He continued his studies with the French zoologist Alfred Mathieu Giard at the marine laboratory in Wimereux (Université Lille Nord de France), and concluded his studies with the English invertebrate zoologist Ray Lankester at University College London.

Pelseneer became recognized in Belgium as well as abroad as one of the most eminent zoologists of his time, but he never obtained an appointment as university professor and thus was not able to transfer his knowledge to students.

He was given drawing lessons by the Belgian painter and sculptor Constantin Meunier, so that he could illustrate his scientific papers himself.

[1] In 1934 he received the degree of Doctor honoris causa from the University of Brussels for his outstanding works on molluscs.

[citation needed] Although Pelseneer was primarily a malacologist, he was interested in all aspects of zoology.