--To assess natural variation in ejaculate quality of male Dark-eyed Juncos (Junco hyemalis), as well as to measure any effect of experimental treatment with testosterone (T), we used cloacal massage to collect sperm samples from captive (1993) and free-ranging (1994, 1995) populations. We made three measurements of ejaculate quality in males, approximately half of which had been treated with T...

When ejaculates are costly to produce, males are expected to allocate their ejaculate resources over successive matings in a manner that optimizes their reproductive success and this may have important consequences for their mates. In seed beetles (Coleoptera; Bruchidae), ejaculates vary in size across species from weighing less than 1%, up to as much as 8%, of male body weight. Ejaculates cont...

Objectives: The aim of this prospective study was to observe immunophenotypic patterns in patients with noninflammatory chronic pelvic pain syndrome (Cat IIIB CPPS) for further description and as possible surrogate markers for diagnosis and treatment. Methods: Eighty-eight patients with a referral diagnosis of chronic prostatitis underwent fractionated urinary cultures including expressed prost...

Males of the bedbug, Cimex lectularius, traumatically inseminate females by inserting a needle-like intromittent organ (penis) through the female's abdominal wall after she has fed. We demonstrate that: (i) mating duration determines ejaculate size; (ii) a female's first copulation in a bout of copulations always lasts longer than subsequent copulations; (iii) the intromittent organ bears sensi...

Food availability in the environment is often low and variable, constraining organisms in their resource allocation to different life-history traits. For example, variation in food availability is likely to induce condition-dependent investment in reproduction. Further, diet has been shown to affect ejaculate size, composition and quality. How these effects translate into male reproductive succ...

In promiscuous species, male reproductive success depends on their ability to mate with fertile females and on the fertilizing ability of their sperm. In such species, theory predicts that, owing to a trade-off between pre- and post-copulatory reproductive traits, males with lesser access to females should increase resource investment into those sperm traits that enhance fertilization success-u...

Sperm are the most diverse cell type known: varying not only among- and within- species, but also among- and within-ejaculates of a single male. Recently, the causes and consequences of variability in sperm phenotypes have received much attention, but the importance of within-ejaculate variability remains largely unknown. Correlative evidence suggests that reduced within-ejaculate variation in ...