The scup, or "porgy," known for its fine flavor and its avaricious pursuit of baited hooks, occurs along the continental shelf of eastern North America. It is most common from Cape Cod to Cape Hatteras, North Carolina, and is encountered only occasionally north of Cape Ann
The scup's laterally flattened body is about two times as long as it is wide. The head, concave dorsally, has a small mouth and high-set eyes. The scup has one long, continuous dorsal fin, which possesses a series of one short and eleven long spines anteriorly. The anal fin also contains one short spine followed by several long ones. The tail is deeply concave and sharply pointed on the corners. The pelvic fins are located directly below the pectoral fins.
The scup's body is a dull silvery color flecked with light blue and displaying 12 to 15 inconspicuous horizontal stripes. The head is marked with dark patches, and the belly is white.
The Massachusetts angling record for scup is 5 pounds 14 ounces, but few adults exceed 2 pounds in width and 14 inches in length. Both males and females reach sexual maturity in their second year. Scup can live up to 14 years of age, but most schools of scup contain no fish older than 3 to 4 years.
Adult scup form into schools of similar-sized individuals in areas with smooth or rocky bottoms. They are particularly plentiful around piers, rocks, offshore ledges, jetties, and mussel beds. They move inshore to southern coastal areas of Massachusetts in May and linger there until October, when most swim to deeper waters offshore or migrate southward to the waters between Cape May, New Jersey, and Cape Hatteras, North Carolina. While along coastal Massachusetts, scup are commonly found at depths of 6 to 120 feet. Young larvae live in very shallow estuarine waters. Juvenile and adult scup move into harbors and along sandy beaches during high tides, and then into deeper channels as the tides recede. Large scup generally occur farther offshore than do smaller, younger ones.
The abundance of scup in a specific area is frequently influenced by water temperature. Scup prefer temperatures greater than 45 degrees F and are most frequently encountered in water temperatures from 55 to 77 degrees F. In New England, water temperatures in early fall occasionally plunge below the scup's tolerance level, killing large numbers of fish.
In southern New England, scup spawn from May to August, with the peak level of activity typically in June. The Buoyant eggs hatch about 40 hours after fertilization. Within several days after hatching, the larvae, having used all yolk reserves, begin to feed upon copepods and other microscopic animals. Adult scup feed upon bottom invertebrates including small crabs, annelid worms, clams, mussels, jellyfish, and sand dollars. Each year as many as 80% of all juvenile scup fall prey to larger predators such as cod, bluefish, and weakfish.
Recreational fishing constitutes a significant proportion of the total harvest of scup. From 1977 to 1985, an average of 24% (ranging from 17% to 33%) of the harvest of scup along the East Coast was taken by anglers. The existing fishery management plan, in effect since 1995, allocates 33% of the allowable harvest to the recreational fishery.
Scup populations on the East Coast have displayed periodic cycles of abundance over the last twenty years, with any change in population density generally lasting for 2 to 4 years before being reversed. Commercial and recreational catches peaked in the 1959s to 1960s, declined markedly by the early 1970s, and recovered to relatively high levels before 1980. Much of the increase in harvest in the 1970s is attributed to an increase in fixed gear and otter trawl activity in the southern New England region. Subsequently, Massachusetts's recreational landings peaked to a high of about 12 million fish in 1986 but have since leveled off with restrictive management to approximately 1.4 million fish annually (1988-2001).
Scup are currently being harvested at the maximum level their populations can withstand. The Massachusetts Division of Marine Fisheries established a minimum legal size limit for scup of 7 inches in 1987. Size limits since have been increased to 9 inches and daily bag limits were implemented for the recreational fishery starting in 2000 to protect this species from the long term effects that an additional increase in harvest might engender.