Pirate Wolf Spider

Pirate Wolf Spider Pirata pirations
Runs over surface of water. Body length about 1 cm. Common around Herefordshire ponds.

Great Pond Snail

Great Pond Snail Limnaea stagnates
Air breathing snail, which comes to surface for oxygen.
A larva of the Pond Olive mayfly Cloeon dipterum can be seen on the upper part of the shell.

Invertebrates - V41

American Bladder Snail  Physa acuta (left)   Marginal Ramshorn Snail Planorbis planorbis (right)
The shells of these two species of aquatic snail coil in opposite directions.

Invertebrates - V42

Swan Mussel Anodonta cygnet
Associated with larger ponds and lakes. The largest can reach 20cm across.

Pea Mussels

Pea Mussels Pisidium sp.
These are only 2 to 3 mm across. Several species are common in ponds.

Horse Leech

Horse Leech Haemopis sanguisuga
This large leech does not suck blood but feeds on a wide range of invertebrates, also amphibian larvae.

Invertebrates - V45

Leech Erpobdella testacea
A small, non-blood sucking leech. Feeds on small invertebrates including worms and fly larvae.


Flatworm Polycelis sp.
Flatworms are relatively simple invertebrates with unsegmented bodies. They tend to glide smoothly using cilia on their underside. Several species are common in ponds.
Polycelis species have a large number of eyes distributed around the front and side margins of the head (top left).

Invertebrates - V47

Water hoglouse Asellus aquaticus
These crustaceans are underwater relatives of the woodlouse. They feed on decaying vegetation and are tolerant of low oxygen levels.