The Yellow Egg Cockle, Laevicardium mortoni (Conrad, 1831), is a common bivalve found in beach drift at University Beach, Corpus Christi Bay, Texas. However, most shells found at this location are not very colorful. On 2013-04-12 I found a nicely colored empty specimen, which i took to the lab to photograph. This shell was about 12 mm (1/2 in) in diameter.

Its shell is subcircular, slightly triangular, with faint commarginal growth lines and fine radial threads. When viewed under magnification, the area near the ventral margin shows minute elongated blisters arranged in commarginal lines (as seen in a couple of photos below).

The coloration in fresh specimens (as the one figured here) is a dirty white to cream background with brown to purple maculations.

The species is found from Massachusetts to Florida and to Texas, from 0 to 84 m (275 ft) depth. In bays it is found near inlets.

Read more about this species in Tunnell et al (2010)’s Encyclopedia of Texas Seashells, page 355, and in the upcoming Texas Seashells, A Field Guide, on page 196.