Acta Zoologica最新文献

Epictia munoai is a small scolecophidian snake from the subtropical region of South America. It inhabits under rocks of preserved environments. Since basic information concerning the biology of this snake remains unknown, we aimed at presenting information on age, reproductive cycle, and daily and annual activity patterns of E. munoai from Southernmost Brazil. Males and females of E. munoai becomes sexually mature from 3 to 4 years of age, and presents a life expectancy of up to 9 or 10 years. The breeding cycle at the individual level is cyclical and discontinuous, and seasonal at the population level, with breed season from late winter to late spring. Epictia munoai is a diurnal snake, active under rocks during the hottest periods of the day, especially during the spring in southern latitudes. Our results provide new and unprecedented information about the natural history of a small species of South American fossorial snake. Information like this is extremely important as it helps to understand the life history of a species, in addition to serving as a basis for studies in areas such as population ecology, historical demography, phylogeography and conservation biology.

Understanding population structure is crucial for predicting species' responses to environmental change and elucidating evolutionary history. This study investigated the population structure of Periophthalmus waltoni in the Persian Gulf and Gulf of Oman using landmark-based geometric morphometrics (GMM) and discrete wavelet transform (DWT) methods on sagittal otoliths. The objectives were to (i) examine otolith shape variation across different populations and (ii) compare GMM and DWT methods for resolving population differences. Both methods distinguished populations based on general otolith shape, with DWT revealing finer details due to its high accuracy in detecting otolith margins. Interestingly, populations from Sistan-Baluchestan and Hormozgan, despite geographical separation, showed minimal variation in shape, suggesting environmental factors may influence otolith morphology. Distinct otolith shapes in the Khuzestan population, likely due to geographic isolation, may be influenced by the mangrove forests near Qeshm Island acting as barriers to larval dispersal. This aligns with molecular data and indicates that the relatively young eastern Persian Gulf may also contribute to these differences. Our findings revealed distinct geographical patterns in otolith shape, highlighting the influence of local environmental factors and larval dispersal on population differentiation. These results provide valuable insights into P. waltoni's population structure and evolutionary history, advancing our understanding of its adaptation to the diverse environmental conditions of the Persian Gulf and Oman Sea.

Egg laying begins with the orderly development of follicles in the chicken ovaries and transportation through the oviduct with deposition of nutrients until the eggs are produced. However, the ovarian follicles and oviduct morphology of Lohmann Brown and Potchefstroom Koekoek laying hens have not yet been studied. The study aimed to determine the morphological variations of the ovarian follicles and oviduct of Lohmann Brown and Potchefstroom Koekoek laying hens aged 40 weeks. The Student's t-test results revealed that breed had a significant effect (p < .05) on the weight of the small white follicles (SWF), large white follicles (LWF) and small yellow follicles (SYF), where Lohmann Brown performed higher than Potchefstroom Koekoek. The outcomes also displayed that breed had a significant effect (p < .05) on the number of LWF and SYF. The results further displayed that breed had a significant effect (p < .05) on the weight of F2, F3, F4 and F5. The outcomes showed that breed had a significant effect (p < .05) on the weights of the infundibulum, magnum and isthmus, where Lohmann Brown displayed a higher performance than Potchefstroom Koekoek. Furthermore, the findings revealed that breed had a significant effect (p < .05) on the lengths of the magnum, isthmus and shell gland, where Lohmann Brown displayed a better performance than Potchefstroom Koekoek. The findings also showed that the discriminant variables in the study are the isthmus length, isthmus weight and magnum length. In conclusion, there are morphological variations in the weights and numbers of the ovarian follicles, and the weights and lengths of the oviduct segments of Lohmann Brown and Potchefstroom Koekoek laying hens.

Sylviocarcinus pictus is a freshwater crab widely distributed across the Amazon basin and coastal basins of northern South America. In the Xingu River basin, Pará, Brazil, the species is found from its middle portion up to the confluence with the Amazon River. This extensive distribution led to questions about the influence of the Volta Grande do Xingu rapids on genetic diversification between populations above and below this area. To explore this hypothesis, 39 mitochondrial gene sequences (COI and 16S rRNA) from 22 samples collected from both areas were analysed in a phylogeographic context. Bayesian Inference and haplotype networks revealed at least two genetically distinct lineages of S. pictus in the Xingu River. The resulting genetic structure found within these populations raised questions about the taxonomic cohesion of the taxon and the potential existence of cryptic species that warrant further investigation. To the best of our knowledge, this is the first molecular study on the genetic structure of a Sylviocarcinus species from the Amazon basin. Given the novelty and the underestimated diversity in this region, we advocate for additional studies on morphological and taxonomic approaches about this taxon to contribute to a future understanding of the evolutionary history of the genus.

Otoliths from four species of scorpaenids–Helicolenus dactylopterus (Delaroche, 1809), Scorpaena elongata Cadenat, 1943, Scorpaena notata Rafinesque, 1810, and Scorpaena scrofa Linnaeus, 1758–were collected from Antalya Bay along the Mediterranean coast of Türkiye. The fish were captured using a commercial bottom trawl net with a mesh size of 44 mm (22 mm in the cod end). The fishing grounds varied in depth from 40 to 160 meters. Scanning electron microscopy (SEM) images were utilized to analyse the otoliths’ characteristics. Twenty-one distinct features were defined to describe their shapes. Among these, 8 characteristics were consistent across both juvenile and adult otoliths, while 13 features exhibited developmental variation. The results reveal four types of variations: ontogenetic, interspecific, intraspecific, and sexual dimorphism. A comparison with previously documented otoliths of these species from different regions indicates a uniformity intraspecifically across extensive geographic ranges, suggesting that these characteristics are valuable for identification purposes. The diagnostic features of the otoliths can aid in confirming species identity. Additionally, a SEM-based iconography of the otoliths for all studied species is provided.

Bangasternus planifrons (Brullé, 1832) specimens collected from Ankara-Bala were studied. The paper presents a scanning electron microscopic examination of ultrastructural features of aedeagus and spermatheca of Bangasternus planifrons (Brullé, 1832) (Coleoptera: Curculionidae: Rhinocyllini) from Türkiye for the first time. The fact that Bangasternus is a genus with three species in Türkiye makes the study more important. Accordingly, detailed investigation of aedeagus and spermatheca is very important to obtain new diagnostic characteristics in Bangasternus. The parts which include systematic characters such as spermatheca, genital spicule, sternite eight and coxite figures were drawn in detail and these characters were discussed on species, genera and tribus levels. While significant differences were observed among the species in genital spicula, coxite, stylus and spermateca, a difference that would reveal a genus discrimination character by evaluating these structures could not be obtained according to the available findings. Photos in stereomicroscope and scanning electron microscope are also given in the text.

Caterpillars have a significant impact on human economy, because their plant-attacking and silk-producing habits. The larval mouthparts play a crucial role in feeding and spinning and exhibit an extremely morphological diversity, which is closely related to their taxonomic status, feeding habits, and even the developmental stages. However, the larval mouthparts have not been fully elucidated in the megadiverse Sphingidae. In this study, the larval mouthparts of Ampelophaga rubiginosa Bremer & Grey, 1853, Laothoe amurensis (Staudinger, 1892), Smeritus planus Walker, 1856, Dolbina tancrei Staudinger,1887, Phyllosphingia dissimilis (Bremer, 1861), and Marumba sperchius (Ménétriés, 1857) were morphologically observed and compared using scanning electron microscopy. The mouthparts of six species are morphologically diverse on the labral notches, mandibles, spinneret and labial palps arrangement of the mouthparts. The morphological diversity of larval mouthparts is briefly discussed, considering their taxonomical and functional aspects.

Killifishes (family Aphaniidae) in southern Iran demonstrate long-time acclimation to extreme euryhaline environments. This study provides a detailed histological and ultrastructural characterization of gill morphology in two sympatric endemic aphaniids, Aphaniops furcatus and Aphaniops hormuzensis, inhabiting an ecologically extreme environment in southern Iran. Specimens were collected from the Khurgu hot-sulphuric spring in the Hormozgan River System which drains into the Persian Gulf, and examined using haematoxylin and eosin (H&E) staining and scanning electron microscopy (SEM). Both species exhibited gill structures typical of teleosts, with primary and secondary lamellae essential for efficient gas exchange. In A. furcatus, gills displayed variations linked to size and gender, with numerous secondary lamellae and a variety of epithelial cells, including squamous, chloride, mucus, blood, and pillar cells. Air exposure led to interlamellar cell masses (ILCM) growth, reducing the lamellae surface area. In A. hormuzensis, gill arches featured a double row of primary filaments with secondary lamellae facilitating oxygen exchange, supported by pillar cells and dense distribution of mucous cells throughout the epithelium. The study highlights the adaptive mechanisms of A. furcatus in response to fluctuating environmental conditions and underscores the evolutionary conservation of gill morphology among teleosts. These findings provide crucial insights into respiratory efficiency and ecological adaptability, emphasizing eco-evolutionary acclimation to extreme aquatic habitats.

Otolith features (length, width and weight) of 74 individuals of Anguilla anguilla collected from the Söke District of Aydın Province in Western Anatolia, Türkiye were studied for the first time to evaluate the level of asymmetry in the otolith features selected for this study. The asymmetry value of the otolith length was greater than that of otolith width and otolith weight. The asymmetry value of the three otolith features increased with an increase in the fish's length. The likely cause of asymmetry in the otolith parameters examined has been discussed in relation with the variability in growth provoked by ecological influence associated with the discrepancy in habitat setting and contaminants present in the Söke District of Aydın Province in Western Anatolia, Türkiye.

The human chin, also frequently referred to as the mental prominence, is a part of the human anatomy whose evolutionary origin and function have divided scientific opinion to this day. There were suggestions it could have been used in defence, assisted in the mastication process, aided in the formation of words (i.e. speaking), or that it played a role in mate choice. None of these explanations were satisfactory. This paper, backed up by observations on people from different parts of the world and cultures, using their chin to hold or clamp down objects resting on a person's arms in front of the body or to free the person's hands for other tasks, offers an explanation that has support from results on the evolution of bipedalism from apes to bipedal australopithecines, including Homo sapiens, and the importance of the hands in hominids as well as the heritability of the trait.