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Becker, George C. / Fishes of Wisconsin

Pirate perch family - aphredoderidae,   pp. 733-738 PDF (2.0 MB)

Page 735

Pirate Perch 735 
Pirate Perch 
Aphredoderus sayanus (Gilliams). Aphredoderus-more 
     correctly "Aphododerus," meaning excrement 
     throat (from the position of the vent); sayanus- 
     for Thomas Say, the distinguished entomolo- 
Common name: Forbes and Richardson (1920) attrib- 
     uted the common name, "pirate perch," to 
     Charles C. Abbott, a pioneer ichthyologist, who 
     observed that a specimen he had in an aquar- 
     ium ate only other fish. 
Adult 67 mm, Wisconsin R. (Sauk Co.), 21 Sept. 1969 
Ventral view. Vent is directly behind throat knob. 
Body stout, slightly compressed laterally, elevated at 
base of dorsal fin; caudal peduncle thick. Length 83- 
100 mm (3.3-3.9 in). TL = 1.26 SL. Depth into SL 
2.8-3.4. Head into SL 2.6-3.0; head broad below, 
preopercle edge strongly toothed and rough to the 
touch; strong spine near upper edge of opercle. Snout 
pointed. Mouth large, oblique, with lower jaw pro- 
jecting; numerous minute, villiform teeth in wide 
bands on upper and lower jaws; back of upper jaw 
reaching to anterior edge of eye. Dorsal fin convex, 
nearer snout than base of caudal fin, and behind pel- 
vic fins; dorsal fin with 2-3 short spines, 10-11 rays; 
anal fin 2-3 spines, 6-7 rays; pelvic fins 1 spine, 6 
rays. Scales strongly adherent, ctenoid, with a single 
row of teeth on exposed edges; cheeks and opercles 
fully scaled. Lateral series scales 48-59; lateral line 
incomplete, developed anteriorly. The sensory canal 
system on head is well developed, and consists of 
relatively large sensory canals and numerous sense 
organ clusters (see Moore and Burris 1956). Diges- 
tive tract 1.2-1.6 SL; in adults, anal opening imme- 
diately behind the throat knob. 
  Back dark olive to black; sides lighter; belly yel- 
lowish. In life, specks of iridescent blue (occasionally 
copper, green, or silver) on back and sides. Two nar- 
row, vertical bars separated by a pale interspace at 
base of caudal fin. Dorsal and caudal fins slate col- 
ored, other fins more lightly pigmented. 
  Breeding males blackish on head and dorsal half 
of body, and tinged with violet. 
In Wisconsin, the pirate perch occurs in the Missis- 
sippi River and Lake Michigan drainage basins, where 
it reaches the northern limit of its distribution. The 
principal population centers of the species are the 
lower Mississippi River, the lower Wisconsin River 
and its tributaries, and the Des Plaines River water- 
  Specimens examined: UWSP 1181 (2) Bear Creek 
T18N R2E Sec 3 (Richland County), 1962; UWSP (1) 
Wisconsin River T7N R4W Sec 15 (Grant County), 
1962; UWSP 1183 (1) Wisconsin River opposite Bos- 
cobel (Crawford County), 1962; UWSP (1) Wisconsin 
River T8N R3W Secs 23 and 24 (Grant County), 1962; 
UWSP 1495 (1) Wisconsin River T7N R4W Sec 21 
(Grant County), 1966; UWSP 1910 (2) Des Plaines 
River TiN R21E Sec 4 (Kenosha County), 1968; UWSP 
2035 (22) Wisconsin River T11N R9E Sec 6 (Columbia 
County), 1968; UWSP 3127 (1) Wisconsin River T13N 
R6E Sec 25 (Sauk County), 1969; UWSP 3772 (1) South 
Branch, Embarrass River T28N R10E Sec 25 (Mara- 
thon County), 1970; UWSP 4345 (1) ditch into Lem- 
onweir River T17N R2E Sec 16 (Juneau County), 1973; 
UWSP 4393 (1) Yellow River T18N R4E Sec 19 (Ju- 
neau County) 1973; UWSP 4401 (1) Lemonweir River 
T14N R2E Sec 11 and 12 (Juneau County), 1973; UWSP 
4441 (1) Lemonweir River T17N R3W Sec 32 (Juneau 
County), 1973; and UWSP 5617 (1) Lyndon Creek 
T14N R5E Sec 1 (Juneau County), 1977. 
  Wisconsin Fish Distribution Study (1974-1978) col- 
lections: (1) Kilbourn Road ditch TIN R22E Sec 6 
(Kenosha County), 1976; (19) unnamed channel, Black 
River T17N R8W Sec 17 (La Crosse County), 1978. 
M. Johnson (pers. comm.) reported this species from 
the Root River, the Des Plaines River, and Brighton 
Creek, (Kenosha County), 1965-1968. L. Andrews 
(pers. comm.) reported it from Swamp Creek below 
Swamp Lake, and lower Rocky Run Creek near its 

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