Flounders are a diverse group of flatfish that inhabit various aquatic environments, from coastal waters to estuaries. These bottom-dwellers have adapted unique characteristics, including their flattened bodies and eyes positioned on one side, which allow them to camouflage effectively on the seafloor. Their size is a common point of interest.
Common Flounder Species and Their Sizes
Several flounder species are commonly encountered, each with distinct size characteristics. The Summer Flounder (Paralichthys dentatus), also known as fluke, is found along the Atlantic coast. Females can grow up to 3 feet, while males reach over 2 feet, with typical catches ranging from 14 to 20 inches and weighing around 1.5 pounds. Females of this species generally live longer, up to 12-20 years.
The Winter Flounder (Pseudopleuronectes americanus) is found in colder waters. These fish can grow over 2 feet in length and weigh up to 6 pounds, though inshore specimens are often 8 to 16 inches. Winter flounders have a longer lifespan, reaching 15 to 18 years. The European Flounder (Platichthys flesus), native to European coastal waters, usually measures about 12 inches (30 cm), but some reach up to 24 inches (60 cm) and weigh as much as 6.5 pounds (2.93 kg).
The Southern Flounder (Paralichthys lethostigma) typically ranges from 15 to 18 inches, with some growing up to 33 inches and averaging 1 to 5 pounds. Pacific Halibut (Hippoglossus stenolepis) are distinct flatfish, not true flounders, but are considerably larger. They can reach lengths of up to 8 feet and weigh over 500 pounds, making them the largest flatfish.
Largest Flounder Ever Recorded
The world record for a Summer Flounder, also known as fluke, is 22 pounds 7 ounces (10.17 kg) and 35 inches long. This catch was made by Captain Charles Nappi off Montauk, New York, on September 15, 1975.
A significant record for a Southern Flounder was set in 1983 by Larenza Mungin in Nassau Sound, Florida, with a fish weighing 20 pounds 9 ounces and measuring 33 inches. A notable catch of a California halibut, a type of flatfish but not a true flounder, weighed 67 pounds 5 ounces and was 44.5 inches long. These record sizes demonstrate the significant growth potential of these fish.
What Influences Flounder Growth
Flounder growth is influenced by a combination of biological and environmental factors. Flounders continue to grow throughout their lives, though the rate slows with maturity. Females generally grow faster and attain larger sizes than males across various species.
Diet and the availability of prey significantly impact how large a flounder can become. These fish are opportunistic feeders, with their diet evolving from zooplankton and small crustaceans in their larval and post-larval stages to larger crustaceans and fish as juveniles and adults. A diet rich in fish prey can lead to substantially faster growth compared to one based solely on invertebrates.
Environmental conditions, particularly water temperature and salinity, also play a role in flounder development. Temperature directly affects growth rates, with optimal ranges promoting healthier and faster development, especially in larval stages. While flounders can tolerate a wide range of salinities, certain levels may be more conducive to growth by influencing the availability of preferred prey. Genetic factors also contribute to individual growth potential, with some populations exhibiting inherent differences in growth rates.