Flatfish

Introduction

Flatfish are a diverse family of fish with a unique and specialized anatomies and life history. Flatfish are among the most popular types of seafood and can be found in many cuisines around the world. But how does a flatfish ultimately make its way to your dinner plate? This blog will explore the life cycle of flatfish and the amazing journey they take from spawning to dinner plate.

Spawning

Flatfish begin their lives as small, semi transparent eggs. These eggs are only slightly larger than grains of salt and in many species, the female flatfish will produce thousands of eggs at a single spawning event. After being expelled into the water, the eggs settle to the seafloor or estuarine environment, where they will remain in a state of suspended development until they are ready to hatch. Depending on the species, this process can take between 2-6 days.

Once hatched, the newly emerged larva are extremely vulnerable. The larva must swiftly develop from this small, weak, semi-transparent form into a juvenile flatfish suitable for survival in the wild. During this transformation, the larva are constantly at risk of predation from other fish, crabs and seabirds.

Settlement and Maturation

Once a larva has grown for a few weeks, it attempts to settle in the seabed. This is a critical and dangerous time for the flatfish, as it is the most vulnerable to predators. Eventually the larva finds a suitable location to settle, such as a crevice or sandy bottom. After settling, the juvenile flatfish begins to further develop and grow. This is accompanied by a physiological transformation, with the right eye migrating to the left side of the head. This process is known as “metamorphosis”, and is the defining characteristic of all flatfish species. At this point, the flatfish begins feeding on the invertebrates living in the sea floor, such as clams, worms and small fish.

Growth and Maturity

Flatfish reach their maximum size at quite a young age; most species reach maturity after at most 1 – 3 years. From this point, the flatfish will continue to grow for the remainder of their lives. Depending on species, flatfish can reach up to 9 meters in length, with ages up to 100 years old. Flatfish have a relatively long lifespan, meaning that once mature, they may spend decades living in the same area and contributing to the local reef ecosystem.

Fishing

After a flatfish has matured and reached a suitable size, it is often captured by fishermen. Flatfish are a popular and sought after target for fishermen for their meat, oil and roe. Flatfish are often taken by trawlers, or netting vessels that drag large nets along the seafloor, as well as hook-and-line vessels which use baited hooks to catch individual fish. The vast majority of flatfish caught in these fisheries are semi-mature juveniles.

Processing and Preparation

Once caught, flatfish are brought to shore for processing. In some cases, the flatfish are sold live and brought to restaurants or markets directly, where they may be eaten as is or further prepared for consumption. More often, however, the flatfish are processed and frozen for later sale. This begins with gutting the fish, and cleaning and weighing the fillets. Next, the fillets are placed in a brine, which helps to preserve the flesh and preserve its texture. Finally, the fillets are skinned, portioned, packaged and frozen.

Transportation

Once processed and prepared, the flatfish is shipped to its final destination. This may be a local grocery store or restaurant, or even another country. Flatfish are shipped in convoy with other types of seafood, or even with fruits and vegetables, depending on the route. Flatfish may be shipped on a plane or a ship, both of which require strict temperature and humidity control.

Preparation and Cooking

Once the flatfish reaches the final destination, it is ready for purchase and consumption. The most popular preparation method for flatfish is to filet the fish, which involves removing the head, tail and any sharp bones from the fillet using a sharp knife. The fillet is then seasoned with spices, oils and herbs, if desired. Finally, the fillet is cooked - usually by baking, grilling, steaming, pan-searing or frying.

Conclusion

Flatfish can journey from spawning grounds to final destination with remarkable speed and efficiency. The journey of flatfish, beginning as an egg and lasting up to one hundred years, is a testament to the wondrous biodiversity of the ocean. While the life cycle and journey of the flatfish may differ depending on the species and region, the process ultimately culminates in the same outcome - a delicious seafood meal.