THE BREEDING HABITS of the PARADISE FISH, 



(POLYACANTHUS OPERCULARIS, Limunis). 



Bv Edgar R. Waitk, F.L.S., Zoologist. 



In a former paper^ I described the nesting habits of the Fighting 

 Fish (Betta jni^jnax, Cantor) as observed in my aquaria. I have 

 since had the good fortune to secure a number of living specimens 

 of the Paradise or Rainbow Fish, Polyacanthus opPTcularis, Lin- 

 naeus," which name, according to Dr. Boulenger,^ represents the 

 original species whence the domestic Macropodui^ viridianratuH, 

 Lacepede,^ is derived. 



This fish is breeding very freely with me, but as its life history 

 is well known I do not propose to do more than point out in 

 what respects its habits differ from those of Betta. 



The male is larger than tlie female, has the fins more produced 

 and the caudal filamentous. Ordinarily the coloration of the 

 sexes is similar, but when breeding the hues of the male are 

 intensified, while the female becomes very pale and loses the 

 beautiful greenish blue bars on the body. None of the illustra- 

 tions I have seen do justice to this beautiful fish. My specimens 

 exhibit ten bars as described by Linnaeus ; published figures 

 show a smaller number.'' 



The nest of Folyacdidluis is usually not so extensive nor so 

 dome-shaped as that of Betta : this may be accounted for by the 

 former fish showing a greater preference for nesting beneath 

 some shelter, as the leaf of a Nardoo {Marsilea) or the crossing- 

 ribbons of Valisneria. The first batch of eggs is frequently 

 produced when but a few bubbles are formed, others being added 

 below as oviposition proceeds. As a consequence the eggs are 

 raised quite out of the water and hatched in this situation. 

 The young ones may be seen wriggling within the egg on the 

 surface of the nest : this lends support to the observation that 

 some existing shelter is used, beneath which the bubbles are 

 blown, otherwise the young would be very conspicuous to an 

 enemy above. 



1 Waite— Ree. Aust. Mus.. v., 1904, p. 293, pi. xxxviii. 



2 LinnfEus — Syst. Nat., ed. x, 1758, p. 283. 



3 Bouleiiijer — Cambridge Nat. Hist., vii., 1904, p. 669. 

 * Lacepede— Hist. Nat. Poiss., iii., 1802, p. 417. 



^ Cuvier et Valenciennes — Hist. Nat. Poiss., vii,, 1831, pi. 197; Valen- 

 ciennes — Rep:. Anim. 111. Poiss., pi. Ixxiv., fig. 2; Pouchet — Rev. 

 Mag. Zool., xxiii., 1872, pi. xxv. 



