Hemigaleus microstoma 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Chondrichthyes Carcharhiniformes Hemigaleidae

Scientific Name: Hemigaleus microstoma Bleeker, 1852
Common Name(s):
English Sickelfin Weasel Shark
Hemigaleus machlani Herre, 1929
Negogaleus brachugnathus Chu, 1960
Negogaleus microstoma Whitley, 1940
Taxonomic Source(s): Bleeker, P. 1852. Bijdrage tot de kennis der Plagiostomen van den Indischen Archipel. Verh. Batav. Genootsch. Kunst. Wet. 24(12): 1-92.
Taxonomic Notes: Previously considered to occur in Australian waters, but the Australian individuals were recently described as a new species, Hemigaleus australiensis (White et al. 2005). Specimens from the Red Sea need to be critically examined.

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2d+3d+4d ver 3.1
Year Published: 2009
Date Assessed: 2007-07-07
Assessor(s): White, W.T.
Reviewer(s): Simpfendorfer, C.A., Stevens, J.D. & Valenti, S.V. (Shark Red List Authority)
The Sickle Fin Weasel Shark (Hemigaleus microstoma) is taken in a variety of inshore fisheries throughout its range. It appears to be a naturally uncommon species, thus the heavy fishing pressure through its range is of great concern. This species is not as productive as the closely related Australian Weasel Shark (Hemigaleus australiensis), i.e., with an average of 4-8 pups per year per female (based on two pregnancies per year) and thus less likely to be able to withstand fishing pressure. It is thus assessed as Vulnerable based on suspected declines as a result of the high level of exploitation throughout its range, which is likely to increase in the future and will have a great impact on a naturally uncommon species such as this.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Indian Ocean, northwest and western central Pacific: India, Sri Lanka, Myanmar, Thailand, Malaysia, Indonesia, Philippines, China, Taiwan and possibly the Red Sea.
Countries occurrence:
China; India; Indonesia; Malaysia; Myanmar; Philippines; Sri Lanka; Taiwan, Province of China; Thailand
FAO Marine Fishing Areas:
Indian Ocean – western; Pacific – northwest; Pacific – western central
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:Not particularly common throughout its range. Appears to be naturally not abundant as with many other hemigaleids.
Current Population Trend:Decreasing
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:Hemigaleus microstoma is known from the insular and continental shelves, in shallow waters to depths of at least 170 m (White et al. 2006). Attains 114 cm TL. Males reach maturity at about 75 cm TL and females from 75-78 cm TL (White et al. 2007). Young are born at about 47 cm TL (White et al. 2007). Litter size is 2-4 (mean 3.3) with possibly two pregnancies per year thus a gestation of less than six months (White et al. 2007). A specialist feeder which feeds almost exclusively on cephalopods.

Threats [top]

Major Threat(s): Known to be caught in inshore and offshore artisanal fisheries throughout its range and retained. Caught in drifting and bottom gillnets and on longlines. Meat is utilized for human consumption and offal is processed into fishmeal (Compagno in prep). Fins are utilized but of lower value due to their small size (White et al. 2006).

Conservation Actions [top]

Conservation Actions: None in place.

Classifications [top]

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
In-Place Species Management
In-Place Education
5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.3. Unintentional effects: (subsistence/small scale) [harvest]
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.4. Unintentional effects: (large scale) [harvest]
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

3. Monitoring -> 3.1. Population trends

♦  Food - human
 Local : ✓   National : ✓  International : ✓ 

♦  Food - animal
 Local : ✓   National : ✓ 

Bibliography [top]

Compagno, L.J.V. 2001. Sharks of the World. An annotated and illustrated catalogue of the shark species known to date. Volume 3. Carcharhiniformes. FAO, Rome.

IUCN. 2009. IUCN Red List of Threatened Species (ver. 2009.2). Available at: www.iucnredlist.org. (Accessed: 3 November 2009).

White, W.T., Last, P.R. and Compagno, L.J.V. 2005. Description of a new species of weasel shark, Hemingaleus australiensis n. sp. (Carcharhiniformes: Hemigaleidae) from Australian waters. Zootaxa 1077: 37-49.

White, W.T., Last, P.R., Stevens, J.D., Yearsley, G.K., Fahmi and Dharmadi. 2006. Economically Important Sharks and Rays of Indonesia. Australian Centre for International Agricultural Research, Canberra, Australia.

Citation: White, W.T. 2009. Hemigaleus microstoma. In: . The IUCN Red List of Threatened Species 2009: e.T41816A10569394. . Downloaded on 18 June 2018.
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