High Reproductive Potential Research Articles

Growth, reproduction and resource allocation in the Norwegian lemming Lemmus lemmus (L.) under controlled conditions

Lemmings from a laboratory colony did not show statistically significant differences in growth between the sexes up to an age of 50 days. After this, growth slowed down, but adult individuals continued to gain weight, some reaching more than 100 g. Reproductive females gained more weight than non-reproductive. Maximal longevity was between 2 and 3 years. The Norwegian lemming has high reproductive potentials. Females became sexually mature at about 3 weeks of age, even down to two weeks, and remained sexually active until the last periods of life. With 8 mammae and an average litter size of 4, our material confirmed the one-half rule. Litter size up to 16 was recorded. With post-partum oestrus, litters were born at 21 day intervals. Pregnancy and lactation therefore overlapped. Resource allocation between the mother’s demands and those of the two sets of progeny, is achieved partly because the lactation period is so much shorter than the gestation period. Thus competition for energy is reduced. We did not observe any negative effects of the presence of sucklings on the ensuing litter. Even with concurrency in pregnancy and lactation the female herself gained some weight. The Norwegian lemming is thus capable of rapid population growth.

Особенности развития генеративных структур некоторых цветковых растений

The paper presents the results of a comparative study of the reproductive biology of a number of Crimean flora species and valuable plants introduced to the south of Russia belonging to various families (Magnoliaceae, Annonaceae, Ericaceae, Campanulaceae, Anacardiaceae, Lamiaceae, Ranunculaceae, Davidiaceae, Nyssaceae, Onagraceae, Papaveraceae), which made it possible to establish some features and regularities in the formation of the generative structures of the reproductive system, consisting in the conjugation of the development of male and female elements, the maturation of sexual gametes and the process of pollination in entomophilous plants. A conclusion was drawn concerning the high reproductive potential of the studied species, which is expressed in the formation of a sufficient number of full-fledged seeds to reproduce. The possibilities of using the knowledge of the reproductive processes of flowering plants in solving certain issues of taxonomy, determining the strategy of reproduction and conservation of phytodiversity, and showing the importance of antecological aspects in plant reproduction, breeding and nature protection were demonstrated. The material is of scientific interest to botanists, ecologists, breeders and other specialists.

Reproductive ecology of fire corals in the northern Red Sea

AbstractScleractinian corals, the principal architects of coral reefs, face substantial threats from ongoing and anticipated climate change and other anthropogenic disturbances. This underscores the significance of investigating alternative reef-building organisms and their contribution to reefs’ resilience. Among these alternatives, colonial hydrozoans of the genus Millepora, commonly called ‘fire corals’, play substantial roles in contributing to coral reef structure and functionality by depositing calcareous exoskeletons. Despite the ecological importance of fire corals, fundamental knowledge gaps remain regarding their biology and reproductive ecology. Here, we present a comprehensive study on the population dynamics, reproductive ecology, phenology, and sex ratio of the three Red Sea fire corals—Millepora dichotoma, M. exaesa, and M. platyphylla—in the Gulf of Aqaba and Eilat. The abundance of M. dichotoma and M. exaesa seems to have remained consistent over the last 50 years across two of the three depth zones surveyed, indicating their potential resistance or resilience. However, at the third depth surveyed, their abundance appears to have decreased. Our extensive in-situ monitoring of breeding events over six consecutive years has revealed a previously undetected relationship between Millepora species breeding events and the lunar cycle. Histological analyses indicated remarkably short reproductive cycles of only 2–3 weeks, recurring multiple times within a single season, in both M. dichotoma and M. exaesa, which is a unique reproductive aspect compared to other reef-building corals. These results highlight the high reproductive and resilience potential of Millepora species. Consequently, fire corals could assume a more substantial role as keystone species in changing environments and future reefs, emphasizing their importance in reef conservation and management.

Evaluation of bread wheat germplasm for adult plant resistance to stem rust using artificial inoculation

Wheat stem rust, caused by Puccinia graminis f.sp. tritici, is a major biotic threat to wheat (Triticum aestivum L.) in many wheat-producing countries worldwide, including Ethiopia. The pathogen is capable of continuously evolving new fungal races with high reproductive potential. It can be easily dispersed by wind over large geographic areas, allowing it to attack resistant varieties. Under optimal environmental conditions, it can cause epidemics leading to severe yield losses (up to 100%). A total of 91 germplasms, comprising 81 advanced bread wheat lines and 10 varieties, including the susceptible check Morocco, were planted using an augmented design. The experiment was conducted with artificial inoculation on spreaders to evaluate their slow rusting response against four virulent stem rust races viz. TTKTF, TKKTF, TTKTT, and TTTTF under field conditions at the Kulumsa Agricultural Research Center during the 2022-2023 offseason. Slow rusting resistance at the adult-plant stage was assessed by measuring the final rust severity (FRS) and the average coefficient of infection (ACI). Accordingly, 50 (61.7%) of the advanced lines and 6 (60%) of the released varieties namely Boru, Abay, Shaki, Kakaba, Deka, and Dursa exhibited low levels of FRS and ACI. In contrast, 31 (48.3%) of the advanced lines and 4 (40%) of the varieties showed high FRS and ACI values. The germplasms with low FRS and ACI values were considered to exhibit good slow rusting resistance and could be recommended for release into production and/or used in breeding programs aimed at achieving durable stem rust resistance in Ethiopia.

Reproductive features of the invasive crab Cronius ruber (Brachyura, Portunidae) on the Canary Islands (central eastern Atlantic), Spain

The main features of the life cycle and ecology of the invasive species Cronius ruber in both its native range and invaded areas are unknown. Therefore, the reproductive traits of this invasive allochthonous species were studied in the Canary Islands, including sex structure, maturity, fecundity, and egg development. Females were more abundant than males, mainly in the size range between 25 and 80 mm CW. Only males were observed in size classes above 80 mm CW. Reproduction of C. ruber is continuous throughout the year, with a new oviposition immediately after the end of the egg incubation period. This process can be repeated in females up to six times, without re-mating, due to the sperm stored by females in the spermathecae. Sexual maturity was estimated at a similar size in both sexes, corresponding to 57–59 % of their maximum observed size. Egg development appeared to be completely synchronous, with a development period lasting slightly less than 1 month. The mean fecundity was 657,282 eggs, with a maximum observed fecundity of 988,509 eggs. This species shows a high reproductive potential, characteristic of invasive species.

Assessing genetic parameters for first parity reproductive traits for early selection in Saanen × Beetal goats of India.

The present study aimed to evaluate the genetic parameters of first parity reproductive traits. Information on 762 reproductive records on Saanen × Beetal (S × B) goats reared for approximately five decades was collected from ICAR-National Dairy Research Institute, Karnal, Haryana (1973-2020). For genetic analysis, single-trait and multiple-trait animal models were used. Gibbs sampler for animal model (GSAM) approach was used for estimating (co)variance components of reproductive traits. Six different single-trait animal models (with or without maternal and environmental effects) were used and the deviance information criterion (DIC) determined the best model. The least squares mean for age at first service (AFS), age at first kidding (AFK), service period (SP), dry period (DP), gestation length (GL), kidding interval (KI), litter weight (LW), number of kids born (NKB) and number of female kids born (NFKB) in first parity were 526.99 ± 4.86, 662.96 ± 5.03, 219.11 ± 6.25, 109.38 ± 6.00, 150.48 ± 0.27, 356.63 ± 4.80 days, 3.87 ± 0.05 kg, 1.27 ± 0.02 and 0.67 ± 0.03, respectively. Lower heritability estimates for these reproductive traits revealed a sparse scope for genetic improvement. Multivariate analysis using Model 1 was carried out to evaluate the genetic and phenotypic correlation of these nine reproductive traits. The genetic correlation of DP and SP was negatively with LW, NKB and NFKB, which is favourable as reduction in SP and DP can improve these economically important traits through indirect selection. Consistent efforts towards genetic improvement of these goat flock poses a promising future for meat industry owing to high prolificacy and good reproductive potential in this flock.

What does not kill you makes you stronger? Effects of paternal age at conception on fathers and sons.

Advancing male age is often hypothesized to reduce both male fertility and offspring quality due to reproductive senescence. However, the effects of advancing male age on reproductive output and offspring quality are not always deleterious. For example, older fathers might buffer the effects of reproductive senescence by terminally investing in reproduction. Similarly, males that survive to reproduce at an old age might carry alleles that confer high viability (viability selection), which are then inherited by offspring, or might have high reproductive potential (selective disappearance). Differentiating these mechanisms requires an integrated experimental study of paternal survival and reproductive performance, as well as offspring quality, which is currently lacking. Using a cross-sectional study in Drosophila melanogaster, we test the effects of paternal age at conception (PAC) on paternal survival and reproductive success, and on the lifespans of sons. We discover that mating at an old age is linked with decreased future male survival, suggesting that mating-induced mortality is possibly due to old fathers being frail. We find no evidence for terminal investment and show that reproductive senescence in fathers does not onset until their late-adult life. Additionally, we find that as a father's lifespan increases, his probability of siring offspring increases for older PAC treatments only. Lastly, we show that sons born to older fathers live longer than those born to younger fathers due to viability selection. Collectively, our results suggest that advancing paternal age is not necessarily associated with deleterious effects for offspring and may even lead to older fathers producing longer-lived offspring.

Parturition of a rear-fanged rainbow water snake (Enhydrisenhydris) involved in snakebite and effects of its envenoming in Nepal

Based on a specimen preserved in the snakebite treatment center in eastern Nepal, this study aims to analyse brief life history (i.e., litter size, parturition date, habitat preference) of Enhydris enhydris, effects of its envenoming, and anthropogenic threat on its populations. One euthanized gravid female E. enhydris collected alive from eastern Nepal by a snakebite victim was examined. The gravid female gave birth to 23 litters on July 11, 2012. This parturition suggested high reproductive potential. Its bite to a man walking on the road caused no ill-effects. However, the use of tourniquet as a part of prehospital care might be detrimental or be obstacle for in-hospital care of snakebite. The conflicts between E. enhydris and humans at roads and human-activity areas are inevitable across the distribution ranges of this species. The continued anthropogenic impact can threaten its populations. This study finding can be a basis for assessing conservation status and options for its conservation as well as prehospital care and prevention of its bites.

Recovery potential of fish and coral populations following ecological disturbance

AbstractThe health of coral reef benthic and fish communities is implicitly connected, yet typically studied and managed separately. By developing a coupled reef population model that connects coral populations and reef fish biomass through the habitat complexity that corals build and fish live among, we aim to address this gap by holistically quantifying ecological feedbacks and responses to ecological stressors. We explored the impacts of fishing effort in conjunction with three types of ecological disturbances as they propagated through a coral reef ecosystem: (1) a disturbance that disproportionately affected small, bio‐energetically vulnerable colonies, (2) a disturbance that predominantly affected large, mechanically vulnerable colonies, and (3) a disturbance that affected colonies of all sizes randomly. We found that joint coral and fish population recovery was fastest and most complete under events affecting small colonies, followed by recovery from disturbances affecting random sizes, and lastly large‐colony disturbances. These results suggest that the retention versus loss of large coral colonies with high reproductive potential critically influenced population recovery. Low fishing levels maintained fish and coral populations and allowed for recovery after disturbances, whereas high fishing levels prevented recovery due to greater fish‐dependent coral mortality. Finally, we tested various formulations of the relationship between coral size and habitat complexity (i.e., exponential, linear, logarithmic) that constrain fish carrying capacity. All formulations led to similar population projections in most disturbance scenarios, but there were exceptions where the timing and trajectory of recovery differed, such as faster and greater recovery potential when complexity is logarithmic with respect to coral size. These findings suggest that fishing and habitat complexity mediate the recovery of coral reef populations, emphasizing the importance of describing linkages between coral size distribution and reef habitat structure. Furthermore, our results highlight the utility of the coupled‐model framework for understanding and managing the impact of disturbances at ecosystem scales.

A Beginner’s Guide to LAP AI

Goats and sheep are extremely fertile animals! The ewe and doe have very high reproductive potential. However, it must be remembered that “sex is a luxury” metabolically speaking. The ewe or doe must be healthy and on a good plane of nutrition be­fore maximum fertility is attained.

Prioritisation of Barriers According to Their Impact on Migratory Fish in the Lowland River Basin District

Artificial barriers are one of the most damaging anthropogenic factors, but are also socio-economic constructions, so the decision between removing a barrier and installing a fishway must be justified. The aim was to develop a system to quantify the amount of suitable habitat for migratory fish above barriers, to assess barriers’ passability, to prioritise them in current and historical terms and to take into account the impact of the reservoir in the selection of barrier management alternatives. For this purpose, the proportion of suitable area and the potential number of spawners were calculated separately for the flooded and free-flowing river sections above the barrier. The effect of the flooded area and fishway efficiency on the potential number of individuals was assessed and the historical importance of the areas above each barrier was evaluated. The results show that the proportion of suitable area in the total area above the barriers varies between 5 and 31%. Short river stretches of high habitat quality have a higher reproductive potential than much longer stretches of lower habitat quality. Dams with fishways can still be among the most negatively impacting barriers if they are located in the migration route of fish into a large part of the basin.

Warming changes the life history composition of marine fish communities at high latitudes

Across marine ecosystems, species are redistributing as a response to increased sea temperatures. In the Arctic, rapid warming causes poleward shifts of boreal species. Which species are redistributing and the drivers of their movements can be related to their life history traits. Here, we aimed to characterize and analyze the spatio-temporal changes in the life history strategy (LHS) composition of fish communities in the Barents Sea (2004-2017). We performed an archetype analysis to characterize species’ LHS based on their life history traits and related it to the equilibrium-periodic-opportunistic framework. Fish species in temperate ecosystems were documented to be largely distributed along the opportunistic-periodic continuum, whereas many fish species in the Barents Sea are distributed along the opportunistic-equilibrium continuum, illustrating the specificity of Arctic fish LHS. During the study period, boreal periodic species showed an increase in the central Barents Sea, a zoogeographic transition area. Simultaneously, Arctic opportunistic species retracted to cold waters, and the abundance of equilibrium strategists increased in the eastern Barents Sea. The expansion of periodic species may be explained by the configuration of their traits. This includes a high reproductive potential, broader diet, and migratory behavior. These traits might increase their tolerance and adaptive capacity to a changing environment. Fish LHS play a crucial role in fisheries management, particularly in promoting better fishing practices for vulnerable populations. By understanding the various LHS adopted by different fish species and their environmental preferences, fisheries managers can develop informed fishing strategies on a broader scale.

Using DNA metabarcoding to separate natural and human provided food in wild boar diet at the northern distribution range of Europe

Wild boar Sus scrofa is increasing in numbers and extending its distribution across Europe and is difficult to control due to high reproductive potential. Dietary quality is a main determinant of wild boar population dynamics, and the extent to which they rely on human‐provided food provide a key to limit their distribution. Yet, we lack data on wild boar diet from northern Europe. Here we use DNA‐metabarcoding of faecal samples (n = 50) to determine wild boar diet during fall and winter in Norway. We mainly aimed to quantify the extent to which wild boar relies on natural or human‐provided food sources. A secondary aim was to determine whether diet varies with individual characteristics (sex, age or weight), season (winter or fall), and between the two regions with wild boar in Norway. We found a high degree of diet variability between individuals. Individuals consuming high amounts of edible fungi consumed low amounts of plant material. The (heavier) male wild boars consumed 50% more human provided food than the (lighter) female wild boars. There was no clear effect of age, season (winter versus fall), or region on diet with the sample size available. The negative correlation between plants and fungi in each sample suggests that using multiple primers targeting different taxa can provide quantitative diet information, and points to an important role of fungi (truffles) during winter and fall. The large individual variation in diet may reflect opportunistic feeding tactics in Scandinavian boreal forests, driven by a lack of acorns and few crops. Our study has relevance for understanding limitations of wild boars at their northern distribution range in Europe, and thus also provides important information for management.

The Occurrence of Suids in the Post-Olduvai to Pre-Jaramillo Pleistocene of Europe and Implications for Late Villafranchian Biochronology and Faunal Dynamics

It has been proposed that suids were absent from Europe during the post-Olduvai to pre-Jaramillo Early Pleistocene (from less than 1.8 to more than 1.2 Ma) and that their “re-appearance” in the late Early Pleistocene would mark the end of the late Villafranchian and the beginning of the Epivillafranchian. Arguments enumerated in favor of this “suid gap” are the lack of suid remains from extensively sampled fossil localities of this age and the high reproductive potential (r-strategy) of suids, which would translate in a high commonness of their remains in the fossil record. However, here it shown that while suids’ reproductive potential is certainly exceptional within artiodactyls, there is no direct relationship between the reproductive strategy and preservation rate of a taxon in the fossil record. In Early Pleistocene localities of Europe and adjoining areas, where suids are present in a fossil assemblage, they are always rare. In terms of number of occurrences (frequency), suids range from being moderately common (~2.0–1.8 Ma) to moderately rare (~1.1–1.0 Ma). Suid material is also described herein from Peyrolles (Issoire, France; reference locality for MNQ 19), a site dated at 1.47 Ma, providing direct evidence for the presence of suids within the purported “suid gap”. The case of suids underlines an important source of caveat in inferring faunal dynamics of the late Early Pleistocene of western Europe—including the dispersal of hominins—i.e., the unequal geographical distribution of the paleontological sites of post-Olduvai to pre-Jaramillo age. Indeed, Peyrolles is the only large mammal site in western Europe located outside the Iberian and Italian Peninsulas reliably dated around 1.5 Ma. In the post-Olduvai to pre-Jaramillo period, there is a paucity of radiometric estimates (or they have too coarse a resolution) and of paleomagnetic excursions detectable in continental deposits. Basically, for this time span, there is a high dependence on biochronological correlations, although, at the same time, these correlations are less reliable—because these are based on a few sites not covering the entire spectrum of environments present in Europe and the sites are not independently dated with methods that outperform biochronology—than those for other periods.

Dispersal and persistence of cup plant seeds (Silphium perfoliatum): do they contribute to potential invasiveness?

Background and aims – The cup plant (Silphium perfoliatum) is being grown in Germany as a promising new bioenergy crop with an increasing area under cultivation in the last years. Its alien status, its high productivity, and high reproductive potential could carry the risk of this species becoming invasive. The present study investigates the dispersal and persistence of cup plant seeds, to contribute to the assessment of its invasive potential. Material and methods – For this purpose, four experimental studies were conducted in Germany, Central Europe: wind dispersal distance was measured in a field experiment for wind speeds up to 7 m.s-1. The seeds were offered to rodents in different habitats near to a cup plant field. We observed seed persistence and germination over 4 weeks storing in water and over 4 years storing in different soil depths. Key results – Cup plant seeds are dispersed by wind only over a few meters. In the forest, rodents removed 100% of the offered seeds, in open habitats none. Independent of the duration of storage in water, germination rate of the cup plant seeds was constantly high. Most of the seeds already germinated in water in the first two weeks. Stored on the soil surface and at 10 cm soil depth, the seeds germinated already in the first two years. Stored at 30 cm depth, one third of the seeds retained their germination ability over four years. Conclusion – Wind serves as short-distance dispersal vector for cup plant seeds. Rodents remove the seeds, but it is unknown whether they disperse them or just eat them. Water could disperse the seeds, which retain their germination ability, over long distances. The cup plant could therefore spread and possibly become invasive in Central Europe, and therefore measures are suggested to prevent its dispersal and spontaneous settlement.

Influence of prickly pear cactus (Opuntia stricta) on the socio-economic status of pastoral livelihoods of rangelands in the Northern Rift Valley of Kenya

This study aimed to evaluate the influence of the prickly pear cactus on the socio-economic status of pastoral livelihoods of rangelands in the Northern Rift Valley of Kenya. The prickly pear cactus (Opuntia stricta) is one of the most widespread and naturalized invasive species in the arid and semi-arid areas of Kenya, with serious negative consequences on rural livelihoods and the environment. The invasiveness of O. stricta is due to its productive and competitive advantages under marginal conditions, limited availability of pests and pathogens, and high reproductive potential. A descriptive survey design was used in this study. In this study, the socio-economic impact of the prickly pear cactus was examined in two sites located in the northern rangeland of the Rift Valley in Kenya. A purposive sampling technique with semi-structured questionnaires administered through an Open Data Kit was used to generate the primary data. In order to examine the influence of O. stricta on the socio-economic status of livelihoods, the study used linear regression analysis. The study concluded that an increase in cactus thicket negatively affects the livelihoods of the pastoral communities. This study recommends that support to the local communities from the government, as well as other developing agencies operating within the region, is necessary for the effective management of the invasive species. Furthermore, development plans for the region must also take into account the socio-ecological impact of the prickly pear cactus in the region.

Seasonal variability drives differences in the structure of the calanoid copepod community in two contrasting regions of the Gulf of Mexico

Abstract Calanoid copepods (CC) are key contributors to the biological carbon pump and pelagic trophic dynamics. The deep-water regions of Perdido and the Bay of Campeche in the western and southern Gulf of Mexico (GM), respectively, differ in hydrography and productivity, leading to potential differences in copepod biomass and community structure. Zooplankton (0-200 m) were collected from the shelf edge to the deep-water region during the winter and summer autumn 2016. Calanoids contributed 38-60% of total zooplankton biomass and 55-70% of overall copepod abundance. The Bay of Campeche had the highest total zooplankton biovolume (287±120 ml 1000 m−3) and total mean copepod abundance (CC and non-calanoids ~146,000 ind. 1000 m−3) during summer-autumn, likely resulting from cross-shelf nutrient transport fueling local productivity. Adult females dominated calanoid numerical abundance (43-50%), thus suggesting a high reproductive potential. Cluster analysis showed differences between seasons (~40% dissimilarity) but not regions. Environmental conditions explained 22% of the variability in community composition; the winter assemblage was significantly related to oxygen concentrations, whereas the summer-autumn community was related to warmer conditions and higher integrated chlorophyll-a concentrations. The CC community responded to seasonal changes more than regionally related hydrographic differences, with likely implications for organic matter cycling and export.

PREGNANCY RATE AND NUMBER OF FETUSES OF WHITE-TAILED DEER RELATED TO BODY MEASUREMENTS AND SERUM METABOLITES

This study aimed to assess the association between fertility and the number of fetuses of free-ranging concentrate-supplemented white-tailed deer (Odocoileus virginianus, texanus, Mearns 1898) from northern Mexico (27 °N) with body measurements and serum metabolites indicative of nutritional status. We studied 119 female deer (31 yearlings and 88 adults) captured in January 2021 using a net gun fired from a helicopter. Ultrasound scanning showed 100 and 97.8 % pregnancy rate and 1.52 ± 0.51 and 1.50 ± 0.59 fetuses/pregnant doe for yearlings and adult does, respectively, with no difference (p > 0.05) between age classes Thoracic circumference (cm) was higher (85.9 ± 4.9 vs. 84.1 ± 4.2; p = 0.039) for does carrying twins vs. singles. None of the serum metabolites indicative of nutritional status affected the fetal number of pregnant does. It was concluded that free-ranging white-tailed deer receiving concentrate supplementation in winter on a semi-arid rangeland has a high reproductive potential. Also, these results indicate that variation in maternal age within this population was not a significant driver of reproductive metrics of white-tailed deer. The plane of nutrition used in the present study was reflected in adequate serum metabolites indicative of nutritional status. Also, thoracic circumference may have prognostic value as a physical marker of multiple fetuses in female white-tailed deer.

Intra-group differences in skin tone influence evaluative and perceptual face processing.

In an exploration of colorist biases across native Melanesian participants, we employed a multi-method approach across three studies to examine evaluative and perceptual processing of 'lighter' and 'darker' non-Melanesian facial targets controlled for attractiveness, sex, and ethnicity. In Study 1, 305 participants evaluated facial attractiveness using surveys. In Study 2, 153 participants alternately mapped lighter and darker faces with positive and neutral attributes across brief Implicit Association Tests. In Study 3, 61 participants underwent a manual sorting task followed by a 'breaking' continuous flash suppression (b-CFS) paradigm to probe 'non-conscious' perceptual biases. Across evaluative measures, male and female respondents consistently preferred lighter-skinned, highly attractive male faces. During b-CFS, lighter and attractive opposite-sex faces entered awareness ('broke suppression') faster than their darker counterparts. We speculate that skin tone may operate as a perceptually salient cue in the presence of facial configurations signaling high reproductive potential.

Microarray Analysis to Determine Gene Expression Changes in Zebrafish Embryos.

Chemical exposure in humans begins from the zygote stage and continues throughout the development of the embryo and the fetus. Zebrafish are one of the most powerful model organisms used in many research areas, including genetics, environmental toxicology, development, DNA damage and repair, cancer, and other diseases. Among the advantages that facilitate the use of zebrafish as a model for studies are features such as high homology with the human genome, small size, and high reproductive potential in short periods. The use of zebrafish embryos in research has increased rapidly due to their advantageous properties, including extrauterine development and the transparent feature of the embryos. However, there are thousands of genes that can be encountered in research, and in this case, the workforce is too much. This workload has been alleviated with the developed technologies. Microarray is one of these technologies. An important parameter in this assay is the RIN value. The RIN value ranges from 1 to 10, indicating mRNA degradation, and therefore helps to decide whether to continue the study. In this chapter, microarray analysis, which is one of the main techniques used in the determination of gene expression in zebrafish embryos, is described.