- 著者
- B. A. Venmathi Maran Susumu Ohtsuka Xu Shang
- 出版者
- The Japanese Society of Systematic Zoology
- 雑誌
- Species Diversity (ISSN:13421670)
- 巻号頁・発行日
- vol.17, no.2, pp.201-219, 2012-11-25 (Released:2018-03-30)
- 参考文献数
- 92
- 被引用文献数
- 4 9
Adults of caligiform copepods are often found in plankton samples, in addition to the naupliar and copepodid stages. Here, we report on adult parasitic copepods of the families Caligidae and Pandaridae from plankton samples collected in Japanese and Chinese coastal waters. The following previously described species were found in 2008: Caligus calotomi Shiino, 1954; C. orientalis Gusev, 1951; C. undulatus Shen and Li, 1959; Lepeophtheirus semicossyphi Yamaguti, 1939; Metacaligus uruguayensis Thomsen, 1949, and Pandarus satyrus Dana, 1852 in Japanese waters; and C. orientalis and C. rotundigenitalis Yu, 1933 in Chinese waters. The findings of adults of Lepeophtheirus and Metacaligus in plankton samples represent the first such a record for each genus. Two new species of Caligus are also described from plankton taken in Japanese waters in 2008 and 2010. An ovigerous female collected from off Iheya Island, Ryukyu Islands, Okinawa Prefecture is described as Caligus quadrigenitalis sp. nov., and two adult females and a male collected from the Seto Inland Sea and off Hirado Island, Kyushu, western Japan is described as Caligus ogawai sp. nov.
- 著者
- B. A. Venmathi Maran Susumu Ohtsuka
- 出版者
- The Plankton Society of Japan, The Japanese Association of Benthology
- 雑誌
- Plankton and Benthos Research (ISSN:18808247)
- 巻号頁・発行日
- vol.3, no.4, pp.202-215, 2008-11-25 (Released:2009-02-25)
- 参考文献数
- 41
- 被引用文献数
- 13 21
Parasitic copepods usually have one or more free-swimming larval/juvenile stages for dispersal or infection. However the present study has revealed that adults and chalimus stages of caligiform copepods have often been discovered in plankton samples collected from East Asia. This is the first report on free-swimming adults of caligiform copepods from Japanese and Korean waters. Adults of the following species have been discovered in this study. In Japanese waters: Caligus coryphaenae (4♂♂), Caligus sp. (1♂), Pandarus sp. (4♂♂, 16 chalimi) off Nansei Islands in May 2003 and 2006; C. sclerotinosus (1♀) near a fish farm, Ehime Prefecture in December 2006; C. undulatus (1♀) off Ube, the Seto Inland Sea in July 2006; and C. undulatus (1♂) in the Ariake Sea in June 2007. In Korean waters: C. orientalis (1♀, 1♂) from brackish waters of the Mankyong River and C. undulatus (1♂) from the Seomjin River in October 2006. It is interesting to point out that C. undulatus has never been recorded as a parasite infecting any host, but has been collected from plankton samples in East Asia, India and Brazil. It is also noteworthy to mention that males (80%) were found more frequently than females (20%) in this study. We considered the following possibilities for the occurrences of caligiform adults originally infecting fish: (1) escaping from irritation or diseases in the host, (2) looking for an opportunity to switch hosts, (3) change in their life mode, and (4) accidental detachment. In the case of chalimi, it could be accidental, because they would be tightly attached to the host using a special organ called the “frontal filament”, and cannot grow up to the adult stage without nutrient supply from the host.