Dear colleagues,
My co-authors and I are pleased to announce the publication of a new paper:
Orbach
DN, Marshall CD, Würsig B, Mesnick SL. 2016. Variation in female reproductive tract morphology of the common bottlenose dolphins (Tursiops truncatus). The Anatomical Record. 299:520-537. DOI: 10.1002/ar.23318
ABSTRACT
Cetaceans exhibit vaginal folds, unusual protrusions of the vaginal wall
into the vaginal lumen. Inconsistent terminology and a lack of
anatomical landmarks in the literature have hindered comparative studies
of the form and function of vaginal folds. Our objectives are to: (1)
develop a standardized measurement protocol for the reproductive tracts
of female cetaceans, (2) assess variation in morphometrics within the
common bottlenose dolphin (Tursiops truncatus), and (3)
determine if vaginal muscle is skeletal, and therefore of somatic origin
in this species. We selected 15 measurements to characterize female
reproductive tracts and evaluated variability using fresh or
frozen-thawed specimens from southeastern USA representing a range of
sexual maturity states and reproductive states (n = 18 specimens).
Presence of skeletal muscle and variation in the density of muscle
banding were assessed using 90 histological samples (n = 5 specimens).
Analyses of the gross morphological data revealed that the dolphins
generally had one large vaginal fold that bisected the vaginal lumen.
Vaginal morphology was similar for sexually mature and immature
specimens and across reproductive states. The histological data revealed
that the vaginal musculature consisted of smooth muscle, consistent
with other mammals, leading us to conclude that vaginal contractions are
likely under autonomic rather than somatic control. No differences were
found in the density of smooth muscle banding among vaginal regions or
sexual maturity states. Our systematic protocol lays the foundation for
evaluating the function (e.g., sexual selection, natural selection) and
evolution of vaginal folds.
Cheers,
Dara Orbach, Ph.D.
Marine Mammal Behavioral Ecology Group
Department of Marine Biology