of the Fishery Board for Scotland. 



169 



VII. — ON THE SPAWNING OF THE LUMPSUCKER (Cyclopterus 

 lumpus) AND THE PATERNAL GUARDIANSHIP OF THE 

 EGGS. By Dr. T. Wemyss Fulton, F.R.S.E., Superintendent of 

 Scientific Investigations. 



(PLATE XI.) 



The lumpsucker is a common fish on our shores in spring, when it 

 comes close in among the rocks to deposit its spawn, the spawning-season 

 extending from February to nearly the end of May. Its food consists 

 of marine worms, ccelenterates, Crustacea, and small fishes; Dr. Murie 

 has taken 100 whitebait (young herrings and sprats) from the stomach of 

 a specimen.* It is stated by several authors that the stomachs of females, 

 especially, often contains nothing save a quantity of fluid ; this is no 

 doubt owing to their being mostly caught during the breeding season, 

 when food is usually not taken by fishes. 



The males are much smaller than the females and somewhat more 

 numerous ; they are brightly-coloured red on the fins and lower surface 

 during the spawning time, while the females are dark leaden blue or 

 slatey-coloured. The mass of eggs produced by a female is large, and 

 may reach as much as 35 per cent, of the total weight; the average for 

 three specimens examiued by me was 27 per cent. In a female, 14| 

 inches in length and weighing 6 lbs. 12 ounces, caught on 16th May, 

 and included in the following table, the eggs weighed 2 lbs., while 150cc. 

 of ovarian fluid escaped from the ovaries. 



The eggs measure about 2"2mm.-2 6mm., and have a volume of 

 4'18cc. ; I found them to number from 79,758 to 136,764 in females a 

 little over 18 inches long. The fecundity of the lumpsucker is therefore 

 high. When examined in the ripe female before extrusion they are 

 usually reddish or salmon-tinted, but may be lilac, pale violet, pale 

 brown, or pink. On extrusion they are pink, but this tint fades on 

 exposure to light, and gives way to a faint greenish or yellowish hue ; later 

 they become dark, owing to the development of pigment in the embryos. 



The whole of the eggs are laid at one time, or at all events this appears 

 to be the usual occurrence, but an examination of the ovaries of the 

 females included in the Table below tends to show that it does not 

 always happen, as several of them were found to be only partly spent. 

 One of the females referred to in this paper, moreover, deposited her eggs 

 in two lots after an interval of thirteen days. The eggs in the ovary, 

 just before extrusion, are bathed in a plentiful fluid, but they are not 

 adherent ; when the fingers are passed through the mass, the feeling 

 conveyed resembles that of contact with a mass of half-boiled sago. 

 Around the eggs the secretion is syrupy, and on separating them glutinous 

 threads pass between them. This substance hardens in sea water and 

 binds the eggs into a large compact spongy mass, leaving narrow channels 

 between by which water enters. It is doubtful, as we shall see, whether 

 this arrangement would not be fatal to many of the eggs were it not for the 

 constant attention of the male fish ; and perhaps the same attention is given 

 by the parents of other shore forms whose eggs are laid in adherent masses. 



*M'Intosh mentions annelids (Nereis), Third Annual Report, p. 60 ; Parnell says it 

 feeds on worms and small fish, Fishes of the Firth of Forth, p. 382 ; Scott found ccelenter- 

 ates (Beroe. Fleumbrachia) annelids, and Crustacea, in their stomachs, Twentieth Annual 

 Report, p. 467 ; Murie's observations are given in Report on the Sea Fisheries of the Thames 

 Estuary, Part L, p. 139. 



