102 



Aquatic Mtt 



Five of the six of these strange sun- 

 fishes possessed characteristics either of 

 the warmouth or of the blue-gill, or in- 

 termediate between those of these two 

 very distinct species. Detailed compar- 

 isons follow : 



In all five specimens the jaws were 

 shorter than in the warmouth, yet longer 

 than in the blue-gill; the lower jaw pro- 

 jected, as in the warmouth, but the teeth 

 on the tongue, as in the blue-gill, were 

 lacking. The black opercular flap, or 

 "ear," was not as stiff and bony as in 

 the warmouth, yet possessed more or less 

 definitely the bluish and reddish margin 

 characteristic of that species. In all, the 

 cheeks were marked with dark mottlings, 

 absent in the blue-gill, but even more dis- 

 tinctly developed in the warmouth. The 

 lower margin of the head was marked, 

 either faintly, or definitely, with the 

 broad blue band diagnostic of the bue- 

 gill. The colors of the body varied 

 greatly, both between individuals and in 

 the same individual (observed in an 

 aquarium) ; in all the rich colors of the 

 warmouth were variously developed, but 

 the dark vertical bars in most of the 

 specimens were more like those of the 

 blue-gill ; the lower sides in proper lights, 

 showed more or less distinctly the 

 silvery-purple sheen of the blue-gill. The 

 single large dark blotch always present 

 on the soft dorsal fin of the blue-gill, 

 was replaced by a variable number of 

 spots, usually fewer, however, than in 

 the warmouth. The iris of the eye in 

 some was entirely brown, as in the blue- 

 gill, but in others was marked with red 

 as in the warmouth. These five sun- 

 fishes appeared to be hybrids between 

 ( 'haenobryttus gulosus and Lcpomis in- 

 cisor. 



The sixth unidentifiable sunfish seined 

 in the Chicago park lagoon mentioned 

 above, similarly combined characters of 



two of the other resident species, the 

 blue-green sunfish (Lepomis cyanellus) 

 and the pumpkin-seed {Lepomis gib- 

 bo sus) . 



The mouth, as in the other hybrids de- 

 scribed above, was intermediate in size 

 between those of the supposed parent- 

 species, and also intermediate in obli- 

 quity ; the lower jaw projected as in the 

 blue-green sunfish, but the maxillary 

 lacked the supplementary bone developed 

 in that species ; the opercular spot was 

 colored as in cyanellus, but the cheeks 

 were mottled with olive-green and bright 

 bue as in gibbosus; the gill-rakers and 

 the pharyngeal bone and its teeth, were 

 intermediate. The body was beautifully 

 marked with vertical mottlings of olive- 

 green and bright blue. The dorsal fin was 

 intermediate in color, but the pelvic 

 (ventral) fins were margined with white, 

 and the anal fin was bordered with 

 orange-vermillion, as in brightly colored 

 examples of the blue-green sunfishes. 

 Should this apparent hybrid have inher- 

 ited the docile habits of the blue-green 

 sunfish rather than the fighting spirit of 

 the pumpkin-seed, it would have been 

 attractive as an aquarium fish. 



The three other supposedly hybrid 

 sunfishes collected by the writer were 

 seined singly last summer in the Huron 

 River of Southern Michigan, in each 

 case in company with both of the appar- 

 ent parent-species — the blue-gill (Lepo- 

 mis incisor) and the pumpkin-seed (Le- 

 pomis gibbosus). Each of the three dif- 

 fered more notably from each of the 

 other two than would be expected if they 

 represented a distinct species. In all 

 characters each was either intermediate 

 between, or like either one or the other of 

 the parent-species. How varied and ir- 

 regular this resemblance was, further- 

 more, may be seen from the following 

 detailed comparison (in which the speci- 



