Intersexual Differences Research Articles

Differential growth rate, water use efficiency and climate sensitivity between males and females of Ilex aquifolium in north-western Spain.

Dioecious plant species, i.e., those in which male and female functions are housed in different individuals, are particularly vulnerable to global environmental changes. For long-lived plant species, such as trees, long-term studies are imperative to understand how growth patterns and their sensitivity to climate variability differentially affect the sexes. Here, we explore long-term intersexual differences in wood traits, namely radial growth rates, water use efficiency quantified as stable carbon isotope abundance of wood cellulose, and their climate sensitivity in Ilex aquifolium trees growing in a natural population in NW Spain. We found that sex differences in secondary growth rates were variable over time, with males outperforming females in both radial growth rates and water use efficiency in recent decades. Summer water stress significantly reduced the growth of female trees in the following growing season, while the growth of male trees was primarily favoured by cloudy and rainy conditions the previous fall and winter combined with low cloud cover and warm conditions in summer. Sex-dependent lagged correlations between radial growth and water availability were found, with a strong association between tree growth and cumulative water availability in females at 30 months and in males at 10 months. Overall, our results point to greater vulnerability of female tress to increasing drought, which could lead to sex-ratio biases threatening population viability in the future.

Musculoskeletal Dimension and Brightness Reference Values in Lumbar Magnetic Resonance Imaging-A Radio-Anatomic Investigation in 80 Healthy Adult Individuals.

Background/Objectives: Magnetic resonance imaging (MRI) is the preferred diagnostic means to visualize spinal pathologies, and offers the possibility of precise structural tissue analysis. However, knowledge about MRI-based measurements of physiological cross-sectional musculoskeletal dimensions and associated tissue-specific average structural brightness in the lumbar spine of healthy young women and men is scarce. The current study was planned to investigate characteristic intersexual differences and to provide MRI-related musculoskeletal baseline values before the onset of biological aging. Methods: At a single medical center, lumbar MRI scans of 40 women and 40 men aged 20-40 years who presented with moderate nonspecific low back pain were retrospectively evaluated for sex-specific differences in cross-sectional sizes of the fifth lumbar vertebrae, psoas and posterior paravertebral muscles, and respective sex- and age-dependent average brightness alterations on T2-weighted axial sections in the L5-level. Results: In women (mean age 33.5 years ± 5.0 (standard deviation)), the investigated musculoskeletal cross-sectional area sizes were significantly smaller (p < 0.001) compared to those in men (mean age 33.0 years ± 5.7). Respective average musculoskeletal brightness values were higher in women compared to those in men, and most pronounced in posterior paravertebral muscles (p < 0.001). By correlating brightness results to those of subcutaneous fat tissue, all intersexual differences, including those between fifth lumbar vertebrae and psoas muscles, turned out to be statistically significant. This phenomenon was least pronounced in psoas muscles. Conclusions: Lumbar musculoskeletal parameters showed significantly larger dimensions of investigated anatomical structures in men compared to those in women aged 20-40 years, and an earlier onset and faster progress of bone loss and muscle degradation in women.

VARIABILITY OF SOMATOTYPES ACCORDING TO HEATH-CARTER IN ADULT CHUVASH PEOPLE

Introduction. In the range of topical problems of modern human morphology, the doctrine of bodily constitution occupies an important place, but there is a shortage of data on population variability of somatotypes in the literature. The purpose of this cross-sectional study was to study age and sex variations in body composition components using the Heath-Carter method in the Chuvash rural population examined in several villages in the Mariinsky-Posad, Morgaushsky and Yadrinsky districts of Chuvashia and Chuvash villages in the Aurgazinsky and Bizhbulyaksky districts of Bashkiria. The tasks included the determination and analysis of somatotypes according to Heath-Carter of men and women in age subgroups of adult Chuvash and assessment of age-related variability of sexual dimorphism of somatotype scores. Materials and methods. The study sample consists of 802 men aged 18–89 years (M = 46.9) and 738 women aged 18–90 years (M = 48.6) examined in 1994, 1999 and 2002. Age and sex differences were assessed using one-way analysis of variance. Mahalanobis distances were used to rate the sexual dimorphism of somatotype components. Results and discussion. Sex differences in the assessment of somatotype variations in the Chuvash population turn out to be most significant for the characteristics of endomorphy, with higher values in women. The values of endomorphy in men after 30 years practically did not change, but in women it continued to increase until the 6th decade, and then decreased with age. There were practically no differences in the mesomorphy; very small differences were found in ectomorphy between men and women aged 18-30 years. Mesomorphy increases from 18-30 years to 50 in both sexes; the ectomorphy shows opposite age trends. A leveling of sex differences in all body composition components was recorded in the older part of the combined sample (70 – 80 years old). Conclusions. Local patterns of age-related variability in body composition components for ethnic Chuvash are shown. For the first time, using representative material, indicators of sexual dimorphism have been determined for the complex of components of endomorphy, mesomorphy and ectomorphy in the Chuvash, showing the maximum intersexual differences in the age range of 41-60 years. A predominance of endomesomorphic body types in both sexes was revealed, with a tendency towards balanced mesomorphy in men (the youngest male subgroup is characterized by an ectomesomorphic somatotype).

Eye morphology in four species of tiger beetles (Coleoptera: Cicindelidae)

Compound eyes undoubtedly represent the widespread eye architecture in the animal kingdom. The insects' compound eye shows a wide variety of designs, and insects use their visual capacity to accomplish several tasks, including avoiding enemies, searching for food and shelter, locating a mate, and acquiring information about the environment and its surroundings. Broad literature data support the concept that visual ability lies in the way the eyes are built. Since the resolution and sensitivity of the compound eye are partly determined by the density of the ommatidia and the size of the facets. Morphological parameters of the compound eyes could influence the function of the visual organ and its capacity to process information, also representing a sensitive indicator of different habitat demands. In this study, we compared compound eyes' parameters in four closely related species of tiger beetles to disclose differences arising from different habitats. Furthermore, to investigate whether there are consistent intersexual differences, we also compared the most relevant parameters of the eye in males and females of four selected species. Our results show sex-related and interspecific differences that occur in examined species.

Experiments with a set of cooperative enrichment devices used by groups of Indo-Pacific bottlenose dolphins

Dolphins in the wild cooperate to find food, gain and maintain access to mating partners, look after their young ones, or for the sheer joy of play. Under human care, environmental enrichments provide mental and physical stimulation and opportunities for the dolphins to practice their natural abilities. In this review, I focus on a set of enrichment devices we designed for cooperative problem-solving. They allowed the dolphins to utilize and improve their cognitive skills, leading to improved socialization within the group. While the devices provided appropriate challenges to the dolphins, they also allowed the investigation of the impact of demographic and social factors on the cooperative actions. We found that age and relatedness had no impact on cooperation; in turn, cooperation increased with group size. In addition, during the use of these cognitive enrichments, partner preference and intersexual differences were revealed in cooperative actions. The novel multi-partner devices were not only used by dolphin pairs but also by dolphin trios and quartets, providing evidence for group-level cooperation. In addition, a novel food-sharing device was used prosocially by dolphin pairs. Finally, the introduction of these cognitive enrichments leads to measurable short- and long-term welfare improvement. Thus, the use of these cognitive enrichments paired with systematic data collection bridged science with welfare. Future studies will investigate intersexual differences in independent groups, the emergence and function of cooperative interactions, and the socio-dynamics using cognitive enrichments.

Sex-specific scaling of leaf phosphorus vs. nitrogen under unequal reproductive requirements in Eurya japonica, a dioecious plant.

Previous work searching for sexual dimorphism has largely relied on the comparison of trait mean vectors between sexes in dioecious plants. Whether trait scaling (i.e., the ratio of proportional changes in covarying traits) differs between sexes, along with its functional significance, remains unclear. We measured 10 vegetative traits pertaining to carbon, water, and nutrient economics across 337 individuals (157 males and 180 females) of the diocious species Eurya japonica during the fruiting season in eastern China. Piecewise structural equation modeling was employed to reveal the scaling relationships of multiple interacting traits, and multivariate analysis of (co)variance was conducted to test for intersexual differences. There was no sexual dimorphism in terms of trait mean vectors across the 10 vegetative traits in E. japonica. Moreover, most relationships for covarying trait pairs (17 out of 19) exhibited common scaling slopes between sexes. However, the scaling slopes for leaf phosphorus (P) vs. nitrogen (N) differed between sexes, with 5.6- and 3.0-fold increases of P coinciding with a 10-fold increase of N in male and female plants, respectively. The lower ratio of proportional changes in P vs. N for females likely reflects stronger P limitation for their vegetative growth, as they require greater P investments in fruiting. Therefore, P vs. N scaling can be a key avenue allowing for sex-specific strategic optimization under unequal reproductive requirements. This study uncovers a hidden aspect of secondary sex character in dioecious plants, and highlights the use of trait scaling to understand sex-defined economic strategies.

Sex-specific heterothermy patterns in wintering captive Microcebus murinus do not translate into differences in energy balance

The physiological mechanisms of responses to stressors are at the core of ecophysiological studies that examine the limits of an organism's flexibility. Interindividual variability in these physiological responses can be particularly important and lead to differences in the stress response among population groups, which can affect population dynamics. Some observations of intersexual differences in heterothermy raise the question of whether there is a difference in energy management between the sexes. In this study, we assessed male and female differences in mouse lemurs (Microcebus murinus), a highly seasonal malagasy primate, by measuring their physiological flexibility in response to caloric restriction and examining the subsequent impact on reproductive success. Using complementary methods aiming to describe large-scale and daily variations in body temperature throughout a 6-month winter-like short-day (SD) period, we monitored 12 males and 12 females, applying chronic 40% caloric restriction (CR) to 6 individuals in each group. We found variations in Tb modulation throughout the SD period and in response to caloric treatment that depended on sex, as females, regardless of food restriction, and CR males, only, entered deep torpor. The use of deeper torpor, however, did not translate into a lower loss of body mass in females and did not affect reproductive success. Captive conditions may have buffered the depth of torpor and minimised the positive effects of torpor on energy savings. However, the significant sex differences in heterothermy we observed may point to physiological benefits other than preservation of energy reserves.

Sexual dimorphism and allometry in the head and body size of two viperid snakes (genus Vipera)

Sexual dimorphism in the size and shape of the body and head is the result of manifold selective pressures acting on organisms. In snakes, sexual size dimorphism is common and has been well-studied. However, intersexual differences in relative head size and shape have attracted far less attention. Similarly, the allometric properties of head shape and size in snakes are poorly known. Here, we analyse sexual dimorphism in two viperid species: European adder Vipera berus (Linnaeus, 1758) and Steppe viper Vipera renardi (Christoph, 1861). We measured body length, tail length and several head characteristics: head length, head width, head height, pileus length, interorbital distance and internarial distance. Our findings were that males and females of both species did not differ in body length (SVL), but that males tended to have significantly longer tails; there were also significant differences in head characteristics – males tended to have higher heads, and larger internarial and interorbital distances. The head dimensions displayed negative allometry when compared against SVL but when scaled against head length, dimensions like head height and head width exhibited positive allometry. We argue that these differences may be related to sexual selection and that the wider heads may also serve as antipredatory signal.

Diet composition of three amphisbaenian species (Amphisbaena alba, Amphisbaena pretrei, and Amphisbaena vermicularis) from Northeast Brazil

Amphisbaenians usually have a diet composed of a wide variety of small arthropods, with some species being more selective in their feeding and others considered more generalist. Using only specimens deposited in scientific collections, the diet composition of Amphisbaena alba Linnaeus, 1758, Amphisbaena pretrei Duméril and Bibron, 1839, and Amphisbaena vermicularis Wagler, 1824 from the Northeast region of Brazil was analyzed. Except for individuals of A. alba, due to the small sample size, we also investigated the possible intersexual difference in the volume, length, and number of prey in the diet of amphisbaenians and the possible relationship between prey volume and body size (snout–vent length) of individuals was analyzed. The diet of worm-lizard in general was composed of termites, cockroaches, ants, and beetle larvae, and no intersexual differences were found in the size, length, and number of consumed prey. The body size of A. pretrei and A. vermicularis showed no relationship with the volume of prey consumed. Amphisbaenians presented a characteristic diet of opportunistic generalist predators, with several food categories in the composition of their diets, indicating that the studied species feed according to the availability and abundance of prey in the environment.

Sexual dimorphism in skull size and shape of Laticauda colubrina (Serpentes: Elapidae).

Sexual dimorphism in size and shape is widespread among squamate reptiles. Sex differences in snake skull size and shape are often accompanied by intersexual feeding niche separation. However, allometric trajectories underlying these differences remain largely unstudied in several lineages. The sea krait Laticauda colubrina (Serpentes: Elapidae) exhibits very clear sexual dimorphism in body size, with previous studies having reported females to be larger and to have a relatively longer and wider head. The two sexes also differ in feeding habits: males tend to prey in shallow water on muraenid eels, whereas females prey in deeper water on congerid eels. I investigated sexual dimorphism in skull shape and size as well as the pattern of skull growth, to determine whether males and females follow the same ontogenetic trajectories. I studied skull characteristics and body length in 61 male and female sea kraits. The sexes differ in skull shape. Males and females follow distinct allometric trajectories. Structures associated with feeding performance are female-biased, whereas rostral and orbital regions are male-biased. The two sexes differ in allometric trajectories of feeding-related structures (female biased) that correspond to dietary divergence between the sexes. Sea kraits exhibit clear sexual dimorphism in the skull form that may be explained by intersexual differences in the feeding habits as well as reproductive roles. The overall skull growth pattern resembles the typical pattern observed in other tetrapods.

Distribution and Biology of Duskyfin Glassy Perchlet Parambassis wolffii (Ambassidae) in the Mekong River Delta, Vietnam

The results of the study of the distribution and biology of the duskyfin glassy perchlet Parambassis wolffii (Bleeker, 1850) in the Mekong Delta in 2019–2020 are presented. It is established that the species reaches the highest abundance and biomass in the freshwater part of the delta. The water temperature at which individuals of the species were encountered was 27.8–34.1°C, salinity, up to 1.51‰, depths, from 2 to 35 m. The maximum total length of females and males was 20.0 and 14.7 cm, respectively, and the maximum age was 6 years. The parameters of the von Bertalanffy equation are as follows: the maximum length is 17.2 cm, the growth rate constant is 0.18, t0 = −2.35. The value of the coefficient b in the equation on the weight-length relationship is 3.002 ± 0.056 for females (isometry) and 2.774 ± 0.064 for males (negative allometry). Intersexual differences by the in Fulton’ condition factor were established: in females 3.71 ± 0.04, in males 3.53 ± 0.03. The first mature individuals were found at a length of 7–8 cm at the age of 1+.

Evaluation of secondary sexual dimorphism of the dioecious Amaranthus palmeri under abiotic stress

The evolution of secondary sex-specific traits of dioecious species under abiotic stress conditions has received limited research, especially in the case of Amaranthus palmeri, a fast adapting and highly competing plant. Here, we have examined the interactive effects of abiotic stress on mineral accumulation, chlorophyll a and b content, and the operating capacity of Photosystem II (PSII) in both male and female A. palmeri plants grown under three different intensities of white light, and under N, K or P deficiency. Mineral profiling of the leaves and stems (with inflorescence) highlighted intra- and intersexual differences in their accumulation pattern and mineral associations. Chlorophyll a and chlorophyll b were different between the male and the female plants, being slightly lower in the latter, at high light intensity towards maturity, or under K or P deficiency. Further, slight, although statistically significant differences were recorded in the chlorophyll a/b ratio, which was lower at the higher light intensity in the female, over that in the male, plants towards maturity. Chlorophyll fluorescence parameters, i.e., steady state and maximum fluorescence increased under high light intensity, whereas the PSII operating efficiency decreased in the female plants, indicating reduced PSII capacity. Sex-specific differences in A. palmeri showed a differential response to stressful conditions because of differences in their ontogeny and physiology, and possibly due to the cost of reproduction. We suggest that the breeding system of dioecious species has weaknesses that can be used for the ecological management of dioecious weeds without relying on the use of herbicides.

Sexual shape dimorphism in Bufo verrucosissimus (Pallas, 1814) from Lake Borçka Karagöl, Türkiye

Sexual dimorphism, i.e., differences in morphology between sexes of a species caused by intersexual differences in the strength or direction of sexual or natural selection, is prevalent throughout the animal kingdom. Contrary to differences in body size, little is known about sexual shape dimorphism in anurans. Here we investigated intersexual shape differences in Bufo verrucosissimus (Pallas, 1814) by taking 27 linear measurements to characterize body morphology of 23 males and 23 females. Relative to their overall body size, males had longer limbs and larger eyes, while females displayed larger parotoid glands and had wider heads. We speculate that these intersexual differences may have arisen due to differences in natural and sexual selection regimes acting on males and females, especially during foraging, mate searching, or intrasexual competition.

Distinct inter and intrapopulation variation in the otolith shape and size of Mullus barbatus (Actinopterygii: Mullidae) from the Bizerte and Ghar El Melh lagoons in Tunisian waters

ABSTRACT This study aimed to assess the geographic variation in otoliths’ shape and size and the effect of potential fluctuating asymmetry (FA) in otolith size on the stock structure of Mullus barbatus collected from the Bizerte and Ghar El Melh lagoons located in northeastern Tunisia and to evaluate the relationship between the otolith mass asymmetry (OMA) and total length (TL). Analysis of the otolith shape showed a statistically significant intersexual shape difference, i.e. asymmetry, in the left and right and left-left and right-right otoliths between populations of the two lagoons. In addition, significant intersexual differences were detected in Lo, Wo, and Mo, as well as in FA, between the left and right otoliths among the two populations. Moreover, no statistically significant relationship (P > 0.05) was found between OMA and TL between and within the two populations. At the intrapopulation level, a significant intrasexual asymmetry was observed in the left and right, as well as on left-left and right-right sides, otoliths’ shape and size only within the Ghar El Melh lagoon. Discriminant function analysis of the otoliths’ contour shape confirmed the presence of two separate stocks representing the Bizerte and Ghar El Melh lagoons, which should be managed separately. This significant inter and intrapopulation asymmetry detected in otolith shape and size due to FA can be attributed to the instability of larval development caused either by environmental stress associated with variation in water temperature, salinity, feeding conditions and pollutants or due to poor living conditions of larvae resulting from unfavourable environments.

Intersexual and body size-related variation in chemical constituents from feces and cloacal products involved in intraspecific communication of a fossorial amphisbaenian.

Many animals rely on chemical cues for intraspecific communication. This is especially important in fossorial animals because visual restrictions of the underground environment limit the opportunities for visual communication. Previous experiments showed the ability of the amphisbaenian Trogonophis wiegmanni to discriminate between several categories of conspecifics based on chemical cues alone. However, in contrast with many other reptile species, T. wiegmanni does not have external secretory glands, but uses uncharacterized secretions from the cloaca in intraspecific chemosensory communication. Using gas chromatography-mass spectrometry (GC-MS), we analyzed the lipophilic compounds from feces and cloacal products freshly extracted from the cloaca of male and female T. wiegmanni. We identified and estimated relative proportions of the compounds found, and tested for intersexual and body-size related differences. We found a total of 103 compounds, being some steroids (mainly cholesterol and cholestanol), some alkanes and squalene the most abundant and frequent. Further, we found intersexual differences, with males, especially larger ones, having higher proportions of several alkanes between C13 and C24 and of squalene than females, which had higher proportions of several steroids and also of nonacosane and methylnonacosane than males. We compared these findings with secretions of other animals and discuss the potential role of these compounds and their variations in intraspecific communication of amphisbaenians.

Blondes do it better? A comparative study on the morphometry and life-history traits of commercially important skates blonde ray Raja brachyura, thornback ray Raja clavata, and spotted ray Raja montagui, with management implications

Due to data limitation and challenges with species-specific reporting, the management of European skate fisheries currently lacks measures tailored to individual species. Given these caveats, detailed information about skate stocks at the species level is warranted. The morphometry and life-history parameters were determined for samples of 170 individuals (58 Raja brachyura, 92 R. clavata, 20 R. montagui) collected by observers in commercial fisheries, and two bottom trawl surveys (December 2020 – August 2021) in the Southern North Sea and Eastern English Channel. A combination of three morphometric measurements were considered and proven successful (3.846% misclassification, N = 78) in species discrimination for easily confusable species R. brachyura and R. montagui. Through the application of these morphometric descriptors in electronic catch monitoring via Artificial Intelligence (AI), the misidentification of easily confusable species may be reduced in future catch reporting from surveys, fisheries-dependent data, and market sampling. Additionally, the morphometric differences between species may have implications for species’ catchability, and gear modification to avoid bycatch of skates under the European Landing Obligation (LO). The length-weight relationships indicated a faster rate of increase in body mass per unit of size for R. montagui. Life-history trait parameter estimates were obtained for R. clavata and R. brachyura. Age was determined through digital processing of images from visually enhanced whole vertebral centra (0.01% crystal violet staining). Age reading precision was low (CV > 45%, PA < 60%). The von Bertalanffy and logistic growth models provided more accurate fits for the length-at-age data than the Gompertz model. Macroscopic maturity assessment revealed that male R. montagui matured at the smallest size (Lm = 57.5 cm), while female R. brachyura matured at the largest size (Lm = 87.6 cm). Maturity ogives were fitted for males (L50 = 65.4 cm) and females (L50 = 84.1) of R. clavata and females of R. brachyura (L50 = 82.7 cm), with statistically significant intersexual differences for R. clavata. The Legal Minimum Landing Size (LMLS) measures of smaller sizes may not offer adequate protection (to immature specimens) of the skate species in the present study, that mature at larger sizes. The life-history trait parameters for growth and maturity are discussed in relation to published results of earlier studies, and no major changes in the life-history parameter traits were observed in recent years. The interspecific differences in the morphometries and life-history traits of R. brachyura, R. clavata, and R. montagui highlight the need for species-specific data collection and management considerations of skate stocks in the Northeast Atlantic Region at the local and EU level.

Use of third molar eruption based on Gambier's criteria in assessing dental age.

The biological aspects of determining the dental age of subadults represent an important interdisciplinary scientific link with applications in criminal law and in forensic anthropology and dentistry. In criminal procedural law, it is necessary to determine the exact age of an undocumented person in view of the application of the provisions on juvenile offenders and minor victims. Chronological age can be estimated from the development of the third molars, as these are the only teeth that develop at the age of 18. The aim of this study was to verify the applicability of the Gambier method based on the eruption of the third permanent molars in the mandible and maxilla, to contribute to forensic age assessment. The analyzed group that met the criteria consisted of 811 orthopantomograms (OPGs) (339 females and 472 males) between the ages of 13 and 25years. The OPGs were retrospectively analyzed according to the method of Gambier et al. (Int J Legal Med 133:625-632, 29), which refers to the eruption stages of the third molar. Differences between eruption stages of maxillary and mandibular third molars were statistically significant in both biological sexes. Intersexual differences in mean age were significant only at stage 3 for any M3 tooth and at stage 1 for mandibular M3. There were no statistically significant differences between the left and right mandibular and maxillary third molars, respectively. Differences between mandibular and maxillary M3 were significant only for stage 1 in males on the left side and for stage 2 in both sexes and sides. The method used allowed the best classification of individuals into minor and adult groups (based on phase D-90.41% of individuals, based on the third stage of the mandibular left third molar-86.29%). Based on the results obtained, we can assume that the method cannot be used alone in the initial examination of living individuals, since all four third molars must be assessed and there are no additional findings from practice.

Allometric analysis of sexual dimorphism and morphological variation in two chromosome races of the Sceloporus grammicus complex (Squamata: Phrynosomatidae) from Mexico

Sexual dimorphism is a widespread feature in the Animal Kingdom. In lizards of the Sceloporus grammicus complex, studies of sexual dimorphism that analyze the allometric trajectories of body traits remain unexplored. Here we investigate sexual dimorphism in key phenotypic traits, including body size (snout-vent length, SVL) as well as head length (HL), head width (HW), and forearm length (FL). We use an allometric approach to detect differences in scale relationships among body parts in the S. grammicus complex in Mexico. We focus on two chromosomal races within this complex, F5 (2n = 34) and FM2 (2n = 46). In the complex, we found that males are larger than females in all morphological variables, and this pattern was confirmed in both races. We determined negative allometric trajectories (SVLvs.HL and HW), isometry (SVLvs.FL) and intersexual differences in the slopes of the SVLvs.HL and HW; the males showed steeper slopes. Thus, the growth of the head is more pronounced in males than females. Additionally, we found between-race differences in these trajectories (SVLvs.FL) and in all morphological variables (F5 lizards are larger than those of the FM2 race), which correlate with their chromosomal divergence. We discuss biological implications of our findings in relation to sexual selection and natural selection.

Sexual dimorphism and bilateral difference of fingerprint sweat pore among Slovak population

Third level dermatoglyphic markers show a high level of individuality. Despite this fact, the occurrence of individual sweat pore types is still insufficiently studied due to their problematic extraction. The aim of our study was to evaluate the variability of sweat pore types on distal fingertips in the Slovak population and to establish the most uniform method for delineating the evaluated fingerprint area of 1 cm2 in size to avoid bias in the obtained data. In this study, the variability of seven sweat pore types (round, rhomboid, elliptical, square, rectangular, triangular, hexagonal) on distal phalanges were investigated in a sample of 60 volunteers (30 females and 30 males) from the Slovak population. The evaluated area was 1 cm2. Since none of the previously used definition methods seems to be completely reliable, we developed our own method using individual types of dermatoglyphic patterns. This method allowed an uniform location of the studied fingerprint area. The results suggest that sweat pores, like other dermatoglyphic characteristics, have strong identification potential. Several statistically significant bilateral and intersexual differences were found in both male and female populations. Significant intersexual differences in all categories were found in rhomboid and rectangular sweat pore types. Their use could be applied to partial or otherwise unusable fingerprints. The results of this study could help to incorporate these prints into the identification process, allowing their full use.

Sex Differences in Thermal Tolerance of Nine Ornamental Fish Species from the Poecilidae, Cichlidae and Cyprinidae Family

Thermal tolerance and intersexual differences of nine ornamental fish species (Chindango demosoni, Aulonocara stuartgranti, Mylandia lombardoi; Cichlidae; Carassius auratus, Pethia conchonius, Branchydanio rerio; Cyprinidae; Xiphophorus helleri, X. maculatus, Poecilia reticulate; Poecilidae) were determined in this study. CT-min of the species ranged between 9.63 and 11.37 in poecilids, 11.29 and 12.53 in cichlids, 4.67 and 8.46°C in cyprinids, while CT-max ranged between 39.12 and 40.53 in poecilids, 37.82 and 39.37 in cichlids, 36.12 and 40.30°C in cyprinids. While intersexual differences in the CT-min/CT-max values were not evident in cichlids and cyprinids, these values significantly differed across poecilids. The females of poecilids were approximately 0.5 to 1°C more resistant to both low and high temperatures than their males. Among the species included in our study, due to their resistance to low temperature, especially C. auratus and a lesser extent B. rerio and P. conchonius were considered the most suitable ones for outdoor aquaculture in subtropical regions. However, if they are cultured outside of their natural distribution, it should be noted that upon escapement from aquaculture facilities to nature, they may interfere with the ecosystem and compete with native species there due to their wide range of thermal tolerance.