I for one really enjoyed Nightlife. It moved along at a good pace and Vanessa is clearly one of the most beautiful women to appear in the series. (of course seeing Gretchen Corbett in a bikini wasnt too shabby either).

In Nightlife it is interesting how Columbo kept digging to tie the two murders together. Although for most the episode it was just one murder and one missing person.

It was a good way to end the series.

why 9 fish? the tank is half the height, so you would expect 7, being half of the 14 in both other tanks

Actually it's not half, or better yet, keep in mind I only watched the italian version and that sometimes the numbers are different between versions, so I don't know if that also goes for the english one, but in the italian version the tanks are 1 meter vs 60 cm deep, that's 60% of the deepest one, so with 14 fish in the big one it would be 8,4 in the small one, so I guess they rounded up to 9.