Green bookshelves are stacked to the ceiling with a menagerie of preserved fish in large glass jars: a pocket shark from Florida, dogfish from Somalia, minnows from Pearl River and hammerhead sharks from Florida.

Walking into the Royal D. Suttkus Fish Collection, the largest fish archive in the world, is a bit like stepping into a witch’s lair.

More than 7,000 species, totaling around 7 million specimens, have been collected and preserved at the collection, part of Tulane University’s Biodiversity Research Institute — yet few in New Orleans know about the peculiar archive on the West Bank.

The Suttkus Fish Collection began when Tulane professor and ichthyologist Royal Suttkus arrived in New Orleans in 1950. He began collecting fish from the waterways of the region.

The collection quickly outgrew its original space on Tulane’s main campus and was moved in 1968 to a number of World War II-era bunkers along the Mississippi River in Belle Chasse.

Much of the collection is made up of specimens from freshwater river basins in the Gulf South. “Suttkus was interested in surveying and understanding Southeastern rivers and what was in them,” said Justin Mann, the collection's manager. “Both to further scientific knowledge, as well as to protect the waters and ensure that all the species are well understood.”

The Pearl River was a regular site for Suttkus to capture varieties of fish including bream and bass. Each time a specimen was collected, he would mark the location, time, water quality and habitat conditions.

All of the specimens — amphibians, reptiles, mussels and crustaceans also were caught — were preserved and ultimately cataloged.

Suttkus’ work provided a snapshot of the natural history of the area over many decades, a now irreplaceable body of knowledge.

In his career, he named and described 35 new fish species, 29 of which are freshwater species found mostly in the Southeastern United States.

The fish specimens are mostly preserved in glass jars of various sizes, though larger specimens such as the fierce-teethed gar are stored in large steel boxes. Each specimen is fixed in formaldehyde and then soaked in ethanol, preserving them for generations to come.

In March 2017, the archive grew substantially when it received 85,000 new specimens. The University of Louisiana at Monroe announced that it would eliminate the school’s fish and plant collection to make way for an improved running track.

The university said the specimens would be destroyed if a home for them was not found by July. The Suttkus Collection, along with other natural history collections at Mississippi State University, the University of Texas and other schools, absorbed more than 6.5 million specimens.

Scientists around the world use the Suttkus Collection for various research purposes, from identifying new species to better understanding ones already known.

“There are archives like this all over the country, and the reasons they exist are systematic and taxonomic issues such as discovery of new species and understanding the relationships among different species,” Mann said.

Another important use of the archive is documenting fluctuations in fish populations in the region. Since 1950, many of the rivers and bayous where Suttkus collected samples have experienced major changes, such as salinization from rising sea levels.

Because of Suttkus’ lifetime of work, changes in fish populations are documented in the archive and can be measured against current levels. As Louisiana loses more and more wetlands each year, the archive becomes a more valuable source of information.

One highlight of the collection is a pocket shark, a small, deep-water shark that is one of two specimens ever captured. (The other one is in Siberia.)

Measuring about 12 inches long, the blue-gray shark has a pocket next to its front fins. The purpose of the small pocket is a mystery, though scientists hypothesize that it secretes a bioluminescence to light the way in the dark of the deep ocean.

The National Oceanic and Atmospheric Administration caught the pocket shark off the coast of Louisiana while studying sperm whales. It brought the rare shark to the archive, where scientists were able to identify the specimen and place it in the genus Mollisquama.

One way the archive has made that sort of valuable information available is through digitizing everything in the collection. “We were one of the first collections of our kind and definitely of our size to be fully digitized,” Mann said.

The National Science Foundation supported the digitization work with a number of grants, and the archive developed what is now the leading software program for georeferencing collection information.

The Suttkus Fish Collection is not open to the public, so many New Orleanians might not know about this fount of natural history knowledge in their backyard. But the archive is a center of research on both local fish populations and the environments in which they are found — vital information for understanding changes in the environment and climate.

It also is a reminder that the world is a vast and complex place, filled with species beautiful and strange that populate the depths below.

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