When Irena Jevtov decided to use coral for her postdoctoral research at MIT about the immune system, she had questions: Where could she find research-grade coral, and how do you take care of it?
“I was told that there is a great fish expert, Mr. London,’’ said Jevtov, standing in an MIT basement room stacked six rows high with 1,000 tanks holding 30,000 silvery zebra fish.
Scientists in a wide range of fields, including medicine, study fish and other marine organisms to learn how the human body functions in health and disease. But they don’t always know how to care for them.
From coral to zebra fish, Ellis London gets the call.
The owner of a Framingham fish and aquarium store, London — known as Mr. London — has been the go-to expert on marine organisms for dozens of Boston-area researchers for more than 40 years.
Nancy Hopkins, a professor of biology at the Massachusetts Institute of Technology whose work with zebra fish led to breakthroughs in cancer and genetics, relied heavily on London when her fish were ailing, she said.
“I will never forget our relief as he came through the door of the lab with a little black bag in hand, just like an old-fashioned doctor’s bag,’’ she said in an e-mail.
On a recent day, London, 70, wearing a blue checked shirt and suspenders, was at MIT as part of his regular rounds, checking in on the zebra fish and the mechanical and biological systems that keep them thriving — and answering Jevtov’s questions about coral.
He gave the lowdown on types of coral and their capacity to produce mucus to Jevtov, who studies mucus and the immune systems of simple animals for clues about how the complex human immune system works.
Largely self-taught, London knew so much about fish as an undergraduate at Boston University that his adviser gave him a job teaching basics to graduate students. He quit school after two of his advisers left, set up his shop in Framingham, called Tropical Isle Aquarium, and carved out a niche business as a fish consultant to scientists.
“I speak their language,’’ London said. Sometimes that language is Latin. Ask London anything about fish and he’s likely to answer you with the Latin name.
“Give me a Latin fish name and I’ll remember it,” he said, but added, “I’m notoriously bad with people’s names.’’
Last month, between caring for the 50,000 fish at his store and reading six fish magazines, London answered questions about octopus care for researchers at the Harvard School of Engineering and Applied Sciences.
“It keeps me in academics,’’ London said.
He has particular expertise with zebra fish, whose eggs grow outside the mother’s body. The zebra fish is widely used as a research animal, especially by scientists studying development, genetics, and cancer.
“The cells are fairly transparent for the first week of life so you can watch everything happening in development. You can see things going wrong,’’ said MIT research scientist Adam Amsterdam.
Few scientists were working with zebra fish in 1989 when Hopkins brought 21 of them to MIT on a flight from Germany. His lab painstakingly cataloged 400 genetic mutations in the fish, noting which ones related to cancer.
“We’re looking for additional genetic changes that have to happen for cancer to happen, to identify new targets for cancer therapy,’’ said Amsterdam.
Two years ago, Hopkins’s zebra fish lab, which was spread across multiple rooms and floors, moved into one central location that accommodates any researcher on campus who wants to work with zebra fish. Four MIT research teams currently use the facility, Amsterdam said.
Young zebra fish grow in a separate nursery room. At 5 to 14 days old, they are so tiny they are fed paramecium, single-cell organisms grown in the lab. Full grown, the silvery fish are as long as a person’s pinky, feed on brine shrimp, and can live five years.
“A fish system is an ecosystem, not just fish and water,’’ Amsterdam said. “Getting it all to work without killing your fish is not trivial.’’
Throughout her research work, Hopkins said, she relied heavily on London to keep the fish healthy and credited him in a 1992 research paper she wrote.
“He was so incredibly helpful in dealing with crises, providing advice, teaching us how to care for fish, that I saw him as an essential member of our team,’’ Hopkins said.
London said he was often able to assess the health of the fish just by looking at them.
“It’s important because fish in experiments can’t be given antibiotics,’’ London said.