Hirudo troctina, Johnson, 1816

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 : 1287-1288

Biology of Hirudo troctina

Very little is known about the geographic distribution, ecology and reproduction of this elusive species. Although great quantities of H. troctina were exported from North Africa in the middle of the 19th century, in the past 150 years this species has been mentioned only two or three times in the scienti c literature. This raises the question whether there has been a serious decline in the natural populations of this elusive leech, as has happened with H. medicinalis now recognized as endangered ( Sawyer, 1981).

In order to stimulate research into the biology and taxonomy of H. troctina and related leeches of North Africa, the following practical key to known jawed leeches of the region should prove useful:

1 Segmentally repeating pigment pattern on dorsum.. Hirudo troctina Johnson, 1816 Anus small; caudal sucker about two-thirds to three-quarters maximum body width; each jaw with about 65 (60–100) teeth.

– No segmentally repeating pigment pattern on dorsum......... 2

2 Caudal sucker relatively small, about half maximum body width..................... Haemopis sanguisuga ( Linnaeus, 1758) Anus prominent; each jaw with two rows of fewer than 20 teeth.......

– Caudal sucker large, its diameter about equal to or larger than maximum body width............... Limnatis nilotica ( Savigny, 1822) Anus small; each jaw with about 40–50 teeth.