title: Signals of vitellogenesis and estrus in female hawksbill turtles.
abstract: This study reports a viable means of identifying the vitellogenic cycle and limited estrus period in hawksbill turtles for the purposes of developing captive breeding program, based on the combination of blood metabolite parameters (triglyceride, total protein, and calcium levels), feeding status, and ovary condition. Follicle size of two focal captive females showed clear seasonal changes, with major development occurring between March and May (19.0-24.4 mm), and exceeding 25 mm between June and September. Triglyceride, total protein, and calcium levels dropped with follicular development and maintenance (March to October), and then began to rise when follicular retraction occurred from October onwards. The two focal turtles reduced food intake during intensive follicular development (April to May). These findings suggest that blood metabolite parameters and feeding conditions are inferred by the vitellogenic cycle. An additional 10 females exhibiting follicular development were mated with a single male for 7-day period between May and June. Follicle size was measured immediately prior to pairing, and a statistically significant difference in follicle size of 10 females was recorded between the seven failed (20.9 mm) and three successful (23.6 mm) mating events. This indicates follicle development is essential to successful mate and monitoring of vitellogenic cycle may help improve the success rates of captive hawksbill breeding programs.
authors: 1 Okinawa Churashima Foundation, 888 Ishikawa, Motobu, Okinawa 905-0206, Japan.
authors: Isao
authors: I
authors: Kawazu
authors: Masakatsu
authors: M
authors: Kino
authors: Makio
authors: M
authors: Yanagisawa
authors: Konomi
authors: K
authors: Maeda
authors: Ken
authors: K
authors: Nakada
authors: Yasuhiro
authors: Y
authors: Yamaguchi
authors: Yutaka
authors: Y
authors: Sawamukai
mesh_terms: D000818:Animals; D001798:Blood Proteins; D002118:Calcium / Q000097:blood; D003247:Conservation of Natural Resources; D004971:Estrus / Q000502:physiology*; D005260:Female; D008297:Male; D010053:Ovary / Q000502:physiology; D013997:Time Factors; D014280:Triglycerides / Q000097:blood; D014426:Turtles / Q000502:physiology*; D014818:Vitellogenesis / Q000502:physiology*
chemical_list: D001798:Blood Proteins; D014280:Triglycerides; D002118:Calcium
keywords: feeding condition; follicle size; follicular development; mating; plasma metabolite concentrations