Scallop

Pecten novaezealandiae  (Scientific Name) Maori Name: Tupa   RULES AND REGULATIONS Please check the latest rules and catch limits for scallops in your area on the MPI website: https://www.mpi.govt.nz/fishing-aquaculture/recreational-fishing/fishing-rules/

DESCRIPTION

Scallops would have to be one of New Zealand’s most sought after shellfish. The roe and muscle are most commonly eaten - raw or cooked - fantastic.
Scallops belong to the Pectinidae family.  They have fan-shaped bivalve shells with deep ridges that radiate from the hinge. The upper valve of the shell is flat, and the lower valve is concave. The valves are held together by the hinge and open and close by one large adductor muscle. This is located in the middle of the scallop. The adductor muscle is so developed because the scallop is an active swimmer. It uses this muscle to snap open and close in order to propel itself through the water. Colours are variable including brown, orange, yellow, pink or flesh-coloured or a mix of these. They are characterized by having two types of meat in one shell (the adductor muscle), called “scallop” which is white and meaty, and the roe, called “coral”, which is usually bright orange.
Scallops have up to 100 simple eyes strung around the edges of their mantles like a string of beads. They are reflector eyes, about one mm in diameter and can detect moving objects as they pass. They cannot resolve shapes, but can detect changing patterns of light and motion, helping them to sense danger.
 

HABITAT

Scallops are found around the coast in the sandbanks and mud banks of sheltered bays from the low tide mark out to about 50 metres depth.  They lie on the sandy seabed with the flat shell uppermost. You will see a slight shape in the sand which looks like a half circle. Scallops are often found singly and sometimes grouped in beds, but usually where there is one there are others close by. Scallops will move to find better feeding grounds throughout the year.

 
LIFE CYCLE

Scallops start their life as a free-swimming embryo and begin to develop between 36 and 48 hours. After 14-20 days the scallop (at this stage known as a spat) attaches itself to a rock formation, branch or other shell on the ocean bottom by using a byssus or byssal thread.  At 30-60 days it’s around 1-5mm. At this stage it will retract its anchor line (byssus) and drop to the bottom to begin its adult life.  A typical scallop shell starts to form and is considered an adult at around 5-7 cm. This may take between 180 - 365 days although it will not reach its recreational size limit until one and a half to three and a half years. The age of a scallop can be determined by the concentric rings (growth lines) of their shells. For seafood enthusiasts, the inedible byssus is often called the ‘beard’ and is removed before cooking.

 
FOOD & DIGESTION

Most scallops are filter feeders and eat plankton. Coincidentally, the plankton can include scallop larvae. Siphons bring water over a filtering structure where food becomes trapped in mucus.  Next, the cilia on the structure move the food toward the mouth. The food is then digested in the stomach and digestive gland. Waste is passed on through the intestine and exits via the anus.content, but are still rich in potassium and calcium. Gurnard works well with many flavours.