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Pi irf III — Eleventh Annual Report 



IX.— NOTES AND MEMORANDA. 



1. On Protective Resemblance in the Lumpsucker. By 

 W. Anderson Smith. 



Protective similarity is very common amongst fishes, and more especially 

 amongst those inshore. The sand gobies — Gobius minutus — are so much 

 like the sand amongst which they sojourn, as to be indistinguishable except 

 when on the move. Most flat fish seem to change to an extent in colour- 

 ing, to meet the ground on which they are found ; and throughout the 

 Jaminarian zone the law of imitation for protective purposes is very 

 general. Perhaps the simplest and most interesting example of such 

 Imitation is to be found in the young of the lumpsucker, Cyclopterus 

 lumpus, a little greenish-blue creature without any great activity. Besides 

 its similarity in colouring to the olive-green seaweed amongst which it 

 dwells, I have been struck with its protective similarity in another 

 direction. At low water on Loch Creran I have seen the young in multi- 

 tudes, when the capsules were being thrown from the seaweed, hovering 

 about these, and making no effort to escape, further than dodging along- 

 side one of the capsules which was an exact counterpart of itself, both in 



a, a, a, Young lumpsuckers. b, b, Seaweed capsules, 

 size and general tone of colouring. It required a very sharp eye to note 

 the difference ; and, indeed, when some scores were mixed up together, it 

 became next to impossible to distinguish the living fish from the Alga. 

 Their movement was a quick jerk, and then quiet, when moving from 

 point to point. In the early spring — March-April — these little GyclopteH 

 came up in numbers from the quieter waters where the lobster traps were 

 set, dotted all over the traps, as these were drawn out of the water, at 

 Lochbuie, in Mull. At this time they were only 1 inch in length, 

 although the shore during the former months — February-March — had 

 been plentifully strewn with their coralline-ova. As they are deep and 

 round little creatures they possibly increase slowly in length, and were 

 then probably a year old or thereabouts, and the exceptionally heavy fishes 

 of this species occasionally taken, up to 12 or 14 lbs., must be of great age. 

 Like all the British sucker-fishes they are comparatively sluggish creatures ; 

 they live on decayed animal matter, and, according to some, on the excreta 



