While advances in imaging technologies have opened new pathways for scientists to study natural phenomena, researchers continue to make remarkable discoveries using techniques that have been around for decades. John Sparks, associate curator in the Museum’s Department of Ichthyology, uses enzymes and dyes to reveal key anatomical structures in different species of fishes for study of their function and evolution.

Among his study subjects are ponyfishes (family Leiognathidae), a group of bioluminescent fishes common in the Indian Ocean and Western Pacific that have a light organ. This internal structure, which varies among ponyfish species, surrounds the esophagus and contains luminescent bacteria, the source of the fish’s light. The light organ is larger in males, which have a second species-specific anatomical feature: translucent skin patches, which allow them to use the light organ in displays to attract mates in turbid waters. (Bioluminescent organisms will be explored in the exciting new exhibition Creatures of Light: Nature’s Bioluminescence, which opens at the Museum on March 31, 2012.)

Seventeen-year-old Ryan wanted to understand whether the popular insect repellant DEET, worn by many tourists to ward off mosquitoes, had any effect on the dinoflagellates in these bays. His investigation, outlined in the essay The Effects of DEET on the Bioluminescent Dinoflagellate, Pyrocystis fusiformis, earned Ryan one of this year’s Young Naturalist Awards.

Museum scientists John Sparks and David Gruber have traveled the world in search of bioluminescent and biofluorescent organisms. On Wednesday, November 2, at 7 pm, the pair will host November’s SciCafe, Alive and Glowing: Adventures in Bioluminescence and Biofluorescence, and shed light on the way these phenomena have appeared throughout the tree of life. Dr. Sparks will also curate the Museum’s upcoming special exhibition Creatures of Light: Nature’s Bioluminescence, which opens March 31. Below, Sparks and Gruber answer a few questions about their enlightening research.

Two extraordinary new species discovered by scientists at the American Museum of Natural History — a toothy leech and a Louisiana batfish — have been named in the Top 10 New Species of 2011, a ranking compiled by the International Institute for Species Exploration (IISE) at Arizona State University. Every year taxonomists at the IISE review thousands of new species uncovered over the preceding calendar year.

One of the Top 10 is Tyrannobdella rex, which means “tyrant leech king,” a new species of blood sucker with ferociously large teeth lining a single jaw. It was discovered in Perú when the leech, which is less than 2 inches in length, was plucked from the nose of a girl who had recently been bathing in a river. T. rex was first brought to the attention of Mark Siddall, curator in the Museum’s Division of Invertebrate Zoology, when he received a specimen collected by Dr. Renzo Arauco-Brown, a Peruvian medical doctor. Siddall immediately recognized it as a new species. Part of the research for the paper, originally published in PLoS ONE, involved an expedition by two of Siddall’s students, Anna Phillips and Alejandro Oceguera-Figueroa, to gather new specimens for DNA analysis.