Zoogeography of planktonic brackish-water calanoid copepods in western Japan with comparison with neighboring Korean fauna

Abstract

Brackish-water calanoid copepods, defined as those predominantly inhabiting oligo-and mesohaline waters, were investigated at 45 rivers in western Japan during 2006-2009 to review their faunas and, for comparison, 4 rivers of Korea in 2006. Eight species (Acartia ohtsukai, A. sinjiensis, A. tsuensis, Pseudodiaptomus inopinus, P. ishigakiensis, Sinocalanus sinensis, S. tenellus and Tortanus derjugini) were identified as brackish-water calanoid copepods from Japan. Among them, P. inopinus was most often collected; it occurred in 38 rivers. Acartia tsuensis and A. sinjiensis were also frequent species in Japan. Pseudodiaptomus ishigakiensis discovered from Kyushu Island is new to the mainland of Japan. From the rivers of Korea six species were identified (A. ohtsukai, A. sp., P. inopinus, P. sp., S. tenellus and T. dextrilobatus). Based on the present and previous studies, a total of 13 brackish-water calanoid copepods have been recorded from Japan and Korea, of which eight species, including three continental relicts (A. ohtsukai, S. sinensis and T. derjugini) in Kyushu Island, are common to both regions. Among them, only two species (P. inopinus and S. tenellus) are distributed widely on both Japanese and Korean coasts of the Tsushima (Korea) Strait. This indicates that the faunas of brackish-water calanoid copepods are very different between Japan and Korea despite the short geographical distance (about 170 km) and that the Tsushima Strait has played the role of an effective barrier for their dispersion.

Occurrence characteristics of two sibling species, Pseudodiaptomus inopinus and Pseudodiaptomus poplesia (Copepoda, Calanoida, Pseudodiaptomidae), in the Mankyung River estuary, South Korea

“…Pseudodiaptomus koreanus from the Seomjin River estuary in south-central Korea is also restricted to oligohaline and mesohaline waters and differs from P. inopinus in that it mainly occurs in oligohaline conditions (Park et al 2005;Soh et al 2012). Around the Japanese mainland, P. inopinus and Pseudodiaptomus nansei coexist, but the latter species is restricted to Nansei Islands (Sakaguchi and Ueda 2010;Sakaguchi et al 2011). Recently, Sakaguchi and Ueda (2010) distinguished a separate species, P. nansei, from P. inopinus on Kyushu Island, Japan, and also identified the presence of P. inopinus in the eastern Sea of Japan; the population on the Pacific side of Japan consists of a complex of species that are morphologically similar but genetically distinct.…”

“…In Korean estuaries, five species of the genus Pseudodiaptomus have been recorded, and two species, Pseudodiaptomus inopinus and Pseudodiaptomus poplesia, are predominant (Suh et al 1991;Soh et al 2001). Of these two species, P. inopinus is more common and widespread in brackish and/or freshwaters of northeast Asia in general and Korea in particular (Chen and Zhang 1965;Shen and Song 1979;Chang and Kim 1986;Oka et al 1991;Uye et al 2000;Lee et al 2007;Chang 2009;Sakaguchi et al 2011). In contrast, P. poplesia has only been documented on the Yellow Sea side of the Korean Peninsula and in estuaries of the South China Sea (Shen and Song 1979;Soh et al 2001;Tan et al 2004;Lee et al 2007;Shang et al 2007;Chang 2009).…”

Dynamics of Spatial Abundance of Zooplankton in Morella Coastal Waters, Central Maluku

“…Melihat peran strategis dari zooplankton dalam rantai makanan di suatu perairan, maka kajian tentang kelimpahan perlu dilakukan. Beberapa kajian tentang zooplankton di perairan dari berbagai perairan di dunia telah dilakukan seperti di perairan sekitar Portugal (Marques et al, 2006;Marques et al, 2008), di perairan sekitar Jepang (Itoh, et al, 2011;Sakaguchi et al, 2011), di perairan sekitar India (Fernandes dan Ramaiah, 2014). Untuk perairan Indonesia, khususnya di Kawasan Timur Indonesia (KTI) telah dilakukan di Teluk Piru (Yusuf dan Praseno, 1978), Laut Banda (Baars et al, 1990;Arinardi et al, 1990), Teluk Kao (Wiadnyana, 1997); di Teluk Ambon (Yusuf, 1979;Sutomo dan Anderson, 1984;Sutomo dan Yusuf, 1987;Sutomo, 1987;Mulyadi dan Radjab, 2009;Mulyadi, 2011a) dan di Pesisir Nusalaut (Mulyadi, 2011b).…”

Morphological divergence of Pseudodiaptomus inopinus Burckhardt, 1913 (Copepoda: Calanoida) between the Japan Sea and Pacific coasts of western Japan

“…Shen & Tai 1962, Mizuno & Miura 1984. It is a very common and often the most abundant copepod in brackish-waters of the mainland of Japan (Sakaguchi & Ueda 2010, Sakaguchi et al 2011. Because of morphological differences among the literature from different localities, we (Sakaguchi & Ueda 2010) suggested that P. inopinus is a species complex.…”