Worldwide authority

Afrithelphusa monodusa

MARQUETTE — You won’t find any freshwater crabs living in inland waters in the Marquette region. However, Northern Michigan University biology professor Neil Cumberlidge has seen plenty in his day.

He had to travel to Africa, though, to see many of them.

Cumberlidge was recently awarded a Doctor of Science degree from the University of Hull in the United Kingdom. Unlike an honorary doctorate, this higher degree was bestowed upon him based on his extensive body of published work as an authority in the field of African freshwater crab biology. Cumberlidge also holds a doctoral degree in zoology.

A committee of internal and external examiners judged Cumberlidge to have made a substantial and sustained contribution to scientific knowledge beyond that required of a doctorate. Baroness Virginia Bottomley, University of Hull chancellor and a former cabinet minister in the governments of Margaret Thatcher and John Major, presented the degree to Cumberlidge at a congregation ceremony

African freshwater crab biology might seem like an esoteric topic to many. So how did Cumberlidge become a leading authority on such a subject?

He earned a bachelor’s degree in zoology in England, where he grew up, and then entered a graduate program to study marine biology.

“What they did there was crabs and lobsters and shrimp and such,” Cumberlidge said.

That might sound like a tasty seafood buffet to many folks, but to Cumberlidge, it was an introduction to an intellectual aquatic world.

Cumberlidge eventually got a job in Nigeria, where he took his “crab knowledge” and began to study freshwater crabs in the area.

That’s been his specialty ever since.

When people think of African wildlife, animals like giraffes and elephants probably spring to mind more than freshwater crabs. However, these animals are unique too, even though they don’t have long necks or tusks.

“They can get sort of big as your fists, plus legs and paws and everything,” Cumberlidge said of freshwater crabs. “They can be a fair-sized animal. They also come tiny.”

They also aren’t necessarily the bland-looking creatures some people might envision.

Case in point: One of his Ph.D. students is collecting in the highlands in Cameroon and has come across vividly colored crabs in crater lakes on the tops of volcanoes.

“These are new discoveries,” Cumberlidge said. “These are new species we’re writing up now, but we’ve sequenced them already.”

He suspects the crabs’ bright colors are due to the minerals that are bubbling up in the water.

Cumberlidge’s study methods are varied.

When trying to determine biodiversity — discovering how many species are out there — it’s “cheap and easy,” he said.

“You just go collecting, and then you take field notes and you can do studies of populations and habitats and all of that,” Cumberlidge said.

He and other researchers also take tissue samples from, say, a leg or gills, from specimens to get DNA and sequence it.

That information goes into a huge data bank, a website called GenBank, an annotated collection of all publicly available DNA sequences that researchers can use the website to search for similar sequences.

“DNA barcoding is what we call it,” Cumberlidge said.

What are the practical reasons for having healthy populations of African freshwater crabs?

“Some of them have medical importance,” Cumberlidge said. “So, in Africa and around the world, they carry a parasite that causes lung fluke disease.”

That disease, he noted, is found in humans, who if they eat the crabs can get the illness. Since the symptoms are similar to tuberculosis, if people aren’t familiar with the parasite, the wrong treatment could be given.

Learning more about the crab parasite, then, would result in the proper diagnosis.

Crabs also have importance, he said, in the aquarium trade and, of course, eating. Who doesn’t love crab?

Even for people who never come across a freshwater crab in their lives, it’s important they exist; they’re also an important part of the food web.

Among African crab species, about a third are threatened with extinction, Cumberlidge said. Freshwater crabs, Cumberlidge noted, are more vulnerable to loss of habitat than their saltwater brethren, and habitat loss is a primary cause of a population drop, as is pollution. Climate change is another big factor, he said, because it’s changing rainfall patterns in the tropics.

With habitat loss, water diversion is a problem.

“There aren’t many rivers left on this planet that are not dammed at some point, any major rivers, and the damming has a big impact on the ecosystem,” Cumberlidge said.

All of his research had led him to being recognized by the University of Hull.

Cumberlidge’s most recent degree, the Doctor of Science recognition, is a degree the British university system gives if a recipient already has a Ph.D.

“This doctorate is based on ‘what you have done since you’ve got your doctorate?'” Cumberlidge said.

After being nominated, he had to combine his publications and write a lengthy rationale on why his research is meaningful.

Obviously, it’s meaningful on a global scale, but it has a personal connection as well.

Cumberlidge just named a new species after his wife, Nheena Weyer Ittner, founder and executive director of the Upper Peninsula Children’s Museum.

The crab, known as Potamonautes nheenae,is from Gabon.

“In regards to having a crab named after me … it’s a huge honor!” Ittner said in an email. “Now people can officially refer to Nheena as a real crab!”

Cumberlidge is on sabbatical from NMU where he teaches a variety of courses: animal physiology; advanced human physiology, a graduate course; human anatomy and physiology; and evolution.

Graduate students also study freshwater crabs, he said.

While on sabbatical, he will revise information on African freshwater crabs — in Africa, of course — and be involved in other projects.

Cumberlidge has a project going on in Singapore to save an endangered species there, which is in its third year, and is chairman of the Freshwater Crustacean Specialist Group that has worked on a listing of world freshwater crabs for the International Union for the Conservation of Nature.

He also plans to travel to Shanghai in about a month to run a conservation workshop for Chinese scientists on freshwater crab conservation.

Who would think that a specific animal population about a half a world away would take Cumberlidge to such far corners of the earth?

It’s probably good that he and others take such an interest in freshwater crabs.

“It’s not as if you remove the species, the world will end, but if the species is dying off, it’s an indicator that you’re poisoning that water so badly that even this species can’t make it,” Cumberlidge said. “Crabs are quite hardy, you know. They’re quite strong, but they can’t live if you dry up their river bed or put pollutants in it so there’s no oxygen left. They just can’t complete their life cycles.”

Christie Bleck can be reached at 906-228-2500, ext. 250. Her email address is