Redescription of Micaria beaufortia (Araneae, Gnaphosidae), with notes on Afrotropical Micaria

Three species of Micaria Westring, 1851 are known to occur in the Afrotropical Region, two from Namibia and one from South Africa. All three species are known from a single sex only, either from the male (M. tersissima Simon, 1910) or from the females in the case of M. beaufortia (Tucker, 1923) and M. chrysis (Simon, 1910). In this paper, we redescribe the female of M. beaufortia and describe the previously unknown male of this species. This species has pseudosegmented tarsi and complex scopula formed by two paired rows of setae; these characters are unknown in other Micaria. The setae covering the legs in M. beaufortia are briefly described and the scopula is compared with that of M. fulgens (Walckenaer, 1802). A paired mating plug, previously unknown in Micaria, is documented in M. beaufortia. It was found that M. chrysis and M. tersissima, considered in the World Spider Catalog (2017) as endemics of Namibia, were actually described from Northern Cape Province, South Africa. The taxonomic position of these two species is briefly commented on and distribution records of all three species are mapped.

OCCURRENCE OF ANOESTRUS IN MICE CAGED IN GROUPS

SUMMARY When female mice were caged in groups of thirty, regular oestrous cycles did not occur in the majority of animals. The vaginal smears of these mice were mucified and some remained so for 40 days. Cycles promptly returned when the mice were caged individually. The ovaries of the grouped mice were significantly lighter than those of individually housed controls, although the body weights were not different. Fewer of the grouped animals had tubal ova and corpora lutea were absent from, or atrophic in, some of the ovaries. A decidual reaction was obtained in only one of ninety animals following trauma of the endometrium. When grouped mice were subsequently paired, mating occurred 3 nights later in 53%. When females were caged singly the occurrence of mating was distributed more evenly over the first 4 nights. Regular oestrous cycles did not occur in blind mice while they were grouped or in mice when they were separated by partitions in the cage. It is concluded that anoestrus occurs when mice are grouped and results from a depression of pituitary gonadotrophic function. This depression is independent of mutual visual or tactile stimuli.