Conversation so far:
what is the length of a black panther
Black leopards range from three to seven feet in length. Black jaguars range from 5.6 to 7.9 feet.
what causes the black panther to be black
Melanism in the jaguar is conferred by a dominant allele, and in the leopard by a recessive allele.
is the whole litter of cats black
Melanistic and non-melanistic animals can be littermates.
does the black cat color offer any advantages
It is thought that melanism confers a selective advantage under certain conditions since it is more common in regions of dense forest, where light levels are lower.

Question: are the cats completely black
Self-contained rewrite: are black panthers completely black