Euvola ziczac
A zigzag-patterned scallop with blue eyes and a unique jetting motion.
Euvola ziczac, called the zigzag scallop, is a bivalve mollusc in the family Pectinidae. It lives along the Atlantic coast of North America, from North Carolina down to the West Indies and Bermuda.
This species has gone by several names. Its old scientific name was *Pecten ziczac*, and many current sources still list both *Euvola* and *Pecten* for clarity. Like all scallops, it has two calcium carbonate shells that are rounded at the outer edges and flatten near the prominent hinges. On each side of the hinge are projecting “ears,” or auricles, which give scallops their characteristic shape. In Bermuda, zigzag scallops commonly reach 120 mm, but they are usually smaller in the Caribbean.
The shells have a wavy, crenulated edge and colored rays that range from white to orange, yellow, or gray. Within this pattern are clear annual rings, making age determination easy for a trained observer. The lower valve is cup-shaped, while the upper valve is flat to concave. A zigzag stripe pattern on the shells gives the species its name, and the scallop also moves in a zigzag pattern when jetting.
Along the edge of the mantle, zigzag scallops have a row of bright blue eyes called ocelli. These are sensitive to changes in light intensity and signal the animal to close its shell if it senses a shadow or other disturbance. The scallop also closes up if exposed to air or mildly threatened. Small sensory tentacles surround the ocelli and line the conspicuous inner fold of the mantle, helping regulate water flow in and out.
Historically, zigzag scallops were found in several Bermuda areas, including Harrington Sound, where recreational fishers once caught them in large numbers. Overfishing through the 1970s wiped out the population so badly that a series of SCUBA surveys in 1987 found only two scallops at two different sites. Besides Bermuda, they occur off Cape Hatteras in North Carolina, throughout the Gulf of Mexico and the Caribbean, and as far south as Santa Catarina, Brazil.
These scallops live in shallow waters two to seven meters deep near the shore, forming beds in sandy areas. They are adapted to the temperature and salinity swings of the intertidal zone. Individuals bury themselves in sediment, leaving only their tentacles projecting above the surface—usually the only visible part.
Quick Facts
- Genus
- Euvola
- Species
- ziczac
Facts from the source article.
Lore & Background
The zigzag scallop is known by many names; its scientific name was previously Pecten ziczac, but current literature often lists both Euvola and Pecten for clarity. Its shells are rounded along the outer edges and flattened near the prominent hinges, with projecting 'ears' or auricles. The shells show a wavy, crenulated outer edge and colored rays varying from white to orange, yellow, or gray, with well-defined annual rings that make age determination relatively easy. The lower valve is cup-shaped, while the upper valve forms a flat to concave lid. The species gets its name from the zigzag pattern of stripes on its shells and also moves in a zigzag pattern when jetting.
Zigzag scallops have a series of bright blue eyes (ocelli) along the edge of their mantles, sensitive to changes in light intensity, causing the animal to close its shell if a shadow or disturbance is sensed. They also close their shells if exposed to air or mildly threatened. Surrounding the ocelli are small sensory tentacles lining the inner fold of the mantle, which regulate water flow. Historically, they were found in several areas around Bermuda, including Harrington Sound, where they were a popular recreational catch. Overfishing through the 1970s decimated the population; a 1987 SCUBA survey around the island discovered only two scallops at two different sites.
Reader's Guide
Euvola ziczac holds significance as a species with a distinctive appearance and behavior, including its zigzag shell pattern and jetting motion. Historically, it was a popular recreational catch in Bermuda, particularly in Harrington Sound, but overfishing through the 1970s severely reduced its population, as evidenced by a 1987 SCUBA survey that found only two individuals. The species inhabits shallow waters between two and seven meters deep, forming beds in sandy areas, and buries itself with sediment except for its tentacles. Its concave upper valve holds a thin layer of sediment thought to prevent fouling organisms from colonizing. While scallops are commercially important globally—Bermuda imports an estimated 50,000 pounds of scallops annually, and almost one million tons are cultured worldwide—zigzag scallops had not been cultured until recently, mainly because their low densities usually cannot support commercial fisheries. The species is also notable for its bright blue eyes and dribble spawning behavior, where individuals spawn at slightly different times within the same season rather than in synchronous mass events.
Did You Know?
- The zigzag scallop gets its name from both the zigzag pattern of stripes on its shell and its zigzag movement when jetting.
- It has a series of bright blue eyes (ocelli) along the edge of its mantle that are sensitive to changes in light intensity.
- A 1987 SCUBA survey around Bermuda discovered only two zigzag scallops at two different sites due to overfishing through the 1970s.
- Zigzag scallops are hermaphroditic 'dribble spawners' that spawn twice annually, with no synchronous mass spawning events.
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