BMC Zoology最新文献

Background: Among the 16 Neotropical genera of Philodromidae, Cleocnemis has the most troublesome taxonomic situation. Remarkable morphological differences among several genera historically said to be related to Cleocnemis denote controversial notions and general uncertainty about the genus identity. Thus, to clarify the genus limits and contribute to the understanding of Neotropical Philodromidae, we conducted a morphological analysis, along with Bayesian Inference and Maximum Likelihood molecular phylogenetic analyses focusing on Cleocnemis and related genera of Thanatinae. All of the 14 species previously placed in Cleocnemis were studied, and eight of them included in the molecular analyses based on fragments of 28S rDNA, histone H3, 16S rDNA, and cytochrome oxidase I (COI).

Results: Cleocnemis was recovered as polyphyletic. Most of its species are distributed into six lineages allocated into five morphologically recognizable groups: Group I [Cleocnemis heteropoda], representing Cleocnemis sensu stricto and two new junior synonyms, Berlandiella and Metacleocnemis; Group II [Tibelloides bryantae comb. nov., Tibelloides punctulatus comb. nov., Tibelloides reimoseri nom. nov., and Tibelloides taquarae comb. nov.], representing Tibelloides gen. rev., which was not recovered as monophyletic; Group III [Fageia moschata comb. nov., Fageia rosea comb. nov.], representing the genus Fageia; Group IV ["Cleocnemis" lanceolata]; and Group V ["Cleocnemis" mutilata, "Cleocnemis" serrana, and "Cleocnemis" xenotypa]. Species of the latter two groups are considered incertae sedis. Cleocnemis spinosa is maintained in Cleocnemis, but considered a nomen dubium. Cleocnemis nigra is considered both nomen dubium and incertae sedis. We provide a redelimitation of Cleocnemis, redescription, neotype designation, and synonymy of type-species C. heteropoda. Taxonomic notes on composition, diagnosis, and distribution for each cited genus are also provided. Phylogenetic results support the division of Philodromidae into Thanatinae new stat. and Philodrominae new stat. and suggest expansion of their current compositions. Terminology of genital structures of Philodromidae is discussed.

Conclusions: Our results bring light to Cleocnemis taxonomy and enhance the understanding of the relationships within Philodromidae, especially through the assessment of neglected Neotropical taxa.

Background: Pleistocene climate fluctuations have strongly modified species genetic diversity and distributions. The Chinese pangolin (Manis pentadactyla) has been recognized as a critically endangered animal due to heavy poaching and trafficking. However, the effect of Pleistocene climate fluctuations on the genetic diversity and spatial distribution of the Chinese pangolin remains largely unknown. Here, we combined whole genome sequencing data, analysis of complete mitochondrial genomes, and a large amount of occurrence data from field surveys to infer the ancestral demographic history and predict the past spatial dynamics of the Chinese pangolin in Guangdong Province, China.

Results: Our results indicated that there were two subpopulations, which showed similar trends of population size change in response to past climatic changes. We estimated a peak effective population size (N_e) during the last interglacial (LIG), followed by a marked decrease (~ 0.5 to fivefold change) until the last glacial maximum (LGM) and a rebound to a small peak population size during the Mid-Holocene (MH). The estimated time of the separation event between two subpopulations was approximately 3,000-2,500 years ago (ka). We estimated that the distribution of suitable areas shrank by 14.4% from the LIG to LGM, followed by an expansion of 31.4% from the LGM to MH and has been stable since then. In addition, we identified an elevational shift and suitable area decreased significantly during the LGM, but that the geographic extent of suitable areas in the western region increased from the LIG to present. The eastern region of Guangdong Province had the highest habitat suitability across all the climate scenarios.

Conclusions: Our results suggested that Pleistocene climate fluctuations played an important role in shaping patterns of genetic diversity and spatial distribution, and that human stressors likely contributed to the recent divergence of two Chinese pangolin subpopulations sampled here. We argue that a key protected area should be established in the eastern region of Guangdong Province. As such, this study provides a more thorough understanding of the impacts of Pleistocene climate fluctuations impacts on a mammalian species in southern China and suggests more robust management and conservation plans for this Critically Endangered species of special interest.

Background: The 3D computed tomography produces detailed images of the digit bones in addition to the angiograph render volume 3D of the CT shows the relation between the arteries, bones, and tissues of the digit. Therefore, the present study used those imaging techniques to provide a complete description of the digit bones and arteries' origin, distribution, and course and their relations with surrounding structures in the Dromedary Camel. Which would serve as a guide for surgeons and students in distinguishing normal digit structures. The study used eight hind limbs of four adult camels of both sexes (two males and two females), aged 9-15 years (Mean ± SD, 11.80 ± 2.59 years). The samples were injected with latex with lead oxide were undergone 3D render volume CT (128-slice multi-detector CT scanning protocol) and angiography x-rays.

Results: The blood vessels and correlated structures such as bones, tendons, and ligaments were examined using 3D CT in all directions, which was easier to view than angiography and dissected specimens. The arterial supply to the camel's hind foot was the A. digitalis plantaris communis III. The angiography render volume 3D of CT explained the blood supply of the bones and joints of digital regions and showed a good visualization of the many digit arteries. The metatarsals, the phalanges, and the sesamoid bones were visualized. A. plantaris medialis superficialis, A. digitalis plantaris communis III, A. digitalis plantaris communis II and IV, A. interdigitalis, rami articularis medialis and lateralis to the fetlock joint, ramus medialis and ramus lateralis of the A. digitalis plantaris communis III, A. digitalis plantaris propriae III et IV abaxialis, A. digitalis plantaris propriae III et IV axialis, Ramus phalangis axialis and abaxialis of the first phalanx, Ramus phalangis axialis and abaxialis of the second and third phalanges, and A. metatarsae plantaris III were visualized. The study discovered new blood vessel sources in dromedary camels, such as the ramus articularis to the fetlock and the ramus plantaris phalangis abaxialis proximalis and distalis of the first phalanx.

Conclusions: The digital circulation angiography investigates the circulatory pattern of the camel hind digit, which can assist clinicians in diagnosing digit region affections. 3D CT explained improved visualization of bones and arteries, including many small branches in relation to surrounding structures, in some views better than others.

Background: The animal signaling theory posits that conspicuous colorations exhibited by many animals have evolved as reliable signals of individual quality. Red carotenoid-based ornaments may depend on enzymatic transformations (oxidation) of dietary yellow carotenoids, which could occur in the inner mitochondrial membrane (IMM). Thus, carotenoid ketolation and cell respiration could share the same biochemical pathways. Accordingly, the level of trait expression (redness) would directly reveal the efficiency of individuals' metabolism and, hence, the bearer quality in an unfalsifiable way. Different avian studies have described that the flying effort may induce oxidative stress. A redox metabolism modified during the flight could thus influence the carotenoid conversion rate and, ultimately, animal coloration. Here, we aimed to infer the link between red carotenoid-based ornament expression and flight metabolism by increasing flying effort in wild male common crossbills Loxia curvirostra (Linnaeus). In this order, 295 adult males were captured with mist nets in an Iberian population during winter. Approximately half of the birds were experimentally handicapped through wing feather clipping to increase their flying effort, the other half being used as a control group. To stimulate the plumage regrown of a small surface during a short time-lapse, we also plucked the rump feathers from all the birds.

Results: A fraction of the birds with fully grown rump feathers (34 individuals) could be recaptured during the subsequent weeks. We did not detect any significant bias in recovery rates and morphological variables in this reduced subsample. However, among recaptured birds, individuals with experimentally impaired flying capacity showed body mass loss, whereas controls showed a trend to increase their weight. Moreover, clipped males showed redder feathers in the newly regrown rump area compared to controls.

Conclusions: The results suggest that wing-clipped individuals could have endured higher energy expenditure as they lost body mass. Despite the small sample size, the difference in plumage redness between the two experimental groups would support the hypothesis that the flying metabolism may influence the redox enzymatic reactions required for converting yellow dietary carotenoids to red ketocarotenoids.

Rabbits have been proposed as a model for the human meibomian gland (MG), a large specific sebaceous gland in the eyelid that consists of secretory acini arranged laterally and related to the central duct via short ductules, with the central duct continuing as an excretory duct to open at the free margin of the lid. First detected at embryonic day 18 as an aggregation of mesenchymal cells in the tarsal plate, it completes its development approximately 2 weeks postnatal when the separation of the eyelids is completed. The Transmission electron microscopy supports the meibocytes' gradient maturation to the meibum's synthesis. While the differentiating cells, their cytoplasm, are well packed with lipid droplets, the basal cells are characterized by a high nuclear to cytoplasm ratio. The androgen and estrogen receptor proteins are expressed in the basal cell and the meibocytes, and increase in age increases in the expression of these proteins. Additionally, the cytokeratin (CK14) is expressed in the basal and differentiating cells of the acini and the ductal epithelium. Therefore, the duct cells of the MG are common in all stem cells. These data concluded that the MG plays a major role in maintaining the health of the ocular surface and preservation of visual acuity. Any abnormalities in the structure of the MG lead to its dysfunction and changes in lipid secretion.

Background: Fundamental knowledge on the seasonal reproductive microanatomy and endocrinology of reptiles has been collected from several studies of various species. The present study was to determine annual changes in hormonal profiles, and detailed histomorphometric and histochemical characteristics of the entire male reproductive system of the tropical agamid lizard, Leiolepis ocellata.

Results: Male L. ocellata individuals (n = 75) collected from the territory of two provinces (Lampang and Tak) in northern Thailand exhibited annual variation in sex hormonal, histomorphometric, and histochemical characteristics of the male reproductive system. The reproductive cycle was subdivided into eight reproductive periods (early first active, first active, resting, second recrudescent, second active, regressive, quiescent, and first recrudescent), thus displaying a bimodal pattern with two actively reproductive periods. Circulating sex hormones (testosterone, estradiol, and progesterone) peaked in the first active (February) and the second active (June-July) periods. Likewise, gonadosomatic index (GSI) and histomorphometric variables of the testes and of the genital ducts (rete testis, ductuli efferentes, ductus epididymis, and ductus deferens) revealed their highest values in the first active period. Marked increase in protein and carbohydrate production was detectable in the ductuli efferentes during the active periods.

Conclusions: The male reproductive cycle of L. ocellata showed a biannual pattern of the hormonal profile, and detailed histomorphometric and histochemical characteristics of the entire reproductive system. Hence, the present study provides improved basic knowledge on the reptilian reproductive biology with comparative viewpoints to other reptiles.

Background: According to our acknowledgment this is the first full anatomical description of the studied laryngeal mound of the Egyptian Cattle Egret (Bubulcus ibis, Linnaeus, 1758). This study was obtained with the aid of scanning electron microscopy (SEM) and histological techniques. Heads of ten healthy adult male Egyptian cattle egrets were used in this study.

Results: The laryngeal mound (Mons laryngealis) was a pear-shaped musculoskeletal elevation. It represented 20.55 and 67.87% of the total length of the oropharyngeal floor and the pharyngeal floor, respectively. By SEM view, the lateral aspect of the caudal third of the laryngeal mound had a serrated mucosal appearance, forming of 6-7 finger-like projections. Furthermore, the terminal part of the laryngeal mound (except the middle part) was bordered a transverse row of pyramidal-shaped papillae, which demarcated from the esophagus. Histologically, laryngeal salivary glands termed (cricoarytenoid salivary glands) of the laryngeal mound were simple tubular type and were arranged in one row within the lamina propria connective tissue close to the lamina epithelialis. Those glands were surrounded by abundant aggregation of lymphocytes, extended overlying the surface lining epithelium. The glottis within the laryngeal mound was supported by hyaline cartilages; dorsally by paired arytenoid cartilages, ventrolaterally by cricoid cartilage, and caudodorsally by procricoid cartilage. Two groups of intrinsic laryngeal skeletal muscles have connected the cartilages. The glandular epithelium of the laryngeal salivary glands and chondrocytes of the laryngeal cartilages showed strongly positive alcian blue reaction.

Conclusions: The laryngeal mound shows certain features that are unique as an adaptation to lifestyles and bird's habitat.

Background: The measurement of the energy available for growth (scope of growth, SFG) can be used in bivalves to make a long-term prediction in a short-term experiment of the condition of the individual. In order to tackle the best conditions for captive maintenance of Mediterranean Pinnids, a SFG study was conducted using Pinna rudis as a model species. Three diets were examined to test the viability of live microalgae and commercial products: i) a control diet using 100% of live microalgae based on the species Isochrysis galbana (t-ISO), ii) a 100% of commercial microalgae diet based on the product Shellfish Diet 1800®, and iii) a 50/50% mix diet of I. galbana (t-ISO) and Shellfish Diet 1800®.

Results: SFG results showed significant differences among diets in the physiological functions measured and suggested lower acceptability and digestibility of the commercial product. Negative SFG values were obtained for the commercial diet which indicates that it should be rejected for both Pinnid maintenance. The mixed diet showed improved physiological performance compared to the commercial diet, resulting in a higher SFG that had no significant differences with the control diet. However, in the long-term, the lower digestibility of the mixed diet compared to the control diet could lead to a deterioration of individuals' conditions and should be considered cautiously.

Conclusions: This work represents the first case study of SFG in Pinna spp. and provides fundamental data on dietary needs for the critically endangered species, P. nobilis.

Background: The nematodes of the genus Helicotylenchus are root parasites of a wide variety of plants, and certain species can cause serious damage to their hosts. During a survey of the plant-parasitic nematode associated with tomato, a population of Helicotylenchus was collected from tomato roots and soil samples. Thus, one of the objectives of the study was to confirm the specie of Helicotylenchus obtained from the tomato samples based on morphological and molecular characteristics. In addition, a mass pure culture of plant-parasitic nematodes is key to pathogenicity studies and many other biological studies. However, a successful mass rearing method for Helicotylenchus has not been reported. Thus, the other objective of the study was to establish a method of culturing Helicotylenchus.

Results: Based on both the morphological characteristics and molecular analysis of the internal transcribed spacer (ITS) and D2-D3 expansion region of 28S ribosomal RNA (rRNA) sequences the specimens were identified as Helicotylenchus microlobus. Phylogenetic analysis with the rRNA sequences of the ITS and 28S D2-D3 regions was consistent with molecular identification, suggesting this population formed a highly supported clade with other H. microlobus populations. Additionally, a method for culture of H. microlobus on carrot disks was established, and the effect of temperature on the reproduction rate (Rr) of H. microlobus was investigated. The optimum temperature for culturing H. microlobus on carrot disks was 27.5 °C and, after inoculation with 30 females of H. microlobus at 27.5 °C for 90 days, Rr reached 406.

Conclusions: To our knowledge, this is the first detailed description of H. microlobus from tomato in China. This study also demonstrated that the carrot disk method is suitable for the culture of H. microlobus. This study lays a foundation for other related research on H. microlobus, and has significance for the study of Helicotylenchus.

Background: The reproductive cycle of the recently described sponge Tethya meloni was investigated for a period of 15 months (September 2018 - November 2019) in the Mar Piccolo of Taranto (Southern Italy) and was compared with data previously collected for the other two sympatric species of the same genus known for Mediterranean Sea, T. citrina and T. aurantium.

Results: T. meloni is a gonochoric species with a sex ratio strongly shifted towards females. Asexual budding was a seasonal process, limited to few specimens. In a specimen collected in September 2018 both oocytes and buds occurred, suggesting that in T. meloni the sexual and asexual phases may coexist both at the population and individual levels.

Conclusions: The data obtained from this research compared with the available literature confirm the high temporal variability of the reproductive cycles in the Mediterranean species of Tethya, but with common general characteristics. In sexual reproduction, the oocyte production period lasts several months, with a peak between summer and autumn while spermatogenesis, shorter but with greater reproductive effort, follows the onset of oogenesis. The asexual reproduction phase of T. meloni, on the other hand, occurs in a short period and seems to have less importance in the overall reproductive process.