While the Sea Serpent (lat. Hydra) is the largest constellation of the night sky, the small, "male" water snake (lat. Hydrus) is rather inconspicuous. Only the main star Alphard is a star of the magnitude 2.
How to spot Hydrus
The constellation of Hydrus is located in the southern hemisphere and is particularly easy to see in winter, sometimes in spring. It lies between the two Magellanic clouds, below Eridanus and between the Toucan and the Horologium.
At the end of the 16th century, a Dutch fleet traveled to the legendary Spice Islands to create new trade relationships. Under Captain Keyser, the positions of 135 stars were measured during this journey, which were later included by Peter Plancius in his sky maps. From these he recognized twelve new constellations, including "De Waterslang". A few years later, the constellation was recorded as "Hydrus" in the new Sky Atlas.