Family Hemigaleidae – The Weasel Sharks

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  Small to medium sized sharks (most between 100-150 TL)
  
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  Hemipristis elongatus – maximum length of 240cm; most adults under 200cm
  
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  Horizontal, oval eyes with nictitating eyelids
  
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  Long labial furrows
  
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  Intestine with spiral valve
  
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  Strong ventral lobe of caudal fin
  
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  Wavy dorsal edge of caudal
  
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  Dorsal fin margin undulated
  
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  Large, saw-edged teeth in upper jaw
  
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  Hooked lower teeth protrude from mouth
  

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  Worldwide in fossil record
  
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  Earliest fossils from the Middle Eocene 34-56mya
  
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  Indo west-Pacific – 7 species
  
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  East Atlantic – 1 species (Paragaleus pectoralis)
  
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  Tropical and subtropical
  
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  Continental and insular shelves
  
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  Depths range from shallow to 170 m
  
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  Demersal, benthopelagic, coastal sharks
  

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  Viviparous with yolk-sac placenta
  
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  Minimum population doubling time more than 14 years
  
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  Fecundity ranging from 1-19
  
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  Gestation time of 6 months to one year
  
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  Pregnancy rates of 30% for Hemipristis elongatus off Australia indicate that females may breed every other year
  
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  Biennial or triennial reproductive cycles have also been described for Paragaleus pectoralis
  
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  Mate in March-May and parturition in May-June (P. pectoralis)
  

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  Varied diet
  
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  Some are specialist feeders of cephalopods, especially octopus
  
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  Feed on cephalopods, crustaceans, and small fish
  
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  Hemipristis elongatus also feeds on sharks and rays
  
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  Some live in reefs and weedy areas for prey
  

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  Common and important in fisheries
  
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  Taken regularly in inshore artisanal fisheries
  
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  Intensive and largely unmanaged net and trawl fisheries occur throughout most of the sharks range
  
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  Hemigaleus microstoma is fished in high numbers in SE Asia
  
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  Used for human consumption, the liver is processed fro vitamins, fins for oriental shark fin trade, and by-products for fishmeal
  
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  Thought to have a very low resilience to fishing, with a maximum population doubling time of more than 14 years
  
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  Hemigaleus microstoma listed as least concern
  
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  Hemipristis elongatus is listed as vulnerable except in Australia (Least Concern)
  
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  Chaenogaleus macrostoma, Paragaleus leucolomatus, Paragaleus pectoralis, Paragaleus randalli, and Paragaleus tengi are not in IUCN Red List
  
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  Most are considered harmless to humans, except Hemipristis elongatus, which is considered potentially dangerous because of large teeth and shallow habitat
  

Bass, A.J., Heemstra, P.C., and Compagno, L.J.V. 1986. Carcharhinidae. P. 67-87. In M.M. Smith and P.C. Heemstra (ed.s) Smith's sea fishes. Springer-Verlag, Berlin.

Carrier, J.C., Musick, J.A., and Heithaus, M.R.. 2004. Biology of Sharks and their Relatives. CRC Press, Boca Raton, FL. pp. 51, 73.

Compagno, LJV. 1984. FAO Species Catalogue, Vol 4. Sharks of the World. An annotated and illustrated catalogue of shark species known to date. Part 2 – Carcharhinigormes. FAO Fish. Synop. 125 (4/2):251-655.

Compagno, L, M. Dando, and S. Fowler. 2005. Sharks of the World. Princeton University Press, Princeton, NJ. pp. 283-287.

Nelson, J.S. 2006. Fishes of the World, 4^th ed. John Wiley and Sons, Inc, NJ. p. 62.

Simpendorfer, CA, 2003. Hemigaleus microstoma. In: IUCN 2007. 2007 IUCN Red list of Threatened Species. www.iucnredlist.org. Downloaded on 24 October 2007.

White, W.T. 2003. Hemipristis elongatus. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 24 October 2007.

White, W.T., Last, P.R., and Compagno, L.J.V. 2005. Description of a new species of weasel shark, Hemigaleus australiensis n.sp. (Charcharhiniformes: Hemigaleidae) from Australian waters. Zootaxa 1077:27-49.

Capape C, Diatta Y, Diop M, Reynaud C, Guelorget O. New data on the reproductive biology of the Atlantic weasel shark, Paragaleus pectoralis (Chondrichthyes : Hemigaleidae) from the coast of Senegal (eastern tropical Atlantic). CYBIUM 29 (4): 363-371.