Microlife: Duck pond - Floating pondweed

September 1-4, 2008
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This sample was from the edge of a large duck pond by the highway. The vegetation taken consisted of floating Potamogeton or pondweed with thin, grass-like leaves, with other plants occurring further out. It contained very numerous snails about 2-5 mm in size, mostly pond snails but some ramshorns, as well as a few damselfly larvae.

Duck pond
Pond snails
Damselfly larva on pondweed

Vorticellids were predominant, forming large clusters on the pondweed, snails, and on surface films. Nothing else occurred in abundance, but when individual snails were put on the slide there was often a ciliate, rotifer, or arthropod with them. For algae, only a single Pseudopediastrum was found among the snail droppings.

↬ Thanks to Michael Plewka, author of plingfactory: life in water, for the identification of Mytilina as well as confirming Notommata tripus and to Bruce Taylor for confirming Strobilidium.

Kingdom Plantae
…Phylum Chlorophyta – green algae

Pseudopediastrum - about 35 µm

Kingdom Chromista
…Phylum Ciliophora – ciliates

Strobilidium - about 35 µm
Spirotrichea - about 60 µm
Vorticellid dividing
Vorticellidae, dividing - bodies about 50, 45 µm

Kingdom Animalia
…Phylum Gnathifera – rotifers & allies

Lepadella - body about 90 µm
Notomma tripus
Notommata tripus - body about 120 µm
Mytilina - about 220 µm

…Phylum Mollusca

Pond snail
Lymnaeidae - shell about 1.3 mm [composite]

…Phylum Arthropoda – insects, crustaceans & allies

Cyclopoida - about 370 µm
Midge larva
Chironomidae, larva - about 1.0 mm

Unknown objects

Egg-like - about 190 µm