Myxine formosana 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Myxini Myxiniformes Myxinidae

Scientific Name: Myxine formosana Mok & Kuo, 2001

Assessment Information [top]

Red List Category & Criteria: Data Deficient ver 3.1
Year Published: 2011
Date Assessed: 2009-11-13
Assessor(s): Mincarone, M.M. & Mok, H.-K.
Reviewer(s): Polidoro, B., Knapp, L. & Carpenter, K.E.
This species is only known from a small area of southwestern Taiwan. It was once considered abundant, but has historically been targeted by local fisheries which have declined significantly to the point that the fishery ceased in the late 1990s. However, little or no baseline population data is available to calculate decline. It is listed as Data Deficient. More information is needed on this species distribution, population status, life history, biology, and the impact of current and historical threats.

Geographic Range [top]

Range Description:This species is located off southwestern Taiwan but its actual distribution range is not known due to insufficient sampling.
Countries occurrence:
Taiwan, Province of China
FAO Marine Fishing Areas:
Pacific – northwest
Additional data:
Lower depth limit (metres):1500
Upper depth limit (metres):588
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The population information for this species is known from many specimens collected through surveys and from fish markets. Historically this species was previously large enough to support a small fishery (before 1997). The population has likely declined due to over-exploitation from fishery.
Current Population Trend:Unknown
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:This species is located on slopes at depths from 588-1,500 m (Mok and Kuo 2001). The size range appears to be stratified by depth. According to Mok and Kuo (2001), 120 specimens ranging in length from 102-380 mm were collected in three different sites off southwestern Taiwan at depths of 588, 753, and 843 m, whereas 271 specimens ranging from 131-768 mm were also collected off southwestern Taiwan at deeper waters (1,000-1,500 m). This species is caught using shrimp traps (Mok and Kuo 2001).

The copulatory organ is absent for this species. The gonads of hagfishes are situated in the peritoneal cavity. The ovary is found in the anterior portion of the gonad, and the testis is found in the posterior part. The animal becomes female if the cranial part of the gonad develops or male if the caudal part undergoes differentiation. If none develops, then the animal becomes sterile. If both anterior and posterior parts develop, then the animal becomes a functional hermaphrodite. However, hermaphroditism being characterised as functional needs to be validated by more reproduction studies (Patzner 1998).

Threats [top]

Major Threat(s): Before 1997, Myxine formosana was captured with plastic shrimp traps (365 cm length, 16 cm diameter) off southwestern Taiwan by the fishermen from Tong-Kung (Mok and Kuo, 2001). It was a small fishery but activity was intensive across the species' currently known distribution range. It is not known exactly how many vessels were operating within the fishery. It should be noted that since the late 1990's, the fishery has ceased, likely due to major decline in population abundance levels.

Conservation Actions [top]

Conservation Actions: There are no conservation measures in place, but more research is needed on this species' biology, population size, distribution and impact of trap fishery operating across the species' distribution range.

Citation: Mincarone, M.M. & Mok, H.-K. 2011. Myxine formosana. The IUCN Red List of Threatened Species 2011: e.T196055A8999096. . Downloaded on 19 June 2018.
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