family hemigaleidae the weasel sharks l.
Skip this Video
Loading SlideShow in 5 Seconds..
Family Hemigaleidae The Weasel Sharks PowerPoint Presentation
Download Presentation
Family Hemigaleidae The Weasel Sharks

Loading in 2 Seconds...

play fullscreen
1 / 12

Family Hemigaleidae The Weasel Sharks - PowerPoint PPT Presentation

  • Uploaded on

Family Hemigaleidae The Weasel Sharks . Sara McCutcheon. General Characteristics. Small to medium sized sharks Horizontal, oval eyes w nictitating eyelids Long labial furrows Spiral intestinal valve Strong ventral lobe of caudal fin Wavy dorsal edge of caudal

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Family Hemigaleidae The Weasel Sharks' - PamelaLan

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
general characteristics
General Characteristics
  • Small to medium sized sharks
  • Horizontal, oval eyes w nictitating eyelids
  • Long labial furrows
  • Spiral intestinal valve
  • Strong ventral lobe of caudal fin
  • Wavy dorsal edge of caudal
  • Upper teeth large and saw-edged
  • Lower hooked teeth protrude from mouth
taxonomy 8 species in 4 genera
Chaenogaleus (1 sp.)

Hemipristis (1 sp.)

Hemigaleus (2 spp.)

Paragaleus (4 spp.)

Taxonomy8 species in 4 Genera

1 Chaenogaleus macrostoma – Hooktooth shark

2 Hemigaleus microstoma – Sicklefin weaselshark

3 Hemigaleus australiensis – Australian weasel shark

4 Hemipristis elongatus – Snaggletooth shark

5 Paragaleus leucolomatus – Whitetip weasel shark

6 Paragaleus pectoralis – Atlantic weasel shark

7 Paragaleus randalli – Slender weasel shark

8 Paragaleus tengi – Straighttooth weasel shark

  • Continental and insular shelves
  • Tropical and subtropical waters
  • Depths range from shallow to 170 m
  • Demersal
  • Benthopelagic
  • Coastal
  • Indo-West Pacific for 7 species
  • East Atlantic for Paragaleus pectoralis
reproductive biology
Reproductive Biology
  • Viviparous with yolk-sac placenta
  • Minimum population doubling time more than 14 years
  • Fecundity ranging from 1-19
  • Gestation time of 6 months to one year
  • Biennial or triennial reproductive cycles Mate in March-May and parturition in May-June
  • Varied diet
  • Feed on cephalopods, crustaceans, and small fish
  • Some are specialist feeders of cephalopods, especially octopus
  • Hemipristis elongatus also feeds on sharks and rays
  • Some live in reefs and weedy areas for prey
  • Common and important in fisheries
  • Taken regularly in inshore artisanal fisheries
  • Intensive and largely unmanaged net and trawl fisheries occur throughout most of the sharks range (except for Australia)
  • Hemigaleus microstoma is fished in high numbers in SE Asia
  • Used for human consumption, the liver is processed fro vitamins, fins for oriental shark fin trade, and by-products for fishmeal
  • Thought to have a very low resilience to fishing, with a maximum population doubling time of more than 14 years
  • Most are considered harmless to humans
  • Hemipristis elongatus is considered potentially dangerous because of large teeth and shallow habitat
iucn red list
IUCN Red List
  • Hemigaleus microstoma listed as least concern
  • Hemipristis elongatus is listed as vulnerable except in Australia (Least Concern)
  • Chaenogaleus macrostoma, Paragaleus leucolomatus, Paragaleus pectoralis, Paragaleus randalli, and Paragaleus tengi are not in IUCN Red List

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 – Carcharhiniformes. 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, 4th ed. John Wiley and Sons, Inc, NJ. p. 62.

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

White, W.T. 2003. Hemipristis elongatus. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. 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. (Carcharhiniformes: 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.