In actuality, it isn't black. Usually what appears to be black is either the undercooked liver, called the tomally which is a dark green or the undercooked lobster eggs called roe whicj are a dark red.
A lobster
black
there is one ive found, its called the 'black lobster clothing company'
black
A lobster
a lobster
Donald Weir has written: 'Black lobster'
It is just stuff out of an anus ;)
The asker of the question provided this additional information as background to the question: "I had a lobster last night from a well-known establishment... and when I pulled the tail off, I found some things I never found in a lobster before: black goo and this red paste that went all the way down through the middle of the tail." Answer: There is no black tomalley. The black substance inside the abdominal cavity along with the green tomalley in a cooked lobster is called the coral and is found in the female lobster. It is the eggs or roe of the lobster, and those who like tomalley are usually big fans of the coral. The red stripe running down the middle of the back of the tail is likely the digestive tract. It is the color of what the lobster has eaten. Before eating the tail, peel off the digestive tract. It will not be harmful to eat after the lobster is cooked, but may be gritty and not very tasty.
A rock lobster is just a distinct type of lobster. There are many kinds of lobster, such as the rock lobster and the blue spiny lobster.
Iron is a possibility. Some iron alloys are black, and iron can rust in water.