Picta Turrid Shell, Polystira picta

Picta Turrid Shell, Polystira picta. Shell courtesy of the commercial fishermen of the greater Los Cabos area, Baja California Sur, March 2016. Size: 4.8 cm (1.9 inches) x 1.4 cm (0.4 inches).

Phylogeny: The Picta Turrid Shell, Polystira picta (Reeve, 1843), is a gastropod mollusk that is a member of the Turridae Family of Turrids Shells. The genus Polystira is one of twenty-five genera in this family, and there are also twenty-five species in this genus. The name picta comes from Latin, meaning painted, referring to the brown markings on the shell.

Description: Picta Turrid Shells are slender, high-spired, and fusiform (spindle-shaped). They consist of seven or eight angled whorls. They have a long open siphonal canal and a narrow aperture. The exterior is sculpted with coarse and fine spiral ridges that continue to the outer lip giving the lip a zigzag appearance. The exterior of the shell is white and varying amounts of brown specks or blotches that on some shells form stripes or chevrons. The interior is white. Picta Turrids Shells reach a maximum of 5.7 cm (2.2 inches) in length and 1.7 cm (0.7 inches) in height. They are similar to the Noble Giant Turrid Shell, Polystira nobilis, which has a wider body.

Habitat and Distribution:  Picta Turrids are found in muddy sand environments at depths between 20 m (65 feet) and 80 m (260 feet). They are a subtropical to tropical Eastern Pacific species that are found in all Mexican waters of the Pacific Ocean with the exception that they are absent from the West Coat of the Baja Peninsula.

Ecology and Behavior:  Picta Turrids are a poorly studied and understood species. There is very limited documentation of their diet, predation, reproduction or ecosystem interactions. Other species in Family Turridae are predators that feed primarily on polychaetes. They are gonochoric and reproduce sexually,  with internal fertilization. The eggs are laid in protective capsules. There is no mention in the available literature of them engaging in any types of parasitic, commensal, or symbiotic relationships. From a conservation perspective they have not been formally evaluated.

Synonyms: Pleurotoma picta.