Browsing by Author "Nagasawa, Kazuya"
Sea lice, Lepeophtheirus salmonis and Caligus orientalis (Copepoda: Caligidae), of wild and farmed fish in sea and brackish waters of Japan and adjacent regions: A review K Nagasawa -
Zoological Studies, 2004 - Institute of Zoology, Academia SinicaThis paper reviews various aspects of the biology and effects of 2 caligid copepods, Lepeophtheirus salmonis and Caligus orientalis, on wild and farmed fish in sea and brackish waters of Japan and adjacent regions. Lepeophtheirus salmonis is a common parasite of wild adult chum (Oncorhynchus keta) and pink (O. gorbuscha) salmon migrating in northern Japanese waters. Masu salmon (O. masou) have the lowest level of infection. Juvenile chum salmon are sometimes infected. This parasite is also found on salmonids in Korean and Russian waters. The species occurs on coho salmon (O. kisutch) and rainbow trout (O. mykiss) farmed in coastal waters of northern Japan, but its infection is not a serious problem, because only young fish are reared and harvested in less than a year of culture and thus no fish are cultured during summer. This situation is very different from that in Scotland, Ireland, Norway, and Canada where L. salmonis causes serious damage to farms of Atlantic salmon (Salmo salar). Caligus orientalis is a parasite of coastal marine and brackish-water fish in Japan and neighboring countries (Taiwan, China, Korea, and Russia). This parasite has a wide host range and has been reported from over 20 fish species from different orders and families. It infects farmed and experimentally reared fish, such as rainbow trout in Japan, grey mullet (Mugil cephalus) and black porgy (Acanthopagrus schlegeli) in Taiwan, and Mozambique tilapia (Oreochromis mossambicus) in China. Heavy infection results in appetite reduction and death of fish. The parasite is one of the most important pathogens at brackish-water fish farms in Far East Asia.
ArticleF Moravec, ER Cruz-Lacierda & K Nagasawa -
Acta Parasitologica, 2004 - Polish Academy of Sciences, Institute of ParasitologyNematode specimens of two Procamallanus species, P. (Procamallanus) planoratus Kulkarni, 1935 and P. (Spirocamallanus) guttatusi (Andrade-Salas, Pineda-Lopez et Garcia-Magana, 1994), were collected from broadhead catfish Clarias macrocephalus (Clariidae, Siluriformes) and orange-spotted spinefoot Siganus guttatus (Siganidae, Perciformes), respectively, from the Philippines. Their examination, including scanning electron microscopy (SEM) that was used for the first time in these species, made it possible to obtain new data on their morphology, to elucidate their systematic status, and to redescribe them. Procamallanus clarius Ali, 1957 and P. heteropneustus Ali, 1957 are considered junior synonyms of P. planoratus. Heavy P. guttatusi infections found in Siganus guttatus reared in Fish Hatchery of SEAFDEC AQD in Tigbauan, Iloilo indicate that this parasite may have negative implications on the health condition of fish in culture.