My friend Marion Nixon, who has died aged 95, was well known to generations of research scientists for her ingenious work in clarifying much of what we know about octopuses, including how they feed and digest their food.

Having received her PhD from University College London in 1968 for her work on octopuses, Marion went on to publish around 70 papers and book chapters on octopuses and squids, both living and fossil. For about 30 years she also worked as a research assistant to John Z Young, the former head of the UCL department of anatomy, helping him to publish a large number of academic papers and textbooks.

An image by the 19th-century Italian naturalist Giuseppe Jatta of Octopus vulgaris, the common octopus. This was one of Marion Nixon’s favourite images of the animal

In many of his publications, Young singled out Marion for special gratitude, acknowledging the essential part she played in doing much of the work necessary to publish his works: while it was Young who dictated the text for these publications, it was Marion who worked behind the scenes, collating academic references, editing, revising, proofreading, and coordinating with publishers. The publication of the book The Brains and Lives of Cephalopods, in 2003, six years after Young’s death, was mostly due to Marion’s perseverance. Her diligence and attention to detail freed up much of Young’s time, enabling him to maximise his output during the latter part of his career.

Marion’s own research contributions, by clarifying and confirming exactly how octopuses feed, debunked myths such as the idea that octopuses feed on crabs by dissolving their flesh externally (in a similar way to spiders): she showed that, in fact, octopuses break their food into small pieces, which are eaten and digested normally. In the 1960s, Marion was one of the first to use video cameras in science, recording the movements of the musculature and organs of the octopus’s mouth region.

Marion was born in Thornton Heath, south London, the daughter of Ernest Putnam, an insurance salesman for Eagle Life, and Ethel (nee Bond), a seamstress. After attending Selhurst grammar school for girls, she studied for a BSc degree in zoology at Chelsea College of Science and Technology, then worked as a technician at the Royal Free hospital, Hampstead, and at St Mary’s Medical School, in Paddington, before becoming research assistant to Young at UCL. On the staff at St Mary’s she met Dennis Nixon, a physiologist, whom she married in 1955.

On three occasions, Marion spent the summer working at the Zoological Research Station in Naples, Italy, and would drive from London all the way to Naples, via France and northern Italy, to broaden her children’s experience of the world.

Marion was soft-spoken but not shy of expressing her opinions. With her wonderfully pleasant, modest manner, she was a charming woman. An excellent cook, she regularly treated her family and friends to a wide variety of English, French and Italian dishes, accompanied by good wine.

Dennis died in 1972. Marion is survived by their children, Ann and Peter, and grandchildren, Andrew and Cameron.