Turret Shells of the Turritellidea Family
Four Turret Shells of the Turritellidae Family can be found in this website:
Phylogeny: Turret Shells of the Turritellidae Family are gastropod mollusks in the order Caenogastropoda incertae sedis. (incertae sedis is Latin for uncertain seating, meaning they are not sure where it goes). Their assignment to this order is considered temporary. Caenogastropods make up about 60% of the marine gastropod species. They are characterized by having a coiled shell, a single gill, an auricle in the heart, and a distinct radula (rasp-like tongue). There are five superfamilies and one family within this order. The Turritellidae Family is one of twenty families in the superfamily Cerithioidea. The Turritellidae Family is large and consists of five subfamilies, fifty-two genera, and three hundred twenty-six species. Shells in this family are also commonly called Tower Shells, Screw Shells, or Turritellids.
Description: Turret Shells have elongated, narrow, shells that have many whorls. Most species have between ten and eighteen whorls. Some of the family members have whorls separated into a corkscrew shape. Turret Shells can be distinguished from other long shells, such as Augers and Miters, by their convex whorls, lack of a siphonal canal, and rough, non-lustrous exterior. They have external sculpting that generally follows the whorls and may include ridges, fine lines, or beaded cords. They have small, squarish to round, aperture. The outer lip is smooth and thin. The columella is smooth and curved. Their opercula are corneous (horn-like). Turret Shells are small to large in size, with the largest species in the family reaching around 17 cm (6.6 inches) in length.
Habitat and Distribution: Turret Shells are found in large colonies on, and within, mud and sand substrates They live in the intertidal zone, and at depths up to 1,930 m (4,900 feet). They are found worldwide in polar to tropical seas. At least sixteen species from this family are found in Mexican waters.
Natural History: Turret Shells are usually suspension feeders that use their gill filaments to filter organic matter from the surrounding water. Some species may be grazers or depositional feeders. In turn they are preyed upon by shorebirds, crabs, fish, and predatory mollusks. Turret Shells are generally gonochoric, though some are protandric hermaphrodites. Reproduction may occur through internal fertilization, indirect fertilization by sperm packets, or spermcasting. Some species brood the eggs in the female’s mantle cavity, while others lay their eggs in clusters of capsules attached to hard surfaces. Turret Shells are edible and larger species are harvested, on a small commercial scale, as food. Others are harvested for use in shell crafts.