About Terebratalia transversa (Sowerby, 1846)
Terebratalia transversa (Sowerby, 1846) has highly variable morphology, which makes presenting accurate morphological details of the species difficult. Its overall body shape varies immensely: some individuals are prolate spheroids, while others are oblate spheroids. Shell features also vary widely, with both smooth and ribbed shells occurring within the species. Because of this high variation, researchers have proposed that meristic traits cannot be used to create a homogeneous classification for T. transversa. Significant populations of Terebratalia transversa are found in waters off the Pacific Northwest of the United States. Scientists have specifically collected this species by dredging in the San Juan Channel off the coast of Washington, USA. The species lives in both tidal and sub-tidal habitats. The molecular composition of the seawater in these habitats strongly impacts shell size, as carbon-oxygen isotope ratios in the surrounding water affect the species' shell growth rates.
