In several mammalian species, lactating females show blunted neural, hormonal, and behavioral responses to stressors. It is not known whether new fathers also show stress hyporesponsiveness in species in which males provide infant care. To test this possibility, we determined the effects of male and female reproductive status on stress responsiveness in the biparental, monogamous California mouse (Peromyscus californicus).Breeding (N=8 females, 8 males), nonbreeding (N=10 females, 10 males) and virgin mice (N=12 females, 9 males) were exposed to a 5-min predator-urine stressor at two time points, corresponding to the early postpartum (5–7 days postpartum) and mid/late postpartum (19–21 days postpartum) phases, and blood samples were collected immediately afterwards. Baseline blood samples were obtained 2 days prior to each stress test. Baseline plasma corticosterone (CORT) concentrations did not differ among male or female groups. CORT responses to the stressor did not differ among female reproductive groups, and all three groups showed distinct behavioral responses to predator urine. Virgin males tended to increase their CORT response from the first to the second stress test, while breeding and nonbreeding males did not. Moreover, virgin and nonbreeding males showed significant behavioral changes in response to predator urine, whereas breeding males did not. These results suggest that adrenocortical responses to a repeated stressor in male California mice may be modulated by cohabitation with a female, whereas behavioral responses to stress may be blunted by parental status.

Descriptions of three known species of Cynura, i.e., C. cerambus, C. klunderi and C. papillata, are given, including SEM micrographs of C. cerambus and a tabular compendium for all species of the genus. The phylogenetic relationships of C. klunderi are inferred from molecular data. Bayesian analyses of small subunit (SSU) of rRNA sequences support a position nested among the Plectidae suggesting the secondary simplification in the morphology of pharyngeal valvular apparatus in Cynura and the 'return' from a terrestrial to a marine environment in this genus.

A population of Placodira lobata from the USA is described using both light and scanning electron microscopy and compared with the descriptions of the type specimens of the same species. The phylogenetic relationships of the species are inferred from molecular data and places P. lobata in a clade that unites genera with mostly simple morphology of the labial region, like Cephalobus, Acrobeloides, Heterocephalobellus and Metacrobeles, but also includes species of Zeldia and Chiloplacus.A sample containing specimens of P. lobata was collected by the first author during a desert sampling trip in 2006. Since the number of recovered specimens was too low (only a few adults were found), the same locality was revisited in 2009 and more specimens were recovered from soil. Nematodes were extracted by a modified tray extraction method and fixed in 4% formaldehyde for morphological studies and DESS (Yoder et al., 2006) for molecular analysis. For LM, specimens were transferred to pure glycerin by a slow evaporation method and mounted on permanent slides in glycerin with paraffin as support for the cover slip. For SEM studies, some specimens were postfixed in 1% osmium tetroxide (OsO 4 ) and transferred to pure acetone through an acetone/distilled water series. Specimens were critical point dried in liquid CO 2 , mounted on stubs, gold-plated under vacuum to a thickness of 200 Å using a sputter coater, and examined in a Hitachi S-4300 SEM at an accelerating voltage of 10 kV.