Turtles regularly move between backwaters and the main river channel, which highlights the likely disturbance from backwater detachment, a water saving practice in the lower Murray River. “
“In terrestrial animals with rigid protective structures, the ability to upright
after being overturned can make the difference between life and death, especially in suboptimal thermal conditions or in the presence of predators. This trait is assumed to be under strong selection. Different factors can influence righting ability, body dimensions and body mass for instance. As selleck chemical these morphological traits diverge among populations, inter-population variability in righting ability is expected. Previous studies on tortoises were performed within single populations and they usually
focused on juveniles raised in captivity, precluding an assessment of the AUY-922 purchase inter-population variability in a natural (realistic) context. In the current study, we quantified the righting performance in four populations of free-ranging adult tortoises. We found strong differences in righting success among populations and between genders, suggesting possible adaptations to local conditions. For instance, the topography (e.g. slopes) of each study site varied markedly. On average, males were more successful in righting themselves than females. Body size did not influence righting performances in males, but larger females were less successful compared to smaller ones. MCE The success in righting was positively correlated with carapace domedness (height) and short bridges. “
“Pectoral fin loss
is a dramatic evolutionary phenomenon that has occurred independently in different teleost lineages. Here, we report the first case of pectoral fin loss in the Mastacembelidae (Teleostei: Synbranchiformes), with the discovery of a new species of mastacembelid from Lake Tanganyika (LT), Mastacembelus apectoralis sp. nov. M. apectoralis can be distinguished from all other mastacembelid species by its complete loss of pectoral-fin rays, distal pectoral radials and pectoral radials, as well as a reduction in pectoral girdle elements that include smaller and less well-developed coracoid and minute scapular bones. Other distinguishing characteristics include a near absence of scales, lack of pigmentation and the presence of well-developed adductor muscles. A previous multigene phylogeny of mastacembelids placed M. apectoralis sp. nov. within the LT species flock, having diverged from its sister species Mastacembelus micropectus∼4.5 million years ago. M. micropectus also shows a reduction in the size of its pectoral fin and endoskeletal girdle, and has largely cartilaginous pectoral radials and a reduced number of pectoral-fin rays. Here, we compare the pectoral girdle of M. apectoralis and M. micropectus with LT and non-LT African mastacembelids. M.