One issue is to which President or Congress a particular year's deficit should be attributed. U.S. Congressional terms start on Jan. 1, Presidential terms later in January, and the fiscal year on Oct. 1, so none of them exactly match up.
These nephridia, which are called protonephridia, are branched tubules of ectodermal origin. They are closed at the internal ends by terminal cells, or solenocytes, and open to the exterior by means of excretory pores, or nephridiopores.
Daphnia ambigua is the scientific name for a species belonging to a group of animals known as Water Fleas.. Daphnia ambigua is one of the most common Daphnia in our area, although Daphnia are not fleas at all. They are Crustaceans, cousins of crayfish and shrimp. Daphnia live in lakes, ponds, and slow-moving streams.