The Haddock Fish

Fish World | The Haddock Fish | The haddock or offshore hake is a marine fish distributed on both sides of the North Atlantic. Haddock is a popular food fish and is widely fished commercially.
The haddock is easily recognized by a black lateral line along the white side (not to be confused with pollock, which is the reverse, ie white line on black side) and a conspicuous dark spot above the pectoral fin, often described as a ' fingerprint "or the" Devil's fingerprint "or" St. Peter's mark ".
Haddock is most commonly found at depths of 40-133 m (130-436 m), but has a range as deep as 300 m (980 ft). It flourishes at temperatures from 2 to 10 ° C (36-50 ° F). Youth prefer shallower waters and larger adults deeper water. Generally, adult haddock not engage in long migratory behavior as the young fish, but seasonal movements are known for all ages. Haddock feed primarily on small invertebrates, although larger members of the species occasionally eat fish.
Growth rates of haddock have changed significantly over the last 30-40 years. Currently, growth is rapid, with haddock reaching their adult size much earlier than previously noted. However, the extent to which these younger fish contribute to reproductive success of the population is unknown. Growth rate of haddock, however, slowed in recent years. There is evidence that this is the result of an exceptionally large year class in 2003.  Spawning occurs between January and June, peaking during late March and early April. The main spawning grounds in the waters of middle Norway near southwest Iceland, and Georges Bank. An average-sized female produces about 850,000 eggs, and larger females are capable of up to 3 million eggs per year.

The haddock, a member of the cod family lives both American and European shores of the Atlantic. In the northwest Atlantic Ocean, it ranges from the southern tip of the Grand Banks to Cape Cod in the summer and it extends its range southward to Cape Hatteras, North Carolina, in the winter. The haddock, like the closely related cod, are easily distinguished from other coastal Massachusetts fish by their three dorsal and two anal fins. The front dorsal fin is triangular in shape and larger than the next two. The rear two are square, the middle dorsal is slightly larger than the previous. Of the two anal fins, the second or rear one is a mirror image of the third dorsal fin. Haddock can be distinguished from other closely related members of the cod family by a black lateral line and a large spot on each side of the body above the pectoral fins. The largest recorded haddock weighed 37 pounds and measured 44 inches in length. Few haddock exceed 20 to 24 inches in length, 3 to 5 pounds in weight and 9 to 10 years old.
Both sexes are sexually mature by the time they are 2 to 3 years old. The haddock off Massachusetts reproduce on sandy, rocky or muddy bottoms from January to June, with the greatest activity in March and April. Will spawn offshore in depths of 100 to 600 feet at temperatures of 35-45 degrees F. Georges Bank is the most productive spawning area in the northwest Atlantic. Fertility (number of eggs produced in one year) of women is related to their body size. Females weigh 2.2 pounds produce about 170,000 eggs, while the largest females may have as many as three million eggs in one breeding season.

Haddock inhabit deep, cool waters, rarely entering estuaries or river mouths. They are often found at depths of 140 to 450 feet and generally avoid depths of less than 30. Haddock preferred substrates of gravel, smooth rock or sand strewn with shells and water temperatures of 35-50 degrees C. Season they migrate to areas that are optimal habitat conditions to offer. In winter, haddock move to deep water where the temperature is warmer and more constant than in shallower areas. Most overwinter coast of southern New Jersey to Cape Hatteras. By early spring, they look more northerly parts of New England, moving into the shallower waters of the Gulf of Maine and Georges Bank, where they stay all summer.

Before descending to the ocean floor, haddock larvae feed on microscopic copepods. Benthic youth and adults feed on almost any slow-moving invertebrates including small crabs, marine worms, shellfish, starfish, sea cucumbers, sea urchins and occasionally squid. Herring, sand lance, small eel or other juveniles seldom appear in their diet.

Scientific classification 

Kingdom: Animalia
Tribe: ChordataActinopterygii
Order: Gadiformes
Family: Gadidae 
Genus: Melanogrammus Gill, 1862 
Species :  M. aeglefinus