#9 on this particular list

Beluga Sturgeon

Living up to 120 years these interesting looking creatures can grow to be nearly 7 meters in length.

I will have to say that this particular list obviously is not placing the creatures in the order of size because we passed up elephants a long time ago and some of them they weigh 13,000 pounds, which is 4 times more than these huge fish. 

However, the biggest is yet to come.

Beluga (sturgeon)

The largest accepted record is of a female taken in 1827 in the Volga estuary at 1,571 kg (3,463 lb) and 7.2 m (23 ft 7 in).^[7] Another specimen reportedly weighed 1,220 kg (2,690 lb) and measured 6.1 m (20 ft 0 in) in length.^[8] Several other records of aged sturgeon exceed 5 m (16 ft 5 in).^[7] These great sizes mark the beluga as the largestfreshwater fish in the world.

Beluga of such great sizes are very old (continuing to grow throughout life) and have become increasingly rare in recent decades due to the heavy fishing of this species. Today, mature belugas that are caught are generally 142–328 cm (4 ft 8 in–10 ft 9 in) long and weigh 19–264 kg (42–582 lb). The female beluga is typically 20% larger than the male.^[11] An exceptionally big beluga caught recently reportedly weighed 960 kg (2,120 lb) and measured 3.4 m (11 ft 2 in)......................wow, we could feed a days worth of illegal immigrants crossing the southern border with one of those (-:

A 1000-kg, 4.17-m-long beluga fish from the Volga river (National Museum of Tatarstan, Kazan, Russia)

Uses

The caviar of a beluga sturgeon, the main reason for the massive overharvesting of this species.

Beluga caviar is considered a delicacy worldwide.^[12] The flesh of the beluga, though, is not particularly renowned but is a hearty white meat similar to that of swordfish.