Hirudo troctina, Moquin-Tandon, 1846

Hechtel, Fred O. P. & Sawyer, Roy T., 2002, Toward a taxonomic revision of the medicinal leech Hirudo medicinalis Linnaeus, 1758 (Hirudinea: Hirudinidae): re-description of Hirudo troctina Johnson, 1816 from North Africa, Journal of Natural History 36 (11), pp. 1269-1289 : 1287

Diagnosis of Hirudo troctina

Based on our observations H. troctina can be diagnosed formally as follows (see Sawyer, 1986: 13, 684): Hirudinidae (monostichodont; no pharyngeal ridges terminating between jaws); Hirudininae (male paired ducts of ‘hirudoid’ type: i.e. epididymis and ejaculatory bulb present and looped, not forming linear series [see Richardson, 1969]); vagina with small distinct caecum; no vaginal duct; vagina bulbous, upright and not folded; ejaculatory bulbs relatively small in relation to massive epididymes; characteristic pigmentation: one annulus of each segment with four (or six) black spots (not longitudinally striped).

Hirudo troctina can be distinguished from its congener H. medicinalis as follows:

1 Dorsum with four (or six) metameric black dots.. Hirudo troctina Johnson, 1816 Vagina bulbous, upright and not folded; epididymis massive in relation to ejaculatory bulb.

– Dorsum essentially longitudinally striped, lacking metameric black dots.................... Hirudo medicinalis Linnaeus, 1758 Vagina a folded, elongated tube in non-juveniles; epididymis not much larger than ejaculatory bulb.