A Biodiversity Information System for Cheshire, Halton, Warrington & Wirral

Hi Tom

It sounds like the horse leech Haemopis (sometimes even Haemopsis) sanguisuga. This got its name supposedly from the old word that meant coarse or rough not because it attaches itself to horses. It actually consumes its prey whole, sucks it dry, and spits it out but it maybe attaches itself to larger animals for dispersal purposes - I saw it anchored onto a toad once. It can cover good distances apparently. Quite selective in its choice of ponds in Cheshire...mostly with an element of mud and good weedy margins; not rare but localised.

Andy Harmer

Andy,

Thanks for the info. The only other time I've seen these was a few years ago in Upton Rocks Park, Widnes, in a small water-filled scrape in open grassland, no more than a couple of square metres in area and approx 50m from the nearest pond. The scrape had been created by accident, when one of our contractors started digging out for a footpath, realised he was in the wrong location and stopped. Rain filled the scrape over the next few days, then these leeches magically appeared, wriggling back and forth. I picked one out and it immediately clamped itself to the palm of my hand. As with Palace Fields, the scrape dried out and was eventually backfilled by the contractor, but where did the leeches come from? (and where did they go when the water evaporated?) Are there leech eggs all around us in the soil, just waiting for that chance-in-a-million inundation?

Do you think it's a safe enough bet to enter H. sanguisuga on Rodis?

Cheers,
Tom.

Eggs from this leech are found on land under stones in damp habitats. I imagine in spring and summer the land and air is full of pond inverts dispersing and colonising. Some leeches like the duck leech Theromyzom tessulatum prefer to hitch a lift in the nasal cavity of water fowl whereas the horse leech may prefer to disperse under its own steam.

As far as entering the record onto RODIS...I can't speak for the county recorder (is there one?) but I would probably tell you off for not getting a photograph but then accept it because there is no other leech of that size and colour known in Cheshire and H sanguisuga is a leech found regularly in and around the Halton area.

Andy

But the behaviour, attaching themselves to your ankle, sounds more like medicinal leech Hirudo medicinalis. How long were you in the water? Did they make a bee-line for you as soon as you got in? I've spent hundreds of hours wading in ponds and ditches and have never had a horse leech attach itself to me.

I've never been to Runcorn so don't know the site. Classic medicinal leech habitat is shallow pools in extensive pasture where they feed on and get carried around by livestock, but they don't need livestock. There are large populations in southern England thought to be sustained by amphibians.

Medicinal leeches have two quite obvious narrow red longitudinal stripes. They can also be recognised by their behaviour if they are hungry: if you slap the edge of the water when it is warm, any in the vicinity will swim towards the disturbance.

Bear in mind they are protected species. It would be illegal to take, kill or injure them.

John Bratton
Menai Bridge

Hi John

'Runcorn moat ' is a little misleading....it is a small ephemeral water feature in a 1960's newtown housing estate squeezed between a main road, houses and a car park. I surveyed it last year from the scorched bridge avoiding crisp packets, asda trolleys, propane cylinders and various 'recreational' paraphanalia. Cors Goch Reserve this aint!

Like you John, I've never had one attach itself to my wader but I've seen one attach itself to a toad which couldn't shift it, try as it might.

Andy

Andy, now I know why you were sacked by 'Visit Runcorn'!

John, in answer to your comments, perhaps I used a bit of poetic licence: the attachment was genuine and alarmingly strong, but I don't remember seeing any red lines on them and they didn't exactly make a bee line for me. In fact, I spotted them when I pulled up one of Andy's recently planted marginals (Ragged Robin I think), to make an access for a small excavator, (as I said earlier, long story). The leeches were in the bottom if the planting hole - so perhaps they came in with the Ragged Robin - and I was so excited I pursued them, cornered them and 'encouraged' them onto my bare foot.

I also used to poke wasps' nests with sticks when I was a kid. Can't help myself.