All recorded subdivisions were active during jaw adduction, although onset times and activity durations differed among them. Bite force ranged from 1 to 93 N at the most anterior bite point, and

from 3 to 258 N at the most posterior bite point. Mechanical advantage, in lever and posterior out lever, as well as the DAPT cross-sectional area of the majority of the adductor mandibulae subdivisions scaled with isometry; consequently bite force at both bite points also scaled with isometry. Bite force in S. barracuda increased in proportion to total length during ontogeny, which may be associated with a piscivorous diet throughout its life. When compared to other fishes, values of bite force in S. barracuda are among the lowest relative to its body size. “
“Ansell’s mole-rat, Fukomys anselli, is a social subterranean mammal and exhibits an Opaganib molecular weight extreme reproductive division of labour. Reproduction

in the colony is restricted usually to a single female. Complete colonies captured throughout an entire calendar year were euthanased and the histology of the gonads and plasma hormone concentrations were measured in reproductive and non-reproductive members of both sexes. In males, the circulating levels of testosterone were significantly higher in the reproductive male than the non-reproductive males. The mean testes mass for the reproductive males corrected for body mass was not significantly greater than that of the non-reproductive male. Similarly, the mean testes volume of reproductive males was not greater than that for the non-reproductive males but the seminiferous tubule diameter was Dichloromethane dehalogenase significantly greater in the reproductive males than the non-reproductive males. Reproductive females characteristically possessed corpora lutea of ovulation and pregnancy in their ovaries and this was met with much higher progesterone concentrations in the reproductive females 34 nmol/L compared with 4 nmols/L in the non-reproductive females. In contrast, non-reproductive females showed a complete range of follicular genesis,

but they did not possess corpora lutea of ovulation or pregnancy, in turn they show depressed progesterone concentrations. The current evidence suggests that in Ansell’s mole-rats, the non-reproductive males and females refrain from sexual activity by being subordinate and moreover, related to the breeding pair. “
“Small isolated populations often show lower genetic variability. Demographic bottlenecks lead to loss of genetic variation too. Arctic foxes (Vulpes lagopus) have been isolated since the Pleistocene on Mednyi and Bering Islands (Commander Islands). In 1970–1980, the Mednyi population passed through a severe bottleneck due to a mange outbreak. Previous studies showed lack of genetic diversity in the contemporary Mednyi population that could be due to the long history of isolation and/or the recent bottleneck.

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