Chlamys opercularis is also called Aequipecten opercularis in the scientific community. Commercially they are known as queen scallops, “queens” or “queenies”.
Chlamys opercularis is preyed on upon primarily by marine bottom-dwellers, such as Asteria rubens (common starfish), Pagurus spp. (hermit crabs), and Cancer pagurus (brown crab). It is also preyed on by Callionymus lyra (demersal fish). An anti-predator adaptation of this species includes jet propulsion swimming. The predator that has the biggest impact upon C. opercularis populations is humans. Because this organism is considered a delicacy, it is fished in great quantities.
Known Predators:
Chlamys opercularis is distinctly left convex (the left valve is more rounded than the right valve). The shells vary in colors and patterns of pigmentation, which can be affected by both environmental and genetic factors. Their shells are also primarily calcitic, making them relatively insusceptible to dissolution and recrystallization. They can grow up to 90 mm in shell height. In general, scallops lack siphons and the anterior adductor muscle. A large and well-developed posterior adductor muscle is used for locomotion. Young individuals often attach to surfaces by byssal threads (silky filaments). Numerous light receptors (eyes) also line the edge of the mantle.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
Chlamys opercularis has a lifespan of 8-10 years.
Typical lifespan
Status: wild: 8 to 10 years.
Chlamys opercularis has shown optimal growth during the cooler seasons of late autumn and early winter. This species is primarily found on firm, sandy gravel or mud at depths of more than 100 meters, where the water temperature is cooler. Chlamys opercularis can also be attached to various kinds of algae, Bryozoa, hydroids, and clean shell and general benthic epifauna. The number of individuals of C. opercularis using natural substrata as juvenile habitats has not been quantified. Reports have shown that maerl grounds (areas formed from loose-lying coralline red algae and characterized by high tides and water movements in the photic zone) support large numbers of C. opercularis and are believed to act as a nursery area. However, there is no evidence that individuals of C. opercularis prefer to live on maerl or if maerl is the initial settlement habitat.
Habitat Regions: saltwater or marine
Aquatic Biomes: benthic
Chlamys opercularis is a widely distributed bivalve mollusc primarily found along Neogene deposits in the east coast of the North Atlantic Ocean and adjacent seas. Boundaries of its range include northern Norway and the Faroe Islands in the north, south to the Iberian Peninsula, and western Ireland to the west (including the Isle of Man in the United Kingdom) and the Mediterranean and Adriatic Seas to the east.
Biogeographic Regions: atlantic ocean (Native ); mediterranean sea (Native )
Chlamys opercularis filter feeds. This species was once thought to only consume phytoplankton but recent research indicates zooplankton is also an important source of nutrients. Zooplankton species that C. opercularis consumes include halacarid mites, calanoid copepods, halacarid fragments, copepod fragments, crustacean nauplii, barnacle cyprids, and cladocerans.
Animal Foods: aquatic crustaceans; zooplankton
Plant Foods: phytoplankton
Foraging Behavior: filter-feeding
Primary Diet: omnivore ; planktivore
Chlamys opercularis has a variety of ecosystem roles. Because it is heavily fished, many undersized animals are thrown back into the water. Small individuals of C. opercularis can sustain shell damage during this process, which makes them especially vulnerable to predation. Starfish (Asteria rubens) will prey upon these individuals. Chlamys opercularis is infected by microsporidians. Little is known about these parasites, except that they are found in the digestive tract of C. opercularis and use the scallop's blood to move around the body.
Ecosystem Impact: creates habitat
Commensal/Parasitic Species:
Chlamys opercularis has a high commercial fishing value. There is a large European market, especially in the United Kingdom and Spain, for fresh C. opercularis. A high demand for C. opercularis is economically important for humans because it not only provides a food source that can be exported for profit, but also creates many jobs. Fisheries and governments are trying to push the industry towards sustainable aquaculture, which could be less destructive to the natural ecosystem, less harmful in discarding undersized scallops, and more environmentally friendly. A more sustainable system could also be more economically viable and ensure a more consistent yield of product.
Positive Impacts: food
Seafood processing employees can acquire occupational asthma as a result of prolonged exposure to C. opercularis. Processing plants can put strict instructions on how to handle C. opercularis and keep the facilities clean, which may slow productivity or increase costs.
Chlamys opercularis development is influenced by both environmental and inherited factors. Additionally, their life cycle includes the trochophore and veliger larval stages. Generally, development can be described by three phases based on the nature of the energy source and the nature of the locomotion used. The first phase is considered lecithotrophic, a phase in which nutritional requirements for larvae do not extend beyond what is provided within the egg. Lecithotrophic species also have a reduced larval period during which no specific food is consumed. The second and third phases are considered planktotrophic, a phase in which larvae ingest plankton suspended in the water column. The first phase, or embryonic phase, is extremely vulnerable to environmental conditions and requires locomotion to ensure that the early larvae move into the water column. After fertilization occurs, the offspring remain on or near the seabed for a couple of days until developing into trochophore larvae. In the second phase, or dispersal phase, the trocohophore larvae rise to the surface of the water and is transported by water currents into the water column. Eventually, the trochophore larvae become veliger larvae. The third phase occurs when veliger larvae find a suitable substrate to settle on to undergo metamorphosis and juvenile life before becoming adults.
Development - Life Cycle: metamorphosis
This species is not listed, but there is a high demand for its harvest. Fisheries and governments are working to a more sustainable aquaculture for this species.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Chlamys opercularis grows on maerl and possibly communicates with it through active molecules gamma aminobutyric acid or other surface properties of the maerl. Responses to stress from potential predation or changes in environment are innate. Because C. opercularis senses danger through disturbance, it detects when fish trawls are approaching.
Communication Channels: tactile ; chemical
Other Communication Modes: vibrations
Perception Channels: tactile ; vibrations ; chemical
Chlamys opercularis spawn externally, with released sperm fertilizing released eggs.
Mating System: polygynandrous (promiscuous)
Chlamys opercularis is a simultaneous hermaphrodite, containing both a proximal creamy-colored testis and a distal bright red ovary. Sexual maturity occurs at one year. When spawning takes place, sperm are normally released into the environment initially. Fertilization occurs when the eggs are subsequently released and come into contact with the sperm. The release of gametes into the surrounding water usually occurs in the warmer months of spring and summer, but the actual time varies depending on the region and from year to year.
Breeding season: Chlamys opercularis breeds in the spring and summer.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: simultaneous hermaphrodite; sexual ; fertilization (External )
There is no parental protection, however, the eggs provide yolk to sustain the lecithotrophic larvae.
Parental Investment: pre-fertilization (Provisioning)
The queen scallop (Aequipecten opercularis) is a medium-sized species of scallop, an edible marine bivalve mollusk in the family Pectinidae, the scallops. It is found in the northeast Atlantic and is important in fisheries.
At about 7 cm (3 in) in size, this is one of the smaller scallop species which are commercially exploited. The shell of this species is sometimes quite colourful, and it is also thin and brittle. It has about twenty radiating ribs. The left valve is slightly more convex than the right one. One auricle of the right valve is larger than the other which creates a notch near the hinge used by the modified foot in young scallops to spin byssal threads.[2] Older scallops are free swimming.
Right and left valve of the same specimen:
Right valve
Left valve
The queen scallop feeds on a diet of plankton, and is commonly found up to 40 m (130 ft) below mean sea level, although it has been known to exist up to 400 m (1,300 ft) below sea level. This species is distributed from Norway south to the Canary Islands and the Mediterranean and is common in the North Sea on beds of sand and gravel.[3]
The Isle of Man in the British Isles is famous for the queen scallop, or "Manx queenie" as it is known locally. Due to the vagaries of landings over the years, Manx fishermen have worked on technical conservation regulations, in order to ensure that stocks of the queenie have remained robust. These have included restrictions on fishing times, closed seasons, and limitations on the number of dredges permitted. There are also two conservation areas in the island's territorial waters; one has been in place since 1989 and the other was created in 2008; these areas are closed to mobile fishing. These conservation areas are supported by the fishing industry; the fishermen themselves started the initiative to create the Douglas closed area. Data analysis appears to support the viability of these areas, which appear to help ensure that the Manx queenie can be fished sustainably.
The Isle of Man Queenie Festival is an annual, week-long celebration of the Manx queenie, with many restaurants, hotels and pubs serving queen scallops. This festival includes various events including sailing, diving, barbecues, beach days, sea swims, entertainment and plenty of queen scallops.[4]
Isle of Man queenies have been awarded the European Union Protected Designation of Origin (PDO) stamp.
The queen scallop (Aequipecten opercularis) is a medium-sized species of scallop, an edible marine bivalve mollusk in the family Pectinidae, the scallops. It is found in the northeast Atlantic and is important in fisheries.
