Reproductive Biology and Sexual Behavior

Behaviour ◽  
2002 ◽  
Vol 139 (4) ◽  
pp. 545-572 ◽  
Author(s):  
Stephen Pruett-Jones ◽  
Matthew Deangelis ◽  
Carina Gronlund ◽  
Philip Ward ◽  
Jerry Coyne

AbstractAmong all species in the genus Drosophila whose sexual behavior has been studied, D. pegasa is unique in that males exhibit no courtship behaviour before they mount females. Instead, the male simply climbs on top of the female and rides on her abdomen ('grasping') for long intervals, often an entire 8-h observation period. In this study we conducted a series of observations and experiments to quantitatively describe grasping behaviour in D. pegasa and examine its relationship to social environment and the reproductive biology of the species. All observed courtship bouts involved grasping behavior, and males always initiated copulation during a grasping bout. The frequency of grasping and the average duration of a single grasping bout increased with the number of flies present. Males often copulated several times during a single grasping bout, and such multiple copulations during a single mounting also appear unique in the genus. Unexpectedly, the number of sperm that a male transferred to a female during a single grasping bout was negatively correlated with the number of copulations. This relationship was apparently due to repeated copulations by males who were unsuccessful at transferring sperm. Multiple copulations without sperm transfer may result from cryptic female choice. Male grasping behaviour in this species appears to have evolved as a substitute for display and courtship behaviours, but possibly also as a mate-guarding behaviour since males continue to grasp after they have successfully transferred sperm. The tarsal claws and pulvillar pads of D. pegasa are disproportionately larger than those of related Drosophila species, evolutionary changes that may facilitate grasping by males.


Author(s):  
Alan N. Hodgson

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.


2004 ◽  
Vol 171 (4S) ◽  
pp. 429-429
Author(s):  
Masayoshi Nomura ◽  
Naohiro Fujimoto ◽  
Donald W. Pfaff ◽  
Sonoko Ogawa ◽  
Tetsuro Matsumoto

2000 ◽  
Vol 16 (3) ◽  
pp. 147-149 ◽  
Author(s):  
Martin Grann

Summary: Hare's Psychopathy Checklist - Revised (PCL-R; Hare, 1991 ) was originally constructed for use among males in correctional and forensic settings. In this study, the PCL-R protocols of 36 matched pairs of female and male violent offenders were examined with respect to gender differences. The results indicated a few significant differences. By means of discriminant analysis, male Ss were distinguished from their female counterparts through their relatively higher scores on “callous/lack of empathy” (item 8) and “juvenile delinquency” (item 18), whereas the female Ss scored relatively higher on “promiscuous sexual behavior” (item 11). Some sources of bias and possible implications are discussed.


2011 ◽  
Vol 16 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Hanneke de Graaf ◽  
Ine Vanwesenbeeck ◽  
Liesbeth Woertman ◽  
Wim Meeus

This review examines associations between parenting styles and the psychosexual development of adolescents. Methods and results of empirical studies of associations between parental support, control, and knowledge and the sexual behavior and sexual health of adolescents are described and evaluated. The results show that, in general, higher scores on support, control, and knowledge relate to a delay of first sexual intercourse, safer sexual practices, and higher sexual competence. Despite the vast amount of literature on this subject, the majority of these studies focus on single dimensions of parenting and unidirectional parenting influences. This review generates hypotheses regarding interactions of different parenting styles and reciprocal associations between parents and their children. There is a need for more dynamic, dialectical studies of parenting, and children’s sexual development.


1984 ◽  
Vol 39 (11) ◽  
pp. 1324-1325
Author(s):  
Saul Rosenzweig
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document