CARP-FISHES. 
715 
Fam. CYPRINIDtE. 
Air-bladder free ( not enclosed in a capsule). 
The family of the Cyprinoids, the largest in the 
whole class of fishes, contains about 1,000 described 
species, most of them, however, from Asia and North 
America, so that only a hundred species occur in Europe, 
and only a score belong to the Scandinavian fauna. The 
majority of our fresh-water fishes are comprised, how- 
ever, in this family. All the Cyprinoids prefer fresh water 
and are most commonly found in lakes, rivers, ponds, and 
fens. Still most of our species also occur in the brackish 
water of the Baltic. Not a single member of the family 
is a predatory fish properly so called ; most of them live 
chiefly, though not exclusively, on vegetable substances. 
They may with every reason be called omnivorous. In 
a certain sense they may be regarded as Ruminants: 
the Carp, the Tench, and the Bream are adduced as 
examples of this; but as a rule food passes rapidly 
through their intestinal canal: a Goldfish fed with wheat- 
bread passes after some minutes a white, vermiform mass 
of excrement, which hangs from the vent. They are 
sensitive in a high degree to atmospheric influences; 
but some of them, though they do not properly belong 
to an Arctic temperature, can in a torpid state survive 
the process of being frozen". Even in a milder climate 
they are known in cold weather to collect in dense 
shoals, which lie still in the deepest parts of the water; 
and Valenciennes 6 states of the Barbel of Southern 
Europe that he once found a company of this species 
which during the winter had packed themselves together 
in the hollow trunk of a tree. 
Among the peculiarities in the reproduction of 
these fishes we shall here remark only one, which is of 
general interest, but belongs to a species foreign to our 
fauna, the little Bitterling ( Rhodeus amarus ), a form 
fairly common in Eastern and Central Europe and at 
most about 9 cm. long. It has long been known that 
the eggs of some fish are found among the branchial 
lamellae of the painter’s mussel ( Unio pictorum) ; but until 
Mouth fringed with at most four (or no) barbels. 
1869 it was a matter of doubt to what species these 
eggs belonged. Before this time Krauss (1858''), Kess- 
ler (1860 d ), Dybowski (1862"), and Siebold ( 1868') 
had described an external oviferous tube, sometimes 30 
mm. long, which in the female Bitterling is developed 
during the spawning-season from the margins of the 
urogenital opening just behind the vent, and into which 
the comparatively large, ellipsoidal eggs — sometimes 3 
mm. long — force their way and arrange themselves in 
a single row. Noll £/ at last discovered that the said 
eggs in the branchial cavity of the painter’s mussel be- 
long to the Bitterling. By observations which he has 
since completed, he showed that, when the eggs are ripe, 
the female Bitterling applies the oviferous tube to the 
inspiratory opening of the painter’s mussel, into which 
the male at, the same time emits his seminal fluid. In 
this Avay about 40 eggs may be forced one by one into the 
branchial cavity of the mussel, Avhere they attach them- 
selves to the branchial lamella? and are developed until 
the fry have attained a length of about 11 mm. The 
young of this fish thus lead a kind of parasitic life, a 
commensalism from Avhich they liberate themselves, 
when capable of an independent existence, by making 
their Avay out through the expiratory tube of the mussel. 
The spawning-season of the Cyprinoids occurs in 
spring and summer, Avhen both sexes assume a brighter 
and more handsome dress, and the males develop sharp, 
tubercular excrescences on the scales, Avhich excrescences 
fall off, hoAvever, simultaneously Avith the fading of the 
coloration, as soon as the spawning-season is over. 
To man these fishes are of no inconsiderable value 
and utility. Most of them have a soft, Avhite, and pa- 
latable flesh, and in Scandinavia, as on the Continent, 
are the objects of lucrative fisheries. This is not the 
case in England, Avhere fresh-Avater fishes in general are 
little esteemed 6 , and the Cyprinoids in particular (Avith 
the exception of the Carp) have a bad reputation. 
“ Pallas (of the Crucian Carp), Zoogr. Ross. Asiat ., tom. Ill, p. 298. 
b Cuv., Val., Hist. Nat. Poiss., torn. XVI, p. 13. 
c Jahreshefte d. Ver. f. vaterl. Naturk. in Wurttemberg, 14 Jahrg., p. 121. 
d At the Conference of Naturalists at Konigsberg, according to Siebold. 
e Cyprinoiden Livlands, p. 87. 
f Susswasserfische Mitteleuropas, p. 118. 
g Zoologisclier Garten 1869, p. 257; 1870, p. 237; 1877, pp. 351 — 362. 
h Day lays the blame of this on the English cook’s ignorance of the proper method of dressing fresh-water fish for table. 
