He worked at the Museum of Natural History in Regensburg, and wrote on a range of topics under the pseudonyms Garduus and G. Tilesius (an anagram).

He has been accused of plagiarism and has been described as vain, boastful, superficial, a cheat, a liar, and a "tragi-comic figure" by Embrik Strand and Walther Horn.

He was the sole member of a society, the Münchener Verein für Naturkunde, which issued honorary diplomas in a bid to gain favours from selected entomologists.

Such honorary diplomas were offered to Lorenz Oken (an erstwhile mentor of Gistel) and Maximilian Perty, with pseudonymous signatures.

[1][2] Gregor Mendel was said to have failed an exam to become a teacher because he made a mistake on the orders of mammals, having referred to Gistel's Naturgeschichte des Thierreichs.