Born in Brookfield, Illinois, in 1969, Mark Henry Sabaj Pérez has a B.S. (1990) and M.S. (1992) from the University of Richmond, Virginia, and a Ph.D. (2002) from the University of Illinois, Urbana-Champaign.
His career in ichthyology began as an undergraduate in 1989 when Drs. William S. Woolcott and Eugene G. Maurakis invited him to assist their field investigation and video documentation of spawning behaviors in nest-building chubs and dace in the streams of eastern North America. His Masters thesis documented newly observed reproductive strategies in five species of minnows in the genera Exoglossum, Nocomis, Rhinichthys and Semotilus.
In 1992 he became a doctoral student of Lawrence M. Page, and from 1995-2000 served as full-time collection manager of fishes at the Illinois Natural History Survey. In 2001 he relocated to Philadelphia to become collection manager of fishes at the Academy of Natural Sciences.
Between 1991 and 2015 he published 45 peer-reviewed papers with a total of 68 co-authors on topics that include spawning behaviors in minnows, darters and loricariids, and taxonomic descriptions of 27 new taxa including one new genus and 15 new species of thorny catfishes (Doradidae), 6 new species of Loricariidae, one new species of river ray (Potamotrygonidae), one new species of Akysidae, one new subspecies of threadfin (Polynemidae), and two new species of crayfishes. His specific area of taxonomic expertise is the catfish family Doradidae (thorny catfishes), on which he recently co-authored a molecular phylogeny and re-classification of all genera and nearly all species.
Mark has field and collecting experience in freshwater ecosystems throughout the United States and on four continents including a total of 34 expeditions to Argentina, Bolivia, Brazil, Canada, Colombia, Finland, Guyana, Mongolia, Peru, Suriname, Thailand and Venezuela. His 1998 Expedition to Kaiteur Falls, Guyana, was featured in a 2002 article in National Geographic entitled “Catfish Hunters” and his most recent work in Mongolia is being filmed for a documentary on the geology of the Hangay Plateau. He was a co-Principal Investigator on the All Catfish Species Inventory (http://silurus.acnatsci.org), a global project funded by the US National Science Foundation to discover and classify all species of catfishes. In 2013, NSF approved funding for his latest collaborative project entitled: Baseline Survey of the Lower Xingu River Rapids, Brazil: a Highly Diverse, Globally Unique, and Immediately Imperiled Ecosystem.
He lives with wife Maria Cristina Sabaj Pérez and their daughter Sofia in Mt. Airy, Philadelphia.