The impact of Rumex vesicarius seed water extracts on mice fertility

Rumex vesicarius (RV) is an edible wild annual plant, and it is reported that it contains a good source of minerals, protein, and ascorbic acid. Several studies have indicated the anti-liver damage, anticancer, antimicrobial, and antioxidant properties of the RV plant. There are currently no reports regarding the effect of RV on fertility. Therefore, this study focuses on the impact of RV water seed extracts on mice fertility. RV plants were collected, and water seed extracts were prepared; 50 mg/kg body weight (BW) of this was then injected into the mice (male and female) using an oral feeding tube 5 days before mating (group I) or during caging of the females with the males for 1 week to detect their fertility rate. In the different female groups, no significant difference between their BW and their newborn’s BW in the treated and control groups was found. Female fertility, pregnancy, and offspring rates showed some variation within each female group and between the different female groups. In comparing the fertility and offspring rate between the different groups, there was a significant difference (P < 0.05) between groups I and III females and between groups I and IV females, while the other groups showed no significant differences. In contrast, the other groups showed no significant differences. Regarding the impact of the water seed extract on males, the BW was approximately the same in control and treated males.

On the Contribution of Reproductive and Offspring Investment on Fertility: Human and Animal Societies

Differences in investment into reproduction or offspring rearing are plentiful throughout the world, from the cells inside our bodies to complex sociological interactions among humans. Such differences can lead to profound impacts on species' fitness, fertility, and reproductive rates, sometimes in startling ways. In this paper, we create a simple game-theoretical model to qualitatively investigate the effects of such differential investment. We focus on fertility in human societies and show that more wealthy individuals produce more offspring within a a mating group. However, when assortative mating mechanisms are introduced, this effectively leads to a speciation event, and a higher reproduction rate for poorer individuals is noticed, capturing what we call the "wealthy-to-poor switch". We discuss extensions and implications of this work to nupital gifts in ecology and to clonal competition in cancer cell lines under the influence of treatment.

Correlation, regression estimates and heterosis of Archachatina marginata snails in Calabar, Nigeria

White skinned ectotypes were used in a study to estimate heterosis, correlation and regression. Data collected on the snails and their eggs included body weight (BWT), shell length (SLH), shell width (SWH), “mouth” length (MLH) and “mouth” width (MWH); and egg weight (EWT), egg length (ELH) and egg width (EWH), respectively. These data were used to estimate correlations between pairs of traits, heterosis and to predict weight from other morphometric traits among three mating groups [black skinned x black skinned (BAM X BAM), white skinned x white skinned (WAM X WAM) and their cross BAM X WAM)]. Results obtained from the study showed that evaluated traits expressed strong, positive and highly significant (P<0.01) correlation values that ranged from rp= 0.86 to rp = 0.99 among the snails mating groups. The correlation values of traits evaluated on eggs laid by these snails ranged from mild (rp = 0.49) through moderate (rp = 0.59, rp= 0.70) to strong/close (rp = 0.89). Regression estimates values obtained ranged from mild (1.30) to high (6.25), an shell width best predicted hatchlings body weight in the black skinned x black skinned (BAM X BAM) mating group, while “mouth” length best predicted hatchlings body weight in the white skinned x white skinned (WAM X WAM) mating group. Traits evaluated for percent heterosis expressed positive and significant (P<0.05) values between the mating groups, with the crossbred (BAM X WAM) mating group having advantage over the purebred (BAM X BAM and WAM X WAM) mating groups. It could therefore be concluded that in the face of appropriate selection programme, heterosis can be exploited to improve snails reproductive and growth traits. It can thus be recommended that having information regarding the association of weight with other contributing traits/parameters is crucial before starting any breeding programme.

How do whale barnacles live on their hosts? Functional morphology and mating-group sizes of Coronula diadema (Linnaeus, 1767) and Conchoderma auritum (Linnaeus, 1767) (Cirripedia: Thoracicalcarea)

Whale-associated barnacles are intriguing in terms of their planktonic food sources, mating habits, and mechanisms of host attachment. We present observations of the whale-associated barnacles Coronula diadema (Linnaeus, 1767) and Conchoderma auritum (Linnaeus, 1767) obtained from dead humpback whales (Megaptera novaeangliae (Borowski, 1781)) collected in Korea. Shell bases of Coronula diadema are inflected and sharp-edged with hollow coring tubes at the periphery. The coring tubes are filled with whale skin, supporting the model that shell accretion into the whale skin is achieved by basal constriction to achieve strong attachment. Conchoderma auritum attaches to the shell surfaces of Coronula and has a pair of tubular ear-shaped structures on the capitulum. Both species have short and thick-segmented cirri that allow feeding in strong currents. The distal ends of the cirri in both species are often equipped with sharp, large claw-like setae, which are likely used to capture large zooplankton for food. Coronula diadema and Conchoderma auritum are simultaneous hermaphrodites. Coronula diadema can mate up to nine surrounding individuals. Conchoderma auritum lives in clumps and mating group size can up to 26 individuals.

An Evolutionary Ecological Approach to Sex Allocation and Sex Determination in Crustaceans

This chapter reviews sex determination and sex allocation strategies among crustaceans with different sexual systems (gonochorism, sequential and simultaneous hermaphroditism, and androdioecy), from the perspective of evolutionary ecology. The discussion includes genetic, environmental, and cytoplasmic sex determination in free-living and parasitic crustaceans, timing and frequency of sex change especially in partial protandry, the effects of mating group size on resource allocation by simultaneous hermaphrodites, and sex ratio and determination in androdioecious crustaceans. The fascinating diversity of crustacean reproduction stimulated theoretical biologists to construct models to explain them, and empirical biologists attempted to test hypotheses derived from those models. This review clearly shows that the interaction between theoretical and empirical studies has facilitated understanding of the evolutionary conditions of diverse sexual strategies among crustaceans. Since sexual strategies often interact with other aspects of adaptive strategies such as life history, integrating different aspects into both theoretical and empirical studies will provide further understandings into crustacean sexual systems. In addition, the authors point out the potential of phylogenetic comparative analyses using natural history data as a tool to understand the tempo and mode of evolution of sex allocation strategies.

Pregnancy rates in hair sheep after Ovsynch synchronization and a combined intracervical fixed-time artificial insemination and 10-day mating period

Aim: This study aimed to evaluate the pregnancy rates in hair ewes using an Ovsynch synchronization protocol under a breeding system that combines fixed-time insemination plus a 10-day mating period as an alternative. Materials and Methods: Through an experimental study (n=27), ewes were randomly located into one of three treatments: (1) Pre-synch (n=9): Prostaglandin F2α (PGF2α)+Gonadotropin-releasing hormone (GnRH)+PGF2α+GnRH; (2) Ovsynch (n=9): GnRH+PGF2α+GnRH; and (3) control: Ewes bred by natural mating (NM) (n=9). Ewes were fixed-time inseminated (fixed-time artificial insemination [FTAI]) with fresh semen, collected just before the insemination time through vaginoscopy at 16 h after the second GnRH (gonadorelin) injection. Each experimental group was placed separately during 15 days and, after this time, fertile rams were allowed back with ewes for a 10-day mating period. Control group ewes remained with the rest of the herd suitable for breeding and were bred under NM. Pregnancy diagnosis was performed by ultrasound at 28-, 56-, and 84-day post-breeding to differentiate between FTAI and NM pregnancies. Total (FTAI±NM) pregnancy rates at 56-day post-breeding were used to compared Pre-synch, Ovsynch, and control. For this purpose, two-tailed proportions comparison z-test was used with a 95% confidence level, for testing as the null hypothesis whether two proportions were equal. Results: Pregnancy rates were higher in control ewes (66.4%) than FTAI (46.6%). When pregnancy rates after a 10-day mating period (40%) were added, the final rate (86.6%) was significantly (p<0.05) higher in Ovsynch-based protocols. The pregnancy rate was significantly lower in FTAI ewes compared to FTAI +10-day mating group (p<0.05). The overall pregnancy rate was 88.0, 85.7, and 67.0 (p>0.05) for Pre-synch, Ovsynch, and control ewes, respectively. Conclusion: These results provide evidence on the benefits of combined FTAI protocols for improving the reproductive efficiency of sheep.

Early social conditions affect female fecundity in hermaphrodites

Social conditions experienced prior to sexual maturity influence reproduction later in life in many animals. In simultaneous hermaphrodites, variation in mating group size influences reproductive investment. As the mating group size increases, reproductive resources devoted to the female function decrease in favor of the male function. Prior to sexual maturity, many hermaphrodites have a protandrous phase during which they produce sperm and can fertilize hermaphrodites’ eggs. In the simultaneously hermaphroditic polychaete worm Ophryotrocha diadema, the cost of male reproduction during adolescence is spread over the whole energy budget of worms as shown by a reduced growth rate, a delayed age at sexual maturity and the shortening of life span compared to protandrous males that do not reproduce. Little is known on whether social conditions experienced during development affect reproductive investment of immature individuals. We investigated whether social conditions affected the length of the protandrous phase, body size and also the subsequent female fecundity of same-age protandrous individuals of O. diadema, which did not had to face competition for egg fertilization. Results show that in large group sizes protandrous males lengthened their protandrous phase, slowed down body growth and decreased their individual investment at the first egg laying compared to protandrous males that were reared in isolation. In the successive egg layings worms adjusted their egg output to the current social conditions. We interpreted these results as an indication that early social conditions represent a social stress resulting in a reduction of the overall reproductive resources up to the first egg laying.

Flexible mating tactics and associated reproductive effort during the rutting season in male reindeer (Rangifer tarandus, L. 1758)

Polygynous males can change their mating tactics across their lifetime, but information is scarce on the flexibility of this trait within a given season and the relative costs and benefits of using different tactics. Here, we monitored individually marked male reindeer Rangifer tarandus and classified their mating tactics as harem-defense, sneaking, or mixed. The costs of the male reproductive effort were assessed using both direct (i.e. percentage of body mass lost) and indirect measures (i.e. activity patterns such as feeding, standing, and walking), while mating group size and reproductive success were recorded as mating effort benefits. Our results show that reindeer males may switch between the harem-defense and sneaking tactics throughout the same breeding season, providing further support to the notion that reproductive tactics are flexible in ungulates. The costs and benefits of male mating effort vary according to the mating tactic, reaching the highest values in harem-holders and the lowest values in sneaking males. Moreover, males who switched between the sneaking tactic and the harem-defence tactic tended to achieve higher mating success than males who consistently used the least costly tactic. Indeed, all harem-holders successfully sired offspring, whereas only two out of three mixed-tactic males sired one calf, and sneaking males did not sire any calves. In conclusion, our results show that reindeer males can modulate their mating efforts during the same breeding season by switching between the most costly harem-defense tactic and the least costly sneaking tactic, suggesting individual solutions to the balance between reproductive effort and mating opportunities.