Of the determining factors of copulation duration across arthropods, I reviewed variance in forest millipedes. The objective was to calculate duration. null hypothesis mean and were independent body mass. Copulation standard deviation squared for 4 populations millipedes seen literature. correlated with it’s (r=0.95, r2=0.90, n=5, p=0.01). Durations ranged from C. anulatus (34.9 minutes) inscri...

Males in many taxa are known to exhibit behavioural plasticity in response to the perceived intensity of sperm competition, reflected in Drosophila melanogaster by increased copulation duration following prior exposure to a rival. We tested the prediction that males do not adjust their copulation effort in response to the presence of a competitor in Drosophila species where there is little or n...

urethra from compression during copulation. Consistent with a role in mechanical support, certain primates and carnivore species that have prolonged copulation also have a longer baculum. A role in female stimulation also seems likely, particularly in species where copulation is prolonged with multiple intromissions, thrusting or multiple ejaculations. Copulatory stimulation can have important ...

The nematode, Mehdinema alii, occurs in the alimentary canal of the decorated cricket Gryllodes sigillatus. Adult nematodes occur primarily in the hindgut of mature male crickets, whereas juvenile nematodes are found in the genital chambers of mature male and female crickets. Here, we present experimental evidence for the venereal transmission of M. alii in G. sigillatus. Infectivity experiment...

Microinjection of apomorphine into the ventral tegmental area (VTA) of male rats was previously shown to delay the onset of copulation and slow its rate, presumably by stimulating impulse-regulating autoreceptors on cell bodies of the A10 mesocorticolimbic dopamine tract. Such stimulation would be expected to slow the firing rate of these neurons and, thereby, to impair locomotion and/or motiva...

Steroid hormones prime neural circuits for sexual behavior, in part by regulating enzymes, receptors, or other proteins affecting neurotransmitter function. Dopamine facilitates male sexual behavior in numerous species and is released before and/or during copulation in three integrative neural systems. The nigrostriatal system enhances readiness to respond; the mesolimbic system promotes many a...

In a wide variety of animal species, females produce vocalizations just before, during, or immediately after copulation. Observational and experimental evidence indicates that these copulation calls are sexually selected traits, functioning to promote competition between males for access to the calling female. In this paper, we present an acoustic analysis of variation in the form of copulation...