THE SECONDARY SEX CHARACTERS AND REPRODUCTIVE BEHAVIOR OF GONADECTOMIZED STICKLEBACKS TREATED WITH METHYL TESTOSTERONE

1963 ◽  
Vol 41 (4) ◽  
pp. 611-628 ◽  
Author(s):  
Evelyn Hui Wai ◽  
William S. Hoar

Treatment of intact juvenile or gonadectomized adult male and female stickle-backs with methyl testosterone, either by immersion in dilute solutions or by implantation of pellets into the body cavity, induces male secondary sex characters. The effect, as quantified by measurements of the height of the brush border tubules in the mesonephros, is the same in both sexes and reaches a maximum in 3 to 4 weeks. Both the gonadectomized males and females develop prespawning aggressive and territorial behavior if maintained 4 or 5 weeks under long-day photoperiods (16-hour day alternating with 8-hour darkness). Such behavior does not appear under a short photoperiod. The administration of methyl testosterone does not intensify aggressive behavior in either the 8-hour or 16-hour photoperiod fish. The combined effects of long photoperiods and methyl testosterone induces nest-building behavior (characteristic of normal breeding males) in 50% to 60% of the castrated males and about 6% of the gonadectomized females. The behavior of the treated males is qualitatively and quantitatively similar to naturally matured fish but that of the females shows differences. Although male sexual behavior may also be induced in androgen treated castrates it has not been observed in the females under comparable experimental procedures.

Author(s):  
M. Barson

Clarias gariepinus were collected from Lake Chivero, Zimbabwe, and examined for nematode parasites from November 2000 to May 2002. Of the 202 specimens collected, 42.6 % were infected with third-stage larvae of Contracaecum sp. in the body cavity. The intensity of the infection was 1-7 worms per fish (mean intensity = 2.2). Seasonal variation in the prevalence of the parasite was not obvious and there was no significant difference in the prevalence of infection between males and females (c2 = 2.228; P > 0.05). No significant relationship between host size and prevalence was established. There was also no significant relationship between intensity and the body condition factor (r = 0.11; P > 0.05). The low parasite prevalence may have been caused by the disruption of the infection cycle since piscivorous birds, which are the final hosts of the parasite, do not feed on C. gariepinus in Lake Chivero.


1971 ◽  
Vol 33 (1) ◽  
pp. 119-125 ◽  
Author(s):  
Edward Clifford

Body-satisfaction and self-satisfaction scales based on the work of Secord and Jourard (1953) were given to 146 male and 194 female adolescents ranging in age from 11 through 19 yr. Response tendencies of males and females are significantly different, females expressing more dissatisfaction with themselves and their bodies than do males. The expression of body- and self-satisfaction was not related to age for this range. Despite differences in response tendencies, male and female adolescents tended to react to body- and self-satisfaction items in a similar fashion. For both sexes the same degree of relative dissatisfaction was expressed for those aspects of the body experience associated with growth, namely, height, weight, and physique. It is also suggested that the relative expression of dissatisfaction with height, weight, chest, waist, and hips may reflect cultural factors associated with concerns with weight gain in an affluent society, rather than concerns with stylized standards of beauty.


1998 ◽  
Vol 76 (10) ◽  
pp. 1815-1821 ◽  
Author(s):  
W J Loughry ◽  
Paulo A Prodöhl ◽  
Colleen M McDonough ◽  
W S Nelson ◽  
John C Avise

We used microsatellite DNA markers to identify the putative parents of 69 litters of nine-banded armadillos (Dasypus novemcinctus) over 4 years. Male and female parents did not differ in any measure of body size in comparisons with nonparents. However, males observed paired with a female were significantly larger than unpaired males, although paired females were the same size as unpaired females. Females categorized as possibly lactating were significantly larger than females that were either definitely lactating or definitely not lactating. There was no evidence of assortative mating: body-size measurements of mothers were not significantly correlated with those of fathers. Nine-banded armadillos give birth to litters of genetically identical quadruplets. Mothers (but not fathers) of female litters were significantly larger than mothers of male litters, and maternal (but not paternal) body size was positively correlated with the number of surviving young within years, but not cumulatively. There were no differences in dates of birth between male and female litters, nor were there any significant relationships between birth date and maternal body size. Body size of either parent was not correlated with the body sizes of their offspring. Cumulative and yearly reproductive success did not differ between reproductively successful males and females. Average reproductive success (which included apparently unsuccessful individuals) also did not differ between males and females. The majority of adults in the population apparently failed to produce any surviving offspring, and even those that did usually did so in only 1 of the 4 years. This low reproductive success is unexpected, given the rapid and successful range extension of this species throughout the southeastern United States in this century.


2011 ◽  
Vol 9 (2) ◽  
pp. 355-362 ◽  
Author(s):  
Fabrício Barreto Teresa ◽  
Eliane Gonçalves-de Freitas

We described the reproductive behavior of the small South American cichlid Laetacara araguaiae in streams from Brazil. We predicted that this species will show reproductive cooperation and division of labor between males and females in a similar way presented by other substrate-spawner cichlids. Thus, we studied 34 pairs in the pre-spawning (n = 11), egg/wriggler (n = 11) and fry (n = 12) phases. In the pre-spawning phase both sexes become involved in nest building and territorial defense, but females emphasizes building nest (p = 0.03), while males invest more time in territorial defense (p = 0.04). After spawning, male and female alternate between rearing eggs and defending nest in the territory. In the egg/wriggler phase females devotes more time rearing the brood while males remain defending territory (p = 0.02). These differences disappear when young are in the fry stage, and parents jointly stay closer to fry (p = 0.98). However, at this phase, there is a reduction in the frequency of threats shown by males (p<0.01) and an increase in the frequency of attacks shown by female (p<0.01) that could be a response to an increased demand for parental defense. Our results indicate that the reproductive cooperation between males and females of L. araguaiae is marked by division of labor in the early reproductive phases and by sharing of parental duties as brood develops.


1960 ◽  
Vol 8 (2) ◽  
pp. 181 ◽  
Author(s):  
J Robb

The internal anatomy of Typhlops shows a number of interesting features which support the hypothesis that the typhlopids are wrongly classified among the Ophidia, and that they should either be given subordinal rank, equivalent to the Sauria and the Serpentes, or be made an infra-order of the Sauria. The alimentary, vascular, respiratory, and reproductive systems are described in detail for the first time. The most striking peculiarities occur in the respiratory and reproductive systems. Unlike most snakes, Typhlops has two functional lungs, one occupying most of the anterior third of the body cavity, and the other smaller one lying immediately behind it. All the pulmonary blood vessels are well developed. The male reproductive organs are solid, grooved, protrusible structures, each of which is contained within a connective tissue sheath in the postanal region. These organs are unlike the hemipenes of any snake or lizard of which a description can be found. Both male and female animals possess a large cloaca1 gland in the postanal region. There are also several uncommon features in the alimentary and vascular systems.


1979 ◽  
Vol 7 (2) ◽  
pp. 153-156 ◽  
Author(s):  
Roger C. Bailey ◽  
Norman E. Hankins

The Somatotype Rating Scale (SRS) was administered to 35 male and 35 female college students. The SRS allowed subjects to rate their own body build, their wished-for body build, and the body build of the typical and ideal male and female. While there was close agreement between males and females on the measures, females exhibited more dissatisfaction with their body build and greater congruency between their self-concept and their same-sex stereotype than did males. Results were discussed as possibly revealing the emergence of a mesomorphic body build ideal in both sexes.


2020 ◽  
Vol 11 (01) ◽  
Author(s):  
Ekta Melkani ◽  
Manju Mehta

Most of the families of a village Mangali in Hisar block of Haryana are involved in production of wooden beads for decades. The production process is a joint effort made by both male and female members of the family. However the works done by male members start from procurement of wood to making of beads till their marketing whereas women work to string the beads for whole days and give them finishing looks for selling in not more than 50-100 rupees per day that too only if work is available in abundance. Even the male members only get a limited selling price as all the benefits are secured by the middlemen. The women also face physiological hazards and musculo-skeletal discomforts for doing all the works sitting on floor in a bending posture. The plight of the women is so high that even after the long day seasonal field works, they are sitting over floors in a bent posture which is causing them discomforts over the body for next many days. The activities performed by the women which are related to beads are numerous in nature like jewellery, crafts, etc, and hence the postures. Squatting and cross legged are the major postures that are observed among the women in forward-bent condition and which cause them further musculo-skeletal disorders. A workstation having the facilities regarding back support, eye-level works, wrist support, storage and light requirements is suggested. The multipurpose workstation can help the women to healthy work not for the bead works only but also for other housing chores to speed the activities and enhance the productivity.


1972 ◽  
Vol 61 (3) ◽  
pp. 463-484 ◽  
Author(s):  
J. R. Williams

Physcus seminotus Silv. (properly P. sp. nr. seminotus Silv.) and P. subflavus Annecke & Insley (Aphelinidae) are parasites of the sugar-cane scale insect Aulacaspis tegalensis (Zhnt.) (Diaspididae) in East Africa and they have been purposely introduced into Mauritius where A. tegalensis is an important pest. P. seminotus has brachypterous, flightless females and P. subflavus winged females but their biology is essentially similar. The parasites are arrhenotokous and fertilised and unfertilised eggs are deposited in different sites concomitant with development of female and male larvae on different primary hosts. Female larvae develop endoparasitically in A. tegalensis from fertilised eggs deposited in the host's body cavity. Male larvae develop ectoparasitically on immature Hymenoptera in A. tegalensis from unfertilised eggs deposited in the air-filled cavity of the latter's integumentary remnant. The males of the two Physcus spp. are therefore hyperparasitic and they frequently develop on the immature stages, both male and female, of their own kind (autoparasitism). Unfertilised eggs are laid by virgin females and also by mated females, the latter being able to deposit fertilised and unfertilised eggs at will, depending on the egg site encountered. Sexual dimorphism occurs at all stages, including the deposited egg. The preovipositional adult is the preferred stage of A. tegalensis for deposition of fertilised eggs and development of females is most rapid in such hosts. Development in young hosts is arrested until the hosts have grown to virtually their full size. The host of a male is apparently a matter of chance in so far as evelopment will occur on larval and pupal Hymenoptera of various species found in the empty, inflated, brittle integument of parasitised A. tegalensis. Only one individual, whether male or female, develops per host. Oviposition behaviour of mated females is such that superparasitism is largely avoided but it is liable to occur frequently when virgin females oviposit. Adult females will feed on the body fluids of A. tegalensis that are released by insertion of the ovipositor and also on sugary fluids. They live a month or more, ovipositing continually at a gradually decreasing rate, and laying usually 50–100 eggs.


Zootaxa ◽  
2019 ◽  
Vol 4560 (1) ◽  
pp. 164
Author(s):  
DANIARA COLPANI ◽  
CESAR JOÃO BENETTI ◽  
NEUSA HAMADA

Gyrinus rhyssonotum sp. n. is described and illustrated based on adult males and females collected in Barcelos County, Amazonas state, Brazil. The new species belongs to the subgenus Oreogyrinus Ochs, 1935 and it is compared with Gyrinus (Oreogyrinus) fittkaui Ochs, 1963 and G. (O.) opalinus Régimbart, 1883, both occurring in the Brazilian Amazonas and G. (O.) colombicus Régimbart, 1883 and G. (O.) venezolensis Ochs, 1954, these two latter alien to the Brazilian fauna but with which G. (O) rhyssonotum sp. n. seems to be more closely related, though the new species can be distinguished from both by a series of characteristics, mainly observed in the body shape, elytra, pronotum, and in male and female genitalia. 


2020 ◽  
Author(s):  
Arodí P. Favaris ◽  
Amanda C. Túler ◽  
Weliton D. Silva ◽  
Sérgio R. Rodrigues ◽  
Walter S. Leal ◽  
...  

AbstractCyclocephalini beetles of genus Cyclocephala (Coleoptera: Melolonthidae: Dynastinae) use flowers of some plants as food, shelter, and mating stands. However, little is known about floral scent chemistry involved in this interaction. Here we show that a sesquiterpene alcohol mediates attraction of Cyclocephala paraguayensis Arrow on bottle gourd flowers, Lagenaria siceraria (Curcubitaceae). Both males and females started to aggregate on flowers at twilight; after that, mating began and remained for the entire night. The major constituent of the airborne volatiles from L. siceraria was fully characterized as (3S,6E)-nerolidol, which elicited electroantennographic responses on male and female antennae. Field bioassays showed that traps baited with the natural stereoisomer or a mix of nerolidol isomers captured significantly more males and females of C. paraguayensis than control traps. Analysis from the gut content of these Cyclocephalini beetles showed the presence of pollen, suggesting that they also use bottle gourd flowers for their nourishment. Taken together, these results suggest that (3S,6E)-nerolidol plays an essential role in the reproductive behavior of C. paraguayensis by eliciting aggregation, mating, and feeding.


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