Pol^centropsis Abbreviata 



WALTER LANNOT BRIMD, F. Z. S. 



Here indeed is a rare fish, and I have 

 seen it alive but once. The name signi- 

 fies a fish with many spines and abbrevi- 

 ated tail. It is not a large species, a 

 mature specimen averaging between two 

 and two and one-half inches long, but it 

 is a voracious rascal, and must therefore 

 be kept alone. The illustration shows this 

 species with Nandus marmoratus below, 

 a whim of the artist bringing the two 

 forms together, though it would not be 

 advisable to associate these species in an 

 aquarium. 



In color our subject is warm brown 

 with dark mottlings. The eye is reddish 

 chestnut ; mouth very large. The caudal 

 fin and the extremities of the soft dorsal 

 and anal fins are transparent and nearly 

 invisible, thus adding to the foreshort- 

 ened appearance of the fish. 



Sexual differences are difficult to de- 

 termine. During breeding activities a 

 short ovipositor protrudes from the vent 

 of the female, the abdominal line being 

 convex, due to the distended ovaries ; in 

 the male the abdominal contour is quite 

 straight. 



The breeding habits are interesting. 

 The male constructs a nest of bubbles 

 under floating leaves. After close con- 

 tact between the sexes the female as- 

 sumes a position under the nest, back- 

 downwards, thrusts her ovipositor into 

 the nest, and therein deposits the eggs 

 singly. In the aquarium, with this accom- 

 plished, she should be removed. The 

 eggs number about one hundred, and 

 hatch in five or six days. The tank should 

 contain not more than three inches of 

 water, and be maintained at a tempera- 



ture between 80 and 85 degrees ; 75 de- 

 grees will be an agreeable temperature at 

 other times for older fish. 



The water should be well aerated and 

 contain abundant microscopic life to sup- 

 port the growing fry. Tiny daphne 



should follow, and then the live foods 

 usually provided for carnivorous fishes — 

 mosquito larvae, small mealworms, fry of 

 live-bearing fishes and similar materials. 



The species is a native of tropical West 

 Africa, and was first discovered by Dr. 

 W. J. Ansorge, in 1900, in the Niger 

 delta. It is described as rare, and when 

 found occurs in brooks, rivers and 

 ponds. 



Polycentropsis and Nandus are mem- 

 bers of the group of fishes called Nan- 

 didse, which has representatives in South- 

 east Asia and South America as well as 

 in Africa. 



