Body Traits Research Articles

QUANTIFYING SIZE AND SHAPE DIFFERENCES BETWEEN MUTURU AND N'DAMA BREEDS OF CATTLE

Body weight and eight linear body traits, namely heart girth, body and diagonal lengths, height at withers and at hip, width of loin and at pelvic bone, and depth at rear flank, were measured forthniylıtly on 32 Muturu bulls, 16 of which were born in the dry season (Muturu -D) and the remaining 16 in the rainy season (Muturu-R), and on 11 N'dama bulls. Correlations between all pairs of traits in all groups were high, positive and significant (r > 0.093). The first two principal components derived from the correlation matrix of the linear measurements, PCI and PC2 accounted for at least 98% of total variance in all cases and were regarded as, size' and 'shape' vectors, respectively. Whereas PC1 gave largest weight to heart girth, PC2 gave largest weight to two or more different other linear measurements in the three groups. N'dama had the best conformation, followed by Muturu -D and then Muturu - R. PC-based prediction models were more parsimonius than linear measure-based models and are considered preferable for selecting animals for "optimal" balance. Also, in addition to discriminating between the two different breeds, PC- based discriminant functions were able to discriminate among individuals within the same breed on the basis of putritional differences. These functions are therefore recommended for classifying animals according to different macro and micro criteria.

Variants in GH, IGF1, and LEP genes associated with body traits in Santa Inês sheep

ABSTRACT: Growth hormone (GH), insulin-like growth factor 1 (IGF1), and leptin (LEP) can be candidate genes for association studies because they play vital roles in the metabolism process. Thus, this study aimed to identify variants in these genes associated with body traits in Santa Ines sheep. The following were recorded: body weight at 100 (BW100) and 240 days (BW240), average daily gain (ADG), withers (WH) and croup (CH) heights, body length (BL), thoracic (TG) and leg (LG) girths, thoracic (TW) and croup (CW) widths, body depth (BD), rib eye area (REA), fat thickness (FT), and carcass finishing score (CFS). Single-locus association analysis was performed with 11 variants in IGF1, 18 in LEP, and 16 in GH. Moreover, two haplotypes in IGF1 and one haplotype in LEP were evaluated in haplotype association analysis. The single-locus analysis revealed 23 suggestive additive effects (p < 0.05), but no additive effect was found at the Bonferroni threshold. Haplotype association analysis revealed 19 additive effects, of which ten were at the Bonferroni threshold (p < 0.0074). In IGF1 gene, haplotype replacements were associated with ADG 20.51(7.37), CH 4.09(1.21), WH 3.52(1.20), BL 3.94(1.19), TG 3.88(1.30), TW 1.13(0.36), and LG 3.40(1.08); while in the LEP gene the haplotype replacement was associated with BW100 1.83(0.51), BD −2.51(0.56), and CFS −0.24(0.06). Therefore, there are haplotypes in IGF1 and LEP genes associated with body traits in Santa Ines sheep, which can be useful in marker-assisted selection.

Biometric measurements of body and internal organ traits of indigenous chickens on free range in South-Eastern Nigeria

A biometric study of the body conformation and internal organs of the indigenous chickens on free range in rural areas of Imo State in South-Eastern Nigeria was conducted using 5 Local Government Areas. It was observed that the predominant plumage colours were black (51.25%) and brown (36.25%) for the hens while the cocks were predominantly black (30.36%) and red (25.01%). The dressed colour of the birds was majorly yellow and white comprising of (70.68%) and (29.32%) for the hens and (77.75%) and (22.25%) for the cocks, respectively. Shank colour was black (95.4%) and white (4.65%) for the hens, while the cocks were (54.24%) black and (46.76%) white respectively. The mean shank length, neck length and back length of 6.725±0.09 cm, 11.11±0.20 cm and 17.77±0.29 cm were estimated for the hens, while the cocks had mean shank length, neck length and back length of 7.79±0.13 cm, 11.35±0.30 cm and 18.29±0.44 cm, respectively. The mean body weights of the hens and cocks were 868.48±21.18 g, and 1032±57.84 g, respectively with cocks being significantly (P&lt;0.05) higher in body weight and back length than hens. The mean biometric and internal organ measures of chickens per Local Government Area (LGA) were also investigated with no significant (P&gt;0.05) differences among chickens in the five LGAs except for weight of proventriculus and full intestine. Regression equations for the prediction of body weight using the biometric and internal organ measurements were obtained under two functional forms (linear and semi-log) which showed a weak coefficient of determination (R2) ranging between 7.5 to 24.3% for biometric measurements, and a strong coefficient of determination (R2) ranging between 21.4 to 98.89% for internal organs. There was no significant correlation coefficient (r) between the biometric measurements taken, but strong and significant correlation (r) was shown between internal organs and body weight. Therefore, indigenous chickens of South-Eastern Nigeria exhibit wide variability among phenotypes in terms of physical appearance, biometric measurement and internal organ characteristics. More so, the internal organs can be predicted more effectively than biometric measurements by the body weight, using regression models of the two functional forms; and significant indirect selection can be made to improve internal organs like gizzard weight using the bodyweight, due to significant correlation coefficient established.

Heterotic effect on body weight and morphometric traits of crossbred buck kids of Red Sokoto and West African Dwarf goats

&#x0D; &#x0D; &#x0D; &#x0D; This study was conducted to evaluate the effect of crossbreeding on body weight and morphometric traits of crossbred buck kids produced from a mating of Red Sokoto(RS) and West African Dwarf(WAD) goats in a humid tropical environment. Results showed that the main crossbred (RS x WAD) buck kids had significantly higher body weight at 20 weeks (8.98 ± 0.43kg) than the reciprocal (WAD X RS) individuals (8.22± 0.12kg) . The Red Sokoto (RS X RS) buck kids maintained overall superiority for body weight (10.48 ±0.49kg) and other morphometric traits namely; body length (72.62 ± 3.18cm), height-at-withers (54.62 ± 3.10cm) and heart girth (63.20 ± 2.41cm)than other genetic groups. Direct and percentage heterosis for body weight and the morphometric traits were positive for the RS x WAD buck kids except for body length which was negative. The reciprocal WAD x RS buck kids had negative values for all measured parameters indicating that the WAD sired buck kids showed no improvement for these body traits following crossbreeding. It was therefore concluded that rapid improvement in growth traits of WAD goats could be achieved by main crossbreeding involving mating of RS bucks with WAD does.&#x0D; &#x0D; &#x0D; &#x0D;

Influence of sire on internal egg quality and linear body traits of Japanese quail raised in the humid tropical environment

A total of 270 pedigreed-hatched day old chicks of three strains of Japanese quail generated from a base population of 36 adultswere used in a randomized complete block design to estimate the influence of sire on the internal egg quality and linear body traits of the birds. Parameters measured were internal egg quality traits - albumen height, yolk height, albumen weight, yolk weight, albumen diameter, albumen length, yolk width, yolk length, yolk index, and haugh unit, and growth traits - body weight, thigh length, breast length, body length, keel length, wing length, and shank length. Results showed that linear bodyparameters were significant (P&lt;0.05) except body weight at week 9. Panda white x Cinnamon brown (PWxCB) progenies out-performed the progenies of the other strains mainly at week 9. The PWxCB strain had the highest values in the following: body weight (159.30), thigh length (4.76), breast width (7.40), body length (11.94), keel length (6.77), and shank length (3.44). The haugh unit value was significantly (P&lt; 0.05) different among the three strains mainly at week 8 with CBxCB strain having higher value of (89.07) followed by PWxCB strain (89.03). The phenotypic correlations between the linear body parameters andinternal egg quality traits in Cinnamon brown x Cinnamon brown (CBxCB) strain were significant (P&lt;0.01) in keel length and yolk weight (0.534) and between shank length and yolk weight (0.473) at week 9. For PWxCB strain, high significant (P&lt;0.01) correlation were seen between shank lengthand albumen length (0.631) at week 8, body weight and yolk index at week 9. Silver brown x Cinnamon brown (SBxCB) strain also showed high positive significant (P&lt;0.01) correlation between shank length and yolk weight (0.541), breast width and albumen weight (0.537) and between body length and albumen weight (0.625) at week 9.These positive correlations imply that by direct selection for any linear body trait for increased meat production, there will be a remarkable genetic improvement in the internal egg quality trait. It can be concluded that PWxCB is a strain of choice for improved growth and internal egg quality characteristics.

Discrimination of the Nigerian local turkeys into breeds using linear body measurements

Turkey is one of the poultry species that is declining in Nigeria due to its importation as frozen turkey. In this study, a total of 78 day-old random-bred Nigerian local turkey poults were used to generate another 232 day-old poults to discriminate Nigerian local turkey based on linear body measurements. Three phenotypic classes (Black, White and Spotted) were obtained as base population and used to generate F1 progeny. Experimental design was a randomized complete block (RCBD) with phenotypic class as major factor of interest and hatch as block. Linear body measurements (LBMs), namely body length (BDL), shank length (SHL), keel length (KLL), breast width (BW), wing length (WGL) and drumstick length (DSL) were significantly different at weeks 7, 9, 11 and 19. There were two discriminant functions. The variance ratio (eigenvalue) of each of the two discriminant functions were not significant (p&gt;0.05). The percentage of the total variance explained was 87.7% and 12.3% for the two functions respectively. Group centroids for the phenotypic classes were 7.210, -1.254 and -5.956 for Black, White and Spotted turkeys respectively. The magnitudes and signs of the group centroids indicate that the three phenotypes are distinctly different from one another when BDL (weeks 7, 11, 13 and 15), WGL (weeks 7, 9 and 11), KLL (weeks 7, 9 and 15) and SHL (weeks 11 and 21) are used as the discriminating factors. The study shows that linear body measurement is a reliable classification criterion for discriminating among the phenotypes, which are therefore, correctly described as different breeds/strains. Therefore, for rapid improvement in local turkeys and breed development, these linear body traits could be used to enhance its discrimination, classification and appropriate grouping into breeds. The present findings could assist in the design of long-term genetic improvement programmes for local turkey breeding and production in Nigeria.

Growth rate, phenotypic correlation and repeatability estimates of body weight and linear body traits of Cobb and Arbor Acre broiler strains

Correlation coefficients are useful tool in animal breeding as a means of predicting potential response. In this study, body weight (BW) and linear body traits records of Arbor Acre and Cobb broiler strains obtained at 3 – 8 weeks were used to compare the growth performance of the strains as well as estimate the phenotypic correlations (rp ) among BW and the linear body traits. Repeatability (R) values of BW and the linear body traits were estimated at weeks 3, 5 and 7. Atotal of 200 day old chicks, 100 each of Arbor Acre and Cobb were used for the study. The linear body traits considered were body length (BL), shank length (SL), chest circumference (CC), keel length (KL), wing length (WL) and drum stick length (DSL). Significant differences (P&lt;0.05) were observed between the strains for BW and the linear body traits at the various weeks. BW differed significantly at weeks 5, 6 and 7, which ranged from 1036.67 ± 36.93 – 1736.67 ± 46.41 for Arbor Acre and 930.00 ± 20.59 – 1563.33 ± 33.26 for Cobb. Arbor Acre showed significant (P&lt;0.05) superiority to Cobb in their linear body traits in most of the weeks. BW had high significant (P&lt;0.05; P&lt;0.01) positive rp with the linear body traits, which ranged from 0.535 (KL) – 0.842 (BL) for Arbor Acre and 0.523 (SL) – 0.834 (BL) for Cobb. The rp among the linear body traits in both Arbor Acre and Cobb were positive but ranged from moderate to high. The R estimate of BW of Arbor Acre and Cobb were all very highly repeatable at weeks 3, 5 and 7 ranging from 0.90 – 0.99. R values for the linear body traits ranged majorly from moderate {(0.31 – 0.67 and 0.37 – 0.69)}to high {(0.78 – 0.97) and 0.97) and (0.71 – 0.92)} for Arbor Acre and Cobb, respectively across the weeks evaluated. The result of this study indicates that Arbor Acre could be a strain of choice for rearing in our study area owing to its superiority over Cobb in terms of growth performance. All the linear body traits measure were good estimators of BW in both strains as well as each other, implying that any phenotypic selection on one trait will lead to improvement of others. The high repeatability estimates of body weight and some of the linear traits indicate that fewer records would be required to adequately characterize the inherent growing ability of the birds at the various stages of growth.

Estimates of repeatability for body weight and conformation traits in three breeds of grower pigs

The aims of the study were to provide estimate of repeatability on the body weight and body traits of the three genotype of grower pigs. Data on 30 growing pigs comprising of three strains, landrace, large white and Duroc of the same age were used to estimate the repeatability ® of body weight (BDW), and linear body traits measured from 2-8 weeks of growth and development. The linear body traits measured was: Head length (HDL), Body length (BDL), body girth (BDG), Ham length (HML), Ear length (ERL) and Neck circumference (NCG). Repeatability estimate for body weight of the three strains were relatively high (0.62, 0.71 and 0.64) for landrace, large white and duroc respectively at 8 weeks of growth. The repeatability values ranged from low to high for other linear body traits (0.2 – 0.52) in the three strains of pigs at early stage of growth. The high repeatability estimates noted for most of the traits imply possible high expected genetic response from inherent transmitting ability of the pigs of traits with moderate's repeatability and the low repeatability estimates recorded for some other traits imply that collection of additional records and improvement of non-genetic factors influencing performance will improve these traits. The three genotype of pigs although were better in terms of development performance, but additional measurements and improvement of non-genetic factors influencing repeatability traits will be needed to realize expected respond from selection.

Characterization of indigenous cattle genotypes based on linear body traits in the humid tropics

Selection for trait of interest is a major problem in cattle production when faced with the challenge of varied growth traits in different genotypes. Low understanding of the production potentials of these cattle breeds constitute problems in effective improvement of physical body characteristics. A total of 18 cattle was used to characterize the Nigerian local cattle genotypes based on quantitative traits. Three genotypic groups {White Fulani (WF), N'Dama (ND) and White Fulani x N'Dama (WFxND)} crosses were used for the experiment. Experimental design was a completely randomized design (CRD) with genotypic group as major factor of interest. Quantitative traits measured were body length (BDL) (cm), hip height (HHT) (cm), heart girth (HG) (cm), horn length (HL) (cm), tail length (TL) (cm), ear length (El) (cm) and neck length (NL). Results showed that there were significant differences (p&lt;0.05) in body length in weeks 99 – 111 and 112 – 124 with the White Fulani and N'Dama genotypes having longer bodies. The values ranged from 33.00 to 39.29cm in WF, 39.49 to 39.59cm in N'Dama and, 18.25 to 32.90 in WF x ND. There were significant (p&lt;0.05) differences in hip height of cattle in age interval of 99-111 and 112-124 weeks of age, with the White Fulani and N'Dama genotypes having highest hip. The genotypes showed significant (p&lt;0.05) differences in heart girth in 99 and 124 WOAwith the White Fulani and N'Dama genotypes having widest heart girth. The genotypes showed significant (p&lt;0.05) differences in horn length in all the weeks with White Fulani showing superiority. The genotype had longer horns in the White Fulani and followed by WF x ND across the week intervals. The values ranged from 14.99 to 15.20cm in WF, 5.75 to 10.19cm in N'Dama and, 3.00 to 4.29 in WF x ND. The tail length of the three genotypes showed significant (p&lt;0.05) differences in 99-111 and 112-124 WOA. Higher values were obtained in White Fulani genotype which showed longer tails than the N'Dama and WF x ND. There were significant (p&lt;0.05) differences in neck length of the cattle genotypes in 112-124 WOA. Higher values were obtained in White Fulani genotype which showed longer neck than the N'Dama and WF x ND. White Fulani could be used to enhance growth of Nigerian indigenous cattle in the study area. The present findings could assist in the design of long-term genetic improvement programmes for cattle production in Nigeria.

Differentiating morpho-functional patterns of the five most common deep-sea benthic anglerfishes (Lophiiformes) from Andaman and Nicobar Islands (eastern Indian Ocean)

Anglerfishes are widely distributed from shallow to deep-water habitats occupying different ecological niches. To explain this adaptability, we performed a morpho-functional study on common benthic anglerfishes inhabiting the Indian deep-sea waters. Sensory capabilities of species were examined using the morphology and morphometry of sagitta otoliths (related to detection sound and hearing) and eye size (related to visual communication). We also performed an analysis of the degree of functional niche overlap using fish body traits to understand the coexistence of species. Otoliths showed a morphological pattern similar to that of other anglerfishes: an archaesulcoid sulcus acusticus and variability in the irregularity of the dorsal margin. This last feature affected the allometric relationships between the otolith morphometry and fish length, as well as the otolith relative sizes of each species. The findings suggested that bigger otoliths are associated with the increase of depth distribution of species up to 1000 m, from which it decreases. Our hypothesis is that anglerfishes with irregular otolith shapes could be linked to more nocturnal feeding behaviour because they were characterized by greater eye sizes. The results also indicated interspecific significant differences in functional traits providing a low niche overlap. Therefore, our study supports the hypothesis of an environmental and ecological specialization of benthic anglerfishes.

Temporal variation in body measurements in three Taurine cattle populations of Burkina Faso supports introgression of Zebu genes into West African Taurine cattle

A total of 769 adult females belonging to 3 taurine and one zebu cattle populations sampled in 3 provinces of Burkina Faso were assessed for 19 body measurements during two different years (2014 and 2018). The aim of this research was to identify temporal morphological variation in cattle bred in the humid southern zones to obtain empirical evidence supporting a possible introgression of zebu cattle genes into Gourounsi and Lobi taurine cattle breeds. Zebu cattle samples were used as out-group for both 2014 and 2018 subsets. Least square means of body measurements allowed to classify Burkina Faso taurine cattle into three subgroups according to body size (Gourounsi–Sanguié –GourS-, Gourounsi-Nahouri –GourN- and Lobi from the tallest to the smallest respectively). Principal Component Analysis suggested that in 2014, taurine populations were structured. Dispersion map constructed using the two first factors informed that the GourS population was well separated from both the Lobi and the GourN, which, in turn, overlapped. However, in 2018 a strong signal of homogenization was identified, with GourN partially overlapping the other two populations. Linear Discriminant Analysis suggested that about 20% of both GourS and GourN individuals were reciprocally misclassified. Clues for such increase have been pointed out by MANOVA analysis. Although on 2014, Lobi cattle was clearly smaller than Gourounsi and both GourS and GourN populations showed clear differences on body traits, on 2018 it could be assessed an increase in size in Lobi cattle and a strong homogenization signal within Gourounsi cattle. Zebu cattle gene flow southwards in Burkina Faso is likely to have caused these changes, suggesting a fast erosion of taurine cattle genetic background. &#x0D; Keywords: Body traits, quantitative traits, Gourounsi cattle, Lobi, Burkina Faso.

The relationship between altitudinal gradients, diversity, and body size in a dung beetle (Coleoptera: Scarabaeinae: Onthophagus) model system

Mountainous regions represent an excellent model to test ecological hypotheses encompassing assemblage diversity and body traits of species. Among insects, there is no uniform body size pattern across temperature gradients, suggesting that processes controlling body size may differ among species. The aim of this study was to explore diversity and body size patterns of dung beetle species of the genus Onthophagus Latreille, 1802 across altitudinal gradients at two mountains in Mexico. Tropical mountain species were sampled from 2200 to 3400 m a.s.l. In both mountains, there was a decrease of richness and abundance of Onthophagus with increasing altitude. There were contrasting relationships between beetle body size and altitude, which varied depending on the data set analyzed. Furthermore, interspecific variations of body size were not related to the number of altitudinal bands recorded by each species. Species from high altitudes were also recorded at lower mountain altitudes, suggesting that diversity at the highest altitudes represents a subgroup of lowland diversity. This may indicate that the fauna inhabiting higher elevations could be the most eurytopic one. Here we present an example of an assemblage that partially contradicts Bergmann’s rule, with contrasting effects of altitude on dung beetle body size.

A general size- and trait-based model of plankton communities

Multicellular zooplankton, such as copepods, are the main link between primary producers and fish. Most models of plankton communities, such as NPZ-type models, ignore the life-cycle (ontogeny) of multicellular zooplankton. Ontogeny has profound implications on population dynamics and community structure. Our aim is to provide a generic food-web framework of planktonic communities that accounts for zooplankton ontogeny. We propose a model framework along the Nutrient–Unicellular–Multicellular axis – a “NUM” framework – as an alternative to the NPZ modelling paradigm. NUM is a mechanistic size- and trait-based model based on traits and trade-offs at the individual level. Here the multicellular component describes the population dynamics of key copepod groups, characterized by their adult size and feeding mode. The unicellular compartment accounts for auto- mixo- and heterotrophic protists. We also consider nitrogen dynamics and carbon export from copepod fecal pellets. All parameters have been fitted to cross-species data. By approximate analytical solutions and dynamic simulations, in both constant and seasonal environments, we investigate the patterns of body sizes and traits that emerge within the community. We show that copepods of several adult sizes and feeding modes commonly coexist, and that competition and predation by large copepods on small/juvenile copepods is an important factor in shaping the community. We also show competition between heterotrophic protists and small copepods through intraguild predation. Finally, we discuss how copepods can attenuate the fecal pellet export. This conceptually simple, yet realistic framework opens the possibility to improve end-to-end size-structured models of marine systems and investigate biogeochemical processes.

Molecular and phenometric characterization of Bhakarwali goat breed of India

Bhakarwali is recently registered as 34th goat breed of India. It is distributed in the hilly tracts of Jammu and Kashmir. The breed is distinct with superior qualities such as high temperature resistance and milk, meat and fiber productivity under the low input system. It’s characterization at phenotypic level was carried out by surveying the breeding tract and at genotypic level by microsatellite markers. Information on body traits, performance traits and managemental practices were collected by interviewing the goat keepers. All the microsatellite loci selected for diversity analysis were polymorphic and a total of 190 alleles were identified across the 23 microsatellite loci. OMHC1 depicted the highest number of alleles (15) while ILSTS065 had the lowest (2) with 8.26±0.663 mean number of alleles per locus. Expected number of alleles ranged from 1.065 (ILSTS044) to 6.755 (OMHC1) with a mean value of 3.613±0.367 alleles per locus. The observed heterozygosity ranged from 0.063 (ILSTS044) to 0.915 (OMHC1) with a mean of 0.629±0.045. Corresponding values of expected heterozygosity varied between 0.061 (ILSTS044) to 0.852 (OMHC1) with a mean of 0.639±0.043. Heterozygote deficiency was negligible as average FIS value was only 0.002±0.033. Bottleneck was examined using all the three mutations models and was found to be absent. Normal L-shaped curve indicated lack of mode shift in the population. This is the first-hand report on current diversity status of Bhakarwali goat and is expected to be useful in planning conservation and in facilitating their effective use in future breeding programs.

Gene flow relates to evolutionary divergence among populations at the range margin.

BackgroundMorphological differentiation between populations resulting from local adaptations to environmental conditions is likely to be more pronounced in populations with increasing genetic isolation. In a previous study a positive clinal variation in body size was observed in isolated Roesel’s bush-cricket, Metrioptera roeselii, populations, but were absent from populations within a continuous distribution at the same latitudinal range. This observational study inferred that there was a phenotypic effect of gene flow on climate-induced selection in this species.MethodsTo disentangle genetic versus environmental drivers of population differences in morphology, we measured the size of four different body traits in wild-caught individuals from the two most distinct latitudinally-matched pairs of populations occurring at about 60°N latitude in northern Europe, characterised by either restricted or continuous gene flow, and corresponding individuals raised under laboratory conditions.ResultsIndividuals that originated from the genetically isolated populations were always bigger (femur, pronotum and genital appendages) when compared to individuals from latitudinally-matched areas characterised by continuous gene flow between populations. The magnitude of this effect was similar for wild-caught and laboratory-reared individuals. We found that previously observed size cline variation in both male and female crickets was likely to be the result of local genetic adaptation rather than phenotypic plasticity.ConclusionsThis strongly suggests that restricted gene flow is of major importance for frequencies of alleles that participate in climate-induced selection acting to favour larger phenotypes in isolated populations towards colder latitudes.

A genome-wide association analysis for body, udder, and leg conformation traits recorded in Murciano-Granadina goats

Morphological traits are of great importance to dairy goat production given their effect on phenotypes of economic interest. However, their underlying genomic architecture has not yet been extensively characterized. Herein, we aimed to identify genomic regions associated with body, udder, and leg conformation traits recorded in 825 Murciano-Granadina goats. We genotyped this resource population using the GoatSNP50 BeadChip (Illumina Inc., San Diego, CA) and performed genome-wide association analyses using the GEMMA software. We found 2 genome-wide significant associations between markers rs268273468 [Capra hircus (CHI) 16:69617700] and rs268249346 (CHI 28:18321523) and medial suspensory ligament. In contrast, we did not detect any genome-wide significant associations for body and leg traits. Moreover, we found 12, 19, and 7 chromosome-wide significant associations for udder, body, and leg traits, respectively. Comparison of our data with previous studies revealed a low level of positional concordance between regions associated with morphological traits. In addition to technical factors, this lack of concordance could be due to a substantial level of genetic heterogeneity among breeds or to the strong polygenic background of morphological traits, which makes it difficult to detect genetic factors that have small phenotypic effects.

Genotype by environment interactions of harvest growth traits for barramundi (Lates calcarifer) commercially farmed in marine vs. freshwater conditions

Barramundi (Lates calcarifer), also known as Asian seabass, is a commercially important tropical aquaculture species farmed in diverse culture production systems and salinities (marine to freshwater). Despite adaptability to different culture conditions, selective breeding programs to improve growth rates in barramundi should consider the impact of genotype by environment (GxE) interactions on genetic gains. Barramundi juveniles from 144 families, originating from 24 dams and 54 sires were farmed in a seawater (SW) raceway in Bowen (QLD, Australia) and a freshwater (FW) pond environment in Townsville (QLD, Australia) - both operated under commercial culture conditions. Fish were sampled at 15 months post-hatch (mph) in the SW raceway (mean 1718 ± 309 g weight (W), 454 ± 28 mm total length (Lt) and 141 ± 11 mm body depth (BD) (n = 752)) and at 21 mph in the FW pond (mean 1905 ± 426 g W and 451 ± 39 mm Lt and 144 ± 15 mm BD (n = 752)). DNA parentage analyses were used to assign progeny to their respective parents, and the final dataset comprised of 1116 offspring. Moderate-low heritability estimates were found for body traits (W h2 = 0.46 ± 0.10; Lth2 = 0.41 ± 0.12; BD h2 = 0.49 ± 0.13; body shape H h2 = 0.41 ± 0.12; and Fulton's K condition factor h2 = 0.15 ± 0.07). Deformities (Def) were observed in 1.8% of fish in SW and 25.1% of fish in FW, although negligible additive genetic effects were evident (Def h2 = 0.05 ± 0.04). GxE interactions were found to be moderate for harvest growth traits (W GxE rg = 0.81 ± 0.11; Lt GxE rg = 0.64 ± 0.18; BD GxE rg = 0.78 ± 0.13; H GxE rg = 0.71 ± 0.17), and high for Fulton's K condition factor (K GxE rg = 0.36 ± 0.31; P > 0.05). This study reveals the presence of weak to moderate re-ranking of genotypes for harvest growth traits in L. calcarifer farmed in marine and freshwater conditions, suggesting that GxE interactions should be taken into account in a breeding program servicing multiple environments. Incorporation of sib-information from extreme salinity environments into the selection criteria of a breeding program may therefore optimize the realization of genetic gains across distinct commercial conditions.

Male genitalia's evolutionary rate is higher than those of body traits: the case of two Liolaemus lizards' group

AbstractDifferent studies suggest that reproductive characters evolve faster than non‐reproductive characters. Males in the order Squamata have paired copulatory organs called hemipenes, with high morphological diversity, including differences in size, shape, and ornamentation. Some studies in the species‐rich lizard genus, Anolis suggest that genital traits evolve faster than the rest of the body. However, these studies were made considering only a few traits, across a wide phylogeny, without considering species relatedness, which may inflate differences in evolutionary rates. Here, we study two phylogenetic distantly related lizard groups, which differ in the number of species, but have similar divergence times. We evaluate as follows: (1) evolutionary rate, models of evolution and phylogenetic signal among the different genital and non‐genital traits; (2) which kind of traits (genital and non‐genital) are divergent across sister species and (3) whether the species‐rich group shows a faster rate of trait change. We studied 24 Liolaemus lizard species, belonging to two monophyletic groups that differ in species number: L. elongatus' clade, which has more species than L. lineomaculatus' clade. We studied 20 different traits (9 genital and 11 non‐genital) and calculated their phylogenetic signal, evolutionary rate of change and models that best explain the evolutionary change. Our results show that: (1) in general, genital traits evolve faster than non‐genital ones in both groups, and both phylogenetic signal and best evolutionary model vary depending on the trait. (2) Genital traits diverged more among sister species within the L. lineomaculatus group, but within the L. elongatus group, both sets of traits show similar degrees of divergence. Finally, (3) the species‐rich group (L. elongatus), has the highest genital evolutionary rate but also the highest non‐genital evolutionary rate.

Adaptation and constraint shape the evolution of growth patterns in passerine birds across the globe

BackgroundGrowth trajectories should be adapted to selective factors of each species’ environment. However, major shaping forces of growth and development are unclear, especially when studying several traits at once. Birds provide an ideal opportunity to analyze growth patterns across species due to there being enough available data. We tested the relative importance of nest predation risk, the number of care-givers, nest height, foraging substrate, clutch size, and latitude on growth patterns of passerine birds (Passeriformes) using phylogenetic comparative methods. Specifically, we studied the evolution of fledging time, average and peak growth rates, and relative development at fledging of body mass and tarsus, wing, and tail length.ResultsUsing a comprehensive literature search and data quality control, we obtained data on growth in 231 species based on 295 populations. Species with long development in the nest grew slowly and had well-developed traits at fledging. Species breeding under high nest predation risk, building their nests close to the ground, and those living in northern temperate regions fledged early and grew fast, sometimes fledging with less developed body mass and traits critical for locomotion (tarsus, wing, and tail). On the other hand, the number of caring adults, clutch size, and species’ foraging substrate had very limited predictive value for growth patterns across passerine species.ConclusionsShortening of the nestling period was a primary means of accelerating development (in relation to nest predation, nest height, and latitude), sometimes supplemented by higher peak growth rates of body mass, tarsus, and wing (especially in relation to latitude). Overall growth patterns of passerines were adaptively tuned to nest predation risk and nest height, with northern temperate species having especially short nestling periods and fast growth rates of body mass, tarsus, and wing.

Morphological variation in two sigmodontine rodents along the mainland and the Fuegian archipelago in Chilean southern Patagonia

BackgroundAnalysis of morphological variation in archipelagos has been essential to understand the evolution of terrestrial vertebrates. In particular, these natural scenarios allow to assess morphological changes experienced by insular fauna compared to their mainland counterparts. In mammals, morphological changes of insular forms have been observed in size and shape of body and cranial traits. The southern Patagonia of Chile represents a unique scenario to analyze morphological variation in two of the most widely distributed small rodents along western southern South America: Abrothrix olivacea and Oligoryzomys longicaudatus.MethodsWe applied linear and three-dimensional geometric morphometric tools to analyze the variation in cranial morphology of A. olivacea (N = 80) and O. longicaudatus (N = 49). Sampled localities were distributed in the mainland and islands of the Fuegian archipelago in Chilean Patagonia. Standard multivariate methods, as Principal Components Analysis, and Logistic Regression models were carried out to evaluate differences in size and shape of crania.ResultsWe detected higher levels of morphological variation in the crania of A. olivacea if compared to O. longicaudatus. The variation was associated to cranial size instead of shape.We observed significant differences between insular and mainland individuals in A. olivacea, being the cranium size of this species significantly bigger on islands. Indeed, specimens of A. olivacea from “Isla Wellington”, exhibited the higher increment in cranium size compared to any other mainland and insular site sampled for this species. In contrast, insular and mainland forms of O. longicaudatus did not show significant differences in cranial morphology.ConclusionsWe suggest that the patterns of morphological variation observed in these two small rodents along Patagonia, could be explained in terms of the historical biogeography of the region, and the different ecological features of the studied species.