Dr. Stiassny's early career began with large-scale and groundbreaking morphological studies exploring the evolution and relationships of the cichlids, labroids, and spiny-rayed fishes. As her fieldwork continued, she became ever more concerned with the conservation and biodiversity of freshwater fishes leading to her continued focus on fishes from Madagascar and Africa proper. Over a 10-year period, a
multidisciplinary team led in part by Stiassny studied the complex ecosystems of the lower Congo River. Using a genetic analysis of fishes of the
Teleogramma genus in the area, she has found evidence that the strength of the current and the extensive rapids in the last 200 km of the river form multiple barriers for fish, thus creating a series of tightly-packed, isolated habitats where populations develop independently: "We'd take fish from the other side of the river, and we looked at their DNA, we realized something very strange is happening, they're separated from each other. In some areas, only one fish crosses the river every two or three generations." This peculiar phenomenon accounts for the region's exceptional
biodiversity, with 300 species of fish. She realized how complex the ecosystem was when they found fishes dying of decompression on the surface, which made them realize they were also dealing with fish population that lived at the bottom of what is a very deep river in some places. She enlisted the help of a team from the
United States Geological Survey, which found the river was flowing into a canyon that was 580 feet deep, as well as very strong currents, including some flowing upriver. She has been collaborating with the
University of Kinshasa and the
Marien Ngouabi University to train Congolese ichthyologists. Her research in the lower Congo led her to catalogue a new species of
Teleogramma, which she chose to name
Teleogramma obamaorum to recognize the interest of
Barack and
Michelle Obama for science education and conservation in Africa. Stiassny was the lead curator for the renovation of the American Museum of Natural History's
Irma and Paul Milstein Family Hall of Ocean Life, which reopened its doors in 2003. About what they were trying to achieve with the renovations, Stiassny said: "I want people to walk away with an understanding of how remarkably superlative the oceans really are. Not just in terms of sheer size and beauty, but also in their ecological complexity and the tremendous biological wealth they contain. Perhaps above all, I want them to understand how absolutely critical ocean health is to the health of all life on Earth. The oceans are a series of interconnected ecosystems that can unravel very, very, quickly." Stiassny is on the faculty of the
Graduate Center of the City University of New York. ==Taxa described by her==