Bluespotted Sunfish

Diet and feeding

The FishTraits compilation records these diet categories for this species: aquatic or other vascular plants; invertebrates or larval fish. These are broad categories, not a claim that every individual consumes every example in a category.

Reported feeding positions include bottom feeding and surface or water-column feeding. The compilation combines published observations; diets can vary with age, locality, and available food.

Habitat preferences

Reported habitat associations include streams and small rivers, creeks, still-water habitats.

The source records associations with muck, clay or silt, sand, vegetation, organic debris, large woody material. An association indicates reported use, rather than an exclusive requirement.

Reproduction and parental care

The compilation reports a representative maturity age of 2 years. Its maturity field summarizes mean, median, or modal estimates, usually for females; male estimates can be used when female data are unavailable. It is not a fixed age at which every fish first breeds.

Batch or serial spawning has been reported somewhere in the species’ range. This does not establish the same spawning pattern for every population.

Recorded spawning months are Jul, Aug, Sep for the source’s reporting region (NJ). This is a regional calendar, not a range-wide schedule.

The reproductive-guild classification includes guarding eggs or young at a spawning substrate or nest.

Size and recorded longevity

FishTraits reports a maximum total length of 9.5 centimetres. Some entries use an estimated asymptotic length; this value should not be treated as a certified record catch.

Recorded longevity in the compilation is 6 years. Wild observations were preferred, but captive records were accepted where wild records were unavailable, and unspecified records were assumed wild. The value is not a guaranteed wild lifespan or an aquarium life expectancy.

Identification and appearance

The bluespotted sunfish has a single dorsal fin, spines present in the dorsal and anal fins, three anal spines, a rounded caudal fin, a dark, vertical bar below each eye, middle and rear dorsal spines of approximately equal length, 18 or less scale rows around caudal peduncle, light spots on sides (blue to white in life), and vertical bars that are generally lacking, but if present, indistinct and numbering five or less. For further identification details, see Smith (1985); Page and Burr (1991); Jenkins and Burkhead (1994); Mettee et al. (1996).

Native range

Atlantic and Gulf Slope drainages below Fall Line from southern New York to lower Tombigbee River, Alabama, south to southern Florida; above Fall Line in New York and Pennsylvania (Page and Burr 1991).

Habitat and ecology

The preferred habitats for the bluespotted sunfish are oxbows and side ponds characterized by dense submerged aquatic vegetation (Peterson and Vanderkooy 1997). Enneacanthus gloriosus is an opportunistic forager in areas with submerged aquatic vegetation and exhibits no seasonal pattern of prey consumption (Snyder and Peterson 1980). Bluespotted sunfish is planktivorous, feeding primarily on cyclopoid copepods, cladocerans, chironomid larvae, and ostracods, or similar invertebrate assemblages throughout their range (Snyder and Peterson 1999). In New York and New Jersey, E. gloriosus had a protracted spawning season, extending from late spring through summer (Snyder 1999). In Mississippi, spawning occurred from mid-April thorugh September, and in Florida, spawning occurred between April and October. Snyder (1999) also found that bluespotted sunfish in Florida and Mississippi spawned during their first year of life at <30 mm TL, whereas specimens from New England were found to spawn in their second year between 40 and 50 mm. These fish have been found to adopt a crepuscular feeding pattern in both laboratory and field observations (Casterlin and Reynolds 1980).

Introduction history

The presence of this species in the Jamesville Reservoir is probably due to an aquarium release sometime between 1951 and 1966 (Werner 1972). However, it is theoretically possible that the species migrated up from the Hudson River, through the Erie or Barge Canal, to Oneida Lake, then up the Chittenango River and Butternut Creek into Jamesville Reservoir. Although Werner (1972) states that no specimens have ever been collected in the intervening area, there is a collection from Oneida Lake dating back to 1916; the only other collection in the Great Lakes basin (Smith 1985). These fish may either represent a relict population or an introduction earlier than what was calculated in Jamesville Reservoir (Smith 1985). One factor against the canal migration hypothesis is that there is a 2–3 m-high weir with which a fish moving upstream from Oneida Lake to Jamesville Reservoir would have to contend (Werner 1972). Jamesville Reservoir was created in 1874, the same year the Erie Canal opened (Werner 1972). The origin of the Pennsylvania fish is unknown. They may be either natural populations or accidental introductions. Because this species is sometime kept as an aquarium species, aquarium release is a possible means of introductions in Pennsylvania (Denoncourt et al. 1975). Unknown means of introduction for the Big Black River drainage, Mississippi.