these two references may be useful

Froese, Rainer and Pauly, Daniel, eds. (2006). "Centrolophus niger" in FishBase. January 2006 version.

Tony Ayling & Geoffrey Cox, Collins Guide to the Sea Fishes of New Zealand, (William Collins Publishers Ltd, Auckland, New Zealand 1982) ISBN 978-0-00-216987-5

The main revisionary study that treated the synonymy of C. niger was Haedrich 1967:

Haedrich, R. L. 1967. The stromateoid fishes: systematics and a classification. Bulletin of the Museum of Comparative Zoology v. 135 (no. 2): 31-139.

You will find all the details about Centrolophus niger (Gmelin 1789) and its junior synonyms in the Catalog of Fishes online,

http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp

And the reason for the many synonyms may be plain simple regarding the distribution and lifestyle. The species is almost ubiquitous, but is is a mesopelagic fish, so earlier workers usually had few specimens at hand and were often working rather independently from each other, tending to erect new species on tiny differences they found to existing, and sometimes not very accurate descriptions.

Thank you all for your timely responses, it really helped me in my article!

Much appreciated.