1. Conservation and Ecology of Marine Reptiles MARE 490 Dr. Turner Summer 2012

3. Mammalia Reptilian Origins AvesReptilia

5. Class Reptilia Order Chelonia – marine turtles Order Squamata – marine snakes and iguanas Order Crocodilia – saltwater crocodile

6. Class Reptilia 6,000 living species of reptiles (lizards, snakes, turtles, crocodiles) Dry skin covered with scales (prevent H 2 0 loss) Air breathing Marine taxa include sea turtles, sea snakes, marine iguana, and saltwater crocodile

7. Marine Turtles Marine turtles tied to terrestrial environment for oviposition - process of laying eggs Other Aquatic Reptiles: iguanas, crocodilians, ichthyosaurs - tail undulation for locomotion

8. Marine turtles: lost capacity of tail undulation Developed shortened, rigid body form & corselet (breastplate) Limbs required profound modification from terrestrial existence

9. Limb Modification Forelimbs modified into paddles: - elongate phalanges enmeshed in a continuous matrix of tough connective tissue Foreclaws reduced to three on each limb

10. Order Chelonii 2 Families: Cheloniidae & Dermochelyidae 7 or 8 species found throughout 3 tropical Oceans 3 species have restricted distribution: Flatback – northern Australia Kemp’s ridley – Gulf of Mexico, N. Atlantic Black sea turtle – eastern Pacific

11. Order Chelonii Turtles & tortoises – monophyletic group or clade “Pseudoturtle” Placochelys

12. Order Chelonii Cretaceous – 4 families: Toxichelyidae Protostegidae Cheloniidae Dermochelyidae

13. Order Chelonii - Extinct - Extant

14. Family Toxichelyidae Small/medium sized, broad-shelled marine turtles - diverged from Cheloniidae

15. Family Protostegidae A group of large to gigantic turtles - Rhinochelys sp. Parallels with dermochelyidae

16. Family Protostegidae

17. Order Chelonii - Extinct - Extant

18. Family Cheloniidae Shell covered in horny scutes Variable in number Typically 5 pairs on carapace; 6 of plastron

19. Family Dermochelyidae Reduction in bones of the carapace & plastron No scutes

20. Cheloniid Diversity At one point – 31 genera 5 extant: Chelonia sp. Eretmochelys sp. Lepidochelys sp. Caretta sp. Natator sp.

21. Genus Chelonia Description: 4 pairs of lateral, non-overlapping scutes 2 extant species: Chelonia mydas Chelonia agassizii

22. Genus Chelonia Chelonia mydas: 4-pairs lateral scutes, 1 pair prefrontal scales, non-overlapping scutes, round head, serrated jaw; to 230kg, shell 125cm

23. Family Cheloniidae Chelonia mydas – green sea turtle Herbivore Fibrilopapilloma – 49-92% Nest French Frigate Shoals ≈1,000 females

24. Family Cheloniidae Chelonia mydas – green sea turtle

25. Major Nesting Areas C. mydas

26. Genus Chelonia Chelonia agassizii: 4-pairs lateral scutes, 1 pair prefrontal scales, non-overlapping scutes, round head, serrated jaw; to 230kg, shell 125cm Black pigmentation Restricted to E. Pacific

27. Family Cheloniidae Chelonia agassizii – black sea turtle Pacific coast of S. America 4 pairs of non-overlapping lateral scutes

28. Family Cheloniidae Chelonia agassizii – black sea turtle

29. Major Nesting Areas C. agassizii

30. Genus Eretmochelys Description: 4 pairs of lateral, overlapping scutes 1 extant species: Eretmocheyls imbricata

31. Genus Eretmochelys Eretmocheyls imbricata: 4-pairs lateral scutes, 2 pairs prefrontal scales, overlapping scutes, pointed head, overbite; to 85kg, shell 95cm

32. Family Cheloniidae Eretmocheyls imbricata – Hawksbill sea turtle Shell highly prized; $100/lb Until 1992 – 20 net tons/Japan Nests on beaches of Hawaii 4 pairs of overlapping lateral scutes

33. Family Cheloniidae Eretmocheyls imbricata – Hawksbill sea turtle

34. Major Nesting Areas E. imbricata

35. Genus Lepidochelys Description: 5-6+ lateral scutes, round carapace 2 extant species: Lepidocheyls olivacea Lepidocheyls kempi Olive Kemp’s

36. Genus Lepidochelys Lepidocheyls olivacea: 6+-pairs lateral scutes, carapace nearly circular, 4 bridge scutes with pores, juvenile-charcoal, adult-olive green; to 45kg, shell 70cm Restricted to tropical waters

37. Family Cheloniidae Lepidocheyls olivacea – Olive ridley sea turtle Widely Distributed Doing fairly well Rarely found around Hawai′i 6+ pairs of non- overlapping lateral scutes

38. Family Cheloniidae Lepidocheyls olivacea – Olive ridley sea turtle

39. Major Nesting Areas L. olivacea

40. Genus Lepidochelys Lepidocheyls kempi: 5-6 pairs lateral scutes, carapace very round, 4 bridge scutes with pores, juvenile-charcoal, adult-grey-green; to 45kg, shell 70cm 5-6 Restricted to Gulf of Mexico & S. Atlantic

41. Family Cheloniidae Lepidocheyls kempi – Kemp’s ridley sea turtle Most critically Endangered 1947-42,000 ♀; 1980’s -1,000♀ Shrimp trawl bycatch 5 pairs of non-overlapping lateral scutes

42. Family Cheloniidae Lepidocheyls kempi – Kemp’s ridley sea turtle

43. Major Nesting Areas L. kempi

44. Genus Caretta Description: 5-6 lateral scutes, carapace longer than wide 1 extant species: Caretta caretta Loggerhead Kemp’s

45. Genus Caretta Caretta caretta: 5-6 pairs lateral scutes, carapace longer than wide, 3 bridge scutes with no pores, broad head, red to red-brown; to 200kg, shell 120cm

46. Family Cheloniidae Caretta caretta – Loggerhead sea turtle Nests in S. Japan – only in N. Pacific; prevalent in Gulf of Mexico and Atlantic 5 pairs of non-overlapping lateral scutes

47. Family Cheloniidae Caretta caretta – Loggerhead sea turtle

48. Major Nesting Areas C. caretta

49. Genus Natator Description: 4 pairs of lateral, non-overlapping scutes; 1 extant species: Natator depressus

50. Genus Natator Natator depressus: 4-pairs lateral scutes, 1 pair prefrontal scales, non-overlapping scutes, round head, serrated jaw; to 90kg, shell 100cm Dorso-ventrally flattened

51. Family Cheloniidae Natator depressus – Flatback sea turtle Australia – limited range 4 pairs of non-overlapping lateral scutes Thin, smooth, & waxy

52. Family Cheloniidae Natator depressus – Flatback sea turtle

53. Major Nesting Areas N. depressus

54. Dermochelyid Diversity Single extant species shows very little geographic variability - probably no subspecies exist However discussion of named populations

55. Genus Dermochelys Dermochelys coriacea: Flexible, tapered, & leathery carapace, 5 distinct ridges, no scutes, jaw deeply notched; to 500kg, shell 180cm

56. Family Dermochelyidae Dermocheyls coriacea – Leatherback sea turtle 20,000-30,000 Worldwide Caught in longlines; jellyfish Sighted offshore Kona

57. Family Dermochelyidae Dermocheyls coriacea – Leatherback sea turtle

58. Major Nesting Areas D. coriacea

59. Current Taxonomic Questions 1. What subfamilies should be recognized? 2. Correct placement of flatback? 3. Relationship within Lepidochelys 4. Status of black turtle in eastern Pacific

60. Subfamilies? Probably not Complex history of Order More work to be done within families

61. Flatback Turtle What is the correct placement of the flatback? Originally Chelonia depressa Shows characteristics of both Chelonia & Lepidochelys

62. Systematic Controversies Natator depressus – Taxonomic Assignment? Originally Chelonia depressa Actually more closely aligned with Caretta & Lepidochelys – both carnivorous

63. Relationship Between Ridleys Slight external difference between juveniles - only color patterns Kemp’s Ridley Olive Ridley

64. Relationship Between Ridleys Genetics - differences to species level

65. Systematic Controversies Ridleys? Believe it or not! Readily distinguished by color but not morphometrically Atlantic and Pacific species probably isolated due to formation of Isthmus of Panama – caused large changes in recent speciation (e.g. walrus, bottlenose dolphins, etc.

66. Systematic Controversies Dermocheyls coriacea – Ancient lineage? Distinguished from other turtles by: skeletal features partial endothermy modified external morphology Molecular evidence indicates that leatherbacks represent an early offshoot of the lineage that gave rise to extant marine turtles

67. Eretnochelys imbricata – Origin of unusual diet? Appears to have arisen from a carnivorous ancestor Genus closely aligned with Caretta & Lepidochelys – both carnivorous “So, you think you’re sponge-worthy?” - Elaine Benice Systematic Controversies

68. Marine Turtle Hybrids – Turtle Bastards? Loggerhead female – Green male Loggerhead female – Hawksbill male Kemp’s Ridley female – Loggerhead male Green female – Hawksbill male May be oldest vertebrate lineages known to hybridize in nature

69. Why Do We Care? “Well, that's why I asked. That's how you learn, by asking.. you dumbass.” - Carl Carlson Population/species level distinction is critical for efficient management practices International, National, State regulations Cultural uses Economic implications