1. Pteroplatytrygon (Dasyatis)violacea A Review Henry F. Mollet, Juan M. Ezcurra, John B. O'Sullivan Monterey Bay Aquarium, 886 Cannery Row, Monterey, CA 93940, USA

2. 2 Acknowledgements Monterey Bay Aquarium Brorsen Steve, Greenwald Scott, Farwell Charles, Franklin Veronica, Ingram Kris, Kochevar R, Scott R, Wrobles Dave, Welsh Joe California Catania Dave (CAS), Ebert Dave (US Abalone), Holts Dave (NOAA/NMFS), Morales Pat (CAS), O'Brian John (DFG), Shaw Mike (Sea World), Smirl Kent (DFG), Walker H.J. (SIO), Zorzi George (CAS) USA Bourdon Jim, Conlin Mark, Crow Jerry (Waikiki Aq,), Henningsen Alan (Baltimore Aq.), Neer Julie (LSU), Pooley S (NOAA/NMFS), Rosenberger L (UC) Brazil & Mexico Rincon Getulio (Rio Grande U.), Villavicencio Carlos (UABCS ) Europe Bentivegna Flegra (Zoological Station Naples), Bortolotto Alessandro, (Fondazione Cetacea Milan),Garibaldi Fulvio (LBMLR Genova), Haynes Rod (Benalmadena SLC), Henderson Aaron (NUI Galway) Japan Nishida Kiyonori (Osaka Aquarium), Chai Kiyoshi (KAMPA ) South Africa Compagno Leonard (SAM), Dudley Sheldon (NSB) Australia & New Zealand Francis Malcolm (NIWA), Last Peter (CSRIO), Ministry of Fisheries, Stevens John (CSIRO), Stewart Andrew (MNZ )

3. 3 Introduction La Paz 2000 Penn State 1999 (Jim Bourdon) Guelph 1998 Seattle 1997 (plus poster with Scott Greenwald and Jim Bourdon) New Orleans 1996 Edmonton 1995

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5. 5 Timeline 1800-2000

6. 6 Worldwide Distribution

7. 7 Disc width Distribution

8. 8 Taxonomy Bonaparte (1832-1941). Trygon violaceum, Trygon Cuv. junior synonym to Dasyatis Raf. Fowler (1910). Pteroplatytrygon subgenus of Dasyatis. Compagno (1987). Pteroplatytrygon available as a monotypic genus. Elevated to genus, based on morphometrics, disc color, streamlined eyes. P. Deynat, J. Bourdon (pers. comms.). Dermal denticles and dentition within Myliobatiformes indicated that Dasyatis violacea is clearly set apart from the other Dasyatis.

9. 9 Mass -DW Relationship (back transformed Y-on-X power regressions) M = 49.5 DW 3.607 (n = 15, Edmonton 1995) DW in meters, 50 kg was predicted mass for 1 m DW pelagic stingray April 2000, largest female 0.96 m DW, 49.0 kg M = 44.9 DW 3.321 (n = 181, Monterey 2000)

10. 10 Tooth Replacement Rates with Jim Bourdon and Scott Greenwald Shed rate 3.4 ray -1 day -1 Replacement rate 20.7 days row -1

11. 11 File splitting with Jim Bourdon

12. 12 Dermal Denticles Shed Rate with Jim Bourdon and Scott Greenwald First shed rate for any batoid 0.68 ray -1 day -1 Guesstimate for replacement rate 44-88 days

13. 13 Population Genetics Project with Joe Quattro Now in progress Atlantic: Brazil (Getulio Rincon); Ireland (Aaron Henderson) Med Sea: Western Med (Rod Hayes); Ligurian Sea (Fulvio Garibaldi) Pacific: California (John O'Sullivan, Julie Neer); Hawaii (Jerry Crow, Ed Heist); New Zealand (Malcolm Francis) Additional samples needed & welcome

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15. 15 One Big Problem with VBGF VBGF reasonable with good statistics Applies to captive rays 2 years old and older 1st year growth rates much too large! Affects age estimate of our rays at capture!

16. 16 Comparison of Gompertz & VBGF (3 parameter fits using estimated age) DW oo DW o k Fem 100 15 0.44 Male 71 19 0.55Male 68 -38 0.71 Fem 104 -7.7 0.32 DW oo DW o k VBGFGompertz

17. 17 Comparison of Gompertz & VBGF (3 parameter fits incl. captive pup data)

18. 18 Density Related Fecundity? Review of reproductive data Feeding data at the Monterey Bay Aquarium Could feeding cycles indicate possibility of 2 litters per year if food is available? (i.e. lower density)

19. 19 Gestation and Parturition Review of Med. Sea and Japanese Aq. data Med. Sea Embryos Mean DW for 10 Japanese AQ litters DW o MoMo

20. 20 Gestation and Parturition Review of NW Atlantic and NE Pacific data NW Atlantic ?NE Pacific? suggested off C. Am.

21. 21 Weekly Feeding Amounts Phase 2 (Food Intake is Seasonal) 4 females & 2 males of phase 2

22. 22 Feeding is Seasonal for Both Sexes Males Females X Combined P1? P2??

23. 23 Summary I covered distribution, taxonomy, morphometrics, dentition, dermal denticles. No problems. Growth: Gompertz better than VBGF because 1st year growth rates are likely smaller than what VBGF suggests. Seasonal food intake variation with 2 cycles/year. Probably related to reproduction. Might suggest density dependent fecundity. Need more data for Pacific. Model for pelagic sharks which are difficult to study and impossible to keep in captivity?