Oesophagotrema mediterranea, Chaari & Derbel & Neifar, 2011

Chaari, Manel, Derbel, Hela & Neifar, Lassad, 2011, Oesophagotrema mediterranea n. gen., n. sp. (Platyhelminthes, Digenea, Zoogonidae), parasite of the needlefish Tylosurus acus imperialis (Beloniformes, Belonidae) from off Tunisia, Zoosystema 33 (3), pp. 281-286 : 282-283

Oesophagotrema mediterranea n. sp. ( Figs 1 ; 2 )

TYPE MATERIAL. — Holotype: MNHN HEL 199 Tf 218 . Paratypes: MNHN HEL 200 Tf 219, HEL 201 Tf 220, HEL 202 Tf 221, HEL 203 Tf 222, HEL 204 Tf 223 ; BMHN NHMUK 2011.4.4.1-5.

TYPE HOST. — Tylosurus acus imperialis (Rafinesque, 1810) ( Beloniformes , Belonidae ).

TYPE LOCALITY. — Coast of Sfax, Tunisia (34°46’N, 10°48’E).

OTHER LOCALITIES. — Kerkennah (34°45’N, 11°17’E), Skhira (34°18’N, 10°10’E), Mahdia (35°30’N, 11°4’E), Chebba (35°13’N, 11°8’E), Jideriyah (33°21’N, 11°09’E).

SITE OF INFECTION. — Oesophagus, vomer teeth. PREVALENCE. — 10.34% (9/87).

MEAN INTENSITY. — 7.11 (64/9).

MEAN ABUNDANCE. — 0.73 (64/87).

DESCRIPTION

Based on 14 whole mounted specimens. Body fusiform, longer than wide, 2481 ± 159 (2000-3050; n = 13) long by 759 ± 51 (550-875; n = 14) wide at level of ventral sucker; length/width ratio 1:3.28 (1:2.66-4.36; n = 13). Body surface covered with spines that decrease in number from anterior to posterior end of body. Oral sucker globular 172 ± 15 (105-200; n = 13) by 184 ± 13 (150-230; n = 13), subterminal. Ventral sucker prominent, undivided, 377 ± 19 (320-450; n = 14) by 362 ± 26 (290-440; n = 14), with mid-ventral aperture and small papillae on lips. Oral/ventral sucker ratio 1:2.21 (1.71-1.64; n = 13) length by 1:1.94 (1.64-2.34; n = 13) width. Forebody 630± 98 (300-1000; n = 14) occupies 26 ± 2% (19-33%; n = 13) of body length. Prepharynx short, 36 ± 8 (20-50; n = 8) long. Pharynx oval, 130 ± 6 (120-155; n = 11) by 104 ± 8 (80-135; n = 12). Oesophagus elongate, with slightly thickened wall, 152 ± 28 (75-220; n = 10) long. Intestinal bifurcation in posterior quarter of forebody. Caeca blind, ending at beginning of posterior third of body. Testes 2 oval to subspherical, tandem to slightly oblique, postequatorial in middle third of hindbody; anterior testis 278 ± 27 (225-400; n = 11) by 354 ± 42 (200-450; n = 12); posterior testis 291 ± 40 (235-425; n = 8) by 344 ± 56 (270-475; n = 8); post-testicular space 21 ± 3% (10-29%; n = 11) of body length. Cirrus-sac elongated, curved, claviform, 287 ± 24 (225-365; n = 12) by 93 ± 10 (50-115; n = 12) in maximum width; cirrus-sac overlapping dorsally intestinal bifurcation. Seminal vesicle saccular, oval, undivided. Pars prostatica short, narrow. Ejaculatory duct straight and opening in genital atrium. Genital pore ventral, in sinistral submarginal forebody, at level of pharynx. Ovary subspherical, in anterior hindbody, pretesticular, 159 ± 23 (110-200; n = 9) by 175 ± 16 (140-220; n = 10). Oviduct connected to seminal receptacle, to common vitelline duct and surrounded by developed Mehlis’ gland. Seminal receptacle immediately postovarian, ovoid, elongate, 188 ± 43 (150-225; n = 3) by 110 ± 34 (80-140; n = 3). Laurer’s canal not seen. Vitelline follicles in two symmetrical lateral bunches, 9 on poral side, 8 on antiporal side; extending between ovary and anterior testis. Uterine duct occupying all inter- and posttesticular spaces ventrally, looping dorsally in forebody region. Eggs small, 35 ± 2 (30-40; n = 15) by 21 ± 1 (20-25; n = 15), tanned and operculate.

Figures

FIG. 1. — Oesophagotrema mediterranea n. gen.,n.sp., composite drawing of whole worm (ventral view). Scale bar: 500 μm.

FIG. 2. — Oesophagotrema mediterranea n.gen.,n. sp.: A, terminal genitalia; B, proximal female system. Scale bars: A, 100 μm; B, 200 μm.