The Sexual Behaviour of Two Sibling Drosophila Species

Abstract1. The courtship behaviour of Drosophila melanogaster and D. simulans has been studied. Melanogaster is a generally more active species than simulans and its courtship is more vigorous. 2. The sexual behaviour of both types of male can be readily classified into the same basic elements, orientation, wing display, licking and attempted copulation. 3. Simulans males have longer lag periods before courtship, longer bouts of simple orientation, fewer changes of element when courting and their chief wing display is 'scissoring'. Melanogaster's chief wing display is 'vibration'. 4. Experiments in which the sexual stimulus situation was changed show that with lower stimulation melanogaster males show an increased proportion of scissoring, while with increased stimulation simulans males show more vibration. Additional reasons are given for considering scissoring to represent a lower level of sexual excitation than vibration. 5. The differences between the males can be most simply ascribed to simulans having a slower rise of sexual excitation during courtship than melanogaster, not to any changes in the basic organization of their behaviour. This slowed rise may be related to higher thresholds of response in simulans. 6. The females of simulans are more responsive to visual aspects of their males' courtship, and less responsive to those stimuli perceived by their antennae, than are melanogaster females. 7. It is argued that these changes in courtship behaviour probably resulted from selection acting upon a common ancestral population so as to favour high activity in some environments and low activity in others. These changes will be most readily produced by mutations affecting reaction thresholds and the changes to courtship pattern will follow. Selection will then favour females responsive to the most easily available stimuli from the males' courtship. 8. It is suggested that similar situations occur in other sibling Drosophila species and that as a first step in behavioural divergence, mutations affecting thresholds will be particularly important.

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Mate grasping in drosophila pegasa by

Behaviour ◽

10.1163/15685390260136005 ◽

2002 ◽

Vol 139 (4) ◽

pp. 545-572 ◽

Cited By ~ 4

Author(s):

Stephen Pruett-Jones ◽

Matthew Deangelis ◽

Carina Gronlund ◽

Philip Ward ◽

Jerry Coyne

Keyword(s):

Sexual Behavior ◽

Social Environment ◽

Reproductive Biology ◽

Female Choice ◽

Average Duration ◽

Mate Guarding ◽

Drosophila Species ◽

Courtship Behaviour ◽

Evolutionary Changes ◽

Observation Period

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.

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PHOTOCHEMICAL ACTIVITY OF ISOLATED CHLOROPLASTS IN RELATION TO THEIR SOURCE AND PREVIOUS HISTORY

Canadian Journal of Research ◽

10.1139/cjr50c-006 ◽

1950 ◽

Vol 28c (1) ◽

pp. 114-139 ◽

Cited By ~ 28

Author(s):

K. A. Clendenning ◽

P. R. Gorham

Keyword(s):

Magnesium Deficiency ◽

Previous History ◽

Photochemical Activity ◽

Active Species ◽

Filamentous Green Algae ◽

Swiss Chard ◽

Copper Manganese ◽

Lamb’S Quarters ◽

Natural Inhibitors ◽

Low Activity

A survey of the major subdivisions of the plant kingdom revealed photochemical activity in chloroplasts and chloroplast fragments isolated from unicellular and filamentous green algae, liverworts, horsetails, herbaceous monocotyledons, and dicotyledons. Active chloroplasts were not obtained from mosses, ferns, gymnosperms, and woody angiosperms. Among 80 species and varieties tested in Hill solution by the titration method, 45 showed photochemical activity quotients above 100, 19 had quotients above 500, and six (millet, flax, spinach, lamb's-quarters, Swiss chard, and lettuce) showed quotients above 1000. Photochemical activity varied greatly within both genera and species. The majority of the chloroplast suspensions produced acid in darkness when mixed with ferricyanide – ferric oxalate solution. Natural inhibitors of photochemical activity were found in the cell sap and cytoplasm of several species.Chloroplast activity quotients in ferricyanide – ferric oxalate and quinone solutions increased with leaf maturation, and declined with senescence. Chloroplasts isolated from very young green leaves of active species were photochemically inactive. The activity of the chloroplasts was relatively insensitive to the supply of essential mineral nutrients and water as well as to growth temperature. Chloroplasts isolated from leaves showing pronounced symptoms of nitrogen, iron, copper, manganese, or magnesium deficiency had low activity quotients, but remained photochemically active until the leaves were about to die. The observed responses to previous illumination and darkness did not support the hypothesis that a labile photosynthetic intermediate, stored in the chloroplasts, is required for oxygen production after isolation.Chloroplast activity was stabilized for weeks by snap-freezing suspensions containing 0.5 M sucrose and storing at or below −40 °C. Lyophilization did not prevent storage deterioration at higher temperatures.

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EFFECTS OF INTRACRANIAL IMPLANTATION OF OESTRADIOL AND DIHYDROTESTOSTERONE ON THE SEXUAL BEHAVIOUR OF THE LIZARD ANOLIS CAROLINENSIS

Journal of Endocrinology ◽

10.1677/joe.0.0820373 ◽

1979 ◽

Vol 82 (3) ◽

pp. 373-381 ◽

Cited By ~ 33

Author(s):

DAVID CREWS ◽

ABRAHAM MORGENTALER

Keyword(s):

Histological Examination ◽

Sexual Behaviour ◽

Aggressive Behaviour ◽

Preoptic Area ◽

Anolis Carolinensis ◽

Anterior Hypothalamus ◽

Courtship Behaviour ◽

Male Courtship ◽

Sex Structure ◽

Peripheral Plasma

Intrahypothalamic implantation of oestradiol and dihydrotestosterone rapidly restored sexual behaviour in castrated, sexually inactive Anolis carolinensis. Implants in areas other than the anterior hypothalamus-preoptic area failed to elicit sexual behaviour. Male aggressive behaviour was unaffected by intracranial hormone implants. Histological examination of the renal sex segment, a secondary sex structure, gave no indication of leakage into the peripheral plasma. The effectiveness of oestradiol and dihydrotestosterone in inducing male courtship behaviour when administered intracranially was compared with the relative ineffectiveness of systemic injections of these hormones.

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Behaviour of the Koala, Phascolarctos cinereus (Goldfuss), in CAptivity V*. Sexual Behaviour

Wildlife Research ◽

10.1071/wr9800041 ◽

1980 ◽

Vol 7 (1) ◽

pp. 41 ◽

Cited By ~ 14

Author(s):

M Smith

Keyword(s):

Breeding Season ◽

Sexual Behaviour ◽

Courtship Behaviour ◽

Vertical Position ◽

Agonistic Interactions ◽

Phascolarctos Cinereus ◽

Penile Erections ◽

In Captivity

At the height of the breeding season male koalas frequently attempted copulation. These attempts were often apparently spontaneous, but many followed bellowing or agonistic interactions. Sexual behaviour began at 3 y old in males, except for penile erections, which sometimes occurred in younger males. Males performed no courtship behaviour. Behavioural oestrus was brief, and consisted of four distinct types of activity: jerking, bellowing, mild aggression towards the male, and pseudomale behaviour. Oestrous females could become very excited by the presence of a male, and the four activities were very flexible in their expression. Copulation itself was quite brief and consisted of mounting, thrusting, convulsions, and disengagement. The pair were always in a vertical position in a tree, the male grasping the female's neck in his jaws.

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The sexual behaviour of the pygmy newt, Triturus pygmaeus

Amphibia-Reptilia ◽

10.1163/15685380260462310 ◽

2002 ◽

Vol 23 (4) ◽

pp. 393-405

Author(s):

◽

Keyword(s):

Sexual Behaviour ◽

Courtship Behaviour ◽

Direct Response ◽

Static Display ◽

Male Sexual Behaviour ◽

Tail Movement ◽

Spermatophore Transfer ◽

Sexual Encounters ◽

Three Phases

AbstractThe courtship behaviour of pygmy newts, Triturus pygmaeus, consists of three phases: orientation, static display (often not clearly differentiated from each other) and spermatophore transfer. The repertoire of male sexual behaviour consists of nine different movements. Exhibition, an alert posture in which the male advances with small jumps around the female, is the most frequent behaviour. The predominant tail movement is slow fan, in which the tail is softly undulated from approximately 30° to 140°. In contrast to the tail lashes of the large Triturus species, the tail only occasionally beats against the male's flank and never touches the female. Bait mimic tail movements (described for T. boscai as flamenco) are used to attract the female's attention. The duration of sexual encounters was 2203 s on average, in which males displayed in about 81% of this time. Although the courtship of T. pygmaeus shows clear differences from that of its closest relative, T. marmoratus, it should nevertheless be grouped with the larger Triturus species: conspicuous tail movementes are used to attract the attention of the female, but no direct response is required of her to complete the courtship. En el cortejo de los tritones enanos, Triturus pygmaeus, se pueden distinguir tres fases diferentes: fase de orientación, fase de exhibición estática y fase de deposición del espermatóforo. Las dos primeras no se distinguen claramente, sino que frecuentemente se alternan entre sí. Los machos de esta especie realizan nueve pautas diferentes relacionadas con el comportamiento sexual. Entre ellas, destaca la que denominamos exhibición , en la que el macho, en una posición de alerta con todo su cuerpo muy estirado, realiza pequeños saltos alrededor de la hembra. Este comportamiento, que es el que se observa con mayor frecuencia, parece tener un papel importante como señal visual en el cortejo. Otra pauta importante por su frecuencia es la denominada abanico lento, en la que los machos ondulan lentamente su cola, a la vez que abren y cierran el ángulo (que oscila entre 30° y 140°) que ésta forma con su cuerpo. Otra pauta característica es el latigazo corto, un movimiento brusco de la cola similar al de otras especies de tritones, de las que se diferencia porque la cola sólo ocasionalmente alcanza a golpearse contra su propio cuerpo y nunca llega a tocar a la hembra. Se describe en esta especie una pauta de engaño, flamenco, en la que los movimientos de la cola imitan a los de supuestas presas con el fin de atraer rápidamente la atención de la hembra. Esta pauta había sido descrita anteriormente para T. boscai. La duración media de los cortejos fue de 2203 s, en los que el 81% de este tiempo los machos elaboran pautas de cortejo. Aunque el cortejo de T. pygmaeus muestra claras diferencias con la especie próxima, T. marmoratus, se considera que debe ser clasificado en el mismo grupo, entre los tritones de mayor tamaño, en las que el cortejo se caracteriza por el uso de comportamientos muy conspícuos para la atracción de la hembra, y en el que no se requiere un respuesta directa de la hembra para realizar la deposición del espermatóforo.

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Orchiectomy in Testudo species: technical aspects and effect on courtship behaviour

Veterinary Record ◽

10.1136/vr.105095 ◽

2019 ◽

Vol 184 (18) ◽

pp. 555-555 ◽

Cited By ~ 1

Author(s):

Jean-Michel Hatt ◽

Maya Kummrow ◽

Sandra Wenger ◽

Marcus Clauss

Keyword(s):

Seasonal Variation ◽

Body Mass ◽

Sexual Behaviour ◽

Courtship Behaviour ◽

Group Housing ◽

Partial Reduction ◽

Same Sex ◽

Technical Aspects ◽

Testicular Size

Courtship behaviour of tortoises includes biting, ramming, chasing, same-sex sexual behaviour, and it commonly is excessive in European tortoise species kept as pets. As a result, males are kept individually. To assess the effect of orchiectomy on excessive courtship behaviour in European tortoises, 50 tortoises (Testudo graeca, T hermanni and T marginata) underwent endoscopically assisted orchiectomy from April through September 2013 to 2017. Statistical analyses were performed in relation to species, body mass, testicular size and season and owners were invited to fill out a follow-up questionnaire. Body mass of the tortoises ranged from 334 to 2645 g (mean 1056 g) and the age from 5 to estimated 60 years. Testicular length ranged from 1.4 to 7.0 cm (mean 2.7 cm) and testicular mass from 0.6 to 12.6 g (mean 3.9 g). A complete or partial reduction (allowing group-housing) of the excessive courtship behaviour was noted by 95 per cent of owners and 59 per cent of the owners reported a noticeable change of behaviour within a month of surgery. Given the seasonal variation in testicular size, the best period for castrations in male European tortoises is shortly after brumation (April, May), when testes are proportionally smaller.

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Minimal effects of 17β-hydroxy-17α-methyl-estra-4,9,11-triene-3-one (R1881) on sexual behaviour in prepubertally castrated rams

Journal of Endocrinology ◽

10.1677/joe.0.1100481 ◽

1986 ◽

Vol 110 (3) ◽

pp. 481-487 ◽

Cited By ~ 3

Author(s):

R. F. Parrott

Keyword(s):

Sexual Behaviour ◽

Courtship Behaviour ◽

Final Test ◽

Level Of Activity ◽

Genital Development ◽

Courtship Activity ◽

Behavioural Tests ◽

Tongue Flicks

ABSTRACT Ten adult prepubertally castrated rams were injected with 5α-dihydrotestosterone propionate (DHTP; 20 mg/day) for 3 weeks to stimulate genital development. Thereafter, half of the sheep were injected with testosterone (100 mg/day) for a further 4 weeks, while the remainder received the same dose of 17β-hydroxy-17α-methyl-estra-4,9,11-triene-3-one (methyltrienolone; R1881). All the animals were tested for sexual behaviour on 15 occasions with ovariectomized ewes in which oestrous behaviour was induced by injections of 50 μg oestradiol-17β benzoate at 4- to 5-day intervals. Behavioural tests were of 10 min duration and were carried out thrice weekly over a 5-week period, starting in the final week of DHTP treatment. Animals treated with testosterone showed a highly significant increase in courtship behaviour (tongue-flicks; lunges and nudges) after only four daily injections and this level of activity was maintained to the end of the experiment. However, the incidence of courtship activity in sheep treated with R1881 was similar to that recorded during the period of DHTP treatment. All animals given testosterone displayed mounts with pelvic thrusts and erections, and achieved intromission with ejaculation. These activities remained significantly more frequent than in sheep treated with R1881, starting from tests 9, 8 and 12 respectively. Four of the five individuals in the group given R1881 showed occasional mounts with thrusts, three showed sporadic erections and one sheep intromitted in the final test. These results indicate that, in contrast to the rat, R1881 has only very weak effects on sexual behaviour in the castrated ram. J. Endocr. (1986) 110, 481–487

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