Well-developed Muscle Research Articles

Biological Significance of the Komodo Dragon's Tail (Varanus komodoensis, Varanidae).

The Komodo dragon is a unique reptile with an elongated tail that exhibits hitherto unknown adaptations and functions. This tail, composed of 60-86 vertebrae, serves diverse ecological and physiological roles. In juveniles, it is essential for an arboreal lifestyle and balance, while in adults, it functions as a tool for defense and offensive actions. It possesses characteristic haemal arches and a dorsal keel, along with well-developed muscles which enable precise tail control, influencing the Komodo dragon's maneuverability and directional changes. The tail stores adipose tissue, providing Komodo dragons with the ability to regulate body temperature and independence from other seasonal variations. The tail adipose tissue impacts numerous biochemical processes and may play a crucial role in the animals' metabolic strategies and reproductive capabilities. Its functions include providing essential mineral compounds for the organism, such as calcium, phosphorus, magnesium, iron, and zinc. Analysing the biochemical composition of tail fat is crucial for understanding the health of Komodo dragons.

Intracellularity, extracellularity, and squeezing in the symbiotic organ underpin nurturing and functioning of bacterial symbiont in leaf beetles

Cassidine leaf beetles are associated with genome-reduced symbiotic bacteria Stammera involved in pectin digestion. Stammera cells appear to be harbored in paired symbiotic organs located at the foregut-midgut junction either intracellularly or extracellularly, whereas the symbiont is extracellular in the ovary-accessory glands of adult females and during caplet transmission in eggs. However, using fluorescence and electron microscopy, an intracellular symbiotic configuration of Stammera was observed in Notosacantha species. Detailed inspection of other cassidine species revealed fragmented cell membrane and cytoplasm of the symbiotic organs, wherein Stammera cells are in an intermediate status between intracellularity and extracellularity. We also identified a mitochondria-rich region adjacent to the symbiont-filled region and well-developed muscle fibers surrounding the whole symbiotic organ. Based on these observations, we discuss why the Stammera genome has been reduced so drastically and how symbiont-derived pectinases are produced and supplied to the host's alimentary tract for plant cell wall digestion.

Two new species of the order Monhysterida (Nematoda) from the sea of China.

Two new marine nematode species belonging to the order Monhysterida are described from the sea of China. Halomonhysterazhangisp. nov. is characterized by its relatively small body size; short anterior sensory setae; small, circular amphidial fovea located at the level of buccal cavity base; funnel-shaped buccal cavity; an excretory-secretory system with a large ventral gland and opening as a very narrow canal just posterior to the level of cephalic setae; slightly curved slender spicules with cephalated proximal end and tapered distal end; rod-like gubernaculum without apophysis; two papilliform precloacal supplements just in front of the cloaca; conico-cylindrical tail with two ventral papillae, each with a seta; and distance between the vulva and anus slightly longer than the tail length. This is the first new species of epiphytic nematode reported in China. The second new species, Stylotheristusflagellicaudatussp. nov., has a relatively shorter body and longer tail; striated cuticle; The anterior sensilla arranged in two circles, the first circle consisting of six inner labial setiform papillae (3-4 µm) and the second circle consisting of 16 long setae (12-19 µm); a transversely oval amphideal fovea; a well-developed muscle around the funnel-shaped buccal cavity; short spicules and a gubernaculum composed of a single piece; and precloacal supplements absent. An updated key to all species of Halomonhystera and pictorial key to all species of Stylotheristus are also given.

Body morphology and handgrip strength parameters of the female canoe slalom paddlers.

Introduction: Canoe slalom is a physically very demanding discipline, in which body constitution, body composition, and relative strength are significant factors in high performance. Although anthropometric and strength parameters are relatively well-studied in male athletes, there is a lack of evidence for any conclusions in women. Therefore, the objective of this study was to determine the morphology and upper-limb strength parameters of female canoe slalom paddlers and identify whether morphological differences exist between performance groups. Methods: Altogether, 63 female competitors of the 2023 ICF Canoe Slalom World Cup (n = 29) and 2023 ICF Canoe Slalom World Ranking Competition (n = 34) in Prague (Czech Republic) were examined with a battery of anthropometric tests, segmental bioimpedance analysis, and handgrip strength test. The athletes were divided into groups according to age and performance: elite athletes belonging to the world top 10 according to the ICF World Ranking (WORLD, n = 7), international-level athletes competing during the World Cup (ELITE, n = 22), international-level junior athletes competing in the World Ranking Race (JUNIOR, n = 17), and other lower performance-level athletes competing in the World Ranking Race (REST, n = 17). Results: Female slalom paddlers are, in general, of average body height (∼165cm), lower body mass (∼60kg), BMI (∼22kg/m2), and body fat (∼20%) and without exceptional anthropometric dimensions and proportions. However, differences were detected when performance was factored in. Female paddlers belonging to the world TOP 10 have the largest circumferences of arms and forearms, and their somatotype is more mesomorphic, with a lower proportion of total body fat and a higher proportion of muscle mass. In addition, the WORLD group differs significantly in upper-limb strength. Discussion: The results shows the significance of muscular strength and power for canoe slalom athletes and the importance of well-developed musculature in operating the boat in the unstable environment. Being a successful female canoe slalom athlete requires a well-developed musculature, maximizing strength capabilities while maintaining a low body weight through limited hypertrophy of the lower limbs and a low level of body fat.

Muscle hypertrophy in athlete training from a medical point of view - what do we know

Introduction
 Hypertrophy is the process of increasing the mass of a tissue. In this article, we focused on the impact of the mechanisms of muscle hypertrophy, its effect on the human body, correlation with the course of diseases and tolerance of treatment. We considered the benefits of having well-developed, and also touched on the problems of underdeveloped muscle mass.
 Results
 The main factors causing hypertrophy are resistance exercise training, mechanotransduction, metabolic pathways, ribosomal biogenesis, gene expression and the impact of hormones. The beneficial effect of high concentrations of testosterone and growth hormone, also IGF1, on skeletal muscle hypertrophy has been proven. On the other side, the studies have shown that high concentrations of glucocorticoids, such as cortisol are associated with reduced muscle mass.
 There are many positive aspects of a well-developed muscle mass such as an impact on the prognosis in patients with cancers and sometimes reduces mortality among them. The problems of low muscle mass and sarcopenia are also mentioned. Low muscle mass can affect the poor prognosis of diseases such as cancer, hepatic cirrhosis and COVID-19. Postoperative complications are more common in patients with low muscle mass. One way to prevent this process may be to introduce resistance exercise training in patients struggling with problems of muscular atrophy.
 Conclusion
 Skeletal muscles have multiple functions in the human body. In addition to movement, they play a role in molecular processes like hormonal regulation. In addition, they can, when well developed, positively influence healing processes and the course of disease.

Efficient use of multiculturally cultivated pond fish is a vector for the developmentи of the production of high-quality fish products

Attracting new raw material sources is based on the existing experience of using fish from the national internal and external water bodies in food, including seas, oceans, rivers, lakes and artificial reservoirs. The purpose of the research is to substantiate the conditions and create high-quality fish products for wide consumer demand based on paddlefish processed product. The object of the research is fresh and chilled American paddlefish grown in polyculture conditions together with silver carp for 2 years, as well as developed fish products produced in laboratory conditions. A generalization of the available information and the results of the research allow us to identify the paddlefish as a highly valuable raw material resource for the production of high-quality fish products. The paddlefish is a technologically advanced fish; it lacks scales, has small costal and intercostal bones and well-developed muscle tissue, and is able to increase the mass rapidly. Paddlefish meat and liver contain all the essential amino acids and biologically active substances. Therefore, these raw materials have significant potential in satisfying physiological needs of the body, and also have high digestibility at the level of 90 and 92%, respectively. The implementation of the developed optimization program has made it possible to create recipe-component solutions for new fish products: meat and fish cutlets, pate and canned food. In the course of determining the quality, nutritional and biological value, technological, consumer and quality advantages of the developed products, created on the basis of raw material combinations of pond fish cutting products grown in polyculture conditions have been established. Modified technological production schemes have been recommended and tested.

Analysis of Horse Bones from a Cellar of the 11th⸺12th Centuries near the Western Palace in Kyiv

During archaeological excavations in the Upper Town in Kyiv in 2008, a cellar was discovered next to the Western Palace. Among other materials, there were animal bones, the absolute majority of which were horses’ bones. Based on the bones, it was calculated that the minimum number of individual horses was four. These bones belonged to kitchen remains, as they were fragmented and showed a large number of cutting marks on almost all anatomical parts of the horses. However, they were larger than those that are usually thrown away after cooking. Perhaps, in this case, we are dealing with horse carcasses that were stored as supplies after initial butchering, but never used. The presence of bones from non-meat parts of the body, such as the phalanges, indicates that the animals were slaughtered in the same place. According to the nature of the cut marks, they were probably made with an ax and a knife. Two of the horses were likely males. The sex of the other two could not be determined. Two individuals were five years old, one was 3—3.5 years old, and one was 15—18 months old. Breed characteristics were established only for one individual. The female belonged to medium-legged horses. In addition, the horse performed heavy physical work during life, which is indicated well-developed muscle attachments on the bones. It should be noted that by the 11th and 12th centuries, the practice of eating horse meat had stopped. There are several reasons for this. One of them is changing the role of the horse. At this time, the horse began to be actively used as a draft animal, particularly when cultivating the land, and as a riding animal. Another reason is the spread of Christianity, which prohibited eating horse meat, because it was associated with pre-Christian cults. This is evidenced by several references in the Chronicle. However, under unforeseen circumstances, such as famine during the siege of the city, the practice of eating horse meat could have been returned. It is likely that the horses, the bones of which were found in the cellar, were slaughtered and divided into fragments precisely under unfavourable circumstances for the residents of Kyiv.

Intramuscular vaccine administrations including the adoption of “Zeta-track technique” & “without aspiration slow injection technique” (ZTT & WASiT): a prospective review

Abstract Objective To review the current literature on the practice of intramuscular injections (IMIs), focusing on immunizations. Methods The present study comprises 2 reviews, characterized by high-quality evidence, pertaining to the deployment of the slow injection technique without aspiration (referred to in this paper as the without-aspiration slow injection technique [WASiT]) and combined with the Zeta-track technique (ZTT). The literature review is oriented toward the analysis of 2 features associated with IMIs techniques: safety and pain, integrating new evidence on vaccinee positioning for each muscle site and general relaxation techniques in the multi-parametric analysis. Results The rigorous and in-depth reviews in the current study reveal the usefulness of including, among the international guidelines for via intramuscular immunizations, the adoption of WASiT only for compliant vaccinees, and in combination with all validated techniques for IMIs, and the use of ZTT limitedly if specific well-developed muscles are indicated. All the technique’s limitations are exposed. Conclusions Future research directions are presented by including the author’s study designs to provide indirect evidence for the validity of the rationale of the slow injection technique using scientific methods, and for the conduction of future randomized controlled trials (RCTs) focused on revisiting the adoption of ZTT in a dynamic and integrated immunizations protocol in anterolateral thigh (ALT), ventrogluteal (VG), and also in the deltoid muscle, in the specific cases analyzed.

Динаміка показників загальної фізичної підготовленості кваліфікованих армспортсменів

Purpose: article consisted in the study of the dynamics of indicators of general physical fitness among qualified arm sportsmen. Material and methods. Qualified arm wrestlers participating in the arm sports sections in the fitness centers «Tetra», «TRX», «Pheromon» in Kharkov, as well as in the arm sports federation of the Kharkiv region participated in this study. 25 qualified athletes (19-21 years old) of average weight categories (of 70-80 kilograms) who specialize in arm wrestling were involved in the experiment. The study was conducted during the annual macrocycle in a two-year period from 19 to 20 years and 20 to 21 years. Qualified armwrestlers trained according to the classic program developed for the Youth Sports Academy. Results: for absolute values of general physical work capacity of the tested persons, the increase during the whole two-year period was established. However, the value of relative intensity of increase of absolute values of general physical work capacity at the stages of observations is different. Thus, the results of comparison of indicators of a run on 100 m in the period from 19 to 20 years old made (t=1,11; p>0,05), from 20 to 21 years old (t=1,06; p>0,05), for all time of researches the result (t=1,94; p>0,05), low results testify that a run on 100 m is not a specific exercise for armwrestlers. Comparison of results of long jumps from a place: from 19 to 20 years old (t=0,99; p>0,05), from 20 to 21 years old less significant changes (t=0,89; p>0,05), for two years made (t=2,25; p<0,05) that is a reliably better result and testifies that jumping exercises are not specific for armwrestling. In a pull-up on a crossbar from 19 to 20 years old (t=1,35; p>0,05), from 20 to 21 years old (t=0,94; p>0,05), for two years (t=2,33; p<0,05), it is the best indicator and testifies that armwrestlers have well-developed muscles of the upper extremities which in turn influence on correctness of the exercise of pulling up on a crossbar. Comparison of results of bending and extension of hands in a support lying on a floor made from 19 to 20 years old (t=1,00; p>0,05), from 20 to 21 years old more significant changes were received (t=1,92; p>0,05), and for two years the result made (t=2,66; p<0,05) that is a reliably better result. Comparison of results of a lunge on a crossbar, arms bent at an angle of 90 degrees, made from 19 to 20 years old (t=2,02; p>0,05), in the following year from 20 to 21 years old the significant increase in reliability in results (t=2,29; p<0,05) was received. In two years the increase of result was (t=4,75; p<0,001) that is a high reliable result and testifies that static exercises for armwrestling are the main and they need to be improved from year to year. Conclusions. The revealed differences in the intensity of growth of physical development indicators over the two-year observation period reflect unevenness. Even in such a relatively short period of time (two years) there is a noticeable difference in the intensity of growth of most of the studied indicators of physical development. Thus, the results which characterize age dynamics of indicators of the general physical fitness of skilled armwrestlers of 19-21 years old, testify that the greatest rates of growth on all indicators are observed during three years of training, but only from 19 to 21 years old indicators were reliable, however the value of relative intensity of growth of absolute values of the general physical work capacity at stages of observations is different.

Comparative Anatomical Studies on the Hand of Human and Two Mammalian Species

Background: Morphologically there is a great similarity in the musculoskeletal pattern in different species of the primates especially the development of hands and digits for better functional adaptation to their environment. The factors involved in evolution of modern hand are muscle-tendon architecture, shape, size of bones and articular surfaces in joints. Human hand is functionally highly evolved with manipulative potential for fast and fine skilled activity especially in thumb and index finger as compared with other species.
 Aim: Present study was undertaken to compare the hand anatomy of the Baboon and Squirrel with the Human.
 Methods: Two commonly found mammals in Saudi Arabia i.e. Baboon and Squirrel were selected to reflect the different environmental adaptations. The human hands were provided by the Department of Anatomy. The animals were anesthetized, sacrificed at Anesthesia Department. Fixation done by 9% formaldehyde solution, hands dissected under Zeiss dissecting microscope, Muscle groups identified using 5% iodine stain, Bones and cartilages stained by Alizarin red and Alcian blue stain respectively and photographed (Nikon D3200 digital camera). The hand divided into four parts: Wrist, dorsum of hand, palm and fingers.
 Results: Human Hand: Wrist is wide, bones arranged in two rows gliding over each other for free movements at hand. Dorsum has thin fatty layer, more wrinkles and fewer hairs. Palm has thick skin without hair and well-developed muscles are arranged in groups (Thenar, Hypothenar, Lumbricals and Interossei). Digits have extensor and flexor tendons up to middle and distal phalanx. Thumb is rotated providing opposition and multiaxial movements.
 Baboon Hand: Wrist is short, bones arranged in two rows but fewer movements at hand. Dorsum has fewer wrinkles, more hairs. Palm skin has very thick layer, especially at friction pad located below fingers; muscles are arranged in groups but not fully developed as compared to human.
 Squirrel Hand: Small and close dimensions, five short fingers, pointed, every finger ends with a claw. The skin is thin, covered with hair. Palm is thin but completely free of hair with digital pad. Phalanges are short and all fingers have two phalanges. Thumb has only one phalanx.
 Conclusions: Human hand structure is evolved for better grip and fine movements of hand providing better functional and artistic capabilities.

The impact of body position on measurement of equine lumbar and hindquarter volume using 3-dimensional scans

Well-developed musculature is important for performance yet difficult to quantify. Recently, we validated infrared 3-dimensional (3-D) photonic scanning as an accurate measure of body volume and proxy for regional muscle mass in horses. Our current objective was to determine the impact of body position on measures of lumbar (LV) and hindquarter (HQV) volume. Anatomic markers were placed on 8 horses, positioned at: (1) four hooves square, (2) neck turned ~25°, (3) head raised mean 17 cm, (4) one hind hoof (HH) forward 14±5 cm, (5) a front and contralateral HH ~15 cm all offset, (6) one HH resting. A handheld Occipital Structure Sensor photonic scanner, iPad, Skanect and Materialise 3-Matic programs captured LV and HQV. Measured LV and HQV for whole, same and opposite-side with altered head positions and whole LV and HQV with altered HH positions were compared to volume standing square using repeated measures ANOVA. The volumes of the opposite-side or same-side with altered HH positions were compared to the corresponding side when square using a paired t test with multiple test correction (P<0.017). Head elevated negatively impacted measured left LV (-10% difference,P=0.1) compared to square, however, differences were not significant. Head turned did not impact measured LV. Resting HH significantly increased measured whole (18%,P=0.04) and same-side LV (49%,P=0.001) versus square but not the opposite-side LV. One HH forward (whole 16%,P=0.02; same-side 19%,P=0.01) or all offset (whole 14%,P=0.002; same-side 27%,P=0.0001) significantly increased measured whole or same-side LV versus square. Measured HQV was not impacted by head elevated or limb position but was 2% higher on the opposite-side of the turned head (P=0.01). We conclude that alterations in body position have minimal impact on measured HQV, whereas accurate assessment of LV requires horses stand squarely.

Scanning electron microscopic and histological features of the oral cavity of the Egyptian tortoise (Testudo kleinmanni).

This investigation was led to depict the structural and functional adaptations of the oral cavity of herbivorous Egyptian tortoises using scanning electron and light microscopes. The SEM showed that the triangular papillary tongue possessed three conical papillary subtypes: the rectangular conical on the tip, the round conical on the rest of the dorsal lingual surface and the elongated conical on the caudal portion of the lingual wing. The presence of the serrated lips with their valves compensated for the absence of the teeth. The rostral part had a vomeronasal opening while the middle part had the choana, but the caudal part had numerous openings of the salivary glands. There are three palatine folds: a single median palatine fold, two peripheral palatine folds and the choanal fold. The current histological results show the keratinized dorsal lingual surface, in which the keratinized layer extended to cover the papillae. Two types of lingual glands, according to their position, are papillary superficial and deep lingual glands. Papillary or superficial glands open in the interpapillary spaces via narrow openings, while the deep glands are surrounded by well-developed muscles and open via wide openings on the dorsal lingual surface. An entoglossal cartilaginous structure of hyaline cartilage was found in the mid- and hindtongue, with numerous chondrocytes lodged within the lacunae. Our results conclude that the oral cavity of the herbivorous Egyptian tortoise was adapted to the dietary and vigorous demands of the Egyptian fauna.

A missense mutation in ISPD contributes to maintain muscle fiber stability

BackgroundLivestock and poultry skeletal muscle development was regulated by a variety of genetic factors playing an essential role in this process. In our de novo sequencing, a missense mutation in ISPD exon 2 showed a selected signature for well-developed muscles. However, the relationship between this mutation and muscle phenotypes remains unclear.ResultsBased on the genotype bias of this missense mutation in gamecock chickens, we compared the cross-section of muscle fibers among the individuals with different genotypes with the results showing a genotype preference of this missense mutation in the chickens with hypertrophic muscle fibers. Comparing TT- and CC-genotype ISPD showed that TT- genotype was associated with heavier skeletal muscle and a better effect on myogenesis and myofiber stability. At cellular level, ISPD was identified to inhibit myoblast proliferation, differentiation and antagonize of muscular atrophy.ConclusionIt can be concluded that the missense mutation of Arg84Lys in ISPD was associated with well-developed muscles and demonstrated to improve chicken muscles’ development.

Anatomy of the digestive system of lumpfish (Cyclopterus lumpus) as an adaptation to puffing behavior.

The first description of the histology of the digestive tract of the lumpfish Cyclopterus lumpus showed an adaptation for collecting and storing water. The morphology of this species' tract is mostly typical of carnivorous fishes, having a sac-like stomach for storage and a relatively short intestine of approximately 1.2× the standard body length. The esophagus is relatively short (0.13× standard body length) and thick-walled; it has a thick muscular coat, and its thickness changes from 0.4 to 1 mm during contraction. The stomach has well-developed gastric glands and is divided into the histologically distinguishable cardiac, fundus, and pyloric parts. The intestine has the same structure throughout its entire length. The water-holding ability of lumpfish is provided by well-developed muscles in the esophagus and stomach distensibility, which differs morphologically from the method used by Tetradontidae and Diodontidae species, who store water in the caudal part of the esophagus. The morphology of the digestive tract proved that this species is an intermediate between Tetradontidae and Diodontidae, which could inflate their bodies by swallowing certain amounts of water, and other fishes which are not able to do so. Results of the work extend current knowledge on the morphological capability of the digestive system of teleost fish, providing water-blowing behavior.

Biological aspects of the larva of Sepedophilus testaceus (Coleoptera: Staphylinidae, Tachyporinae): morphology of the posterior abdomen and prey-capture behaviour

ABSTRACT Two aspects of the larval biology of the rove beetle Sepedophilus testaceus (Staphylinidae: Tachyporinae) were investigated, namely the morphology of the posterior abdomen (abdominal apex) and the predatory behaviour of the larvae towards elusive springtails. The larvae move their urogomphi via a single urogomphal muscle. Its presumed antagonist is a cuticular, possibly elastic process that lies below the urogomphus. Additional features of the posterior abdomen include (i) a reduced but well-developed musculature, (ii) segmental exocrine glands of unknown function, and (iii) five rectal diverticula that are externally visible as eversible lobes and that presumably serve as adhesive organs. Segments IX and X deviate from the more anterior abdominal segments in both their external and internal organisation including their equipment with muscles. Comparisons with previous studies suggest that the segmental glands and rectal diverticula are groundplan features of Staphylinidae and Staphyliniformia, respectively. However, the structure and biological relevance of these traits have as yet received little attention. Laboratory-based highspeed videography observations have confirmed that the investigated L3 larvae are predaceous and highly capable of capturing even elusive prey such as springtails with a relatively high success rate of 40%. The larvae attack their prey immediately after accidental contact and detect and localise their exact position via the hair-like sensilla on their antennae and other body parts. Contact with the prey is below threshold, i.e. occurs without releasing the prey’s escape response, and is followed by a rapid grasping movement of about 40 milliseconds on average that is executed by the falciform mandibles of the larva. This is well within the range of the escape response of the springtail.

Regeneration Potential of Jellyfish: Cellular Mechanisms and Molecular Insights.

Medusozoans, the Cnidarian subphylum, have multiple life stages including sessile polyps and free-swimming medusae or jellyfish, which are typically bell-shaped gelatinous zooplanktons that exhibit diverse morphologies. Despite having a relatively complex body structure with well-developed muscles and nervous systems, the adult medusa stage maintains a high regenerative ability that enables organ regeneration as well as whole body reconstitution from the part of the body. This remarkable regeneration potential of jellyfish has long been acknowledged in different species; however, recent studies have begun dissecting the exact processes underpinning regeneration events. In this article, we introduce the current understanding of regeneration mechanisms in medusae, particularly focusing on cellular behaviors during regeneration such as wound healing, blastema formation by stem/progenitor cells or cell fate plasticity, and the organism-level patterning that restores radial symmetry. We also discuss putative molecular mechanisms involved in regeneration processes and introduce a variety of novel model jellyfish species in the effort to understand common principles and diverse mechanisms underlying the regeneration of complex organs and the entire body.

Morphology of the male and female reproductive tracts of virgin and mated Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae).

Predatory insects have reproductive organs rich in complex changes that may be responsible for the success of their population growth. The species Chrysoperla externa is a predator used in biological control programs in Latin America. However, there is no morphological data about the morphology of the reproductive tract in this insect. This study describes the morphology of the reproductive organs of virgin and mated C. externa male and female. The male has a pair of testes yellow in color and five pairs of accessory glands closely associated with the seminal vesicles. The testis follicles are twisted filled with cysts in different developmental stages. The pair of ovaries in the females shows asymmetry with 9-11 ovarioles per ovary with oocytes in different developmental stages and a spherical spermatheca. Virgin and mated males have no differences in the size of the testes, seminal vesicle, and accessory glands. C. externa females show morphological changes in the reproductive tract according to sexual maturation, which is triggered by mating. The ovary activation occurs after female mating. The ovaries are of merotistic polytrophic type. The spermathecal reservoir is lined by a flattened epithelium with a thin cuticular intima and associated with well-developed muscles. It is concluded that the reproductive tract of C. externa is similar in virgin and mated males and females. Egg production is activated only after mating and the development of reproductive tract structures is faster in mated females.

Spermatheca of the scorpionfly Sinopanorpa tincta (Navás, 1931) (Mecoptera: Panorpidae).

The spermathecal structure of the scorpionfly Sinopanorpa tincta (Navás, 1931) was investigated using light microscopy, scanning, and transmission electron microscopy. The spermatheca consists of a bean-shaped spermathecal reservoir and an elongated spermathecal duct. The spermathecal reservoir can be subdivided into a distal portion with well-developed muscles and a proximal transitional portion connected to the spermathecal duct. The spermathecal duct is slender for its basal three-fourths and is greatly thicker for its distal one-fourth, which is mainly responsible for secretory function. A spermathecal pump formed from longitudinal muscle fibers was attached to the reservoir to control the transport of sperm. The lumen of the spermathecal reservoir is lined with a cuticle and filled with spermatozoa after copulation. The epithelium of the distal reservoir comprises a single type of epithelial cells, while the epithelium of the proximal reservoir and the spermathecal duct has three types of cells: secretory cells, duct-forming cells, and common epithelial cells. The secretory cells are rich in mitochondria, rough endoplasmic reticulum, and electron-dense secretory vesicles. The duct-forming cells form cuticular ducts, which connect the secretory cells to the lumen of the spermatheca. The spermathecal reservoir mainly serves as the storage of sperm, but the proximal reservoir as well as the spermathecal duct serves as secretory functions that maintain sperm viability.

­The tadpole of the stream treefrog Hyloscirtus antioquia (Anura: Hylidae: Cophomantini)

ABSTRACT We describe the larval morphology of the stream-dwelling tadpole of Hyloscirtus antioquia based on specimens from the type locality, Antioquia, Colombia. The larvae of H. antioquia (belong to the suctorial ecomorphological guild) show morphological characters commonly associated with lotic habitats, like a depressed body, low fins, long tail, well-developed tail musculature, and oral disc with many labial tooth rows. In addition, the larvae of H. antioquia have the anterior and posterior jaw sheath with small serrations and the inner margin of nostrils with one simple triangular fleshy projection. As in other cases in Hyloscirtus, the tadpole H. antioquia has a large saccular structure that encloses the vent tube, and partially covers the hindlimbs during their development, and also it has the ventrolateral, unpigmented spots in the region proximal to the vent tube. Finally, some aspects concerning the larvae of the tribe Cophomantini are discussed.

Ultrastructure of the Midgut Adult, Trachyderma philistina (Coleoptera: Tenebrionidae)

In the anterior part of the midgut adult Trachyderma philistina, the apical part showed microvilli in the form of membrane with folds and also microvilli appeared slender and uniform. Between these folds of microvilli appeared a lot of ribosomes and rough endoplasmic reticulum. Secretory vesicles are discharged from part of midgut. A well-developed oval nucleus appeared in the cytoplasm near the apical part of the cell. The nucleus is surrounded by a lot of free ribosomes and rough endoplasmic reticulum. Mitochondria appeared near the apical part of the cell. A well-developed thick basement membrane appeared in the basal part of the anterior midgut of adult beetle Trachyderma philistina. In the middle part of the midgut, a very thick well-developed brush border microvilli appeared. Mitochondria and numerous tracheae appeared through cytoplasm. Rough endoplasmic reticulum appeared throughout the cytoplasm. A lot of secretory vacuoles were observed directed apically. A well-developed oval and circular nucleus appeared near the basal part of the cell and surrounded by numerous rough endoplasmic reticulum A well-developed muscle fiber appeared apically and basally. A very thin basement membrane appeared in the basal part of the cell. The peritrophic membrane is absent in the midgut of adult stage Trachyderma philistine while regenerative cells appeared in the basal part of the middle midgut cell. In the posterior part of the midgut, microvilli appeared in the form of membranes due to the presence of numerous organelles that are discharging into the lumen. Lipid spheres and aggregations of glycogen are present throughout the cell. A thin basement membrane was observed.