scholarly journals Female ornamentation and the fecundity trade-off in a sex-role reversed pipefish

2018 ◽  
Author(s):  
Kenyon B. Mobley ◽  
John R. Morrongiello ◽  
Matthew Warr ◽  
Diane Bray ◽  
Bob B. M. Wong
Keyword(s):  
Body Size ◽  
Egg Size ◽  
Sex Role ◽  
Relative Fitness ◽  
Reproductive Value ◽  
Female Fecundity ◽  
Body Width ◽  
Trade Off ◽  
Female Ornamentation ◽  
Female Ornaments

AbstractFemale ornaments are a rare occurrence in nature. One explanation for this is that female ornaments are costly to produce and maintain and, therefore, females must trade-off resources related to reproduction to promote ornament expression. Here, we investigate the potential trade-off between female ornamentation and fecundity in the sex-role reversed, wide-bodied pipefish, Stigmatopora nigra. We measured two components of the female ornament, body width and stripe thickness, and tested the relationship between these ornaments and female fecundity and the mean egg size. Both body width and stripe thickness were strongly and positively related to female body size. After controlling for the influence of body size, we found no evidence of a cost of belly width or stripe thickness on female fecundity. Rather, females that have larger ornaments have higher fecundity and thus a greater relative fitness advantage. However, larger females suffered a slight decrease in egg size, consistent with a potential trade-off between egg size and body size, although no relationship between egg size and ornaments was observed. Our results suggest that larger S. nigra females accurately advertise their reproductive value to males, and underscore the importance of investigating the potential mechanisms that promote and maintain honesty of female ornaments.

scholarly journals Female ornamentation and the fecundity trade-off in a sex-role reversed pipefish

2018 ◽  
Vol 8 (18) ◽  
pp. 9516-9525 ◽  
Author(s):  
Kenyon B. Mobley ◽  
John R. Morrongiello ◽  
Matthew Warr ◽  
Dianne J. Bray ◽  
Bob B. M. Wong
Keyword(s):  
Sex Role ◽  
Trade Off ◽  
Female Ornamentation

scholarly journals Determinants of life-history traits in a fish ectoparasite: a hierarchical analysis

Parasitology ◽  
2011 ◽  
Vol 138 (7) ◽  
pp. 848-857 ◽  
Author(s):  
G. LOOT ◽  
N. POULET ◽  
S. BROSSE ◽  
L. TUDESQUE ◽  
F. THOMAS ◽  
...  
Keyword(s):  
Life History ◽  
Body Size ◽  
Egg Size ◽  
Life History Traits ◽  
Abiotic Factors ◽  
Individual Characteristics ◽  
Trade Off ◽  
Individual Fitness ◽  
Parasite Number ◽  
Egg Number

SUMMARYObjective. Unravelling the determinants of parasite life-history traits in natural settings is complex. Here, we deciphered the relationships between biotic, abiotic factors and the variation in 4 life-history traits (body size, egg presence, egg number and egg size) in the fish ectoparasite Tracheliastes polycolpus. We then determined the factors affecting the strength of the trade-off between egg number and egg size. Methods. To do so, we used 4-level (parasite, microhabitat, host and environment) hierarchical models coupled to a field database. Results. Variation in life-history traits was mostly due to individual characteristics measured at the parasite level. At the microhabitat level (fins of fish hosts), parasite number was positively related to body size, egg presence and egg number. Higher parasite number on fins was positively associated with individual parasite fitness. At the host level, host body size was positively related to the individual fitness of the parasite; parasites were bigger and more fecund on bigger hosts. In contrast, factors measured at the environmental level had a weak influence on life-history traits. Finally, a site-dependent trade-off between egg number and egg size existed in this population. Conclusion. Our study illustrates the importance of considering parasite life-history traits in a hierarchical framework to decipher complex links between biotic, abiotic factors and parasite life-history traits.

Female reproductive characteristics of the Balkan wall lizard (Podarcis taurica) in the northwestern periphery of its range

2010 ◽  
Vol 5 (3) ◽  
pp. 391-395 ◽  
Author(s):  
Katarina Ljubisavljević ◽  
Georg Džukić ◽  
Miloš Kalezić
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Breeding Season ◽  
Egg Size ◽  
Reproductive Traits ◽  
Species Range ◽  
Trade Off ◽  
Female Body Size ◽  
Female Reproductive Traits ◽  
Gravid Females

AbstractWe present data on the female reproductive traits of the Balkan wall lizard in the Deliblato Sand, a large continental sandland in the Pannonian area in the northwestern periphery of the species range. The clutch and egg characteristics of the population were investigated on the basis of clutches laid in laboratory conditions by gravid females captured in one locality. Balkan wall lizards produced at least two clutches in a breeding season. Individual females laid clutches of commonly two (range 1–4) eggs. The female body size had no effect on clutch and egg size. There was no trade-off between egg size and clutch size.

scholarly journals Why are sexually selected weapons almost absent in females?

2013 ◽  
Vol 59 (4) ◽  
pp. 564-568 ◽  
Author(s):  
Anders Berglund
Keyword(s):  
Sex Roles ◽  
Sex Role ◽  
Sharp Contrast ◽  
Trade Off ◽  
Sexually Selected Traits ◽  
Direct Benefits ◽  
Female Ornaments ◽  
Males And Females ◽  
Selected Traits ◽  
Predator Defence

Abstract In sex role reversed species, predominantly females evolve sexually selected traits, such as ornaments and/or weapons. Female ornaments are common and their function well documented in many species, whether sex role reversed or not. However, sexually selected female weapons seem totally absent except for small wing spurs in three jacana species, present in both males and females. This poor female weaponry is in sharp contrast to the situation in species with conventional sex roles: males commonly have evolved sexually selected weapons as well as ornaments. At the same time, females in many taxa have naturally selected weapons, used in competition over resources or in predator defence. Why are sexually selected weapons then so rare, almost absent, in females? Here I briefly review weaponry in females and the function of these weapons, conclude that the near absence of sexually selected weapons begs an explanation, and suggest that costs of sexually selected weapons may exceed costs of ornaments. Females are more constrained when evolving sexually selected traits compared to males, at least compared to those males that do not provide direct benefits, as trait costs reduce a female’s fecundity. I suggest that this constraining trade-off between trait and fecundity restricts females to evolve ornaments but rarely weapons. The same may apply to paternally investing males. Whether sexually selected weapons actually are more costly than sexually selected ornaments remains to be investigated.

scholarly journals I'm sexy and I glow it: female ornamentation in a nocturnal capital breeder

2015 ◽  
Vol 11 (10) ◽  
pp. 20150599 ◽  
Author(s):  
Juhani Hopkins ◽  
Gautier Baudry ◽  
Ulrika Candolin ◽  
Arja Kaitala
Keyword(s):  
Female Size ◽  
Female Fecundity ◽  
Male Preference ◽  
Sexual Signal ◽  
Sexual Ornaments ◽  
Female Ornamentation ◽  
Female Ornament ◽  
Female Ornaments ◽  
Capital Breeder ◽  
Male Mate

In many species, males rely on sexual ornaments to attract females. Females, by contrast, rarely produce ornaments. The glow-worm ( Lampyris noctiluca ) is an exception where wingless females glow to attract males that fly in search of females. However, little is known about the factors that promote the evolution of female ornaments in a sexual selection context. Here, we investigated if the female ornament of the glow-worm is a signal of fecundity used in male mate choice. In support of this, we found brightness to correlate with female fecundity, and males to prefer brighter dummy females. Thus, the glow emitted by females is a reliable sexual signal of female fecundity. It is likely that male preference for the fecundity-indicating ornament has evolved because of large variation among females in fecundity, and because nocturnal males cannot directly assess female size and fecundity. These results indicate that female ornamentation may evolve in capital breeders (i.e. those in which stored resources are invested in reproduction) when females vary significantly in fecundity and this variation cannot be assessed directly by males.

Static allometry suggests female ornaments in the long-tailed dance fly (Rhamphomyia longicauda) are not deceptive

2021 ◽  
Author(s):  
Jessica H Browne ◽  
Darryl T. Gwynne
Keyword(s):  
Body Size ◽  
Prey Capture ◽  
Hind Femur ◽  
Positive Allometry ◽  
Female Ornamentation ◽  
Female Ornaments ◽  
Ornamental Traits ◽  
Steep Slopes ◽  
Dance Fly ◽  
Static Allometry

Abstract Despite their prevalence in nature, the evolution of sex-specific female ornaments is still not well understood. Although in some cases (often carotenoid-based ornaments) they appear to honestly signal quality, such as fecundity, it has been suggested that some female ornaments have evolved to deceptively to obtain matings. We address these two hypotheses in the long-tailed dance fly ( Rhamphomyia longicauda ), where females possess two sex-specific ornaments: pinnate scales on the hind femur and tibia and abdominal sacs that are inflated in female-biased display swarms. Although several studies have suggested that female ornaments in this species are deceptive, evidence is mixed and requires further investigation. Here, we use static allometry (with body size as a proxy for condition) of both ornamental and non-ornamental traits in females (and homologous non-ornamental traits in males) in order to determine whether they are honest or deceptive signals of quality. Most male traits scaled isometrically with body size, however male leg hairs showed positive static allometry, probably because they are involved in nuptial-prey capture or in grasping mates. Ornamental traits in females (abdomen area and tibia scale length) showed significant positive allometry and had steep slopes relative to non-ornamental traits. As larger females invest more in ornamentation relative to smaller females, this suggests that these traits are likely honest, condition-dependent signals of quality. We note that honesty and deception are not mutually exclusive hypotheses. Individuals may vary in their signalling strategy, resulting in, for example, deception from some low condition individuals but honesty overall. Although our finding of positive allometry makes it unlikely this occurs in long tailed dance flies, simultaneous honesty and deception should be considered in future studies of female ornamentation.

An association between ear and tail morphologies of bats and their foraging style

2011 ◽  
Vol 89 (2) ◽  
pp. 90-99 ◽  
Author(s):  
James D. Gardiner ◽  
Jonathan R. Codd ◽  
Robert L. Nudds
Keyword(s):  
Body Size ◽  
Foraging Strategy ◽  
Aerodynamic Performance ◽  
Variance Analysis ◽  
Flight Performance ◽  
Wing Membrane ◽  
Trade Off ◽  
Scaling Relationships ◽  
Membrane Morphology ◽  
Foraging Flight

Most studies relating bat morphology to flight ecology have concentrated on the wing membrane. Here, canonical variance analysis showed that the ear and tail morphologies of bats also strongly relate to foraging strategy, which in turn is correlated with flight style. Variations in tail membrane morphology are likely to be a trade-off between increases in the mechanical cost of flight and improvements in foraging and flight performance. Flying with large ears is also potentially energetically expensive, particularly at high flight speeds. Large ears, therefore, are only likely to be affordable for slow foraging gleaning bat species. Bats with faster foraging flight styles tend to have smaller ears, possibly to cut the overall drag produced and reduce the power required for flight. Variations in the size of ears and tail membranes appear to be driven primarily by foraging strategy and not by body size, because the scaling relationships found are either weak or not significant. Ear size in bats may be a result of a trade-off between acoustic and aerodynamic performance.

Effect of two microalgae concentrations on body size and egg size of the rotifer Brachionus calyciflorus

Biologia ◽  
2008 ◽  
Vol 63 (3) ◽  
Author(s):  
Abdolmohammad Kennari ◽  
Nasrollah Ahmadifard ◽  
Maryam Kapourchali ◽  
Jafar Seyfabadi
Keyword(s):  
Body Size ◽  
Population Growth ◽  
Egg Size ◽  
Scenedesmus Obliquus ◽  
Exponential Phase ◽  
The Body ◽  
Brachionus Calyciflorus ◽  
Food Level ◽  
Chlorella Sp ◽  
Rotifer Brachionus Calyciflorus

AbstractThe rotifer, Brachionus calyciflorus, was grown with two algae species (Chlorella sp. and Scenedesmus obliquus) at different concentrations (0.1, 1 and 10 × 106 cells ml−1). The body size (lorica biovolume) of individual rotifer and their egg size were measured when the populations were roughly in the exponential phase of population growth. The body size of the rotifers differed significantly (P < 0.05) among the two algae species used, however this effect was not observed for egg size. The body size of rotifers fed on higher densities of Chlorella sp. (10 × 106 cells ml−1) was significantly larger than for those fed on lower and medium densities (0.1 and 1 × 106 cells ml−1). Body size and egg size of rotifers fed with different amounts of Scenedesmus did not differ significantly. The egg size was significantly larger at higher food level of Chlorella. A significantly positive correlation was observed between the adult rotifer body size and their egg size.

Zebrafish (Danio rerio) and the egg size versus egg number trade off: effects of ration size on fecundity are not mediated by orthologues of the Fec gene

2010 ◽  
Vol 22 (6) ◽  
pp. 1015 ◽  
Author(s):  
Erin L. Forbes ◽  
Craig D. Preston ◽  
P. Mark Lokman
Keyword(s):  
Danio Rerio ◽  
Egg Size ◽  
Egg Quality ◽  
Quantitative Polymerase Chain Reaction ◽  
Gonadosomatic Index ◽  
Hatching Rate ◽  
Mrna Levels ◽  
Trophic Conditions ◽  
Trade Off ◽  
Ration Size

Few studies have demonstrated plasticity of egg size within the confines of an egg size–number trade-off in response to trophic conditions in fishes. Moreover, the physiological mechanisms that govern this plasticity are not known. Growth differentiation factor 9 (Gdf9) and bone morphogenetic factor 15 (Bmp15) are oocyte-specific factors implicated in follicular growth and ovulation in mammals. In order to investigate whether expression levels of these genes were correlated with ration-dependent changes in fecundity in fish, zebrafish (Danio rerio) were subjected to four different feeding regimens. Counts of spawned eggs or vitellogenic follicles were used to estimate fecundity, whereas quantitative polymerase chain reaction analyses were performed to determine Gdf9 and Bmp15 mRNA levels in response to changes in ration size. Both relative fecundity and gonadosomatic index increased significantly with increased ration size, whereas egg size and hatching rate decreased significantly. No significant differences in Gdf9 or Bmp15 transcript abundance were evident between feeding regimens, suggesting that these growth factors do not govern fecundity in fish. However, favourable trophic conditions markedly affected follicle or egg size and number, with important implications for downstream egg quality and survival.

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