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This article presents a study on skull and mandible alterations in Amazon river dolphins, specifically focusing on the genus Inia spp. The researchers examined 105 specimens and identified various morphological, traumatic, and pathological alterations. The most common alterations observed were the presence of a third condyle and rostrum deviation. Interestingly, the study found no significant differences in the occurrence of these alterations based on sex, sexual maturity, or habitat. The study also identified cases of prognathism, brachygnathism, fractures, and pathological changes such as osteomyelitis and osteoarthritis. The researchers suggest that further research is needed to understand the causes and implications of these skull alterations. [Extracted from the article]

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The article analysis the sexual maturity in captive Amazonian manatees. Topics discussed include use of anatomical observations for evaluating sexual maturity in aquatic mammals; benifits of measuring sex steroid hormones such as testosterone and progesterone for determining sexual maturity in aquatic mammals; and relationship between age, body length and weight in captive Amazonian manatees.

The Amazonian manatee (Trichechus inunguis) is a threatened aquatic mammal endemic to the Amazon basin. The aim of this study was to evaluate the urinary and salivary reproductive hormone levels of captive Amazonian manatees collected during two seasons of the year. Salivary samples from four males and urinary and salivary samples from three females were collected during two seasons (March-June and September-November) over two consecutive years. Salivary testosterone in males was measured by radioimmunoassay and reproductive hormones in females (salivary progesterone and oestradiol and urinary progestogens, oestrogens and luteinising hormone) were measured by enzyme immunoassay. The data were analysed in a 2x2 factorial design, where the factors were year and season. There was no effect of year or season for salivary testosterone. All female hormones showed a seasonal effect (higher hormone levels during March-June than September-November) or an interaction between year and season (P < 0.05). These results strongly indicate the existence of reproductive seasonality in Amazonian manatees; however, apparently only females exhibit reproductive quiescence during the non-breeding season. Further long-term studies are necessary to elucidate which environmental parameters are related to reproductive seasonality in T. inunguis and how this species responds physiologically to those stimuli. The Amazonian manatee is a threatened aquatic mammal endemic to the Amazon basin and the species is a seasonal breeder. The aim of this study was to evaluate the effect of the season on the reproductive hormone levels of captive Amazonian manatees. Different from males, all female hormones levels showed seasonal variation. The results strongly suggest the existence of reproductive seasonality in Amazonian manatees, even in captive conditions; however, apparently only females exhibit reproductive quiescence during the non-breeding season. [ABSTRACT FROM AUTHOR]

Simple Summary: Assisted reproduction techniques are potentially important tools for the creation of gene banks largely focused on preserving female germ cells and tissues, cryopreservation being one of the most important. Since there is not yet a protocol established for the preservation of cat ovarian tissue, we decided to assess our cryopreservation protocol with autotransplantation of the ovary. Our study showed that even though follicular survival was low, follicles were able to survive up to 28 days of transplantation and develop up to the antral stage, which helps elucidate the path for preservation of felid ovaries. Once this technique is improved, it may contribute to the preservation of wild feline species. The aim of this study was to assess a slow-freezing protocol of cat ovarian tissue cryopreservation using autotransplantation. Four adult queens were ovariohysterectomized and the ovaries were fragmented and cryopreserved. After one week, the grafts were thawed and autografted to the subcutaneous tissue of the dorsal neck of each queen, then randomly removed after 7, 14, 28, 49, and 63 days after transplantation. Percentages of morphologically normal primordial and growing follicles (MNFs) were 88% and 97%, respectively, in fresh tissue samples (fresh controls), and 74% and 100%, respectively, immediately after thawing (cryo D0). No MNFs were found after 49 days of transplantation. In both fresh control and cryo D0 fragments, granulosa cells were frequently in proliferation. Two morphologically normal antral follicles were detected in one queen on Day 28 post-transplantation. Connective tissue fibers increased, suggesting replacement of active ovarian cortex by fibrous tissue. Tissue vascularization was observed at 7 days after grafting, and wide blood vessels were clearly visible on Days 49 and 63. In conclusion, although follicular survival was low after cryopreservation and grafting of cat ovarian tissue, follicles were able to develop up to the antral stage, which is an encouraging outcome. [ABSTRACT FROM AUTHOR]