204 
Part HI. — Ninth Anmcal Report 
but of which several hundreds were captured, were invariably alive and 
in good condition on being landed on deck, even when the trawl was 
over for seven hours. Among round-fish whiting suffered most, then 
gurnards and haddock?, and, last of all, cod. Among the flat-fish none of 
the flounders or witch soles were dead, but the numbers of these fish 
captured were small ; the death-rate among plaice, of which more than 
four thousand Avere taken, was only 0*12 per cent. ; lemon soles, common 
dabs, and especially long rough dabs, suffered to a much greater extent. 
The percentages of those dead when the net was hauled are as follows : — 
ry 1 Had- Whit- Giir- -ni • Lemon , Witch 
Cod. 11- 1 Plaice. rj 1 rnon Rough Floimder. ^ , 
dock. ing. nard. Sole. ^^^^ -^^^^ Sole. 
3-9 8-2 86-5 25'3 0-12 4*0 5-5* 13-9 O'O 0-0 
These figures refer to fish which have reached adult size and to imma- 
ture fish taken together. It is, however, important to consider the reten- 
tion of vitality among immature fish, since regulations on this subject 
concern them alone. As has been stated, the immature fish numbered 
6373, of which 3071 were round-fish and 3302 were flat-fish. The num- 
ber of immature round-fish which perished in the trawl was 793, or 25*8 
per cent, of the total number of immature round- fish caught. The number 
of immature flat-fish which succumbed was 167, or only 5 per cent, of 
the total number captured. In both cases the fatality, as might have 
been expected, was somewhat greater among immature specimens than 
among those which had reached adult size ; the death-rate among adult 
round-fish being 18 per cent., and among adult flat-fish 3 per cent. The 
percentage of those which perished in the net varied within wide limits. 
No s[)ecimens of flounder, witch sole, turbot, brill, or common sole, were 
dead when brought to the deck ; but the numbers of the three last-named 
were insignificant. Of 2137 immature plaice only 4, or 0T8 per cent, 
were dead, while nearly half of the immature whitings succumbed. The 
percentages of the immature specimens which were dead are as follows : — 
/->( J TT 1 J 1 wv,-4-- n 1 r)i • Lemon Common Loncf 
,Cod. Haddock. Whitmg. Gurnard. Plaice. g^^^ j^^^^ Rough Dab. 
4-4 35-3 4.5-7 36-6 OlS 9-8 2-6 31-4 
These figures show how various is the relative tenacity of life among 
immature fish belonging to different species. The most tenacious of life 
are plaice, and then follow common dabs, cod, lemon soles, long rough 
dabs, haddock, gurnard, and whiting. 
So far I have dealt with the results of these experiments generally, 
without taking account of either the nature of the bottom or of the length 
of time during which the trawl was down. The character of the bottom 
of course exercises a most important influence on the vitality of the fish. 
On clean sand very few of the fish perished, even when the net had been 
down for seven hours. Several hauls of five hours' duration were made 
on ground of this nature, and all the fish were alive when the net was 
hauled. Further, no immature flat-fish succumbed even in the hauls of 
longest duration, those which perished consisting almost entirely of 
whitings and gurnard. On a muddy bottom the fatality among the 
immature fish was fully four times greater than on sand. Considerable 
numbers succumbed when the hauls lasted for a period of between two 
and three hours, and a few when the net was down for a shorter time, as 
is shown in the appended table. 
