Leeches of southern Africa's Journal

Got any questions?

Ask!
We cannot guarantee that they will be answered, but maybe we might find some pointers or find someone who knows.
Please start by joining the project.

Our marine Leeches are poorly known.

• Pontobdella sp (Warty Leech) is free living under boulders in the intertidal. 20mm. It has wart-like tubercles on each body segment.
• Janusion stellata (was Malmiana stellata) (Moore, 1958) (?= Ottoniobdella), collected on a Toby Fish (Tetraodontidae, unknown species) at Richards Bay.
• Austrobdella oosthuizeni A. Utevsky, 2004, (Crayfish Leech) was collected on Jasus lalandii (Crustacea, Decapoda) at Bloubergstrand. 4mm
• Lizabdella africana A. Utevsky,2007 collected on Liza at Kowie Estuary.
• Branchellion sp (Ray Leeches) recorded by @elizabeth_carr_2001 on iNaturalist (https://www.inaturalist.org/observations/149711681) on Torpedo sinuspersici makes up the fifth species.

also (Pretorius. 2021):

• Zeylanicobdella arugamensis on Clinus
• Ozobranchus margoi on turtles in South Africa (Hughes, Bass & Mentis 1967)
• Stibarobdella macrothela (=Pontobdella macrothela (Schmarda, 1861)) from three catshark spp (Yeld, unpublished)
• Branchellion angeli Sigalas, 1921 from Durban
• Branchellion sp on Callorhinchus capensis (Awa 2012)

The Big 5 Freshwater Leeches

Not the top five, but those over 50mm long. From biggest to smallest. All are bloodsuckers.

Aliolimnatis buntonensis (Hirudinidae): very common in eastern parts of southern Africa from KwaZulu-Natal northwards, not present in southern and western parts. Haematophagous on mammals. 85 mm.

Hirudo michaelseni (Hirudinidae): very common throughout southern Africa. Haematophagous on mammals but also on amphibians and fish. Immature leeches also feed on freshwater snails. 65 mm.

Placobdelloides jaegerskioeldi (Glossiphoniidae) 62 mm.
Restricted to Hippopotamus’ pools. Haematophagous on hippos only.

Asiaticobdella fenestrata (Hirudinidae): restricted to but common in North-western part of southern Africa. Haematophagous on mammals. 60 mm.

Praobdella radiata (Hirudinidae): in eastern parts of southern Africa from KwaZulu-Natal northwards. Not common. Haematophagous in nasal cavities of mammals. 61 mm.

Aliolimnatis oligodonta (Hirudinidae): common in eastern parts, not present in western parts. Haematophagous on mammals. 58 mm.

Praobdella maculata (Hirudinidae): in eastern parts of southern Africa from KwaZulu-Natal northwards. Not common. Haematophagous in nasal cavities of mammals. 52 mm (contracted).

Aliolimnatis obscura (Hirudinidae): common in western part of southern Africa and from southern parts of Namibia and Botswana northwards. Haematophagous on mammals. (size not given).

Medicinal Leeches - Hirudinidae - colour patterns

(Species with stripes tend to have the sides yellow or orange)

1 stripe dorsally

• Hirudo hildebrandti: dorsum with one median black stripe (OR 5-7 dark stripes), ventrum without marginal black stripes

5 stripes dorsally

• Hirudo michaelseni: dorsum with 5 yellow with black border stripes – no median stripe, ventrum with black marginal stripes
• Hirudo hildebrandti: dorsum with 5-7 dark stripes (OR with only median black stripe), ventrum without marginal black stripes

6 stripes dorsally

• Asiaticobdella fenestrata: dorsum with 6 dark bands and large black blotches, ventrum heavily spotted or blotched
• Aliolimnatis obscura: dorsum with 6 dark-brown, narrow stripes – no median stripe, ventrum with black marginal stripes

7 stripes dorsally

• Hirudo hildebrandti: dorsum with 5-7 dark stripes (OR with only median black stripe), ventrum without marginal black stripes
• Aliolimnatis oligodonta: dorsum with median stripe black, and 6 yellow stripes, ventrum with black marginal stripes
• Aliolimnatis buntonensis: dorsum with median stripe light brown, and 6 olive green stripes, ventrum with black marginal stripes

11 stripes dorsally

• Aliolimnatis africana: dorsum with 11 narrow black stripes, first 2 pairs on each side of median stripe segmentally merged to form a chain-like pattern, ventrum with black marginal stripes

No stripes

• Praobdella maculata: dorsum uniformly coloured, spotted with small, black blotches
• Praobdella radiata: dorsum uniformly coloured, without black spots

First of all: get up close - as close as you can.
Then crop your photos, so that the Leech is fully in the frame.
Take lots of pictures.

Best out of water (but not wet), or if in the water, then well down and out of the meniscus - which causes a shine that hides any colours and features.

Things to focus on:

Eyes

The eyes are crucial, especially for the Glossiphoniidae and Salifidae. the eyes may be in 2-4 pairs in various arrangements: and are diagnostic for species.
• The more typical families have 5 pairs of eyes on the outside of the head (in a parabolic arch).

Shape:

take several pictures of the rest state, and while stretched. Fully engorged leeches will be distorted: find some hungry ones.
• long and evenly slender: Salifidae
• tubular - most families
• flattened and varied shapes: Glossiphoniidae - some species can immediately be identified just by their shape - when at rest. Shape can be different if breeding or non-breeding - if more than one shape is present, get all the shapes.

Colouring:

Leeches are brightly coloured and the pattern and colour is useful for identification. Some species have more than one colour "morph". Photographs can record the colours beautifully: do them justice! In fact, some species cannot be identified without their patterns! Patterns may be spotted, longitudinally striped, or transversely banded. Make sure any reflection or sheen does not obscure the patterns.
The best colours appear to be in about 10mm of water - out of water many leeches appear blackish, even when they are colourful.

Guts:

In some groups the number of gut segments (caecae) are useful: these can easily be photographed with back lighting. Try and get a few backlit shots showing the internal organs. Well-fed beasts are best.

Segments.

The segments in leeches are folded into annuli (rings). There can be 3-14 rings per segment. In s Afr we have 3- 5- or 7- rings per complete segment. The easiest way to tell is to look at the ornaments (see next), which are usually on the middle ring of each segment. Crucial are the number of rings in each of the first 6 segments, with fewer rings towards the head, and #7 (from ring 7 onwards the rings are usually constant or "complete"). Where there is no ornamentation, this can be complicated and a ventral view closeup should show the nephropores (kidney ducts), which is much easier with bigger specimens. In some Glossiphoniidae and Salifidae one cannot determine the rings without dissection, but they have other useful features, so dont fret about it.

Ornamentation.

All leaches have sensillae on the middle ring of each segment - these taste and feel. They are usually hard to photograph. There are usually 3-4 pairs of sensillae dorsally and 3 ventrally. Fortunately in some groups these sensillae are on smooth domes (called papillae), or cones (called tuberculae) comprizing several domes on their tips. The pattern and arrangemnt of these is most useful.

If you get the eyes, body shape, annulation, colouring and ornamentation then you are 90% of the way to getting an easy ID ...

Southern African Checklist:
https://www.inaturalist.org/check_lists/4436345-leeches-of-s-Afr?q=&view=photo&taxon=&observed=any&threatened=any&establishment_means=any&occurrence_status=any&rank=all&taxonomic_status=all&commit=Filter

Key below:

Namibian Checklist:
https://www.inaturalist.org/check_lists/4436544-Leeches-of-Namibia?q=&view=photo&taxon=&observed=any&threatened=any&establishment_means=any&occurrence_status=any&rank=all&taxonomic_status=all&commit=Filter