Bleeker was employed as a medical officer in the Royal Netherlands East Indies Army from 1842 to 1860, stationed in Indonesia.
During that time, he did most of his ichthyology work, besides his duties in the army.
He acquired many of his specimens from local fishermen, but he also built up an extended network of contacts who would send him specimens from various government outposts throughout the islands.
During his time in Indonesia, he collected well over 12,000 specimens, many of which currently reside at the Natural History Museum in Leiden.
Bleeker corresponded with Auguste Duméril of Paris.
His work in ichthyology and tropical medicine was recognised by two doctorates honoris causa (Leyden University, 1846; Utrecht University, 1849).

After his return to the Netherlands in 1860, he started publishing the Atlas Ichthyologique des Indes Orientales Néêrlandaises, a comprehensive account of his studies done in Indonesia, featuring over 1,500 illustrations.
It was published in 36 volumes between 1862 and his death in 1878.
Between 1977 and 1983, the Smithsonian republished the work in 10 volumes.

Bleeker published more than 500 papers on ichthyology, describing 511 new genera and 1,925 new species.

He also worked in herpetology, describing at least 14 species of reptiles, most of them described in Reptilien van Agam.

In 1855, he became correspondent of the Royal Netherlands Academy of Arts and Sciences, department Natuurkunde (then Natural Sciences), and in 1862 a member.

In 1856 he was elected correspondent for the Muséum national d'histoire naturelle in Paris.
In January 1864 he received a French knighthood of the Légion d'honneur.
He was president of the Royal Netherlands Institute of Southeast Asian and Caribbean Studies.
Bleeker was employed as a medical officer in the Royal Netherlands East Indies Army from 1842 to 1860, stationed in Indonesia. During that time, he did most of his ichthyology work, besides his duties in the army. He acquired many of his specimens from local fishermen, but he also built up an extended network of contacts who would send him specimens from various government outposts throughout the islands. During his time in Indonesia, he collected well over 12,000 specimens, many of which currently reside at the Natural History Museum in Leiden. Bleeker corresponded with Auguste Duméril of Paris. His work in ichthyology and tropical medicine was recognised by two doctorates honoris causa (Leyden University, 1846; Utrecht University, 1849).
After his return to the Netherlands in 1860, he started publishing the Atlas Ichthyologique des Indes Orientales Néêrlandaises, a comprehensive account of his studies done in Indonesia, featuring over 1,500 illustrations. It was published in 36 volumes between 1862 and his death in 1878. Between 1977 and 1983, the Smithsonian republished the work in 10 volumes.
Bleeker published more than 500 papers on ichthyology, describing 511 new genera and 1,925 new species.
He also worked in herpetology, describing at least 14 species of reptiles, most of them described in Reptilien van Agam.
In 1855, he became correspondent of the Royal Netherlands Academy of Arts and Sciences, department Natuurkunde (then Natural Sciences), and in 1862 a member. 
In 1856 he was elected correspondent for the Muséum national d'histoire naturelle in Paris. In January 1864 he received a French knighthood of the Légion d'honneur. He was president of the Royal Netherlands Institute of Southeast Asian and Caribbean Studies.
Pieter Bleeker