Macvicaria obovata ( Molin, 1859 ) Bartoli, Bray & Gibson, 1989

Zedam, F. - Z., Boukadoum, A. & Tazerouti, F., 2024, Four Species Of Digeneans (Trematoda, Opecoelidae) Of The Gilthead Seabream Sparus Aurata (Teleostei, Sparidae) Off The Algerian Coast In The Mediterranean Sea, Zoodiversity 58 (6), pp. 527-544 : 533

Macvicaria obovata ( Molin, 1859) Bartoli, Bray & Gibson, 1989

H o s t. Sparus aurata (Linnaeus, 1758)

L o c a l i t y. Algerian coast in Oran.

S i t e o n h o s t. Intestine.

R e c o r d s i n t h e M e d i t e r r a n e a n. Ex S. aurata , off Var, Provence, France, Sanary ( Maillard, 1976; Fischthal, 1980; Bray, 1987; Bartoli et al., 1989) Italy ( Molin, 1859, 1861) and off Tunisia ( Gargouri Ben Abdallah et al., 2011; Derbel et al., 2012; Antar & Gargouri, 2018). This is the first record on Algeria’s coast ( fig. 4 ).

D e s c r i p t i o n

[Based on 20 whole-mounted gravid specimens; fig. 5 ; measurements in table 3]

Body elongate oval, rounded at both ends; lateral margins almost parallel, slightly narrowed at the level of ventral sucker. Forebody and hindbody long, occupying 27–31 (28.5) % and 50.6–55.8 (53.6) % of body length, respectively ( fig. 5 , B). Tegument thick, unarmed. Oral sucker transversely-oval, ventro-subterminal. Ventral sucker oval, pre-equatorial, with transverse slit-like opening, the main axis of which is transverse; muscle fibres powerful, radiate from lateral edges of ventral sucker, ventral sucker is bigger than the oral sucker. Prepharynx present, short. Pharynx well-developed, elongate-oval. Esophagus occasionally present; short. Intestinal bifurcation in mid-forebody, anterior to ventral sucker. Caeca thin-walled, with wide lumen, terminate blindly close to the posterior extremity of the body. Testes 2, tandem, contiguous, post-ovarian, transversely- oval, entire, in midhindbody. Cirrus-sac present, claviform, curved, narrower anteriorly, wider posteriorly, sinistral at level of ventral sucker, containing tubular, convoluted internal seminal vesicle, sphincter, separating seminal vesicle from muscular pars prostatica ( fig. 5 , B) and muscular. Ejaculatory duct, located in the proximal part of cirrus-sac. Genital pore, at mid-length between ventral sucker and pharynx. Ovary Spherical to oval, entire, sinistral, just posterior to ventral sucker, pre-testicular; oviduct short. Seminal receptacle voluminous, posterior to ovary. Oötype surrounded by Mehlis’ gland ( fig. 5 , C). Uterus coiled between anterior testis and ovary, ending with metraterm. Metraterm muscular, runs along right edge of cirrus-sac, opens into genital atrium. Vitellarium follicular, in 2 lateral fields interrupted at level of ventral sucker, confluent in post-testicular region. Eggs large, operculate,without filaments.

Figures

Fig. 4. Geographical distribution of three species of Macvicaria: M. obovata (Molin, 1859) Bartoli, Bray and Gibson, 1989; M. maillardi Bartoli, Bray and Gibson, 1989 and M. maamouriae Antar, Georgieva, Gargouri et Kostadinova, 2015 from fish around the world. References for the records are given between parentheses.

Fig. 5. Macvicaria obovata (Molin, 1859) ex Sparus aurata: A — body, ventral views; B — ventral view of the male genitalia; C — ventral view of the female genitalia.