title: First approximation to congenital malformation rates in embryos and hatchlings of sea turtles.
abstract: BACKGROUND
  Congenital malformations in sea turtles have been considered sporadical. Research carried out in the Mexican Pacific revealed high levels of congenital malformations in the olive ridley, but little or no information is available for other species. We present results from analyses of external congenital malformations in olive ridley, green, and hawskbill sea turtles from Mexican rookeries on the Pacific coast and Gulf of Mexico.
  
  
  METHODS
  We examined 150 green and hawksbill nests and 209 olive ridley nests during the 2010 and 2012 nesting seasons, respectively. Olive ridley eggs were transferred to a hatchery and incubated in styrofoam boxes. Nests from the other two species were left in situ. Number of eggs, live and dead hatchlings, and eggs with or without embryonic development were registered. Malformation frequency was evaluated with indices of prevalence and severity.
  
  
  RESULTS
  Mortality levels, prevalence and severity were higher in olive ridley than in hawksbill and green sea turtles. Sixty-three types of congenital malformations were observed in embryos, and dead or live hatchlings. Of these, 38 are new reports; 35 for wild sea turtles, three for vertebrates. Thirty-one types were found in hawksbill, 23 in green, and 59 in olive ridley. The head region showed a higher number of malformation types. Malformation levels in the olive ridley were higher than previously reported.
  
  
  CONCLUSIONS
  Olive ridleys seem more prone to the occurrence of congenital malformations than the other two species. Whether the observed malformation levels are normal or represent a health problem cannot be currently ascertained without long-term assessments.
authors.affiliation: Centro de Investigación en Alimentación y Desarrollo, Mazatlán, Sinaloa, Mexico.
authors.forename: Annelisse
authors.initials: A
authors.lastname: Bárcenas-Ibarra
authors.forename: Horacio
authors.initials: H
authors.lastname: de la Cueva
authors.forename: Isaias
authors.initials: I
authors.lastname: Rojas-Lleonart
authors.forename: F Alberto
authors.initials: FA
authors.lastname: Abreu-Grobois
authors.forename: Rogelio Iván
authors.initials: RI
authors.lastname: Lozano-Guzmán
authors.forename: Eduardo
authors.initials: E
authors.lastname: Cuevas
authors.forename: Alejandra
authors.initials: A
authors.lastname: García-Gasca
mesh_terms: D000818:Animals; D000013:Congenital Abnormalities; D004625:Embryo, Nonmammalian / Q000002:abnormalities*; D005260:Female; D060851:Gulf of America; D008297:Male; D014426:Turtles / Q000002:abnormalities*
keywords: congenital malformations; endangered species; hatching success; mortality; sea turtles