Oviductal fluid counterbalances the negative effect of high temperature on sperm in an ectotherm model.

Global warming is affecting biodiversity; however, the extent to which animal reproductive processes respond to predicted temperature increments remains largely unexplored. The thermal environment has a pronounced impact on metabolic rates of ectotherms; therefore, an interesting question to assess is whether temperature increase might affect specific reproductive mechanisms like sperm performance in ectotherms. Moreover, in many species, oviductal fluid (OF) is known to regulate and maintain sperm quality; however, the role of OF in relation to the effects of high temperature on sperm remains unclear. Our aim was to experimentally test the effect of increased temperature on sperm velocity, swimming path and percentage of motility in neutral conditions at ejaculation (without OF) and in female's reproductive tract fluid (with OF), in a social ectotherm lizard model, Tropidurus spinulosus, which has specific thermal requirements for reproduction. Our results suggest that a rising temperature associated with global warming (+4°C) affects negatively sperm dynamics and survival. However, OF ameliorated the harmful effects of high temperature. This is an important point, as this study is the first to have tested the role of OF in preserving sperm from a warmer pre-fertilization environment. These results contribute to our understanding of how thermal environment changes might affect post-copulatory reproductive mechanisms. This article has an associated First Person interview with the first author of the paper.

Sexual dichromatism and color diversity in the spiny lava lizard Tropidurus spinulosus using lizard visual modelling.

Colors are important vehicles for social signals in many taxa. In Squamata, previous studies have linked color characteristics and chromatic diversity to sexual selection and, particularly, species showing male-biased body size dimorphism also showed male-biased dichromatism and color diversity. Sexual dichromatism may occur in body regions used for conspecific communication and it may be expressed at wavelengths, such as ultraviolet, easily perceivable by conspecifics. We tested this prediction in a social lizard model, Tropidurus spinulosus, using spectrophotometry and visual modelling which enable colors to be interpreted as the individuals of the same taxon see them. Our results indicate that sexual dichromatism occurs in the ventral regions and the flanks, which are the body regions involved in sexual displays. Males show greater color diversity, having larger color volumes and more contrasting colors. These findings reinforce the idea that sexual selection towards males is coupled with the evolution of male-biased, diverse, coloration which could act as a signal in social reproductive contexts.

Audiological outcomes in patients with congenital aural atresia implanted with transcutaneous active bone conduction hearing implant.

OBJECTIVES: The objective of this study is to evaluate the safety and efficacy of the transcutaneous Bone Conduction Implant, the Bonebridge, in patients with congenital aural atresia. METHODS: Audiometry, speech recognition test and free field audiometry were performed. Word recognition scores and speech perception was evaluated using Spanish phonetically-balanced disyllables word list. RESULTS: Fourteen subjects were implanted with the Bonebridge (seven bilateral placements). The study cohort comprised seven males and seven females aged from 3 to 17 years (mean age 9.76yrs). All patients accepted and benefited from the implanted Bonebridge system. The pre-operative PTA4 was 66.4 dB (64.2-68.6, 95-%CI) and improved after activation to 19.2 dB (16.9-21.5, 95%CI), resulting in a mean functional gain of 47,2 dB. Regarding speech discrimination, the pre-operative outcomes of the disyllabic measurements were 34.3% and for monosyllables 27.4%. Following activation the speech discrimination improved to 98.6% and 97.9%, respectively. No infections or adverse device related effects occurred in patient group. CONCLUSION: We have concluded that the Bonebridge implant is an innovative solution for patients with conductive or mixed hearing loss and unilateral loss suffering from congenital atresia. Different surgical techniques may be used for implant placement, based on the patient's anatomy. Studies show improved functional gain, better speech perception, and lower rates of percutaneous complications associated with this implant.

Sperm motility parameters to evaluate the seminal quality of Boa constrictor occidentalis, a threatened snake species.

Semen quality analysis constitutes a powerful tool to evaluate the fertility potential of males in threatened species. The Argentine boa constrictor or lampalagua (Boa constrictor occidentalis) is a threatened snake species and has been included in Appendix I of CITES. The objective of this work is to characterize the sperm of B. c. occidentalis on the bases of dynamic parameters to improve this species conservation. Dynamic parameters were measured in sperm samples using videomicroscopy and image analysis software. The sperm population showed a high degree of heterogeneity in velocity parameter values and 95% of the cells showed a linear pattern of movement. Studies in other species indicate that the number of motile spermatozoa and their movement speed is directly correlated with fertilization success. This work will help to establish basic parameter values for the evaluation of the reproductive potential of populations of B. c. occidentalis and to resolve questions referred to its reproductive strategies.

Electroejaculation in the Chinchilla (Chinchilla lanigera): effects of anesthesia on seminal characteristics.

Repetitive electroejaculation is probably extremely stressful in conscious animals and could adversely affect fertility. The present study was designed to (a) evaluate the effects of anesthesia (40 mg ketamine/kg body weight, i.m.) on a method of electroejaculation used previously in conscious chinchillas (Chinchilla lanigera), and (b) determine the quality of the electroejaculated semen obtained under anesthesia. In Experiment 1 (8 animals), a 4 x 4 Latin square design was used to study the effects of anesthesia and ejaculatory voltage on semen collection, ejaculate volume, sperm concentration, motility, viability, response to the hypoosmotic swelling test (HOST), and acrosomal status. In Experiment 2 (12 animals), the effects of differing voltages and the number of stimuli on ejaculation by conscious or anesthetized males was determined. In both experiments, all the conscious animals ejaculated, but only 60% ejaculated under anesthesia and they required more stimuli and higher voltages to achieve ejaculation. Ejaculate volume was significantly lower in anesthetized (<5 microl) than in conscious animals (>40 microl), but sperm concentration was unaffected. None of the indices of sperm quality were affected by anesthesia. The techniques we have developed in anesthetized domestic chinchillas should be applicable to endangered chinchillas in the wild, and though the number of sperm available is reduced, there are still sufficient for assisted reproduction.