178 
TINKER. 
each of them has a small triangular iin membrane at its 
posterior base; all of them are erectile at the pleasure of the 
fish, and when erected it is seen that they are not seated 
exactly on the median line of the back, but on two lines, 
each removed, almost imperceptibly, to the right and left of 
a median line; on one line there are five spines, on the other 
four, and they arc seated alternately. Every spine, moreover, 
on the right line has a most decided inclination to the right, 
and every spine on the left line to the left, so that the series 
are well represented by the teeth of a saw recently set, when 
they are alternately and purposely bent to the right and left. 
The earinated scales on the sides of the tail, which Cuvier 
makes a character of O. pungitius, are entirely wanting. The 
colour is very uniform, as compared with that of our ordinary 
Sticklebacks; it is a somewhat metallic yellow green on the 
back, gradually becoming paler, and almost white on the belly, 
the whole being irrorated with minute black dots; the fins are 
very pale, almost colourless. The male resembles the female 
until the month of March, when he begins to assume his 
nuptial livery: the median line of the breast and belly then 
becomes black, a colour which day by day extends on either 
side until all the lower parts of the fish become of the most 
intense velvety black; this eventually extends almost over the 
whole body, the back only retaining slight indications of the 
normal colouring. 
It is a fearless and ferocious little fish, instantly reconciled 
to captivity, and attacking with fury any prior inhabitant of 
the vessel in which it is placed. It will frequently seize a 
fellow-prisoner by the gill, the tail, or a fin, and retain its 
grip with the firnmess of a bull-dog; in the same way it will 
instantly seize a worm when presented to it, and allow itself 
to be drawn out of the water without relinquishing its hold. 
The females become very much distended with ova, and deposit 
them simultaneously; they are veiy large, generally eight or 
ten in number, and are immediately devoured if found by 
fishes of the same or other species; its nest is not known to 
me. Unlike other species of Gasterosteus it will not exist 
when confined in salt-water, however diluted. Mr. Newman’s 
doubts of the identity of this species, arising from the difference 
of colour, would have ceased if he had recollected how 
