Water Quality Bugs

Stoneflies are considered to be in Class I, the most pollution sensitive, because they require clean and well-oxygenated water to survive. They are highly sensitive to pollution and their presence indicates good water quality. Damselflies, deer/horse flies, and leeches are less sensitive to pollution and can tolerate a wider range of water conditions.

Gilled snails are more intolerant of pollution compared to air breathing snails. This is because gilled snails rely on their gills to extract oxygen from the water, and pollution can reduce the oxygen levels in the water, making it difficult for them to survive. On the other hand, air breathing snails have adapted to breathe air directly, allowing them to tolerate polluted water to some extent. Therefore, gilled snails are more sensitive to pollution than air breathing snails.

The correct answer is caddisfly larva. Caddisfly larvae are aquatic macroinvertebrates that can grow up to 1 inch long. They have six hooked legs on the upper third of their body, which they use for locomotion and feeding. They are classified as class I organisms, indicating their high sensitivity to pollution. Additionally, caddisfly larvae are known to construct cases made of sticks, rocks, or leaves, in which they live and protect themselves.

A flatworm or planaria is a type of aquatic macroinvertebrate that is not an insect. It has a soft, flat body with an arrow-shaped head and two eyespots. This distinguishes it from the other options, which are all insects or insect larvae. Leeches have a segmented body and suckers at both ends, black fly larvae have a worm-like body with a distinct head and thorax, and scuds have a shrimp-like appearance. Therefore, the correct answer is flatworm or planaria.

The statement is true because all four organisms mentioned - the crane fly larva, the horse fly larva, the leech, and the aquatic worm - do not possess prolegs (fleshy, leg-like structures found on the abdomen of some insect larvae) nor do they have true legs. This similarity in the absence of both prolegs and legs is what makes the statement true.

The water penny is in the most pollution sensitive group, class I.

There is likely some pollution in the water as no organisms from class 1 are present, and only one from class 2. All the other organisms found are pollution tolerant to at least some degree (class 3 - class 5).

The damselflies have three characteristic paddle-shaped "tails" (actually extra gills), whereas a dragonfly has no long "tails" sticking out the back.

Dragonflies are macroinvertebrate nymphs that can grow up to 2 inches long. They have large eyes, a large round abdomen, and six legs. Dragonflies are also classified as class 2 or moderately sensitive to pollution.

This class II bug resembles its land relative, the roly-poly. The correct answer is "aquatic sowbug."