Body Size Characteristics Research Articles

Assessment of Perceived Diversity and Inclusivity of Athletic Training Textbooks

Context Adopting diverse perspectives is increasingly important for athletic trainers (ATs) to provide care that fosters inclusion for all patients. Despite the NATA’s commitment to diversity, NATA membership remains approximately 80% White. Additionally, although ATs work with people from ethnically diverse backgrounds with unique body expression and body-size characteristics, it is unknown whether athletic training textbooks represent this diversity. Objective To investigate diversity characteristics of images including patients and clinicians within athletic training textbooks. Design Cross-sectional study. Patients or Other Participants Twenty percent (n = 15) of athletic training and health care textbooks included on the Board of Certification reference list were selected. Twenty percent of chapters from those textbooks were then randomly selected for inclusion. Main Outcome Measure(s) Descriptive statistics were calculated for person (athlete, nonathlete, clinician), setting (athletic venue, clinic, physician office, other), and demographic categories (perceived skin tone, race/ethnicity, age, gender, body size, body expression). Chi-square tests of goodness of fit were performed to determine significant differences between categories, and χ2 tests of independence were performed to determine differences across person type and category and across textbook domain and category. Results One thousand six hundred sixty-seven people were assessed from 1190 images. Images depicted statistically more persons with light skin tone (86%) assumed to be White (86%), young adults (75%) of average weight (95%), with no body expression diversity (95%). There were no major differences in subject characteristic majorities across person type or textbook domain. Conclusions Like other health care professions, a lack of image diversity was demonstrated within athletic training textbooks. To better recruit diverse students to the athletic training profession, and to prepare professional students to provide culturally competent and patient-centered care, these resources should better represent the diversity of ATs and their patients.

Intra- and interindividual variability in fasted gastric content volume.

Gastric fluid plays a key role in food digestion and drug dissolution, therefore, the amount of gastric fluid present in a fasted state may influence subsequent digestion and drug delivery. We aimed to describe intra- and interindividual variation in fasted gastric content volume (FGCV) and to determine the association with age, sex, and body size characteristics. Data from 24 MRI studies measuring FGCV in healthy, mostly young individuals after an overnight fast were pooled. The analysis included 366 participants who had up to 6 repeated measurements, with a total of 870 measurements. Linear mixed model analysis was performed to calculate intra- and interindividual variability and to assess the effects of age, sex, weight, height, weight*height as a proxy for body size, and body mass index (BMI). FGCV ranged from 0 to 156 mL, with a mean (± SD) value of 33 ± 25 mL. The overall coefficient of variation within the study population was 75.6%, interindividual SD was 15 mL, and the intraindividual SD was 19 mL. Age, weight, height, weight*height, and BMI had no effect on FGCV. Women had lower volumes compared to men (MD: -6 mL), when corrected for the aforementioned factors. FGCV is highly variable, with higher intraindividual compared to interindividual variability, indicating that FGCV is subject to day-to-day and within-day variation and is not a stable personal characteristic. This highlights the importance of considering FGCV when studying digestion and drug dissolution. Exact implications remain to be studied.

An Investigation and Invasiveness Analysis of Two Species of Giant African Snail in a Coastal City of Southern China

Investigations and research on the giant African snail (GAS) mainly focus on Achatina fulica. However, in recent years, a more harmful GAS, Achatina immaculata, has been reported. In order to understand the invasive status of A. immaculata in China, we take Shenzhen, a coastal city in Southern China, as an example to carry out an ecological survey on the field populations of the two species of GAS in various districts. We explore the differences in the invasive characteristics of the two species of snails in terms of their dietary intake, cold adaptation and drought resistance. The results indicate that, based on the phylogenetic tree analysis, more than half of the sampled snails exhibit higher similarity to A. immaculata. The number of wild A. immaculata is significantly greater than that of A. fulica, and 70.64% of the 746 GAS are A. immaculata. At the same time, it is also found that the maximum shell length of A. immaculata is 135.83 mm, with an average shell length of 76.00 mm, which is significantly different from the average shell length of A. fulica (56.57 mm, p < 0.01). The food intake assay shows that there is no difference in the food preferences of the two species, but the food demand of A. immaculata is significantly greater than that of A. fulica (2.32 fold, p < 0.01). In the cold adaptation assay, A. immaculata recovers from the cold dormancy state significantly faster than A. fulica (1.92 fold, p < 0.05), and the speed with which A. immaculata enters the dormancy state in the drought environment is significantly slower than that of A. fulica (0.706 fold, p < 0.05). With the characteristics of a large body size, large food intake and strong resistance to cold and drought resistance, A. immaculata has the potential to be dominant in competition with A. fulica in the same ecological niche, and it has become the main invasive species of GAS in Shenzhen.

Biological maturation, fat mass and cardiorespiratory fitness in prepubescent girls: A mediation analysis.

The association between indicators of maturation and measures of physical fitness are not well correlated and vary according to chronological age, sex, body size, and motor characteristics. It is known that chronological age, maturation, and fat mass are significant predictors of cardiorespiratory fitness in girls, however, the contributions of fat mass to the relationship between maturation and endurance performance are still unclear. The current study aimed to examine whether the association between somatic maturation and running performance in the 20-m shuttle-run in girls is mediated by estimated fat mass. The sample comprised 67 girls, aged 8.00-8.99 years. Stature, body mass, and skinfolds were measured. Estimates of body composition and predicted mature stature (PMS) were then calculated. Current stature was expressed as a percentage of PMS and somatic maturation was given by z-scores of the percentage of PMS. Mediation analysis was performed using the bias-corrected bootstrap approach with 5000 resamples in order to obtain estimates of total, direct, and indirect effects of z-scores of the percentage of PMS on 20-m shuttle-run performance mediated by fat mass. The results show that fat mass mediated the negative effect of biological maturation on 20-m shuttle-run performance in the observed sample of prepubescent girls (Indirect effect: β = -0.177, 95%CI: -0.291 to -0.059). Although the participants were prepubescent girls, poorer aerobic running performance appeared to be partly due to increased levels of fat mass.

Identifying the key body size and maturity characteristics associated with superior physical fitness performance tests: does one size fit all?

Identifying the key body size and maturity characteristics associated with superior physical fitness performance tests: does one size fit all?

Quantitative characteristics and growth hormone gene diversity of thin-tailed sheep in Sitinjau Laut, Kerinci Regency

<p class="MDPI17abstract"><strong><span lang="EN-US">Objective:</span></strong><span lang="EN-US"> This study aims to evaluate the </span><span lang="IN">quantitative characteristics and growth </span><span lang="EN-US">h</span><span lang="IN">ormone gene</span><span lang="EN-US"> diversity of thin-tailed sheep</span><span lang="IN"> in Sitinjau Laut</span><span lang="EN-US">,</span><span lang="IN"> Kerinci Regency</span><span lang="EN-US">.</span></p><p class="MDPI17abstract"><strong><span lang="EN-US">Methods:</span></strong><span lang="EN-US"> The research method used 60 thin-tailed sheep and 60 samples of thin-tailed sheep's blood. The phenotypes observed included: body weight, weight gain, body measurements, and thin-tailed sheep blood samples. The GH gene was identified using the PCR-RFLP method with the Msp1 restriction enzyme. Data analysis included t-test, t<sup>2</sup>-hotelling, principal component analysis, and allele genotype frequencies.</span></p><p class="MDPI17abstract"><strong><span lang="EN-US">Results:</span></strong><span lang="EN-US"> The results showed that body weight, body weight gain, and sizes of male thin-tailed sheep were significantly different (P<0.05) higher than females. The analysis results on the GH|Msp1 gene locus of thin-tailed sheep were monomorphic with one type of allele, namely ++. </span></p><p><strong><span lang="EN-US">Conclusions:</span></strong><span lang="EN-US"> The average body weight, weight gain, and body measurements of male thin-tail sheep were higher than that of females. The body size characteristic of male and female thin-tailed sheep is the chest circumference, while the body shape characteristic of male and female thin-tailed sheep is the chest depth. The fragmentation of the GH|Msp1 gene in thin-tailed sheep is monomorphic.</span></p>

Association study of polymorphisms in miRNA-1687 with growth traits of chickens

Polymorphisms within microRNAs can lead to phenotypic variations in organisms. The purpose of this research was to investigate the potential impact of the pre-miR-1687 single nucleotide polymorphism (SNP) on the economic characteristics of weight and body size in chickens. The SNP was genotyped using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. A linear mixed model was utilized to analyse the associations between the SNP and chicken body size and growth traits. The SNP in the pre-miR-1687 gene was correlated with F2 chicken body weight (BW) at birth and at 4, 6, 8, and 10 weeks of age. The SNP in the gga-miR-1687 gene was correlated with shank length, shank girth, pectoral angle (at 4 weeks), and pelvic breadth (at 8 weeks). Different BW genotypes were observed in the studied flocks. The changes in the secondary structure of pre-miR-1687 and in the free energy values were estimated using online M-fold software. The results serve as a helpful resource for subsequent research on the mechanisms and functions of miRNAs. In addition, the study provides a credible basis for the application of biomolecular technology in poultry breeding.

QUANTITATIVE CHARACTERISTICS OF THE RESULTS OF CROSSING KAMPUNG SUPER CHICKENS WITH ARAB CHICKENS UP TO 2 MONTHS OF AGE


 
 
 This study aims to determine the relationship of egg characteristics, quantitative characteristics of the crossing results of Super and Arabian chickens. The research material was 91 Supra chickens consisting of 43 males and 48 females. The method used was experimental observation method. Data collected on egg characteristics, BW, PBB, and body size were analyzed using t-test. The relationship between variables was analyzed by regression and corre- lation. T2-Hotelling analysis was used to compare the body size vectors of male and female Supra chickens. Prin- cipal Component Analysis was used to determine the determinants of the size and shape of male and female Supra chickens. The results of this study showed that the characteristics of eggs, body weight, body weight gain and body size of male Supra chickens were significantly different (P < 0.05) higher than female Supra chickens. Conclusion: The relationship between egg size and egg weight is positive, the closest correlation between sizes and egg weight is egg width. Body weight, body weight gain and body size of male Supra chickens were higher than females. The characteristics of body size in male and female Supra chickens are chest circumference, while the characteristics of body shape are wing length.
 
 

Variability in body weight and morphology of Uganda's indigenous goat breeds across agroecological zones.

Indigenous goat breeds in Uganda are classified based on average body size parameters and coat color. However, variations in the body size of animals may be influenced by several factors, including management and the environment. To understand the effect of the agroecological zone on the physical characteristics and live weight of Uganda's indigenous goats, this study evaluated the body size characteristics of the three indigenous goat breeds of Uganda across ten agroecological zones. The cross-sectional survey was conducted in 323 households from the ten zones, where 1020 goats composed of three breeds (Mubende, Kigezi, and Small East African) were sampled and measured for body weight, linear body size, and age. We confirmed that Mubende and Kigezi goats from the original homeland had a higher mean body weight than reported in FAO reports. In addition, Mubende appeared to perform better in pastoral rangelands, with a higher mean body weight (38.1 kg) and body size being significantly higher (P < 0.0001) compared to other zones. The mean body weight for the Kigezi breed in the original homeland (34 kg) was comparable to those from Western Savannah grasslands and pastoral rangelands and less than that initially reported by FAO (30 kg). Similarly, there was no significant difference in the linear body size characteristics of Kigezi goats in the home zone of highland ranges relative to those found in other agroecological zones (P > 0.05). Although the Small East African goats were originally found in Northwestern Savannah grassland and Northeastern dryland zones, they performed poorly regarding mean body weight and body size characteristics in the former zone. In the Northwestern Savannah grasslands, the mean body weight (23.8 kg) was even less than that reported by FAO, which ranged between 25 and 30 kg. Finally, we confirmed that Mubende and Kigezi goats are significantly heavier than small East African goats (p ≤ 0.0001). The results of this study can be useful in designing precise management strategies to improve indigenous goat productivity in different environments in Uganda.

Morphological and transcriptomic analyses of embryonic development of red-eared slider Trachemys scripta elegans

Embryology provides an understanding of individual’s origin and developmental patterns. Turtles are among the oldest living reptiles and have unique body structure. However, the morphogenesis and mechanisms of turtles are not fully understood. In this study, we focused on the embryonic development of red-eared slider (Trachemys scripta elegans) which widely distributes in the world. At an incubation temperature of 28 °C, the turtle eggs had a 61-day incubation cycle, and the entire embryonic development process was divided into 27 stages and 3 phases according to variations in age, body size, and morphological characteristics. The early phase of embryonic development (the first 12 stages) were characterized by embryo growth, and the appearance of internal organ precursors. The middle phase (stages 13–20) involved prominent heart division at stage 13 and the appearance of carapace and plastron at stages 14 and 17, respectively. In the later phase (stages 21–27), the hatchlings formed, and the carapace and plastron thickened. Transcriptome analysis of embryos showed enrichment of the differential genes in pathways related to development, metabolism, disease, and cellular processes. The Kyoto Encyclopedia of Genes and Genomes enrichment (KEGG) analysis implied the crucial regulatory role of the axon guidance pathway. Real-time fluorescence quantitative PCR indicated upregulated expression of wnt5a and bmp7 in stages 7 and 16 compared to that in stage 12. This study revealed the development process of red-eared slider embryo and the dynamics of the signaling pathway affecting its development, which supplemented the theory of embryo development, and provided new ideas for the molecular mechanism of turtle embryo development.

Scale insect (Hemiptera: Coccomorpha) morphology is transformed under trophobiosis

Abstract Ants (Hymenoptera: Formicidae) have great potential to exert influence over the morphological evolution of their obligate mutualist partners. Obligately myrmecophilic mealybugs are noted for their unusual morphology, and while this is often attributed to their relationship with ants, a quantitative assessment of this link is lacking. We address this need by evaluating morphological change among mealybugs as a function of ant association. This study considers the associates of 2 independent ant clades—Acropyga Roger, 1862 ants associated with root mealybugs from the families Xenococcidae and Rhizoecidae and herdsmen ants from the Dolichoderus cuspidatus (Smith, F., 1857) species-group associated with mealybugs from the tribe Allomyrmococcini (Pseudococcidae)—and compares them to free-living or potentially myrmecophilic species sampled from among the mealybugs and root mealybugs. We use a combination of geometric morphometric and linear datasets to evaluate characteristics of body shape, body size, leg metrics, and ostiole development. Obligate myrmecophily significantly influences both body shape and size. Myrmecophilous mealybugs are smaller than their free-living counterparts and are either pyriform or rotund in shape rather than oval. Ant-associates from Rhizoecidae also have significantly reduced anterior pairs of ostioles compared to free-living species. Ostioles are involved in defense against natural enemies and mutualist ants typically protect their partners, presumably supplanting the need for structures like ostioles among myrmecophilous species. We discuss the influence ants have on the evolution of their associates in the context of domestication and offer avenues for future exploration.

The Relationship Between Body Size and Bone Weight (Breast and Thigh) in Kampung Chicken (Gallusdomesticus) Results Third Generation Selection

The aim of this study is to identify the characteristics of body size and shape in kampung chickens, as well as the relationship between body size and meat weight. To achieve this, 200 kampung chicken DOC were directly observed using purposive sampling. Purposive sampling where the chickens were divided into 3 groups of body weight, namely high, medium and low.Body size was recorded at 4, 6, 8, 10, and 12 weeks of age, and the weight of flesh and bone at 12 weeks of age was analyzed using the ttest.The samples used to obtain the weight of meat and bones (breast and thighs) were 35 males and 23 females.The study used principal component analysis to identify body size and shape characteristics for males and females. Regression and correlation analysis were then conducted to determine the relationship and closeness between body size and the weight of flesh and bone.The results of the study showed that the body size and weight of flesh and bone in kampung male chickens aged 12 weeks were significantly higher

Phenotypic characteristics of Sakub sheep as local livestock genetic resources

Abstract. Nurasih AD, Sumaryadi MY, Hidayah CN, Nugroho AP, Setyaningrum A, Haryoko I, Yuwono P, Sodiq A. 2023. Phenotypic characteristics of Sakub sheep as local livestock genetic resources. Biodiversitas 24: 5671-5675. Sakub sheep is an indigenous sheep with a giant body in the Brebes Regency. Phenotypic characterization is important to increase the population and productivity of Sakub sheep. By combining quantitative and qualitative data, this study will provide a comprehensive insight into the phenotypic profile of Sakub sheep. This study determined the quantitative and qualitative phenotypic characteristics of Sakub sheep. The Sakub sheep used were owned by smallholder farmers using the survey method with interview techniques, observation, and direct measurement of livestock. Samples were taken using purposive sampling in Pandansari and Wanareja villages, which have the largest sheep populations and are easily accessible. The sheep used were rams and ewes sheep in the age group of 1-1.5 years (P0), 1.5-2 years (P1), 2-2.5 years (P2), 2.5-3 years (P3). Phenotypic characteristics observed included quantitative characteristics of body size and qualitative characteristics of body morphology. Body size was measured using measuring tape and hanging scales, including Body Weight (BW), Body Length (BL), Whither Height (WH), Chest Girth (CG), Ear Length (EL), And Tail Length (TL). Body morphology includes head color, body color, face profile, and tail shape. Quantitative characters were analyzed using descriptive statistics, and qualitative characters were analyzed descriptively using relative frequency. The results showed quantitative phenotypic characteristics of Sakub sheep at the age of 1-1.5 years; 1.5-2 years; 2-2.5 years, and 2.5-3 years, such as body weight, body length, chest circumference, whither height, ear length, and tail length increased with age. The qualitative phenotypic characteristics of Sakub sheep are having a head and body with a combination of colors but dominant white, a convex head profile, no horns, and a thin and fat tail.

Characterization of Myostatin (MSTN) Gene Using PCR-RFLP Method in KUB Chicken

This study aims to obtain MSTN gene diversity and MSTN gene association. The materials used in this study were 96 KUB chickens and 96 KUB chicken blood samples consisting of 41 males and 55 females. This research method is an experiment. Data collected included body weight, weight gain and body size of male and female KUB chickens, and diversity and association of MSTN genes. Data analysis used mean difference test (T-test), T2-Hotelling, Principal Component Analysis (PCA), Genotype and allele frequencies, Hardy-Weinberg equilibrium, Heterozygosity and Polymorphic Information Content (PIC). The results showed that body weight at 1 and 2 months of age, body weight gain at 1-2 months and body size of male KUB chickens at two months were significantly (P&lt;0.05) higher than female KUB chickens. The body size characteristic of male and female KUB chickens is chest circumference (CC) while the body shape characteristic is wing length (WL). The MSTN|MspI gene in KUB chickens is polymorphic. The KUB chicken population is in Hardy-Weinberg imbalance. Heterozygosity of the KUB chicken population showed a value of Ho (0.31) &lt; He (0.51). The MSTN| MspI gene of KUB chicken was associated with body weight, weight gain and body measurements and the best genotype was (-/-).

Beneath the surface: correlates of solitary, paired, and group living in a cryptic burrowing ghost shrimp Trypaea australiensis Dana, 1852 (Decapoda: Axiidea: Calianassidae)

Abstract Marine organisms, particularly invertebrates, are relatively understudied regarding social structure and behaviour, especially those that are cryptic. While empirically challenging to investigate, these species can provide novel insights into the evolution of sociality given their unique ecology. Our aim was to quantify in-situ the social structure and its underlying correlates in the Australian burrowing shrimp, Trypaea australiensis Dana, 1852 (Callianassidae). We show that T. australiensis exhibits intraspecific variation in social structure, being most often found in solitary arrangements, frequently in pairs (including homosexual and heterosexual arrangements), and sometimes in groups. The majority of shrimp in pairs and groups were found in heterosexual pairings or groups of one male and multiple females. Variation in social structure was correlated with variation in body size characteristics, seasonality, and site. These findings demonstrate that a wider array of social structures are exhibited by this species than previously expected, but the obvious limitations associated with sampling a cryptic burrowing species in situ mean that further investigations under controlled conditions, including laboratory behavioural manipulations, will be needed to confirm the current findings. The use of resin casts to understand burrow morphology would be important for understanding the causes of intraspecific variation in this and other cryptic species.

Comparative Transcriptome Analyses of Leg Muscle during Early Growth between Geese (Anser cygnoides) Breeds Differing in Body Size Characteristics.

Goose is an important poultry commonly raised for meat. The early growth performance of geese significantly influences their market weight and slaughter weight, affecting the poultry industry's economic benefits. To identify the growth surge between the Shitou goose and the Wuzong goose, we collected the early growth body traits from 0 to 12 weeks. In addition, we investigated the transcriptomic changes in leg muscles at the high growth speed period to reveal the difference between the two geese breeds. We also estimated the growth curve parameters under three models, including the logistic, von Bertalanffy, and Gompertz models. The results showed that except for body length and keel length, the best-fitting model between the body weight and body size of the Shitou and Wuzong was the logistic model. The growth turning points of Shitou and Wuzong were 5.954 and 4.944 weeks, respectively, and the turning point of their body weight was 1459.01 g and 478.54 g, respectively. Growth surge occurred at 2-9 weeks in Shitou goose and at 1-7 weeks in Wuzong goose. The body size traits of the Shitou goose and Wuzong goose showed a trend of rapid growth in the early stage and slow growth in the later stage, and the Shitou goose growth was higher than the Wuzong goose. For transcriptome sequencing, a total of 87 differentially expressed genes (DEGs) were identified with a fold change ≥ 2 and a false discovery rate < 0.05. Many DEGs have a potential function for growth, such as CXCL12, SSTR4, FABP5, SLC2A1, MYLK4, and EIF4E3. KEGG pathway analysis identified that some DEGs were significantly enriched in the calcium signaling pathway, which may promote muscle growth. The gene-gene interaction network of DEGs was mainly related to the transmission of cell signals and substances, hematological system development, and functions. This study can provide theoretical guidance for the production and breeding management of the Shitou goose and Wuzong goose and help reveal the genetic mechanisms underlying diverse body sizes between two goose breeds.

A high-quality, long-read genome assembly of the whitelined sphinx moth (Lepidoptera: Sphingidae: Hyles lineata) shows highly conserved melanin synthesis pathway genes.

The sphinx moth genus Hyles comprises 29 described species inhabiting all continents except Antarctica. The genus diverged relatively recently (40-25 MYA), arising in the Americas and rapidly establishing a cosmopolitan distribution. The whitelined sphinx moth, Hyles lineata, represents the oldest extant lineage of this group and is one of the most widespread and abundant sphinx moths in North America. Hyles lineata exhibits the large body size and adept flight control characteristic of the sphinx moth family (Sphingidae), but it is unique in displaying extreme larval color variation and broad host plant use. These traits, in combination with its broad distribution and high relative abundance within its range, have made H. lineata a model organism for studying phenotypic plasticity, plant-herbivore interactions, physiological ecology, and flight control. Despite being one of the most well-studied sphinx moths, little data exist on genetic variation or regulation of gene expression. Here, we report a high-quality genome showing high contiguity (N50 of 14.2 Mb) and completeness (98.2% of Lepidoptera BUSCO genes), an important first characterization to facilitate such studies. We also annotate the core melanin synthesis pathway genes and confirm that they have high sequence conservation with other moths and are most similar to those of another, well-characterized sphinx moth, the tobacco hornworm (Manduca sexta).

The effects of body size and training environment on the physical performance of adolescent basketball players: the INEX study

Background Although adolescent basketballers differ in body size, shape, and composition, less is known about how these factors interact during physical development. Aim We used ontogenetic allometry to identify the optimal body size and shape characteristics associated with physical performance in adolescent basketball players, and investigated the effects of training experience, training volume, maturity status, and club characteristics on physical performance development. Subjects and methods Two hundred and sixty-four male basketballers, from five age-cohorts (11–15 years of age), were followed consecutively over three years. Three physical performance components, anthropometrics, training information, and biological maturation were assessed bi-annually. Longitudinal multiplicative allometric models were developed. Results Players with a physique that had a dominant ectomorphic component performed better in all physical performance components. When adjusting for confounders other than size, the development of running speed was independent of body size. Players advanced in maturation were physically fitter. Training data had no significant effect on developmental trajectories of running speed or lower body explosive strength. Club characteristics had no significant association with any physical performance trajectories. Conclusion Leaner players have advantages in physical performance and individual characteristics play an important role, over and beyond club structure, in developing physical performance.

A redescription of Leptochiton belknapi Dall, 1878 (Mollusca: Polyplacophora: Leptochitonidae), the type species of the new genus Belknapchiton

Leptochiton belknapi is revisited, based on a morphological study of more than 340 specimens from different localities in the Pacific Ocean; intraspecific and age variability has been determined and a confirmed distribution of this species has been compiled. The restudy of the species allowed to test the usefulness of a combined character set, which mainly focuses on body size, perinotum coverage, tegmental structures and radula characteristics. By doing so, it turned out that the intraspecific variability is less pronounced than previously assumed. The obtained results and comparison with morphologically similar species, leads to the erection of the new genus Belknapchiton, with Leptochiton belknapi being its type species. The new genus differs from the genus Leptochiton by its elongate oval, large body, rather narrow, sharply pointed perinotum scales with scattered needles, a short radula with a wide central tooth, short first lateral teeth and a strong unidentate (sometimes with denticle-like appendage) head of the second lateral teeth. The vast majority of the 22 species of the new genus inhabit the deep waters of the Pacific Ocean and only B. alveolus (M. Sars MS, Lovén, 1846) is known from the Atlantic Ocean.

Producing xenogenic channel catfish, Ictalurus punctatus with cryopreserved testes and ovarian tissues of blue catfish, I. furcatus

Xenogenesis has been identified as an innovative hatchery technology for hybrid catfish (channel catfish, Ictalurus punctatus ♀ × blue catfish, I. furcatus ♂) embryo production. The xenogeneic process can be accomplished by transplanting primordial germ cells, spermatogonial stem cells (SSC), or oogonial stem cells (OSC), derived from a donor diploid fish into a sterile recipient, which then enables recipient fish to produce donor-derived gametes. Currently, freshly extracted stem cells are used to create xenogens, which is challenging, especially considering germ cell production is donor size and age specific as well as dependent on seasonal cycles. Thus, having frozen stem cells available in germplasm repositories will help to facilitate xenogenesis technology for hybrid catfish production. This study was conducted to assess the effectiveness of fresh and cryopreserved stem cells for germ cell transplantation to support xenogenesis. At 5 days post hatch (DPH), triploid channel catfish were injected with fresh or cryopreserved SSC or OSC labeled with PKH26 dye. At 45 and 90 DPH, body size (total length and weight) and survival of these recipient fish were evaluated. In addition, colonization of fresh and cryopreserved donor cells was evaluated in recipients using PKH26 dye florescence (for percentage of cell area and cluster area) and PCR from gonadal samples. No significant differences in body size characteristics were detected between the fresh and cryopreserved injection treatments at 45 and 90 DPH. Survival was significantly higher in the control treatment than the SSC and OSC injected treatments at both sampling days. Fluorescent imaging revealed that percentage of SSC cell area, SSC cluster area, OSC cell area, and OSC cluster area did not significantly differ between the fresh and cryopreserved treatments at 45 and 90 DPH. There was a significant increase in cell area and cluster area from 45 to 90 DPH for all treatments. According to PCR analyses, a high proportion of xenogens (at 45 and 90 DPH, respectively) were detected in recipient fish injected with fresh SSC (72.2 and 83.3%), cryopreserved SSC (61.1 and 66.6%), fresh OSC (66.7 and 61.1%), or cryopreserved OSC (61.1 and 61.1%). Taken together, our results show that cryopreserved donor stem cells can recover in recipient gonads and perform as well as their freshly extracted counterparts. Hence, cryopreserved stem cells can be used for future germ cell transplantation to support xenogenesis. These findings will enhance the efficiency of germ cell transplantation in xenogenesis for commercial scale hybrid catfish production.