By 1955 the list contained more than 3000 families and individuals.
In 1990, this population contained only three or four individuals.
The populations are very small, with some containing just a few individuals.
The largest tank contains 20,000 individuals of about 80 species.
Certain populations have been observed to contain only female individuals.
A recent estimate is a total of 22 populations containing 8360 individuals.
There are 63 photographs of bodies or body parts, containing 31 individuals.
The two populations of this rare plant contain no more than 30 individuals in total.
While many caves contain only 10 to 15 individuals, the average group size is 100, with a maximum of about 500.
This plant occurs in six areas, two of which contain fewer than five individuals.