Research alert! A new study shows how climate change affected the diversity of Congo River fish during glacial periods—crucial knowledge for understanding modern threats to fish in this species-rich region.

Over the last about 2.6 million years, polar ice caps have continuously expanded and retracted during glacial and interglacial cycles. This is thought to be a significant driver of biodiversity on land, but less is known about its effect on freshwater systems, especially in the Congo River. 

Using molecular tools, scientists focused on four species of fish endemic to the lower Congo River, known as lamprologine cichlids. Their findings, published in the journal Integrative and Comparative Biology, suggest speciation of Congo fish likely occurred when the river’s water level decreased, isolating populations of fish into smaller pockets of water, leading to the rise of new species over time. 

Learn more about how climate change impacts river fish.

Image: © Melanie Stiassny, Lamprologus lethops pictured

Still feeling stuffed from your Thanksgiving feast? Meet the Guineafowl puffer (Arothron meleagris)! Instead of chowing down on turkey, this fish feeds mainly on the tips of branching corals. It gets round not by eating but to avoid being eaten, swallowing water to dissuade predators from attempting such a big bite. If it’s late to inflate, this fish also has bacteria in its body that can be toxic.

Photo: merav, CC BY-NC 4.0, iNaturalist

Don’t mess with this fish! To celebrate Fossil Friday, let’s meet Dunkleosteus terrelli. It lived some 360 million years ago during the Devonian. Fossil records indicate that this animal, one of the first large jawed vertebrates in the ocean, was an aggressive predator. The razor-sharp edges of bones in its jaws served as cutters, and as they rubbed against each other, the opposing jaw blades acted like self-sharpening shears. These bones continued to grow as they were worn down by use. This specimen, on display in the Museum’s Hall of Vertebrate Origins, was found in Ohio!

Visiting the Museum this Thanksgiving? Best availability is on Monday and Tuesday of that week. Here are some tips to help plan your visit!

Photo: Image no. ptc-5861 / © AMNH Library

Ever feel like a fish out of water? Meet the giant mudskipper (Periophthalmodon schlosseri). Believe it or not, this fish needs to breathe air and spends a decent amount of time on land! Found on the muddy shores of mangroves in parts of Southeast Asia, it uses its pectoral fins to “skip” or “walk” across mudflats.

Photo: mysorekid, CC BY-NC-SA 4.0, iNaturalist 

Catch up on #ShelfLife before the launch of Season 2. The story of the Museum's coelacanth shows how natural history collections can yield answers and inspire questions for hundreds of years. Ichthyology Curator Melanie L. J. Stiassny presents the ultimate fish tale and offers a primer on specimen prep.

Women In Museum History: Francesca LaMonte

Assistant Curator of Ichthyology Francesca Lamonte, who worked at the Museum from 1920 to 1962 and specialized in marlins and swordfish, was Ernest Hemingway’s go-to fish authority, and according to a 1952 edition of The Long Island Press, a “general big-game whiz bang.”

LaMonte joined the Museum two years out of college, beginning her career translating scientific papers from French, German, Italian, Spanish, and Russian into English before being promoted to curator nine years later. During her time at the Museum, LaMonte became one of the world’s leading experts on big game fish and was a key player in the founding of the International Game Fish Association (IGFA), a group dedicated to game fish conservation and responsible sport-fishing. The IGFA, which had its first home here at the Museum, still exists today.

As both a curator and member of IGFA, LaMonte participated in a number of ichthyological expeditions. Her specialty was game fish like marlins and swordfish, species about which she published numerous scientific papers. LaMonte was also a prolific writer of game-fishing guides that were acclaimed best-sellers amongst the angling set,and penned vivid accounts of Museum expeditions. In a 1940 issue of Natural History, she described a trip to collect swordfish off of northern Chile:

Just three days through the air from the heat of a Miami June, and we are in the chill of a West Coast winter. Two fishing boats stand in the harbor of Tocopilla waiting for our expedition. All around them the water is alive with anchovies, and the neighboring boats are obscured by flocks of birds swooping down to feed on the small blue-and-silver fishes.

LaMonte’s work as a scientist and writer earned her admiration from some literary lions. Read more about it on the Museum blog.