TENCH. 
751 
The internal organs essentially resemble those of 
the preceding genus. The liver follows the intestinal 
canal backwards in two long, pointed lobes, the right 
lobe being the longest and extending' back to the vent. 
The intestinal canal is short and thick, only slightly 
longer or even shorter than the fish, with only two 
coils and without dilatation or special stomach. The 
air-bladder is large and, as usual, contracted at the 
first third of its length. The anterior, smaller part is 
cylindrical with rounded ends, the posterior part pointed 
behind. The ovaries and testicles are paired and oc- 
cupy the ordinary position. 
The Tench is more of a European fish than the 
preceding species, but otherwise has essentially the same 
geographical range. It occurs throughout the whole of 
Europe, northwards in places to the 62nd degree of 
latitude. It is also known in Asia Minor, and in the 
extreme south of Europe it is common. How far its 
range extends in Siberia, is unknown; but Pallas says 
that it is common around the Yenisei. In the west of 
Europe it does not seem to go so far north as in the east 
of the same continent. Thompson" regarded the Tench 
as of foreign origin in Great Britain and Ireland. Day 
says that it is commoner in the east of England than 
in the west. Kroyer had no knowledge of its presence 
in the north of Jutland; but according to Feddersen 
it has subsequently been found in Lake Ravnstrup, a 
little north of the east end of Liim Fjord. In Norway, 
according to Collett, the Tench occurs at only two 
spots, situated in the coast regions of the extreme 
south, namely Kragero and the park at the Nas Iron- 
works. To the latter locality it has been transplanted 
from Denmark. In the southern tracts of Sweden it is 
fairly common: but the northern limit of its range lies 
in about 60° N. lat., in Werrnland and Westmanland, 
according to the reports sent in to the Fisheries Com- 
mittee of 1881, though it is said to have been planted 
in the District of Gefleborg. In Finland, according to 
Mela, its range extends to 61° 40' N. lat. According 
to Reuter it occurs even at Archangel; but according 
to Grimm 1 its range to the north is bounded in Russia 
by the 62nd degree of latitude. According to Fatio 
it ascends in Switzerland to lakes situated as much as 
1,600 m. above the level of the sea. 
In Sweden the Tench is most commonly found in 
small lakes, ponds, and fens, with a muddy and weed)' 
bottom. It is worthy of remark that this fish also oc- 
curs in the central part of the western island-belt of 
the Baltic, where it invariably chooses its haunts, how- 
ever, in shallow and weedy inlets in the innermost 
part of the archipelago. Sluggish and indolent by na- 
ture, it loves quiet and is destitute of the activity dis- 
played by the majority of the following genera of this 
family. Except during the spawning-season it lives al- 
most constantly at the bottom, most often embedded in 
mud among the weeds. It is especially prone to this 
latter habit in winter, at which time it generally lies 
still in a kind of dormancy; but, according to Siebold, 
it is sometimes met with in this position even in the 
hottest summer. Now and then, though seldom, it may 
be seen in summer, when the water is calm, at the 
surface. Being very tenacious of life, it may be trans- 
ported considerable distances without dying, and is thus 
easily planted in ponds. It was one of the fishes earli- 
est selected for this purpose. 
The spawning-season generally occurs in Sweden 
at the beginning of June or somewhat later, according 
to the state of the weather. The oldest females spawn 
first, the younger ones later in the season. The spawn- 
ing takes place in shallow and weedy inlets, ponds, and 
small lakes, without any boisterous demonstrations. The 
fine, yellowish eggs are deposited on the weeds; they 
are generally hatched in a week’s time. The fry grow 
rather slowly c , though the rate seems to vary according 
to the spawning-place and the state of the water. The 
number of the spawning females is usually less than 
that of the males. Yarbell estimates the proportion 
of the sexes at two males to one female, or not less 
than three to two. This disparity in number might 
have a detrimental effect on the propagation of the 
species, if the fecundity of the Tench did not com- 
pensate the scarcity of females. In a female 1 s / 4 kgm. 
in weight Bloch estimated the number of the ova at 
297,000. Harmer, according to Day, found as many 
as 383,253 ova in one female. 
The food of the Tench consists of mud, worms, 
and insects. It is seldom caught in the seine, generally 
in fish-traps (Jcatsor, see fig. 204, p. 816, belotv, and 
“ Nat. Hist. Irel., vol. IV, p. 136. 
b Fish., Hunt. Russ. Wat., p. 14. 
c In the month of October Lilljeborg took a young Tench 70 mm. long. 
95 
Scandinavian Fishes. 
