2l6 THE CAPE KLIP-FISHES. 



life. On closer examination the little fish can generally be made 

 out, usually of a greenish hue with dark spots which break the 

 contour of the body so that it is frequently almost impossible 

 of detection until they are again disturbed and reveal their posi- 

 tion by movement. The greenish hue is seen only in those in 

 pools with green sea-weed {Ulva) and in the younger forms this 

 colour is very pronounced. Observations made in the Aquarium 

 illustrate the advantage to the fish of similarity with its sur- 

 roundings as regards concealment from its prey. Occasionally 

 small mullet (" Harders "), which at times are found in abund- 

 ance in the rock-pools, are kept in the same tank as the Klip- 

 fish ; they swim about in groups, generally near the surface but 

 sometimes lower down, and the Klip-fish may occasionally be 

 seen watching them intently with body motionless and tail slightly 

 bent preparatory to a sudden spring, the only movement being 

 the rotating eye that follows every motion of the prey, and is 

 apparently somewhat concealed from observation from above by 

 the orbital fringe or tentacle. When the incautious victims ap- 

 proach near enough the Klip-fish launches itself suddenly at 

 them, and usually manages to secure one. 



The diversity of colour is most marked in the adults, and it is 

 of course difficult to determine whether or not the brilliant shades 

 of colour afford an effective protection or concealment as in the 

 case of the young; but many of the fish found in the "sea- 

 bamboo " areas are of uniform tint — a rich bronze-green, or 

 crimson, red, yellow, etc., all of which hues seem to harmonize 

 with the various shades of alcyonaria, sea-weed, etc. In some 

 localities the sea bottom seems to be clothed with extensive 

 growths of the " red coral " or " zee-tak " {Gorgonia flammea) 

 so frequently thrown up on the shore. On several occasions 

 large pieces of this coral were secured for the Aquarium, and it 

 was noticed that a Klip-fish of a bright uniform red colour was 

 Aery fond of resting lengthways along the red branches, and, 

 although a fairly large specimen, was not easy to detect even at 

 close quarters. 



A noticeable instance of resemblance to surroundings, not 

 only in colour, but in general form and habits also, is afforded by 

 one species of Klip-fish, C. jucoriim, to which we shall refer more 

 fully when describing the fish. 



In the mating season — about midsummer — the demeanour of 

 the Klip-fish seems to undergo a change ; the males become 

 fierce and aggressive and their diversified colours are more con- 

 spicuously displayed ; the females also seem to assume brighter 

 hues. 



Fierce contests frequently take place between 'the males. 

 Their method of fighting is peculiar ; the fish circle round each 

 other in a threatening manner but make no attack until a certain 

 position is taken up by each. This may be described as resembling 

 an open letter. The fish lie not directly facing each other but 

 w^ith their heads alongside of each other, the body being gently 

 curved and the tail well bent to the side opposite the antagonist 

 so that by its sudden flexure the heads may be broue"ht violently 

 in contact ; the advantage apparently lies with the fish that can 



