Pumpkin Seed, Sunfish

Etymology Lepomis, in Greek, means ‘scaled gill cover’ and gibbosus means ‘wide margin’. The pumpkinseed sunfish is widely recognized by its pumpkinseed shape, which is where its common name derives.   Description It is an alien species that belongs to the Centrarchidae family. It was first introduced into the Prespa Lakes in 1995-1996. They are typically 6-8 inches in length, but can grow up to 10 inches. They weigh less than 0.45 kg (with the world record being 0.62 kg). They are orange, green, yellow or blue in colour, with speckles over their sides and back and a yellow-orange breast and belly. The sides are covered with vertical bars that are a faint green or blue, which are typically more prevalent in females. Orange spots may cover the dorsal, anal, and caudal fins and the cheeks have blue lines across them. The species is noted for the orange-red spot on the margin of its black gill cover. The pectoral fins can be amber or clear, while the dorsal spines are black. They have a small mouth with an upper jaw stopping right under the eye.   Biology Pumpkinseeds (sunfish) typically live in warm, calm lakes, ponds and pools of creeks and small rivers with plenty of vegetation. They prefer clear water where they can find shelter to hide. They tend to stay near the shore and can be found in numbers within shallow and protected areas. They are active during the day and rest near the bottom in protected or covered areas such as submerged logs during the night. They feed at all water levels from the surface to the bottom in the daylight, and their heaviest feeding time is the afternoon. Among their favourite foods are insects, mosquito larvae, small molluscs and other crustaceans, worms, minnow fry and even other smaller pumpkinseeds. Occasionally they will feed on small pieces of vegetation as well. They have a terminal mouth, allowing it to open at the anterior end of the snout. Pumpkinseed sunfish that live in waters with larger gastropods have larger mouths and associated muscles in order to crack the shells of the larger gastropods. This is the case in the Prespa Lakes. Once water temperatures reach 12-18⁰C in the late spring or early summer, the male pumpkinseeds will begin to build nests. Nesting sites are typically in shallow water on sand or gravel lake bottoms. The males will use their caudal fins to sweep out shallow, oval-shaped nesting holes that stretch about twice the length of the pumpkinseed itself. The fish will remove debris and large rocks from their nests with their mouths. Nests are arranged in colonies consisting of about 3-15 nests each. Male pumpkinseeds are vigorous and aggressive and will defend their nests by spreading their opercula. Females arrive after the nests are completed, coming in from deeper waters. The male then releases milt and the female releases eggs. Females may spawn in more than one nest, and more than one female may use the same nest. Also, more than one female will spawn with a male in one nest simultaneously. Females are able to produce 1 500 to 1 700 eggs, depending on their size and age. Once released, the eggs stick to gravel, sand, or other debris in the nest, and they hatch in as little as three days. Females leave the nest immediately after spawning, but males remain and guard their offspring. The male guards them for about the first 11 days, returning them to the nest in his mouth if they stray from the nesting site.   Distribution Widely spread and world-wide.   Fishing significance Low, considered as a pest.   Impacts Invasive species.   Management Possible ameliorative fishing.