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Becker, George C. / Fishes of Wisconsin

Bullhead catfish family - ictaluridae,   pp. 693-732 PDF (19.6 MB)

Page 698

698    Bullhead Catfish Family-Ictaluridae 
Icta/urus me/as      .     .  . 
  Wallace also described the black bullhead's spawn- 
ing behavior (p. 853): 
* . . While the male and female were oriented in opposite 
directions, the male twisted his caudal fin to one side to- 
ward the female so that it was over her head and eyes. ... 
The male held the female in this way for a period of several 
seconds. The male's caudal fin was more tightly twisted 
over the female's head, and the ventral part of his body 
anterior to the twisted portion was arched almost in a 450 
angle toward the abdomen of the female. The female's 
body was not arched, but her caudal fin was bent slightly 
toward and almost over the male's head. The male's mouth 
was widely opened as if "yawning," and his head was bent 
slightly downward .... During the fourth embrace, the fe- 
male quivered for about one sec and the eggs were depos- 
ited. The male remained perfectly still with its mouth wide 
open.... After the female stopped quivering both fish 
moved apart and lay still for about one min on the bottom 
of the aquarium. 
After a spawning session, both fish began to swim as 
before; the female passed back and forth over the 
center of the nest, fanning the eggs with her pelvic 
    o              Range of the black bullhead 
                   0 Specimens examined 
                   A Wisconsin Fish Distribution Study (1974-75) 
                   o Literature and reports 
                   o Greene (1935) 
 and anal fins, and butting the male's abdomen when 
 he swam near the eggs. Spawning occurred five 
 times within 1 hour. The female fanned and guarded 
 the eggs during the first day, but on the second and 
 third days after spawning the male guarded the nest. 
   The eggs are laid in gelatinous masses with a ge- 
latinous coat. Eggs examined 21 hours after spawn- 
ing had developed to the late gastrula stage (Wallace 
1967). Incubation takes 5-10 days, depending on the 
water temperature. 
  A prespawning female black bullhead, 145 mm 
and 48 g, collected from the Yellow River (Wood 
County) on 25 May, had ovaries 3% of the body 
weight; she held yellow, maturing eggs 0.8-1.3 mm 
diam. A gravid female, 196 mm and 129 g, taken from 
Green Bay (Door County) on 6 June had ovaries 6.3% 
of the body weight; she held 4,005 yellow, almost ma- 
ture eggs, 1.2-1.6 mm diam. 
  The care of eggs by adult black bullheads is un- 
doubtedly similar to that of the brown bullhead (see 
p. 704), in which the pelvic fins slap up and down 
against the egg mass, or the anal fin swirls the mass 

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