Entobdella soleae (Van Beneden & Hesse, 1863)

Kearn, Graham C., Whittington, Ian D. & Evans-Gowing, Richard, 2007, A revision of Entobdella Blainville in Lamarck, 1818, with special emphasis on the nominal (type) species “ Entobdella hippoglossi (Müller, 1776) Blainville, 1818 ” (Monogenea: Capsalidae: Entobdellinae) from teleost flatfishes, with descriptions of three new species and a new genus, Zootaxa 1659, pp. 1-54 : 22-23

Entobdella soleae ( Van Beneden & Hesse, 1864) Johnston, 1929

( Figs. 15J, 27–31, 37)

One of us (GCK) has studied the anatomy, ultrastructure and biology of E. soleae from the skin of the common sole Solea solea extensively (see Kearn 1998, 2004). Some points of relevance to the current project and some new observations on sections of resin-embedded material are given here.

Kearn (1970) reported that E. soleae typically possesses 2 seminal receptacles ( Fig. 37A), but individuals with 1, 3 and 4 receptacles occasionally occur. Kearn (1970) found no evidence to indicate a relationship between receptacle number and age of parasites.

The vaginal opening, diameter of 6 – 7, is located on the ventral surface ( Fig. 27). The opening gives access to a relatively straight, narrow, distal tube (entrance tube), with a diameter between 3 and 8 ( Figs. 28 – 30). In some sections through the distal end of the tube there is a distinct wall but this stained only lightly with toluidine blue ( Fig. 28). There is no conspicuous heavily stained winding region similar to that between the entrance tube and the main vagina in “ E. hippoglossi type 1” and “ E. hippoglossi ” from H. stenolepis and no atrium close to the surface as in “ E. hippoglossi type 2”. Proximally, the distal tube of E. soleae joins abruptly to the much more spacious convoluted proximal region of the vagina ( Fig. 30). Here the tube is narrow (~3) and has a thin wall with a stronger affinity for toluidine blue. The proximal coils of the vagina of E. soleae contain stored sperm and are more spacious than those of “ E. hippoglossi types 1 and 2” and “ E. hippoglossi ” from H. stenolepis , being arranged in a compact entangled knot ( Figs. 30, 31). The proximal coils of the vagina lie close to the wall of the vitelline reservoir ( Kearn 1970), but the junction with this reservoir was not seen in resin sections. In a live adult specimen with anterior hamulus length of about 570 (total body length about 5500), the distal narrow tube is about 95 long, while the distance measured in a straight line between the proximal end of this tube and the vitelline reservoir is about 265.

Each anterior adhesive pad of E. soleae is subdivided into 3 areas ( Kearn & Evans-Gowing 1998) (see also Fig. 37A). The accessory sclerites are strongly curved (hooked) ( Kearn 1964; Fig. 15J) and the tendon associated with each terminates on the anterior (proximal) end of the anterior hamulus ( Fig. 37A). The entire haptor ventral surface is covered with papillae and papillae lateral to the median sclerites are arranged in radiating rows (see Kearn 1998, fig. 4.3 and Fig. 37A). Lyons (1973) estimated that there are more than 800 papillae on the haptor ventral surface. The eyes are conspicuous in the adult and glands of Goto are present ( Kearn 1971a, fig. 2; see also our Fig. 37A).