10
CARL J . SINDERMANN
caused by Vibrio nnguillarum Bergman. The disease occurs during the
warmer months in brackish and salt water ; reports have been most
numerous from the Danish, German, Italian and Swedish coasts, and
the Baltic and North Seas. According to Hofer (1904), the disease
was known and reported as early as 1718 from the Italian coast, and
extensive epizootics occurred repeatedly during the nineteenth century
(reports date from 1825, 1850, 1864, 1867, 1884, 1885, 1889 and 1892).
Signs of red disease include progressive reddening of fins and skin,
visceral hemorrhages, reduced activity and death-often preceded by
loosening and fraying of the skin.
The term " red disease " was introduced by Feddersen (1896) in
reporting an outbreak of the disease in Scandinavian waters. Comparable outbreaks have occurred repeatedly to the present time
(Feddersen, 1897 ; Bergman, 1909 ; Bruun and Heiberg, 1932, 1935 ;
Ljungberg, 1963), often causing significant mortalities and economic
losses. The disease has also been reported from The Netherlands
(Schaperclaus, 1927), Poland (Kocylowski, 1963), and Germany (Schaperclaus, 1934; Mattheis, 1060). Characteristically, infections become
evident among eels stored, even for short periods, in live boxes. Dead
eels may be found in nets, traps and impoundments during epizooticsthe disease apparently spreads very rapidly among captive fish.
An extensive survey was conducted by Bruun and Heiberg (1932)
documenting the widespread occurrence of the disease in Scandinavian
waters a t the time, and providing information about previous outbreaks
dating back to 1880-outbreaks which sometimes brought the fishery
to a standstill.
V'ibrio anquillarum appears to be a truly marine pathogen, limited
to salinities above 9 %, , and unable to survive in fresh water. Infection
may occur through gills or digestive tract. Its effect is most pronounced
and mortalities are most common in late summer, in areas where sea
temperatures exceed 16°C.
Bruun and Heiberg raised new questions in their report on the 1931
epizootic in Danish waters by suggesting that several pathogens may
be involved in red disease from different geographic areas. They
pointed out that only a few of the early studies (Canestrini, 1893;
Inghilleri, 1903; Bergman, 1909) included bacterial examinations, and
that a t least three bacterial disease entities may be involved in salt
water. Schaperclaus (1930) also demonstrated that red disease of eels
in fresh water may be caused by Pseudomonas (Aeromonas) punctata
Zimmerman. Other observations suggest that reddening of the skin of
eels may be a generalized response to abnormal temperatures and reduced availability of oxygen, as well as to bacterial invasion. There
CARL J . SINDERMANN
caused by Vibrio nnguillarum Bergman. The disease occurs during the
warmer months in brackish and salt water ; reports have been most
numerous from the Danish, German, Italian and Swedish coasts, and
the Baltic and North Seas. According to Hofer (1904), the disease
was known and reported as early as 1718 from the Italian coast, and
extensive epizootics occurred repeatedly during the nineteenth century
(reports date from 1825, 1850, 1864, 1867, 1884, 1885, 1889 and 1892).
Signs of red disease include progressive reddening of fins and skin,
visceral hemorrhages, reduced activity and death-often preceded by
loosening and fraying of the skin.
The term " red disease " was introduced by Feddersen (1896) in
reporting an outbreak of the disease in Scandinavian waters. Comparable outbreaks have occurred repeatedly to the present time
(Feddersen, 1897 ; Bergman, 1909 ; Bruun and Heiberg, 1932, 1935 ;
Ljungberg, 1963), often causing significant mortalities and economic
losses. The disease has also been reported from The Netherlands
(Schaperclaus, 1927), Poland (Kocylowski, 1963), and Germany (Schaperclaus, 1934; Mattheis, 1060). Characteristically, infections become
evident among eels stored, even for short periods, in live boxes. Dead
eels may be found in nets, traps and impoundments during epizooticsthe disease apparently spreads very rapidly among captive fish.
An extensive survey was conducted by Bruun and Heiberg (1932)
documenting the widespread occurrence of the disease in Scandinavian
waters a t the time, and providing information about previous outbreaks
dating back to 1880-outbreaks which sometimes brought the fishery
to a standstill.
V'ibrio anquillarum appears to be a truly marine pathogen, limited
to salinities above 9 %, , and unable to survive in fresh water. Infection
may occur through gills or digestive tract. Its effect is most pronounced
and mortalities are most common in late summer, in areas where sea
temperatures exceed 16°C.
Bruun and Heiberg raised new questions in their report on the 1931
epizootic in Danish waters by suggesting that several pathogens may
be involved in red disease from different geographic areas. They
pointed out that only a few of the early studies (Canestrini, 1893;
Inghilleri, 1903; Bergman, 1909) included bacterial examinations, and
that a t least three bacterial disease entities may be involved in salt
water. Schaperclaus (1930) also demonstrated that red disease of eels
in fresh water may be caused by Pseudomonas (Aeromonas) punctata
Zimmerman. Other observations suggest that reddening of the skin of
eels may be a generalized response to abnormal temperatures and reduced availability of oxygen, as well as to bacterial invasion. There