartolii n. sp. appears more robust, with a much wider attachment organ which represents a larger proportion of body length; and the oral sucker and pharynx are larger, the latter also being situated more posteriorly. Furthermore, the gonads of our specimens are distinctly transversely elongate (versus subspherical) and located more posteriorly, the vitelline fields overlap the caeca ventrally (versus intercaecal in W. sarguicola), a prostatic sac is absent, the genital pore is located at the level of the posterior margin of the oral sucker (versus well posterior to this level) and the eggs are distinctly larger (mean 84 Â 40 versus 71 Â 28lm; see Table 1 for metrical data). W. bartolii n. sp. appears more closely related to W. capitellata, especially in the presence of buccal ridges with sclerotised denticles inside the oral sucker, the posterior location of the testes and ovary which are also contiguous, the distribution of the vitelline follicles and the location of the genital pore at the level of oral sucker. The new species can be distinguished from this form, which has only been recorded from Sarpa salpa in the Mediterranean, in its distinctly smaller body (well outside the range for W. capitellata), resulting in the smaller dimensions (both ranges and means) for most features (e.g. lengths of prepharynx and both preand post-pharyngeal body-regions, size of gonads, etc.; see Table 1). The attachment organ of W. bartolii is shorter and wider in relation to body length, and is not as muscular as that described for W. capitellata (see Bartoli, 1987). Furthermore, the caeca lack anterior diverticula, and the more anteriorly located pharynx exhibits a peculiar sclerotised structure of the inner lining. The peculiar inner structure of the oral sucker, i.e. the multidenticulate ridges which appear common in mesometrids (but see Bartoli & Gibson, 1989), has been interpreted by Bartoli (1987) as a formation adapted to the intestinal microhabitat of the parasites (i.e. acting as a microfilter for an intestinal chyme dominated by algal fibres in the herbivorous Sarpa salpa). It is possible that the tulip-like sclerotised oesophageal structure we observed in W. bartolii is also related to preventing the entrance of plant material into the intestinal caeca. Family Lecithasteridae Odhner, 1905 ¨ Genus Lecithaster Luhe, 1901 Lecithaster confusus Odhner, 1905 Material studied Specimens (2) from Boops boops L. Intestine. NE Atlantic (off Malpica, Galicia, Spain, 12.v.2004). Voucher: BMNH 2005.4.18.18. Description (Figure 3A) Based on 2 adult specimens. Body elongate-fusiform, 469–515 long, widest at level of ventral sucker, Table 1. Comparative table for metrical data (in micrometres) of Wardula spp. W. bartolii n. sp. Boops boops NE Atlantic (off Malpica, Spain) Present study Range Mean 3,897 680 736 15 223Â 223 1,330 2,422 1,096 170 Â 121 279 Â 368 294 Â 354 – 150 Â 147 101 Â 122 21, 17 84 Â 40 1,427 3,087 317 249 36.8 – 204 Â 217 2,877 4,501 2,646 172 Â 111 434 Â 470 438 Â 434 – 229 Â 214 – – 77 Â 39 – – – 253 39.1* 79.1 34.0 17.7 1,608 821 – 39.1 – 3,018 1,294 61–65 – – – – 6,481–8,713 744–999 7,359 861 2,231–4,038 319–638 3,140–5,034 500–940 561–982 9-44 167–289 Â 149–298 1,052–1,859 2,000–2,999 833–1,535 128–228 Â 93–162 219–360 Â 267–517 226–351 Â 267–482 Absent 96–197 Â 104–219 70–140 Â 75–175 14–30, 11–20 75–94 Â 33–47 1,131–1,745 2,438–4,192 184–406 145–351 33.2–43.9 76.5–83.3 29.9–37.6 12.0–23.0 1,272–2,149 684–991 W. capitellata (Rudolphi, 1819) Species Host Locality Sarpa salpa Mediterranean (Scandola Nature Reserve, Corsica) Bartoli (1987) Range Mean 3,060 468 Source W. sarguicola Bartoli & Gibson, 1989 Diplodus sargus Mediterranean (Scandola Nature Reserve, Corsica) Bartoli & Gibson (1989) Range Mean Body length Body width at: attachment organ posterior body Pre-oral lobe length Oral sucker Prepharyngeal region length Postpharyngeal region length Prepharynx length Pharynx Anterior testis Posterior testis Prostatic sac Ovary Mehlis’ gland No. of vitelline follicles per field (right, left) Eggs (n=41) Attachment organ length Pretesticular field Posttesticular field Postovarian field Attachment organ as % of body length – 98–165 Â 93–173 511–1,169 1,412–2,933 506–999 109–152 Â 76–96 245–394 Â 245–378 229–362 Â 213–368 109–239 Â 63–100 144–213 Â 149–213 – 30 in total 65–78 Â 24–35 630–960 1,470–2,550 309–1,039 171–656 22–29 – 132 Â 137 839 2,063 735 126 Â 85 291 Â 300 292 Â 285 167 Â 81 175 Â 179 – – 71 Â 28 764 1,913 571 336 25 63 – – – – Pretesticular field as % of body length Prepharynx as % of body length Attachment organ width as % of body length Posterior end of pharynx to anterior testis Anterior end of anterior testis to posterior body end – 160–277 Â 187–288 2,550–3,549 3,549–5,249 2,252–3,188 133–213 Â 85–133 336–533 Â 384–533 336–533 Â 384–480 Absent 203–256 Â 165–240 – – 72–85 Â 30–43 – – – 149–352 39.3–40.7* 41.5** 83.4** 39.3–40.7* 38.4** 11.9** 2,447–3719 1,084–1,594 * 103 ** Estimated from published data (range, mean). Calculated from published drawing. 104 Figure 3. A. Lecithaster confusus Odhner, 1905 ex Boops boops, lateral view; B. Aponurus laguncula Looss, 1907 ex Boops boops, lateral view. Scale-bar: 100lm. 105 117–146. Tegument unarmed. Pre-oral lobe small, 8–10. Oral sucker subterminal, spherical, 58– 75 Â 54–72. Ventral sucker large, subspherical, in anterior half of body, 82–96 Â 85–96. Suckerwidth ratio 1:1.33–1.57. Forebody 34.5–34.8% of body length. Pharynx subglobular, 35 Â 30. Oesophagus absent, ‘Drusenmagen’ distinct. Caeca ¨ wide, terminate at c.50 from posterior extremity. Testes subglobular, symmetrical, just posterior to ventral sucker, 43–51 Â 40–46. Seminal vesicle saccular, elongate-oval, 64–88 Â 29–40, reaches level of testes posteriorly. Pars prostatica 48–128 long; prostatic cell field width 16–43. Sinus-sac somewhat banana-shaped (Figure 3A), 48 Â 14–19. Genital opening just posterior to level of pharynx. Ovary 4-lobed, 48–83 Â 40–58. Seminal receptacle dorsal to posterior ovarian lobes, relatively small, 24 Â 42. Uterine coils between vitellarium and ventral sucker. Eggs 18–19 Â 10–12. Vitellarium consists of 7 tear-shaped lobes; overall field 74– 77 Â 56–74. Post-vitelline region 7.8–13.6% of body length. Remarks Our material is morphologically very close to, and we have identified it as, L. confusus. However, both worms from B. boops, although bearing many eggs, are rather small, and this results in all metrical data falling within the lower ranges of variation reported by Linton (1940) and Overstreet (1973) (see Table 2) for specimens from the Northwest Atlantic. While egg-size corresponds well with the known range for L. confusus, the sucker-ratio is distinctly smaller, the forebody is relatively longer and the postvitelline region shorter (Table 2); but these are likely allometric differences relating to the small size of our worms. B. boops is a new host record, and likely an accidental host, for L. confusus. Genus Aponurus Looss, 1907 Aponurus laguncula Looss, 1907 Material studied Single specimen from Boops boops L. Stomach. NE Atlantic (off Malpica, Galicia, Spain, 12.v.2004). Voucher: BMNH 2005.4.18.17. Description (Figure 3B) Based on 1 ovigerous specimen. Body small, fusiform, widest at level of ventral sucker, 390 Â 143. Tegument unarmed. Pre-oral lobe 10. Oral sucker subterminal, spherical, 56 Â 56. Ventral sucker subglobular, at mid-body, 77 Â 87. Sucker-ratio 1:1.55. Forebody 42.6% of body length. Pharynx subglobular, 30 Â 26. Oesophagus virtually absent. ‘Dru¨ senmagen’ distinct. Caeca wide, terminate at level of posterior vitelline follicles. Testes oval, oblique; right testis elongate-oval, overlapping ventral sucker dorsally, 69 Â 41; left testis transverse-oval, just posterior to ventral sucker, 41 Â 56. Seminal vesicle saccular, 41 Â 29, antero-dorsal to ventral sucker. Pars prostatica narrow, slightly sinuous, c.47 long; prostatic cell field width 21. Sinus-sac oval, 27 Â 19. Genital pore at level of posterior margin of pharynx. Ovary posterior to and contiguous with testes, spherical, 34 Â 33. Seminal receptacle and Mehlis’ gland not seen. Uterus with few eggs (c .20); eggs tanned, operculate, with pointed anopercular pole, 23–24 Â 10–11. Vitellarium consists of 7 claviform follicles; overall field 79 Â 49; anterior group overlapping ovary ventrally. Remarks Morphologically, the single specimen from B. boops agrees well with the redescription of A. laguncula by Bray & MacKenzie (1990) based on material from Clupea harengus L. in the English Channel. This is especially with regard to the characteristic shape of the eggs, which possess a narrow, pointed anopercular pole (Figure 3). B. boops is a new host record and is probably an accidental host for A. laguncula. Family Accacoeliidae Odhner, 1911 Genus Accacladium Odhner, 1928 Accacladium serpentulum Odhner, 1928 Material studied Specimens (2) from Boops boops L. ? Intestine (recovered from internal body wash). One specimen, NE Atlantic (off Malpica, Galicia, Spain, 27.xi.01); second specimen from Mediterranean (off Santa Pola, Spain, 02.vii.02). Voucher: BMNH 2005.4.18.16. 106 Table 2. Comparative data (measurements in micrometres) for Lecithaster confusus Odhner, 1905. Present study Range 469–515 117–146 162–179 8–10 58–75 Â 54–72 35 Â 30 82–96 Â 85–96 48 Â 14–19 64–88 Â 29–40 48–128 16–43 43–51 Â 45–46 50 Â 40 48–83 Â 40–58 24 Â 42 74–77 Â 56–74 18–19 Â 10–12 1:1.33–1.57 34.5–34.8% 7.8–13.6% 24.4 17.1 1,000–1,500 300–500 – – ? Â 130–160 ? Â 70–85 ? Â 230–300 80–110 Â ? Posterior to level of the ventral sucker – – – – Lobes of ovary elongate, similar to lobes of vitellarium – ? Â 250 (smaller than ovary) 15–17 Â 7 1: 1.75 – – 1,000–1,200 400 – – ? Â 140–150 – ? Â 250–270 – – – – – – – – – 15–17 Â 9 1:2.0 22.9* 26.0 330–1,750 180–650 – – ? Â 60–160 ? Â 36–100 ? Â 100–280 – – – – – – – – – 12–20 Â 7–13 Odhner (1905) Range Looss (1908) Range Linton (1940) Range Overstreet (1973) Range 379–1,299 155–485 – – 49–126 Â 55–122 32–73 Â 33–73 110–252 Â 102–232 29–67 Â ? – – – 44–139 Â 380–133 38–157 Â 36–116 67–255 Â 57–177 – – 15–23 Â 9–15 1:1.7–2.3 21.0–37.0% 6.0–28.0% Source Body length Body width at ventral sucker Forebody length Pre-oral lobe Oral sucker Pharynx length Ventral sucker Sinus-sac Seminal vesicle Pars prostatica length Pars prostatica field width Right testis Left testis Ovary Seminal receptacle Vitelline field Eggs Sucker width ratio Forebody as % of length Postvitelline region as % of length *Measured from published drawing. 107 Description (Figure 4) Based on 2 adult specimens (measurements for Atlantic specimen given first). Body very elongate, with almost parallel margins, 7,149 Â 671; 8,163 Â 690. Tegument smooth. Pre-oral lobe very small, 35; 34. Oral sucker ventrally subterminal, subglobular, 342 Â 355; 345 Â 259. Ventral sucker subglobular, much larger than oral sucker, 588 Â 596; 647 Â 422, surmounted on short peduncle, 149 Â 895. Forebody 851; 776 (11.9% and 9.5% of body length). Pharynx elongate-oval, 193 Â 175; 147 Â 164, with additional narrow anterior region, 132 Â 44; 103 Â 60, projecting into lumen of oral sucker. Oesophagus short. Intestine H-shaped, with thick epithelial lining; anterior caeca reach pharyngeal region and posterior caeca unite with excretory vesicle to form uroproct at posterior extremity of body. Testes 2, entire, elongate-oval, tandem and separated by loops of uterus, located just inside anterior half of hindbody, at 1,149; 1,327 from ventral sucker; anterior testis lies slightly dorsally, 579 Â 303; 379 Â 241; posterior testis lies slightly ventrally, 588 Â 421; 422 Â 233. Seminal vesicle long, 3,816 Â 96, tubular, coiled, reaches from level of first vitelline tubules, some distance from anterior testis, to sinus-sac. Large cluster of prostatic cells mostly dorsal to seminal vesicle at level of ventral sucker; field length 395, width 399. Sinus-sac rather elongate, 298 Â 83; 216 Â 60. Genital atrium distinct; genital pore mid-ventral, at about level of posterior margin of oral sucker. Ovary post-testicular, in third quarter of body, separated from testes by loops of uterus, elongateoval or subglobular, 443 Â 237; 233 Â 233; postovarian field 2,246; 3,620 (31.4 and 44.3% of body length). Mehlis’ gland just anterior to ovary, transversely-oval, 132 Â 237; 129 Â 147. Uterus long, slightly coiled; descending loop reaches close to posterior extremity, extends throughout much of hindbody. Eggs numerous, 32–38 Â 17–22 (mean 35 Â 19). Vitellarium consists of numerous branching tubules from 2 main stems (1 ventral and 1 dorsal), extends from level of posterior end of seminal vesicle to level of ovary. Excretory vesicle Y-shaped; arms unite anteriorly at level of pharynx, obscured by strongly stained epithelial cell lining of caeca in posterior part of body; stem narrow; distal extremity of vesicle small; pore terminal. Figure 4. Accacladium serpentulum Odhner, 1928 ex Boops boops, lateral view. Scale-bar: 2 mm. 108 Remarks The morphology of our material generally agrees with the redescription of A. serpentulum by Bray & Gibson (1977). However, it differs from the latter in the following: (i) the testes are entire and not contiguous; (ii) the genital pore is somewhat more anterior, at the level of oral sucker; (iii) the overlap between seminal vesicle and vitellarium is smaller; and (iv) the ovary is more posterior. Our worms also exhibit substantially smaller dimensions than those previously recorded for the NE Atlantic (data from the comparative table in Bray & Gibson, 1977), except for the size of the eggs, which overlaps the range of the material from Sweden described by these authors. On the other hand, our metrical data overlapped with the wide range provided for the Mediterranean worms (as A. nematulum Noble & Noble, 1937) given by Timon-David & Musso (1971). Bray & Gibson (1977) considered this species a synonym of A. serpentulum. Although the worms from B. boops are much smaller, with the uterus not fully expanded, they appear normally developed and contained numerous eggs. The differences we observed may be due to their younger age and/or poorer development in an unusual, and likely accidental, host. This is the first record of A. serpentulum in a fish host other than its typehost (Mola mola), the third record of this species in the NE Atlantic and the second in the Mediterranean. of redescriptions of these species reflects an opportunity to investigate the influence of host on parasite morphology and development. This study has also revealed a higher diversity for Wardula, and represents only the third record of the genus (see Gijon-Botella & Lopez-Roman, 1989, 1996) outside the Mediterreanean area. Acknowledgements This work was supported by grants REN200301758 and BOS2002-878 (MCYT of Spain), CACSA, and HPMD-CT-2000-00037 (20001958 to AK). APO benefits from a grant from ´ MECD. MF is supported by a ‘‘Ramon y Cajal’’ contract from MCYT of Spain. References Anato, C.B., Ktari, M.H. & Doussou, C. (1991) La parasi´ tofaune metazoire de Boops boops (Linne, 1758), poisson ´ teleosteen Sparidae des cotes tunisiennes. Oebalia, 17, ˆ 259–266. ` Bartoli, P. (1987) Caracteres adaptifs originaux des digenes intestinaux de Sarpa salpa (Teleostei, Sparidae) et leur in´ ´ terpretation en termes d’evolution. Annales de Parasitologie Humaine et Compare´e, 62, 542–576. Bartoli, P. & Gibson, D.I. (1989) Wardula sarguicola n. sp. (Digenea, Mesometridae), a rectal parasite of Diplodus sargus (Teleostei, Sparidae) in the western Mediterranean. Annales de Parasitologie Humaine et Compare´e, 64, 20–29. Bray, R.A. & Gibson, D.I. (1977) The Accacoeliidae (Digenea) of fishes from the North-East Atlantic. Bulletin of the British Museum (Natural History), Zoology, 31, 51–99. Bray, R.A. & MacKenzie, K. (1990) Aponurus laguncula Looss, 1907 (Digenea: Lecithasteridae): a report from herring, Clupea harengus L., in the eastern English Channel and a review of its biology. Systematic Parasitology, 17, 115–124. Georgiev, B.B., Biserkov, V.Y. & Genov, T. (1986) In toto staining method for cestodes in iron acetocarmine. Helminthologia, 23, 279–281. ´ Gijon-Botella, H. & Lopez-Roman, R. (1989) Aportacion al ´ ´ catalogo de Digenea de peces marinos del Archipelago de Canarias. Revista Ibe´rica de Parasitologia, 49, 137–138. Gijon-Botella, H. & Lopez-Roman, R. (1996) Parasiting by Wardula sarguicola Bartoli and Gibson, 1989 in Diplodus sargus cadenati De La Paz, Banchot and Daget, 1974 capturated in the Atlantic (Archipelago in the Canary Islands). Parassitologia, 38(1–2) (EMOP VII Abstract), 35. ´ Kostadinova, A., Power, A.M., Fernandez, M., Balbuena, J.A., Raga, J.A. & Gibson, D.I. (2003) Three species of Magnibursatus Naidenova, 1969 (Digenea: Derogenidae) from Atlantic and Black Sea marine teleosts. Folia Parasitologica, 50, 202–210. Linton, E. (1940) Trematodes from fishes mainly from the Woods Hole region, Massachusetts. Proceedings of the United States National Museum, 88, 1–172. Concluding remarks Our knowledge of the digenean fauna of Boops boops is far from complete, especially along the Atlantic coasts of Europe, as indicated by the recent description of Magnibursatus bartolii ´ Kostadinova, Power, Fernandez, Balbuena, Raga & Gibson, 2003 (see Kostadinova et al., 2003). The present small-scale sampling of B. boops from the Atlantic recorded four additional digenean species from this host. While our data suggest that Wardula bartolii n. sp. is a species characteristic of B. boops, the records of L. confusus, A. laguncula and A. serpentulum can be considered as accidental occurrences, reflecting the structure of parasite communities in the benthic habitats along the European coasts of the NE Atlantic. Our inclusion 109 Overstreet, R.M. (1973) Some species of Lecithaster Luhe, ¨ 1901 (Digenea: Hemiuridae) and related genera from fishes in the northern Gulf of Mexico. Transactions of the American Microscopical Society, 92, 23–240. Paggi, L. & Orecchia, P. (1964) I monostomi parassiti di Box salpa. Revisione della famiglia Mesometridae Poche, 1926. Parassitologia, 6, 283–311. Renaud, F., Romestand, B. & Trilles, J.P. (1980) Faunistique et ´ ecologie des metazoaires parasites de Boops boops Linnaeus, ´ 1758 (Teleosteen Sparidae) dans le Golfe du Lion. Annales de Parasitologie Humaine et Compare´e, 55, 467–476. ´ ` Timon-David, P. & Musso, J.J. (1971) Les trematodes digenes du poisson-lune (Mola mola) dans le Golfe de Marseille (Accacoeliidae et Didymozoidae). Annales de Parasitologie Humaine et Compare´e, 46, 233–256.