Zoomorphology最新文献

Ants in the genus Strumigenys have an assortment of structures that appear to hold environmental debris that acts as camouflage to facilitate their ability to feed on collembolans. Species use a species-specific assortment of structures with a general hair- or scale-like form. These structures can be categorized as brush hairs, which expand apically and often have peg- like extensions for greater surface area and holding ability; holding hairs, narrow cuticular structures that often have ridges and pointed extensions of the cuticle; or guard hairs, whose function may not be to hold debris but at times become covered with this material. Additionally, the sculpturing of the head often holds a coating of environmental debris. Each of the six species used in this study had a distinct pattern of these cuticular structures that are different from that of other species and can be considered to have a species-specific character. Six species of Strumigenys are studied using a scanning electron microscope.

In the present study, we investigated the antennal morphology and the distribution and typology of sensilla in antennae of male and female Caligo illioneus illioneus Cramer (Lepidoptera: Nymphalidae), examined by scanning electron microscopy—SEM. The insect was identified by morphological and molecular means, and the COI gene of this subspecies was sequenced and deposited in GenBank. The SEM results showed that antennae of both sexes do not present dimorphism, as they cannot be distinguished from each other in terms of morphology. In addition, the ventral region of the flagellum has longitudinal carinae. In both sexes, seven types of sensilla were identified along the scape, pedicel and flagellum: Böhm’s bristles and sensilla auricillica, basiconica, chaetica, coeloconica, squamiformia, and trichodea. Subtypes I and II were characterized for Böhm's bristles and sensilla basiconica and chaetica according to the length, because morphometric result was statistically different among individuals of the same sex. In addition, the flagellum contains the vast majority of sensilla and their subtypes, except for Böhm’s bristles, present only in the basal region. This study provides valuable information about the antennal morphology and sensilla typology in C. i. illioneus, contributing with morphological evidence on the sensory system of butterflies, mainly in the genus Caligo, which is helpful to assist behavioral and electrophysiological studies.

The current work attempted to examine the histological and immunohistochemical features of the pancreas in the southern white-breasted hedgehog (Erinaceus concolor). Five adult male individuals were used in this study. Utilizing hematoxylin and eosin as well as Masson's trichrome, staining was performed on paraffin sections of the pancreas. Immunofluorescent staining investigated the expression pattern of glucagon, insulin, somatostatin, neuropeptide Y (NY), and pancreatic polypeptide (PP). The exocrine pancreas comprised pyramidal and oval-shaped acini, exhibiting the clustering of zymogen droplets in the apical cytoplasm of acinar cells. The endocrine pancreas was distinguished as a large α islet of Langerhans and small β islets. Alpha cells were localized on the periphery of islets with an intensity of 20.6% ± 12.56. In comparison, Beta cells with 25.14% ± 5.89 intensity were gathered in the middle of the pancreatic islets. Delta cells exhibited 25.69% ± 5.13 intensity and were distributed through the islets. NY and PP cells were detected with 22.74% ± 3.25 and 16.80% ± 4.77 intensity, respectively. These cells showed prevalent distribution in the islets. In conclusion, it appears that although the pancreas of the southern white-breasted hedgehog is generally like other mammalian species, there are some species-specific features in density and dispersal of endocrine cells which can be attributed to the physiological purpose of the pancreas in this species. Future histophysiological investigations are still needed to explore the exact relationship between the histological organization of the pancreas and its function in that animal.

Vision is an extremely important sense in bats and can influence foraging activities. The present study aimed to evaluate morphometric aspects of the eyeballs of Neotropical bats with different feeding habits. Based on the hypothesis that frugivorous and nectarivorous bats likely possess better visual resolution compared to insectivorous and sanguivorous species due to their foraging modes, we predicted that these bats would have larger eyeballs and internal eye structures comparable to those of insectivorous and blood-eating species. Histological analysis allowed for estimating the thickness of the cornea, choroid, sclera, and retina, as well as counting the number of photoreceptor cells in the external nuclear layer of the retina of two frugivorous species (Artibeus obscurus, A. planirostris), two nectarivorous species (Glossophaga soricina, Anoura geoffroyi), two blood-eating species (Diphylla ecaudata, Desmodus rotundus), and one insectivorous species (Nyctinomops laticaudatus). Macroscopic measurements were obtained in four of these species. There is a statistically significant relationship between the type of diet and the morphological differences of the eyeball, confirming our predictions regarding fruit bats, which presented the highest means of ocular parameters while the insectivorous N. laticaudatus and the nectarivorous G. soricina exhibited the lowest. These latter two species had a thinner cornea, indicating a possible lower refractive power and, consequently, lower visual acuity. The blood-eating species showed divergent results. Additionally, the insectivorous N. laticaudatus also had a smaller number of photoreceptor cell nuclei in the outer nuclear layer of the retina, possibly indicating less transduction of light signals by the retina.

The present study aims to describe the anatomical bone, muscular, and nervous components of the capybara’s pelvic limb, associating dissections with radiographic imaging findings. Four animals (two adult females, one adult male, and one young male) were used for macroscopic dissections, and one adult male for radiographic acquisitions. A specimen was prepared for bone descriptions using a maceration procedure. The results demonstrated an elongated thigh bone, the obturator foramen obturator, the ilial wing, and the iliac body straight. The anatomical variations of the pelvic limb of capybaras found were: in the femur, the third trochanter is absent; in the tarsal–metatarsal complex, the I tarsal and the I and V metatarsals are vestigial, and a single portion of the M. sartorius and M. gracilis muscles was demonstrated. Furthermore, variations were found in the origin and insertion of each muscle. Macroscopic musculoskeletal descriptions associated with radiographic analyses made it possible to establish a standard of comparative normality for knowledge of species examinations. The pelvic limb was innervated by nerves that emerge from the lumbosacral plexus, which gives rise to the following nerves: N. gluteus cranialis, N. gluteus caudalis, N. genitofemoralis, N. obturatorius, ischiadicus—rami musculares, N. cutaneus surae lateralis, N. cutaneus surae caudallis, N. pudendus, N. femoralis, N. saphenous, N. tibialis, and N. fibularis communis. In conclusion, the anatomy of the capybara’s pelvic limb locomotor system presents particular characteristics related to its aquatic behavior and the absence of arboreal habits.

The aim of this study was to describe the origin and branches of the brachial plexus nerves in S. villosus, as well as the innervated musculature, contributing information to the field of comparative animal anatomy and providing insights for applied studies. Fifteen adult cadavers (eight males and seven females), previously identified, sexed, and fixed with a 10% aqueous formaldehyde solution were used. The patients underwent digital radiographic examinations of the cervical region to characterize the number of cervical vertebrae. The nerves were dissected to visualize the innervation of the intrinsic and extrinsic musculature of the thoracic limb. With the assistance of a costotome, the vertebrae were removed until visualization of the spinal cord and the roots, which gave rise to the nerve branches. The specimens presented seven cervical vertebrae, and the brachial plexus was characterized as postfixed, formed by connections between the last four cervical spinal nerves (C5, C6, C7, and C8) and the first two thoracic nerves (T1 and T2). The cranial, middle, and caudal trunks originate from the suprascapularis, subscapular, axillary, musculocutaneous, radial, median, and ulnar nerves for the intrinsic musculature and from the cranial pectoral, caudal pectoral, lateral thoracic, long thoracic, and thoracodorsal nerves for the extrinsic musculature. The ventral branches that contributed the most to plexus formation in the right antimer were C5 and C8, while in the left antimer, they were C7. The resulting nerves and the innervation for extrinsic and intrinsic musculature were similar to those observed in other rodents and representatives of the Mammalia class in general.

The study of the microscopic anatomy of the larvae of Entoprocta is interesting in the context of determining the phylogenetic position of this group. It is assumed that the comparison of the organization of larval stages of entoprocts with different life cycle stages of other taxa (bryozoans, cycliophorans, mollusks) may help to find common features in their organization, indicating possible close relationships of these groups. There are few data on the microscopic anatomy of the larvae of entoprocts. The fine structure of larvae of only two solitary species, Loxosomella murmanica and Loxosoma pectinaricola, has been described in detail. Here we described the ultrastructure of the swimming larva of colonial species Barentsia gracilis. Our data clarify some details of the structure of entoproct larvae. The cuticle of larval stages is similar to that of adults. The prototroch is represented by two rows of ciliated cells. The apical and frontal ganglia are devoid of a central neuropil, which distinguishes them from the ganglion of adults. Ganglia include not only nerve cells but also muscle cells. The digestive tract of larvae and adults is similar not only at the histological level but also at the ultrastructural level. Three pairs of pedal glands include cells with electron-dense granules and cells with vacuoles with granular contents. These glands probably secrete different components of mucus. Each of the protonephridia consists of two terminal cells that pass into their own canals, which then fuse together and open by the nephropore on the hyposphere.

The study provides the first comprehensive account of the developmental biology of the Indigo barb in captivity. The males develop a reddish hue on the body and margins of their median fins, as opposed to the dull coloration of the females. The fish spawned 6–7 h after administering the breeding hormone, and the fertilized eggs were demersal and adhesive. The larvae hatched 22 h ± 20 min post-fertilization and were demersal with distinctive crawling movements. The yolk sac larvae were 2.48 ± 0.032 mm in total length, with a non-pigmented body and pear-shaped yolk sac. The pre-flexion stage was attained 4 days after hatching, with a single-chambered swim bladder and melanophore aggregation along the body. The larvae reached the flexion stage on day 16, with a body length of 4.54 ± 0.36 mm and the development of caudal fin rays. On the 28th day, the post-flexion stage had produced all of the fins except the pelvics, a two-chambered swim bladder, and a distinctive sub-dorsal blotch. The presence of a supra-anal band and the emergence of scales over the caudal area characterized the juvenile stage. The baseline information on early ontogeny will be valuable for the conservation and sustainable use of the species.

A study is undertaken using anatomical measurements of specimens attributed to six species of Geospiza, the ground finches from the Galápagos archipelago. In a demonstration of method, a probabilistic approach associated with “sigma taxonomy” is adopted to assess the probability that pairs of specimens are or are not conspecific. We use a definition of a species based on morphometric analyses of the kind previously undertaken on extant vertebrate taxa (including mammals, birds and reptiles), using pairwise comparisons of anatomical measurements in regression analyses of the form y = mx + c from which the log-transformed standard error of the m-coefficient is calculated (“log sem”). The latter statistic is a reflection of variability in morphology. There is a high probability that at a species level, specimens attributed to G. magnirostris are different from those attributed to G. fulginosa, G. difficilis or G. scandens. Results of this study, using probabilistic sigma taxonomy, confirm the refutation of a single species hypothesis. In addition, we apply the log sem method to demonstrate that in case of comparisons between G. fortis and G. scandens (which are known to hybridise), there is a high probability that they are not different at a species level.