A new species of Echiura, Anelassorhynchus panamensis (Family: Echiuridae), is described from the eastern tropical Pacific Ocean. The specimens examined are from collections in the invertebrate museum, Rosenstiel School of Marine and Atmospheric Science, University of Miami, and were collected from a coral reef in Panama. This species is distinguished in possessing a proboscis that is divided distally into numerous lobes of different shapes and sizes, an opaque integument with closely aligned transverse wrinkles, a pair of microscopic ventral setae, two pairs of tubular, postsetal gonoducts with elongated coiled gonostomes and tubular anal vesicles. Peculiar coelomic organs were found in the holotype and in one paratype. This new reef-associated echiuran demonstrated consistently high spatial and temporal abundances. Quantitative sampling of A. panamensis along the Uva Island fore-reef coral rubble/sand microhabitat revealed median population densities between 2–8 individuals per 20 liters of sediment sampled, and median annual densities that ranged between 1 to 7 individuals per 20 liters of sediment over a five-year period (2002–2006).