DISEASES O F MARINE FISHES
33
females become highly modified and penetrate the flesh, often causing
extensive ulceration.
Lwnaeocwn brnnchinlis (I,.) is a parasite of t,he gill region of gadoid
fishes, particularly cod, whiting. pollock and other species froin both
sides of the North Atlantic and from the Pacific (Dollfus, 1953;
Shulman and Shulman-Albova, 1953 ; Kabata, 1961 : Sherman and
Wise, 1961 ; and others). L. brnnchialis has been described as a heart
parasite by Schuurmans-Stekhoven ( 1 936) and Schuurmans-Stekhoven
arid Punt (1937) since the anterior end sometimes penetrates the
bulbus arteriosus of the host. It has been the object of numerous
studies, was reported in the scientific literature as earlp as 1762 by
Strsm, and is considered one of the most harmful of the copepods
parasitic on marine fishes. Intermediate hosts of the parasite include
the lumpfish, Cyclopterus lumpus, flounder, Plruronwtes j l ~ s u s . and
several other pleuronectids. The adult female copcpods, usually
numbering one t o three but occasionally more, attach to the gill region
of gadoids. The head penetrates sometimes t o the heart, in other cases
to the ventral aorta or branchial arteries. causing connective-t' ,issue
hypertrophy and the formation of blood-filled lacunae. Invasion of
the heart causes thickening of the walls so that the lumen of the organ
is markedly reduced (Mann, 1954). Affected fish are almost always
below average weight, and death of young cod can result from blood
loss and pathological changes in heart and aorta. Mann (1952) reported
that infested cod were 20 t o 30% underweight, and had a lower erythrocyte count and decreased hemoglobin content of the blood. Extreme
emaciation of whiting, Gadus nierlangus L., was reported b y Scott
(1929) as the result of L. brnnchinlis infestation. A second species,
L. obtusata, has recently been distinguished by Kabata (1957a) as a
parasite of the haddock. Separation was based on minor morphological
variations in the adult females, site of penetration and characteristics
of the male. Severe impairment of infested haddock, in the form of
anemia, loss of weight, loss of liver fat and possible retardation of
sexual development, was noted (Kabata, 1958). Walford (1958) cited
results of a %year sampling in one English fishing port which disclosed
Lernaeocern parasitization of 10% of haddock, 8004 of whiting and
20% of cod, Parasitized fish were as much as 23:/, below normal
weight.
A second well-known tissue-invading copepod is 8phyrioiL lunipi
(Krsyer), widely distributed in the North Atlantic on the redfish and
several other species (Fig. 10). It has been reported from the Norwegian
coast (Luling, 1951). West Greenland and the Norwegian Sea (Hansen,
1923), Newfoundland (Templeman and Squires, 1960), and the Gulf
33
females become highly modified and penetrate the flesh, often causing
extensive ulceration.
Lwnaeocwn brnnchinlis (I,.) is a parasite of t,he gill region of gadoid
fishes, particularly cod, whiting. pollock and other species froin both
sides of the North Atlantic and from the Pacific (Dollfus, 1953;
Shulman and Shulman-Albova, 1953 ; Kabata, 1961 : Sherman and
Wise, 1961 ; and others). L. brnnchialis has been described as a heart
parasite by Schuurmans-Stekhoven ( 1 936) and Schuurmans-Stekhoven
arid Punt (1937) since the anterior end sometimes penetrates the
bulbus arteriosus of the host. It has been the object of numerous
studies, was reported in the scientific literature as earlp as 1762 by
Strsm, and is considered one of the most harmful of the copepods
parasitic on marine fishes. Intermediate hosts of the parasite include
the lumpfish, Cyclopterus lumpus, flounder, Plruronwtes j l ~ s u s . and
several other pleuronectids. The adult female copcpods, usually
numbering one t o three but occasionally more, attach to the gill region
of gadoids. The head penetrates sometimes t o the heart, in other cases
to the ventral aorta or branchial arteries. causing connective-t' ,issue
hypertrophy and the formation of blood-filled lacunae. Invasion of
the heart causes thickening of the walls so that the lumen of the organ
is markedly reduced (Mann, 1954). Affected fish are almost always
below average weight, and death of young cod can result from blood
loss and pathological changes in heart and aorta. Mann (1952) reported
that infested cod were 20 t o 30% underweight, and had a lower erythrocyte count and decreased hemoglobin content of the blood. Extreme
emaciation of whiting, Gadus nierlangus L., was reported b y Scott
(1929) as the result of L. brnnchinlis infestation. A second species,
L. obtusata, has recently been distinguished by Kabata (1957a) as a
parasite of the haddock. Separation was based on minor morphological
variations in the adult females, site of penetration and characteristics
of the male. Severe impairment of infested haddock, in the form of
anemia, loss of weight, loss of liver fat and possible retardation of
sexual development, was noted (Kabata, 1958). Walford (1958) cited
results of a %year sampling in one English fishing port which disclosed
Lernaeocern parasitization of 10% of haddock, 8004 of whiting and
20% of cod, Parasitized fish were as much as 23:/, below normal
weight.
A second well-known tissue-invading copepod is 8phyrioiL lunipi
(Krsyer), widely distributed in the North Atlantic on the redfish and
several other species (Fig. 10). It has been reported from the Norwegian
coast (Luling, 1951). West Greenland and the Norwegian Sea (Hansen,
1923), Newfoundland (Templeman and Squires, 1960), and the Gulf