Two cases of pseudohermaphroditism in loggerhead sea turtles Caretta caretta

Morphometric Study of the Eyeball of the Loggerhead Turtle (Caretta caretta) Using Computed Tomography (CT)

The short bibliography referring to the anatomy and pathology of the eyeball of turtles poses a challenge for veterinarians and conservationists given the increasing presence of this type of turtle in veterinary and wildlife centres. Although they nest on land, these animals spend a large part of their lives in the ocean, which entails a series of eye adaptations such as well-developed nictitating membranes, palpebral scales, highly sensitive corneas, or sclerotic rings to protect the eye. In our study, we performed a morphometric analysis of the loggerhead turtle (Caretta caretta) eyeball and its internal structures using advanced imaging techniques such as computed tomography (CT). To the best of the authors’ knowledge, there have been no studies published that describe the CT intraocular measurements of presumed normal loggerhead turtle eyes.

Using reproductive technologies to assess the development of secondary sexual characteristics, ovarian senescence and hermaphroditism in the endangered mountain yellow-legged frog Rana muscosa

Anurans can display a host of intriguing sexual syndromes, including hermaphroditism and sex reversal. Using a multifaceted approach for diagnosing and characterising hermaphroditism in the endangered anuran species Rana mucosa , we tracked changes in female reproductive status using hormone monitoring, ultrasound examinations, individual life history, fertilisation records and post-mortem findings. Seven individuals originally sexed as females developed secondary male sexual characteristics, behaviour and hormone profiles and, in some cases, had testicular tissue despite having previously laid eggs. Our results suggest that reproductive technologies can shed light on life history patterns and reproductive anomalies that may affect endangered anuran survival.

Developmental asynchrony and antagonism of sex determination pathways in a lizard with temperature-induced sex reversal

Vertebrate sex differentiation follows a conserved suite of developmental events: the bipotential gonads differentiate and shortly thereafter sex specific traits become dimorphic. However, this may not apply to squamates, a diverse vertebrate lineage comprising of many species with thermosensitive sexual development. Of the three species with data on the relative timing of gonad differentiation and genital dimorphism, the females of two (Niveoscincus ocellatus and Barisia imbricata) exhibit a phase of temporary pseudohermaphroditism or TPH (gonads have differentiated well before genital dimorphism). We report a third example of TPH in Pogona vitticeps, an agamid with temperature-induced male to female sex reversal. These findings suggest that for female squamates, genital and gonad development may not be closely synchronised, so that TPH may be common. We further observed a high frequency of ovotestes, a usually rare gonadal phenotype characterised by a mix of male and female structures, exclusively associated with temperature-induced sex reversal. We propose that ovotestes are evidence of a period of antagonism between male and female sex-determining pathways during sex reversal. Female sexual development in squamates is considerably more complex than has been appreciated, providing numerous avenues for future exploration of the genetic and hormonal cues that govern sexual development.

Reproductive Disorders and Perinatology of Sea Turtles

Sea turtles' reproductive disorders are underdiagnosed, but potentially, there are several diseases that may affect gonads, genitalia, and annexes. Viruses, bacteria, and parasites may cause countless disorders, but more frequently the cause is traumatic or linked to human activities. Furthermore, veterinary management of the nest is of paramount importance as well as the care of newborns (also in captivity). This article gives an overview on the methods used to manage nests and reproductive activities of these endangered chelonians species.