biologist, was born at Heacham, Norfolk, the elder of the two sons of Robert William Theodore Gunther, Oxford University reader in the history of science and his wife Amy, née Neville-Rolfe. After Winchester College, he went to Caius College, Cambridge to read natural science. He married Hilda Mavis Dorothea Carr in October 1929. They had three children: Rosalind Rolfe (1930), Phyllida Margaret (1933), and Hugh Neville Carr (1937).
Appointed by the Discovery Committee as their youngest zoologist in 1924, he worked in the London office with KEMP and HARDY on the preparations, especially for the ship's library, for the Discovery's two year expedition (1925-27) to the South Atlantic. Based in South Georgia from 20 February 1926-17 April 1926 and from 23 February 1927-1 April 1927 he assisted with plankton surveys and attempts at whale marking. After each season he spent time in the Falklands and was present at the unveiling of the Battle Memorial.
On his return to Britain he spent his leave researching the fatty constituents of marine plankton including Vitamins A and D, then worked in the Natural History Museum trying to identify and work on the statistics of the collected plankton samples.
In 1930 he sailed south again as senior scientist on the William Scoresby. During this commission he investigated the behaviour of the Peru Coastal Current followed by a trawling survey of the Patagonian continental shelf from 53°-42°S. He was based in Stanley and returned there between cruises.
His third visit south was for whale marking near South Georgia from December 1936-February 1937. He enjoyed the social life in the Falklands and contributed by 'garnishing' the Town Hall for dances, borrowing plants, flags and other decorative materials. He visited many Falkland settlements, West Point and Hill Cove, riding to Fitzroy, collecting pebbles at Pebble Island and writing diary style letters home (1500 quarto pages in 1925-27) which described every detail of Falkland and ship life. In March 1927 the William Scoresby took shelter in Albemarle harbour as the captain was anxious about water supplies. Gunther, always physically very active, announced at lunch that he would walk to Port Stephens to see whether fresh water was available. He returned on horseback by moonlight. A keen naturalist and observer, he painted watercolours and drew throughout his time there, with an insistence on scientific accuracy. It shows in his drawings of whales in the Discovery Report Vol XXV and in the illustrations to Notes and Sketches reprinted from the Draconian. He contributed to five Discovery reports including one completed by TJ Hart which was based on Gunther's manuscript.
After returning to England he once again worked at the museum writing up all the work done at sea. As a member of the Territorial Army he was called up at the outbreak of war and commissioned 2nd Lt in the 72nd Anti-aircraft Regt RA. In May 1940 he was stationed near North Walsham in Norfolk. When approaching Barton Turf on foot to check that someone was not signalling to the enemy at sea he called at a cottage to read his map and obtain directions to the suspect house. The resident, a Special Constable, directed him on foot, cycled to the house by another route and borrowed a gun from the newly armed Home Guard. Gunther reached the house. The Constable returned with some further Home Guard members and after asking Gunther to hand over his gun, accidentally shot him in the upper leg. He bled to death in Norwich hospital on 31 May 1940. He was awarded the Polar Medal, bronze, posthumously.