Hainault Forest Website

Written, Designed and with Photographs by Brian Ecott

Fauna

 Aquatic Minibeasts

POND SKATER Gerris sp. 15mm long. Common bug on all the forest ponds. Feeds on dead insects on the water surface. Bristles on the tips of legs prevent it breaking through the surface film. Photo: July 1973

WATER SCORPION Nepa cinerea. A  leaf-like, flat bug 30mm long. Two front legs adapted for grasping prey from which it sucks juices. The "sting-like" appendage at the rear is in fact a breathing tube which it uses like a snorkel. Photo: May 1971.  Chigwell Row Pond.

ALDER FLY  Sialis sp. Lays eggs on plants overhanging water. The larvae hatch and fall into the water and are carnivorous.  when developed crawl out of the water and pupate in the mud. Adult flies hatch May-June.  Photo: 11th May 2006.

A MAYFLY LARVA. Ephemeroptera. The larvae have three long tail appendages, and external gills on the abdominal segments, which are varied and used in identification of species. 12mm long. Common in the forest ponds. Photo: July 2004. Sheepwater. A MAYFLY.  Ephemeroptera. Wings held upright. Long tail filaments 2 or 3 in number. Have a brief adult existence for mating and egg laying.  Photo: July 2000.

POND SLATER or HOG LOUSE Asellus.

A small crustacean 10mm related to the woodlice. Common in all forest ponds. Withstands pollution and low oxygen levels. Photo: July 2004  Sheepwater.

BACKSWIMMER Notonecta glauca. 15mm long. Common in all forest ponds and numerous in Sheepwater.  Often seen resting near the surface of the water where they gather oxygen. Photo: July 2004. As its name suggests The Backswimmer or Greater water boatman swims upside down The third pair of legs, covered in hairs, are the longest and used to row through the water. Far right: Microscope view of tip of third leg showing hairs which help to propel it through the water.

Long bodied DRAGONFLY LARVA, Anisopterid or Hawker type.  Dragonflies occur in all the forest ponds. They are carnivorous.

Photo: July 2004. Sheepwater.

Short bodied DRAGONFLY LARVA

Libellulid type. Photo: May 1998

DAMSELFLY LARVA,  Zygoptera. Distinguished from all other aquatic larvae by the three leaf-like tracheal appendages or "gills". Predatory, often lurking among water plants awaiting prey. Photo: May 1998 Several species of Damselfly occur in the forest ponds. 

GREAT DIVING BEETLE LARVA.

Dytiscus marginalis. Up to 50mm A voracious carnivore. The tail filaments are fringed with hair and adhere to the surface film to obtain oxygen. Photo: May 1998.

GREAT DIVING BEETLE LARVA hanging from the surface film. Note the two powerful mandibles which are used hold the prey to enable it to suck out juices from its prey and to dissolve the solid parts.  Photo: July 1971.

GREAT DIVING BEETLE LARVA feeding on mayfly larva. Photo: May 1998.

WANDERING SNAIL Lymnaea peregra.

20mm length. Plentiful in Sheepwater. Like the other snails illustrated here they need to rise to the surface to obtain oxygen.

Photo: July 2004  Sheepwater

GREAT POND SNAIL Lymnaea stagnalis. A large snail up to 55mm in length. Lays sausage-shaped gelatinous masses of eggs on stems and under leaves of water plants.  Common in Roe's well. Photo: July 2004  Feeds on algae which it rasps from the surface of plants and rocks. It will also eat animal matter.

 

   

RAMSHORN SNAIL Planorbis sp.

20mm across. Common in Roe's well.

Photo: July  2004