|Scientific Name:||Takifugu poecilonotus|
|Species Authority:||(Temminck & Schlegel, 1850)|
Fugu poecilonotum (Temminck & Schlegel, 1850)
Fugu poecilonotus (Temminck & Schlegel, 1850)
Tetraodon poecilonotus Temminck & Schlegel, 1850
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Shao, K., Liu, M., Larson, H., Jing, L., Leis, J.L. & Matsuura, K.|
|Reviewer(s):||Zapfe, G. & Lyczkowski-Shultz, J.|
|Facilitator/Compiler(s):||Carpenter, K.E., Comeros-Raynal, M., Harwell, H. & Sanciangco, J.|
In the northwestern Pacific, T. poecilonotus is known from South Korea and Japan to Taiwan and Hong Kong. It is a coastal, euryhaline species which is typically found over rocky bottoms or sandy beaches at depths ranging from very shallow waters to 20 m. It appears to be common and can be locally abundant. Takifugu poecilonotus is not targeted, but it is incidentally harvested in parts of its range. There are no known additional species-specific threats, however, the extent to which T. poecilonotus is impacted by environmental degradation resulting from large-scale anthropogenic activity within its range is largely unknown. There are no known species-specific conservation measures in place for T. poecilonotus, however its distribution overlaps with marine reserves in parts of its range. It is therefore listed as Least Concern. Due to the economic importance of the Takifugu genus, and the prevalence of taxonomic uncertainty within this group, we recommend further taxonomic studies utilizing both molecular and morphological methods.
|Range Description:||In the Northwest Pacific, T. poecilonotus is known from the southern Korean Peninsula throughout Japan, including the Pacific coast (Ikeda et al. 2010), south to Taiwan (Shao 1997) and Hong Kong (Ni and Kwok 1999). In Japan, this species is distributed from 23°–45° N (Masuda 2007). It is found at depths ranging from one to 20 metres.|
Native:China; Japan; Korea, Republic of; Taiwan, Province of China
|FAO Marine Fishing Areas:||
Pacific – northwest
|Range Map:||Click here to open the map viewer and explore range.|
Takifugu poecilonotus is most closely related to T. exascurus (Yamanoue et al. 2008). Due to their relatively recent divergence times, Takifugu interspecific crosses produced by artificial and natural fertilization in both natural and laboratory settings were found to be viable (Fujita 1967, Masuda et al. 1991, Miyaki et al. 1995, Kai et al. 2005). Each combination of Takifugu species is expected to produce fertile hybrid crosses (Yamanoue et al. 2008).
Takifugu poecilonotus is common and can be locally abundant in Japan, where it is seen in small schools of less than 20 individuals (K. Matsuura pers. comm. 2011). During bi-monthly underwater visual censuses in the sub-tidal habitat of Nagahama, Wakasa Bay, Sea of Japan, over five years from January 2002 to December 2006, this species was observed during 153 of 360 transect surveys and was the most frequently observed tetraodontid. Sighting frequency was independent of water temperature. This species was also observed during similar underwater visual surveys conducted from 1970 to 1972, although the exact number could not be found because the survey could not be accessed (Masuda 2007). Fifteen specimens of this species were collected in the surfzone of a sandy beach in Southern Japan, where it was more abundant than T. reticularis (six specimens collected) but far less abundant than T. niphobles (118 specimens collected) (Inoue et al. 2005).
Takifugu poecilonotus is moderately in museum collections. It was represented by 41 lots (FishNet2 database searched March 2014).
|Habitat and Ecology:||
Takifugu poecilonotus is a demersal, euryhaline species found in temperate waters (Pietsch et al. 2000). It occurs near shore on rocky bottoms (Yamada et al. 1995) and in the surf zone of sandy beaches (Inoue et al. 2005). This species exhibits ontogenetic changes in diet, with juveniles (22–27 mm SL) feeding largely on calanoid copepods and larger fish (59–65 mm SL) feeding mainly on mysids and gammaridean amphipods (Inoue et al. 2005). Takifugu poecilonotus also feeds on oyster spat (Saito 2008). This species is known to spawn at the entrance to the Ariake Sea from March to May (Ikeda et al. 2010). The ovaries and liver are extremely toxic, while the testes, skin, and intestine are highly toxic. The flesh is slightly toxic.
The genus Takifugu speciated and radiated in marine waters around China, Korea, and Japan. The highest species density is found in the Bohai Sea, Yellow Sea, and East China Sea, followed by the Sea of Japan and Pacific Coast of Japan, and finally by the South China Sea. Several species have been reported from the Indian Ocean (Yamanoue et al. 2008).
Tetraodontids are characterized by a tough skin that is often covered with small spinulous scales, a beak-like dental plate divided by a median suture, a slit-like gill opening anterior to the base of the pectoral fin, no pelvic fins, no fin spines, a single usually short-based dorsal fin, a single usually short-based anal fin, and no ribs. They are capable of inflating their abdomens with water when frightened or disturbed and are capable of producing and accumulating toxins such as tetrodotoxin and saxitoxin in the skin, gonads, and liver. The degree of toxicity varies by species, and also according to geographic area and season (Allen and Randall 1977, Allen and Erdmann 2012). Fishes in the family Tetraodontidae have the smallest vertebrate genomes known to date (Neafsey and Palumbi 2003).
|Use and Trade:||
Takifufu poecilonotus is incidentally harvested for food but is not targeted (K. Matsuura pers. comm. 2011). Although it is sometimes marketed as "Komon-fugu" in Japan (Noguchi and Arakawa 2008), this species displays a frequent occurrence of considerably high levels of TTX in its muscle tissue, and its preparation and consumption has been been cited as a public concern (Kodama et al. 1984). Despite a ban on the sale of toxic pufferfishes in fish markets, T. poecilonotus may sometimes found in processed fish products in Taiwan (Huang et al. 2014). Takifugu poecilonotus, like other fugu species, is primarily caught by bottom long-line fishing, a method which is highly effective at landing Takifugu spp. pufferfishes (K. Matsuura pers. comm. 2011).
There have been no confirmed population declines in T. poecilonotus. However, it is likely to be impacted by the following:
The Fugu fishery is acknowledged to have undergone significant declines throughout East Asia. Highly effective fishing gear, including modified long-lines and nets with small mesh sizes, rather than excessive fishing effort, have been implicated in the depletion of Takifugu pufferfish resources in parts of East Asia. In Japan, initial efforts to regulate the fishery in the mid-2000s had not achieved desired results by 2010, and were subsequently re-evaluated (Kawata 2012). Although the species-specific effects of the Fugu fishery on T. poecilonotus are unknown, it is likely that populations of this commercially important species are impacted by this fishery.
Genetic effects of Cultured fish on Natural Populations
Fishes of the genus Takifugu have become the focus of increasing aquaculture efforts throughout East Asia. Aquacultured Takifugu are used to meet increasing demand for pufferfish products and to enhance natural populations which have been depleted throughout the region (Kawata et al. 2012). As culture fish are genetically distinct from natural populations, the release of aqua-cultured fish can result in a range of genetic outcomes, from no detectable effect to complete introgression or displacement of wild populations (Hindar et al. 1991). Fishes of the genus Takifugu are relatively recently diverged, and each combination of Takifugu species is expected to produce fertile hybrid crosses (Yamanoue et al. 2008). It is therefore likely that the effect of intentional and unintentional release of cultured Takifugu on the genetic integrity of wild populations is significant.
Regional Threats: Environmental Degradation and Over-Fishing
Major threats to biodiversity of the China seas include over-exploitation of fishery resources and environmental deterioration. The China Seas have faced severe environmental degradation due to a range of anthropogenic activities within a relatively recent and short time frame (Daoji and Daler 2004). The degradation of estuarine environments due to pollution and coastal production is of particular concern, as these areas are characterized by high productivity and represent spawning and nursery areas for many species (Liu 2013). Large areas of the China Seas (Liu 2013) and the Gulf of Thailand (Blaber 2000) are considered to be heavily overfished. Additionally, heavy bottom-trawling in the 1980s and the widespread use of modified driftnets for multi-species fisheries in the Bohai Sea, combined with other anthropogenic stresses, have been implicated in the steady decrease in fish landings in this area (Xianshi 2004). In the Yellow Sea, previously dominant large demersal species became the targets of heavy fishing pressure during the 1950s and 1960s and greatly declined in abundance. By the 1980s, many large pelagic species were also showing great declines in abundance, and since that time the dominant species in the Yellow Sea have been small, planktivorous pelagic species, such as anchovies and sardines (Jin and Tang 1996). In the Yellow Sea, all ecological indexes such as the species number, species richness, species diversity and the evenness were lower in the year 2000 than in the year 1985 (Lin et al. 2005).
There are no known species-specific conservation measures in place for Takifugu poecilonotus, however it is possible that management efforts aimed at sustaining T. rubripes fisheries have benefited T. poecilonutus.
In order to sustain fisheries of the East China Sea, the government of China has implemented a number of management and conservation measures. These include establishing a prohibited-fishing zone along the 50-m depth contour, the establishment of seventeen national nature reserves and five special marine protected areas, the creation of fishery protected areas which are annually closed to trawling, and a summer closed-fishing areas, which prohibit trawling and have been extended to the South China sea, Yellow Sea, and Bohai Sea (Cheng et al. 2007).
|Citation:||Shao, K., Liu, M., Larson, H., Jing, L., Leis, J.L. & Matsuura, K. 2014. Takifugu poecilonotus. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 01 February 2015.|
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