PLAICE. 
397 
each side of its body with such a rapid motion that 
they seem almost to vibrate. These combined efforts 
enable the fish to conceal itself almost quicker than 
the eye can follow, and nothing can be seen but its 
eye, which is of a lovely emerald colour.” The Plaice 
is also capable of making speedy migrations; and it is 
well known that a fishing-ground may one day afford 
an abundant catch, and the next be entirely unproduc- 
tive. Bkehm “ also quotes the perhaps exaggerated state- 
ment of a captain who said that for a whole day he 
had watched the Plaice swimming one after another 
over a sandbank, in a shoal so dense that not a glimpse 
of the bottom could be seen, though the water was 
clear and transparent. 
The Plaice also inhabits fresh water. Krgyer 
found it 6 , though the specimens were only small, in 
Gaarby Lake, at the extreme north of Jutland; and 
Feddersen 8 assigns it to the Laastrup, a stream that 
falls into Liim Fjord. Blanchere also states'* that it 
freely ascends the French rivers which have a sandy 
bottom, as the Loire, Garonne, Dordogne etc. In the 
Dordogne it is even said to deposit its spawn. 
The Plaice feeds on all those marine animals which, 
like itself, prefer a sandy bottom, small fishes, chiefly 
Sand-eels ( Ammodytes ), and lower organisms, princip- 
ally mussels, the shells of which it crushes with its 
pharyngeal teeth. In most cases the anterior part of 
the intestine is crammed with bits of mussel-shells. 
Annelids, crustaceans, and Echinoderms (sea-urchins and 
starfish) also form an important part of its diet. 
In Bohusl&n the spawning-season of the Plaice 
begins in early spring, in April according to Ekstrom, 
or even in February according to Malm 8 . Kroyer ob- 
serves that even in December he has found the ovaries 
well-developed, and during mild winters has met with 
breeding Plaice even in January. In a female nearly 
2V 4 kgrm. in weight Buckland 7 found the ovaries to 
weigh nearly 1 / 3 of the weight of the fish, and he 
estimated the number of the eggs at 144,600. LIensen 
arrived at the following results 7 : 
P 1 a 
i c e. 
Length of 
Weight of 
AVeight of 
Number of 
the body. 
the body. 
the ovaries. 
the eggs. 
48 cm. 
1,050 gr. 
66.0 gr. 
300,000 
36 „ 
457 „ 
132.5 „ 
80,940 
31 „ 
374 „ 
113.4 „ 
111,300 
The average size of the ripe eggs of the Plaice, 
according to the latter writer, is 1*7 — 1*8 111 m. They 
are then transparent, colourless and without oil-globules. 
In salt water they float, but in brackish water they 
sink to the bottom. The newly-hatched fry, according 
to Hensen, are about 5'26 mm. long, with pigmented 
eyes, a large vitelline sac, and the vent close to the 
latter. According to observations made by Mobius and 
Heincke in an aquarium the transference of the eye in 
the young specimens is completed in four weeks. During 
the summer they are met with in inlets and at shallow 
spots with a sandy bottom. At the end of July, ac- 
cording to Kroyer, the fry are about 3 in. long; and 
Fries forwarded to the Royal Museum young Plaice 
between 70 and 83 mm. long, which had been taken 
in Bohuslan in July, 1835. ft. seems doubtful, how- 
ever, whether these latter specimens belonged to the 
fry of that year 7 '. As late as the end of September, 
Sandeberg’s Expedition of 1877 obtained young Plaice, 
between 29 and 43 mm. long, off Waideguba to the 
extreme west of Kola Peninsula, thart had not yet ac- 
quired the characteristic row of protuberances behind 
the eyes. Fry of this size are distinguished by the 
gray colour of the body, densely mottled with dark 
brown and red spots, a colour which they still retain 
at a length of 70 — 80 mm., when the row of pro- 
tuberances has already appeared. The most trustworthy 
character, to distinguish them from the fry of the 
following species, consists in the number of the fin 
rays, the somewhat deeper form of the body, and the 
shorter peduncle of the tail. The length of the base 
of the anal fin — more than half that of the body — 
0 Thierleben , Bd. 8, p. 192, 
b Tidskrift for Fiskeri, l:ste Aarg., p. 44. 
c Naturhist. Tidskr. Kbhvn, ser. 3, vol. XII, p. 76. 
d Nouv. Diet. Gen. cles Peches, p. 636. 
c As we have remarked above, some of the Bohuslan Plaice purchased in Stockholm in 1889 were evidently ready to spawn at the 
beginning of March. 
f Nat. Hist. Brit. Fisli., p. 180. 
CJ Vierter Ber. Comm. Wiss. Unters. Deutseh. Meere (1877 — 1881), p. 306. 
h Cf. the remarks on the growth of the preceding species. 
