Motes on the Breeding Habits of 

 HTie Pigm;9 Sunfish 



W. A. POTSER 



More than a year ago, through the 

 courtesy of the United States Bureau of 

 Fisheries, the writer received a number 

 of specimens of the pigmy sunfish, 

 Elassoma zonatum, collected at Mound, 

 Louisiana. These, barring two or three 

 which have died in the interval, have been 

 under close observation to determine, if 

 possible, the breeding habits. Nothing 

 has heretofore been published in this 

 connection, in fact the species has re- 

 ceived little attention save at the hands 

 of the systematic ichthyologist. The ex- 

 amples when received were about half- 

 grown, measuring from one-half to three- 

 fourths of an inch long. Today, four- 

 teen months later, the average maximum 

 of one and one-fourth to one and one- 

 third inches has been reached. 



Suitable food enters largely into the 

 problem of maintaining this species in 

 the aquarium. Dry prepared foods of 

 the usual sorts and ground dried shrimp 

 will at times be taken while falling, but 

 very little and without avidity, particles 

 reaching the bottom being left unnotic- 

 ed. Shredded fresh fish flesh and raw 

 scraped beef did not seem much more de- 

 sirable. Its predilection for entomostra- 

 cans and the larvae of mosquitoes has 

 been recorded by Dr. Robert E. Coker. 

 In the absence of the mosquitoes the 

 writer had recourse to the white annelid 

 worm, Enchytraeus albidus, with an 

 occasional lot of Daphnia pulex. While 

 the fish were small it was necessary to 

 use only the tiniest enchytraeids, lest 

 larger ones be tackled with disastrous ef- 

 fects. To this end a small mass would 

 be placed in a shallow, flat-bottomed 



glass dish, with dark cardboard beneath 

 to bring the worms into relief, and quick- 

 ly teased apart, the larger being removed 

 with slender dissecting forceps. These 

 worms are obviously preferred, a reason- 

 able number being consumed in a short 

 time, whereas an equal bulk of Daphnia 

 will persist through several days. Though 



-s&tfC/i r 



Pigmy Sunfish Elassoma zonatum 



I have used enchytraeids extensively for 

 quite a number of species of fishes, only 

 in the pigmy have I seen it penetrate 

 through the gills and wriggle free. This, 

 however, rarely occurred, and only when 

 a particularly greedy fish would seize 

 several large ones. Beyond a few spas- 

 modic jerks, the affair did not seem a 

 matter of much moment. The pigmy take- 

 its food with a peculiar little sidewise 

 snap quite unlike other fishes. 



Several color descriptions would be 

 necessary to describe this fish in its 

 varied moods, I say moods because the 

 changes do not altogether seem in the 

 nature of protection, and because the 

 greatest extremes, in both sexes, are in- 

 cidental to sexual activity, and in the 

 male to combat. Usually the basal color 

 is given as olive-green, which, taking 

 fishes as a whole, is an "elastic" color, 

 to be used when we cannot be more 

 definite. The sides are marked by ten 



