A gram-negative filamentous bacterium was isolated from the gills of salmonids, Salmo gairdneri and Oncorhynchus masou, with gill disease. The isolates did not show gliding movement. Growth on Cytophaga agar was pigmented yellow. Colonies were small, translucent, smooth and entire. There was no growth on nutrient agar and meat-extract broth. Acid was produced from glucose and sucrose. Growth was best at 15-20°C. Attempts succeeded in transmitting bacterial gill disease to fingerling trout by adding pure cultures of the bacterium in aquariums. The experimentlly infected gills showed essentially the same symptoms as seen in naturally occurred gill disease.
In November, 1975, a clove worm was detected in the intestines of carp, Cyprinus carpio, which were collected in an irrigation pond farm in Gunma prefecture. They were six month old and 12.5-14.7 cm in body length. The worm was never found in carp which harbored another cestode, Bothriocephalus opsariichthydis YAMAGUTI. A monthly examination revealed that the number of the worm decreased rapidly after November and no worm could be detected from January to May. This suggested that the worm can not survive the winter. Ten worms fixed in 70% alcohol, stained with HE and mounted in balsam were observed:Body slender, 11.0-16.2 mm long by 0.8-2.4 mm wide; Scolex undifferentiated, conic or turncate, 1.2-2.7 mm wide; Cirrus pouch well developed, 0.52-0.68 mm long by 0.40-0.56 mm wide;Uterine coils between cirrus pouch and H-shaped ovary; Postovarian vitellaria medullary; Egg elliptical with thin shell, 44-50×22-34μ. The present worm was similar to the two species of the genus Khawia (Cestodaria:Caryophyllidae) in shape and size, K.japonensis (YAMAGUTI, 1934) YAMAGUTI, 1959 and K. sinensis HSÜ, 1935. These two species are distinguished only by the size of eggs, that is, the eggs of the former have been reported to be 48-57×36-42μ and those of the latter 42-48×25-30μ. Based on the egg size the present clove worm was identified as K. sinensis.