This shell of the Brown-line Niso, Niso aeglees Bush, 1885, is, so far, a one-of-a-kind find for the islands of Sanibel and Captiva (see below). This conical shell measures about 10 mm (about 0.4 inch), and is usually smooth or glossy, presenting no sculpture or ornamentations. Its color is whitish, with a thin red-brown band just above suture (groove separating two adjacent whorls). The species is known to occur in deeper water in the Gulf of Mexico, but this shell was found by Steve Rosenthal on Blind Pass, on Sanibel, on December 20, 2016. The area is known for accumulation of deeper-water species brought in with sand from beach nourishment efforts.
The Brown-line Niso, Niso aeglees, from Blind Pass. Photos by José H. Leal.