Evolution of sexual dimorphism in the plateau brown frog fails to obey Rensch’s rule

Rensch’s rule describes sexual size dimorphism (SSD) that decreases with increasing body size when females are larger than males and SSD that increases when males are larger than females. The plateau brown frog Rana kukunoris, a species endemic to the eastern Tibetan Plateau, exhibits female-biased size dimorphism. Using data on body size from 26 populations and age from 21 populations, we demonstrated that SSD did not increase with increasing mean female snout-vent length (SVL) when controlling for sex-specific age structure, failing to support the Rensch’s rule. Thus, we suggest that fecundity selection (favouring large female size) balances out sexual selection (favouring large male size), which results in a similar divergence between males and females body size. In addition, sex-specific age differences explained most of the variation of SSD across populations.

Rumour – and (Dis)-Unities of Blackness: A Reading of Globalization in Mia Couto’s The Last Flight of the Flamingo

This article examines how Mia Couto uses representations of rumour in his novel The Last Flight of the Flamingo (2004) as a literary medium for interrogating detachment and/ or attachment of the cultural object/ subject of blackness to modern institutions of Africa and the West through the idea of globalization. The article uses the qualitative research methodology for interrogating the efficacy of the representations of rumour in portraying the idea of globalisation. Through textual analysis, the article examines how the author uses the detached large male sexual organ, discovered outside Tizangara, an imagined remote Mozambican town, to encapsulate the rumour about the cases of some missing United Nations peacekeeping soldiers to the fictionalized idea of globalisation. The United Nations’ commissioned inquiry on the missing soldiers precipitates a parading of the local, national and the international delegation around the severed male sexual organ.

Blue Cod, Parapercis Colias, Maturity, Fecundity, Sex Change, and Potential Drivers of Sex Ratio in The Marlborough Sounds

<p>Blue cod, Parapercis colias (Pinguipedidae), are widely considered to be the most important recreational finfish species in the South Island. However, blue cod have been declining in abundance in the Marlborough Sounds for many years, and currently, sex ratios are highly male- biased. Blue cod are believed to be a socially structured hermaphroditic species whose populations are prone to local depletion. A potting survey in the Marlborough Sounds was carried out by NIWA in 2013, and along with environmental measurements, 3247 blue cod were measured, weighed, sexed, and stage of sexual maturity was classified macroscopically at sea. Gonads from a subsample of these fish were removed and preserved. In Chapter Two, the preserved gonads were processed histologically and a species-specific histological maturity key was developed. Histological and macroscopic maturity classifications and length-at-maturity estimates were compared. Additionally, estimates of spawning frequency and batch fecundity were made using histological and gravimetric methods. In Chapter Three, possible drivers of sex ratio were investigated using the survey data. Density, large male influence, and environmental factors were considered. In Chapter Four, the feasibility of using digital imaging software to age blue cod otoliths was investigated using the OtolithM application in ImagePro Premier. There was poor agreement between macroscopic and histological maturity classifications (20%, overall). Macroscopic methods overestimated the proportion of mature fish at length in the larger sample, which led to biased length-at-50% maturity (L₅₀) estimates. Macroscopic L₅₀ estimates differed markedly from histology estimates. Using histological data, male L₅₀ was 26 cm TL. Histology indicated that there was no length at which 100% of females were mature. Therefore, a three-parameter capped logistic model was used. Histologically, female L₅₀ was 23.6 cm TL, and the Cap was 0.78, indicating the proportion of mature females reached an asymptote at 0.78. Spawning frequency was 4.6 days, and mean relative batch fecundity was 6.5 hydrated oocytes per gram body weight (SD = 3.3). Hermaphroditism was confirmed for blue cod and was macroscopically identifiable. The analyses in Chapter Three indicated that density had some effect on sex ratio, and large males influenced local sex ratios. Finally, the imaging software could not accurately estimate age compared to an expert reader, and it produced highly variable age estimates. This research found that the macroscopic maturity classifications for blue cod were inaccurate, and revision of the macroscopic key is suggested. The biased estimates of L₅₀ from macroscopic data could lead to biased estimates of spawning stock biomass (SSB). Batch fecundity was markedly lower than the previously reported estimates. The finding of a macroscopically identifiable hermaphroditic stage suggested that ‘hermaphrodite’ should be added as a sex class in the macroscopic key. From the GLM in Chapter Three, in more dense populations, the proportion of males increased. This may have been from changes to male mating strategies, or density may influence the occurrence of primary and secondary males. Finally, areas with males > 45 cm TL had a higher proportion of females, suggesting that large males should be protected in order to help balance sex ratios.</p>

Blue Cod, Parapercis Colias, Maturity, Fecundity, Sex Change, and Potential Drivers of Sex Ratio in The Marlborough Sounds

<p>Blue cod, Parapercis colias (Pinguipedidae), are widely considered to be the most important recreational finfish species in the South Island. However, blue cod have been declining in abundance in the Marlborough Sounds for many years, and currently, sex ratios are highly male- biased. Blue cod are believed to be a socially structured hermaphroditic species whose populations are prone to local depletion. A potting survey in the Marlborough Sounds was carried out by NIWA in 2013, and along with environmental measurements, 3247 blue cod were measured, weighed, sexed, and stage of sexual maturity was classified macroscopically at sea. Gonads from a subsample of these fish were removed and preserved. In Chapter Two, the preserved gonads were processed histologically and a species-specific histological maturity key was developed. Histological and macroscopic maturity classifications and length-at-maturity estimates were compared. Additionally, estimates of spawning frequency and batch fecundity were made using histological and gravimetric methods. In Chapter Three, possible drivers of sex ratio were investigated using the survey data. Density, large male influence, and environmental factors were considered. In Chapter Four, the feasibility of using digital imaging software to age blue cod otoliths was investigated using the OtolithM application in ImagePro Premier. There was poor agreement between macroscopic and histological maturity classifications (20%, overall). Macroscopic methods overestimated the proportion of mature fish at length in the larger sample, which led to biased length-at-50% maturity (L₅₀) estimates. Macroscopic L₅₀ estimates differed markedly from histology estimates. Using histological data, male L₅₀ was 26 cm TL. Histology indicated that there was no length at which 100% of females were mature. Therefore, a three-parameter capped logistic model was used. Histologically, female L₅₀ was 23.6 cm TL, and the Cap was 0.78, indicating the proportion of mature females reached an asymptote at 0.78. Spawning frequency was 4.6 days, and mean relative batch fecundity was 6.5 hydrated oocytes per gram body weight (SD = 3.3). Hermaphroditism was confirmed for blue cod and was macroscopically identifiable. The analyses in Chapter Three indicated that density had some effect on sex ratio, and large males influenced local sex ratios. Finally, the imaging software could not accurately estimate age compared to an expert reader, and it produced highly variable age estimates. This research found that the macroscopic maturity classifications for blue cod were inaccurate, and revision of the macroscopic key is suggested. The biased estimates of L₅₀ from macroscopic data could lead to biased estimates of spawning stock biomass (SSB). Batch fecundity was markedly lower than the previously reported estimates. The finding of a macroscopically identifiable hermaphroditic stage suggested that ‘hermaphrodite’ should be added as a sex class in the macroscopic key. From the GLM in Chapter Three, in more dense populations, the proportion of males increased. This may have been from changes to male mating strategies, or density may influence the occurrence of primary and secondary males. Finally, areas with males > 45 cm TL had a higher proportion of females, suggesting that large males should be protected in order to help balance sex ratios.</p>

Does recent experience affect large male advantage in a sequentially-mating fish?

In many mating systems, large male body size is associated with dominance in direct contests with rivals and females may exhibit preference for larger males. As such, body size is often positively associated with mating success. However, mating experience can influence the potential advantage of large body size through alterations in behaviour and depletion of sperm reserves. In Japanese medaka (Oryzias latipes), males mate with many females each day, and larger males mate more frequently than smaller males. In an observational experiment, we tested the following alternate predictions: (1) recent mating experience may enhance mating success through a carry-over effect of prior mating, whereby small experienced males gain an advantage over large inexperienced rivals in mating contests; or (2) recent mating experience decreases mating success through a reduction in fertilization due to sperm limitation, effectively dampening the large-male advantage against a small inexperienced rival. We examined the interactive effect of size and recent experience on mating behaviour and success. While mating contests were monopolized by large males, recent experience enhanced mating success, especially in small male winners. Experienced males courted more readily than those without recent experience, suggesting that recent prior mating enhances this behaviour. Furthermore, males who had copulated recently did not exhibit sperm depletion when in the presence of a competitor, nor did female behaviour indicate a preference for inexperienced males. This suggests that males can use sexual experience to increase their reproductive success in future mating situations, which may influence the action of sexual selection and alternative tactics in shaping mating systems.

A Review of the Association of Bladder and Prostate Cancers with Schistosoma Species

Introduction: Schistosomiasis is an infection caused by the deposition of large male and female worms (trematodes) in the bladder veins. Infection caused by this trematode is also known as bilharziasis. The disease has been or continues to be present in African countries and some Asian countries such as Iran, Iraq, Syria, Lebanon, Saudi Arabia, southern Portugal, Greece, and especially Egypt. The entry of Schistosoma haematobium heads into the skin begins with local symptoms, known as swimmers itch, and is more common in people who are in some form of contact with ambient water. The infection affects the kidneys, ureters, bladder and genitals. In endemic geographical areas, schistosomiasis has been implicated as an etiological factor in the pathogenesis of bladder, colon and kidney cancers, especially bladder cancer occurring in such geographical locations almost two decades earlier than in non-native areas. The urinary type of this disease can also cause prostate cancer. Material and Methodes: In this study, the websites of PubMed, Google Scholar and Embase were searched and related articles were reviewed. Results: In this study, the effects of host endocrine system, hormonal imbalance caused by schistosomiasis, as well as the effect of epigenetic changes in the host genome on this parasitic infection and its association with bladder cancer were investigated. The association of schistosome egg soluble antigens with prostate carcinogenesis was also noted. Conclusion: Studies show that schistosomiasis can lead to bladder cancer. But there was not adequate evidence available for prostate cancer and this parasitic infection.

Body size, sex and high philopatry influence the use of agricultural land by Galapagos giant tortoises

As agricultural areas expand, interactions between wild animals and farmland are increasing. Understanding the nature of such interactions is vital to inform the management of human–wildlife coexistence. We investigated patterns of space use of two Critically Endangered Galapagos tortoise species, Chelonoidis porteri and Chelonoidis donfaustoi, on privately owned and agricultural land (hereafter farms) on Santa Cruz Island, where a human–wildlife conflict is emerging. We used GPS data from 45 tortoises tracked for up to 9 years, and data on farm characteristics, to identify factors that influence tortoise movement and habitat use in the agricultural zone. Sixty-nine per cent of tagged tortoises used the agricultural zone, where they remained for a mean of 150 days before returning to the national park. Large male tortoises were more likely to use farms for longer periods than female and smaller individuals. Tortoises were philopatric (mean overlap of farmland visits = 88.7 ± SE 2.9%), on average visiting four farms and occupying a mean seasonal range of 2.9 ± SE 0.3 ha. We discuss the characteristics of farm use by tortoises, and its implications for tortoise conservation and coexistence with people.

The first case of gynandromorphy in Centris pallida (Hymenoptera: Apidae: Centridini)

A case of gynandromorphy is reported for the first time for Centris pallida Fox, a bee species found predominantly in the deserts of the southwestern United States and northern Mexico. This specimen marks only the second report of a gynandromorph within the tribe of oil-collecting bees, Centridini, and the first Centris Fabricius. The specimen exhibits mosaic gynandromorphy, with male and female characteristics randomly distributed throughout the body. Males of C. pallida are morphologically and behaviorally dimorphic (a large and a small male morph), and the male characteristics of the gynandromorph are more similar to the large male morph, which is also most similar in head width to the specimen.

RNA-binding protein Maca is crucial for gigantic male fertility factor gene expression, spermatogenesis, and male fertility, in Drosophila

During spermatogenesis, the process in which sperm for fertilization are produced from germline cells, gene expression is spatiotemporally highly regulated. In Drosophila, successful expression of extremely large male fertility factor genes on Y-chromosome spanning some megabases due to their gigantic intron sizes is crucial for spermatogenesis. Expression of such extremely large genes must be challenging, but the molecular mechanism that allows it remains unknown. Here we report that a novel RNA-binding protein Maca, which contains two RNA-recognition motifs, is crucial for this process. maca null mutant male flies exhibited a failure in the spermatid individualization process during spermatogenesis, lacked mature sperm, and were completely sterile, while maca mutant female flies were fully fertile. Proteomics and transcriptome analyses revealed that both protein and mRNA abundance of the gigantic male fertility factor genes kl-2, kl-3, and kl-5 (kl genes) are significantly decreased, where the decreases of kl-2 are particularly dramatic, in maca mutant testes. Splicing of the kl-3 transcripts was also dysregulated in maca mutant testes. All these physiological and molecular phenotypes were rescued by a maca transgene in the maca mutant background. Furthermore, we found that in the control genetic background, Maca is exclusively expressed in spermatocytes in testes and enriched at Y-loop A/C in the nucleus, where the kl-5 primary transcripts are localized. Our data suggest that Maca increases transcription processivity, promotes successful splicing of gigantic introns, and/or protects transcripts from premature degradation, of the kl genes. Our study identified a novel RNA-binding protein Maca that is crucial for successful expression of the gigantic male fertility factor genes, spermatogenesis, and male fertility.

'Remember Aesi':

In this article I draw upon a definition of ‘dialogical memorial’ offered by Brad West to offer an experimental artist's brief that outlines the various ways that a contemporary monument to the colonial artist, Adelaide Eliza Scott Ironside (1831-1867), could ‘talk back’ to the nineteenth-century statues of her contemporaries, and ‘converse’ with more recent acts of history making. In contrast to the familiar figure of the individual hero, which we associate with the statuary of her age, I suggest a group monument that acknowledges the intimate intergenerational female network which shaped Aesi's life and also ‘re-presents’ – a term coined by the historian Greg Dening – several native born and convict women from the Georgian, Regency and Victorian eras who influenced her life. Instead of elevating Aesi upon a plinth, I recommend grounding this group monument on Gadigal country and planting around it many of the Australian Wildflowers she painted in ways that draw attention to the millennia-old Indigenous uses of the same plants. And finally, by situating Aesi’s monument in the Outer Domain (behind the New South Wales Art Gallery in Sydney’s Botanic Gardens and to the east of the Yurong Pennisula, near Woolloomooloo Bay), in an area where she once boldly assumed centre stage before a large male audience in a flamboyant moment of her own theatrical history-making, I argue that this memorial will have the capcity to speak for itself in ways that challenge the underepresentation of colonial women in Sydney's statuary, abd, as West suggests, do much to ‘alter the stage on which Sydney's colonial history 'is narrated and performed’. [i] Greg Dening, Performances, Melbourne University Press, Melbourne, 1992, p37.