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Order: Hexanchiformes - most primitive sharks - fossil records indicate they date back to late Jurrasic (150 mya) - 1 posterior dorsal fin without spine.

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Presentation on theme: "Order: Hexanchiformes - most primitive sharks - fossil records indicate they date back to late Jurrasic (150 mya) - 1 posterior dorsal fin without spine."— Presentation transcript:

1 Order: Hexanchiformes - most primitive sharks - fossil records indicate they date back to late Jurrasic (150 mya) - 1 posterior dorsal fin without spine - 6-7 gill slits - no nictitating membrane - small spiracle well behind the eye - 5 extant species, 2 families

2 Family: Chlamydoselachidae One species: Chlamydoselachus anguineus Common name: Frill shark speciman collected at 400m off Eden, New South Wales-1998

3 Chlamydoselachidae characteristics slender, eel-like body dark brown or gray asymmetric caudal fin lacks subterminal notch short, round pectorals single dorsal set far back anal fin larger than dorsal

4 Characteristics cont… can grow up to 2 m six large gill slits and gill covers (1 st is continuous across throat) terminal mouth w/lower jaw almost reaching to the tip of the snout Teeth alike in upper and lower jaw. 3 fanglike cusps w/2 smaller cusps btwn. them. Form interlocking rows and point inward. 300 teeth in about 25 rows. (Compagno, 1984)

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6 Global/Habitat distribution Bathydemersal at 120-1280 m Have been found along outer shelves and upper slopes of continental shelf Normal habitat one with low oxygen, high nutrient zones, and soft substratum Found in Japanese waters, Eastern & Western Pacific, Eastern & Western Atlantic

7 Background C. anguineus named by Garman in 1884 Little is known about the species Leonard Compagno has proposed a new species from the Southern African range (yet to be named) Systemist Shigeru Shirai has proposed C. anguineus be in it’s own order

8 Diet/Feeding deep water cephalopods, fishes, other sharks and carrion Specimens caught in Japan reveal diet is 60.5% deep-sea squids and 10.5% deep- sea teleosts. (Martin, 2003) Likely a nocturnal forager that probably vertically migrates.

9 Reproduction Studies done by Sho Tanaka et. al. on 264 frilled sharks caught in Japan from 1991- 1998 Sharks were caught with bottom gill nets or midwater & bottom trawl nets set at 60-240 m in Suruga Bay

10 Reproduction Ovoviviparous w/ ~ 12cm diameter eggs Litter size ranges from 2-10 (mean of 6) Young ~ 550 mm long and 380 g Ability to breed all year Gestation appears to be 3.5 yrs. (Tanaka, 1990)

11 Biology males below 1,100 mm TL and females btwn. 1,400-1,500 TL mm at maturity (Tanaka 1990) C. anguineus has a fold of tissue in the mouth believed to act as a breathing valve.

12 video Frill Shark Scary http://youtube.com/watch?v=iz5zK1vkNvwFrill Shark Scary cbs5.com - Caught On Tape: Rare Prehistoric Shark In Japan http://cbs5.com/watercooler/local_story_024183117.htmlcbs5.com - Caught On Tape: Rare Prehistoric Shark In Japan http://cbs5.com/watercooler/local_story_024183117.html

13 Bibliography Allen, T.. 2003. The Shark Almanac. The Lyons Press, Guilford, CT. pp. 10,44,48. Carrier, J.C., et. al. 2004. Biology of Sharks and Their Relatives. CRC Press, Boca Raton, FL. p. 55 Castro, J.I. 1983. The sharks of North American waters. Texas A&M University Press,College Station, TX. pp.35-36. Compagno, L.J. 1984. FAO species catalogue. Vol. 4. Sharks of the World. An annotated and illustrated catalogue of shark species known to date. Part 1- Hexanchiformes to Lamniformes. FAO Fish. Synop. 125(4/1): 1-249. Cortés, E. 1999. Standardized diet compositions and trophic levels of sharks. ICES Journal of Marine Science 56(5): 707-717. Ebert, D.A. 2003. Sharks, rays and chimaeras of California. University of California Press: Berkeley, California. p. 284 Martin, R. Aidan. 2003. Copyright and Usage Policy. World Wide Web Publication, Retrieved September 6th, 2007 from: www.elasmo- research.org/copyright.htm.www.elasmo- research.org/copyright.htm Tanaka, S., et. al. 1990. The reproductive biology of the frilled shark, Chlamydoselachus anguineus, from Suruga Bay, Japan. Japanese Journal of Ichthyology 37(3): 273-291.


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