General Morphology Research Articles

Morphological and molecular characterization of Filenchus pseudodiscus n. sp. from east Golestan province, north Iran; with an updated phylogeny of Malenchus Andrássy, 1968 (Tylenchomorpha: Tylenchidae).

During a survey in Golestan province, north Iran, two populations belonging to the family Tylenchidae were recovered in association with Quercus sp., and a rotten wood sample of an unidentified forest tree. The first recovered species was mainly characterized by having a disc-like differentiation in the frontal end under the light microscope (LM), proposing it as a tentative member of the genus Discotylenchus. Detailed morphological studies using scanning electron microscope (SEM), however, did not reveal a true disc, but showing the smooth cephalic region, and a narrow annulus behind the cephalic plate. Based upon the cephalic region structure, and by lacking a true disc, the species was identified as a member of the genus Filenchus. This population was further characterized by 555 to 618 μm long females, lateral fields with four incisures, 9 to 10 μm long stylet, spermatheca large, including spheroid sperm, post-vulval uterine sac (PUS) 8 to 12 µm long and gradually tapering to an elongate conoid tail with pointed tip. It was compared with relevant species of Filenchus having four incisures in the lateral fields and similar general morphology. By having a disc-like differentiation in the frontal end under the LM, it was further compared with three similar known species of Discotylenchus. The morphological comparisons with species under two aforementioned genera showed the recovered population belongs to an unknown species, described herein as Filenchus pseudodiscus n. sp. The molecular phylogenetic relationships of the new species using partial small and large subunit ribosomal RNA gene (SSU and LSU D2-D3 rDNA) sequences were reconstructed and discussed. Malenchus gilanensis, the second recovered and studied species was originally established based upon traditional criteria. An updated LSU phylogeny of the genus Malenchus by including M. gilanensis was also presented and its results were discussed.

First discovery of Megantereon skull from southern China

ABSTRACT The sabertoothed cat Megantereon is an iconic carnivore in the Pleistocene of Eurasia, yet its fossil record is extremely rare and highly fragmentary in southern China (and the whole Oriental Realm). Here we report a nearly complete and undeformed skull of Megantereon from Sabretooth Cave, Chongzuo, southernmost China, middle Early Pleistocene. The general morphology allows us to assign it to Megantereon nihowanensis, differing from the northern China population of M. nihowanensis by better developed P4 parastyle and longer c-p3 diastema. The excellent preservation allows us to exam the previous unrecognised cranial characters. Megantereon shows a clear affinity to Smilodon in many aspects, e.g. wide nasal with parallel lateral border and smoothly curved posterior border, presence of moderately developed antero-medial process of the nasal, presence of anterior accessory process of the frontal, and a distinct frontal depression behind the posterior border of the nasal. These characters are markedly different from those of Homotherium, suggesting a deep divergence of the two lineages of sabertoothed cats. The rarity of Megantereon in southern China and southeastern Asia probably suggests this genus is not well adaptive to the closed forest environment.

High Voltage Carbon‐Based Cathodes for Non‐Aqueous Aluminium‐Ion Batteries**

AbstractFour different forms of carbon: activated carbon (AC) from human hair, AC from hemp fibers, a carbon fullerene extract consisting of C60 and C70 fullerene (CFEx) and Super‐P carbon black were tested and compared as cathodes for non‐aqueous aluminium‐ion batteries (AIBs). These materials differ in their general structure, porosity and morphology. Fullerenes display a crystalline structure, whereas hemp fibers, Super‐P and hair are amorphous in nature. Of all materials, AC obtained from hair recorded the highest specific capacity after 50 cycles at 103 mAh g−1 with a Coulombic efficiency of ∼90 % at a current rate of 50 mA g−1. Both hemp fibers and Super‐P achieved their highest specific capacities at 56 mAh g−1 and 84 mAh g−1 respectively. CFEx recorded its highest capacity at 78 mAh g−1 and maintained it for 50 cycles. The cells were charged and discharged to 2.45 V and 0.2 V respectively.

Antennal morphology and sensilla ultrastructure of Ascia monuste (Linnaeus) (Lepidoptera: Pieridae)

Insects have different types of cuticular sensory structures, called sensilla, which are employed in environmental perception due to their direct connection to the nervous system. Antennae are the main structures containing these sensilla in Lepidoptera. This study used scanning electron microscopy to describe the general morphology and the types of antennal sensilla of the great southern white butterfly, Ascia monuste, an important pest that feeds on cruciferous plants during its larval stages. Organizational, distributional, and functional aspects are comparatively discussed, as well as potential sexual dimorphism. Sensilla and general morphology were analyzed using a stereomicroscope and photomicrographs in the ImageJ software. Four types of sensilla were found in males and females: sensilla trichodea, chaetica, basiconica and coeloconica. The number of flagellomeres was different between sexes, with females having more articles and a longer antennal length than males. The capitate antenna of this butterfly had a unique elliptical central sulcus in the median ventral surface of each segment, mostly containing sensilla trichodea. Some organizational aspects of the sensilla chaetica close to the central sulci along the flagellum were observed. The remaining sensilla were randomly distributed on the antenna, mainly at the ventral surface, while the dorsal surface was almost totally covered by scales. This is the first report about ultrastructural morphology of the antenna of A. monuste, whose sensilla appear similar to those of other Pieridae butterflies, suggesting mechanical, chemo-, thermo-, and hygro-sensitivity in this insect.

Putative crayfish burrows from the Upper Triassic Grabowa Formation of southern Poland

The present paper provides the first description of natural casts of arthropod- made burrows recovered from the continental Upper Triassic Grabowa Formation in the southern Poland. Casts' general morphologies and nature of cast- forming sediments – all corroborate the conclusion that the casts are of open tubular burrows once communicated with the surface and subsequently passively infilled with sediments. Despite their fragmentary and ex situ preservation, some of the casts represent branched structures and horizontal components of the original burrows. The surficial morphology is smooth or displays features like: scrap marks, scratches, knobby textures, metameric body parts' impressions, nodes and elongated coiled imprints. Branching, horizontal components and most of the surficial features (excluding nodes and elongated coiled imprints) are assignable to activity of arthropods, possibly crayfish. One specimen displays features known from lungfish burrows. The observed smooth to sculptured variation of surface morphology is likely a function of substrate water saturation – burrowers lived in a phreatic and vadose zones of the groundwater profile and dug within softground and firmground substrates, respectively.

Structure of the pecten neuropil pathway and its innervation by bimodal peg afferents in two scorpion species.

The pectines of scorpions are comb-like structures, located ventrally behind the fourth walking legs and consisting of variable numbers of teeth, or pegs, which contain thousands of bimodal peg sensillae. The associated neuropils are situated ventrally in the synganglion, extending between the second and fourth walking leg neuromeres. While the general morphology is consistent among scorpions, taxon-specific differences in pecten and neuropil structure remain elusive but are crucial for a better understanding of chemosensory processing. We analysed two scorpion species (Mesobuthus eupeus and Heterometrus petersii) regarding their pecten neuropil anatomy and the respective peg afferent innervation with anterograde and lipophilic tracing experiments, combined with immunohistochemistry and confocal laser-scanning microscopy. The pecten neuropils consisted of three subcompartments: a posterior pecten neuropil, an anterior pecten neuropil and a hitherto unknown accessory pecten neuropil. These subregions exhibited taxon-specific variations with regard to compartmentalisation and structure. Most notable were structural differences in the anterior pecten neuropils that ranged from ovoid shape and strong fragmentation in Heterometrus petersii to elongated shape with little compartmentalisation in Mesobuthus eupeus. Labelling the afferents of distinct pegs revealed a topographic organisation of the bimodal projections along a medio-lateral axis. At the same time, all subregions along the posterior-anterior axis were innervated by a single peg’s afferents. The somatotopic projection pattern of bimodal sensillae appears to be common among arachnids, including scorpions. This includes the structure and organisation of the respective neuropils and the somatotopic projection patterns of chemosensory afferents. Nonetheless, the scorpion pecten pathway exhibits unique features, e.g. glomerular compartmentalisation superimposed on somatotopy, that are assumed to allow high resolution of substrate-borne chemical gradients.

Macroanatomic, light and scanning electron microscopic structure of the pecten oculi in northern bald ibis (Geronticus eremita).

Eyes are the most primarily required sensory organs during the migration of migratory birds and Northern Bald Ibises (Geronticus eremita) are known to make long migrations. This study examined for the first time the structure of pecten oculi in northern bald ibises by using macroscopic anatomy as well as light and electron microscopic methods. In the study 20 eye globes from 10 adult bald ibises were used. The pecten was of pleated type. As in most bird species, it was located on the optic nerve head and projects into the vitreous from the optic nerve head. The wider basal part was observed to attached to retina and its free apical part was found in camera vitrea bulbi embedded in corpus vitreum. The pecten had 13-14 accordion like pleats lying between the basal and apical parts. In addition to arterial and venous vessels, numerous capillary vessels as well as melanocytes were observed within each pleat. The bridge binding the pleats at the apical part showed a stronger pigmentation compared to other parts of the pecten. The results of the study indicated that the general morphology of pecten oculi in northern bald ibises which is a migratory bird species were similar to that in other diurnal bird species.

Lysimachia caloneura (Primulaceae), a New Species from Hunan, China

Lysimachia caloneura G. Hao, X.L. Yu & A. Liu sp. nova (Primulaceae) is described and illustrated from Hunan, China. In general morphology it resembles the species in subgen. Lysimachia sect. Nummularia ser. Drymarifoliae, characterized by leaves with black glandular punctuations or striations, yellow corolla, filaments being longer than anthers and basally connate into a short tube, and a dorsifixed anther opening by lateral slits. Lysimachia caloneura is to some extent similar to L. patungensis, but differs from the latter by its tiny size and by having a strikingly dark green abaxial leaf surface and narrow light green bands along the main veins on the adaxial surface.

Comparative anatomy study of teeth types in Barracauda and Tilapia fish

This study investigates the general morphology and the ultrastructure of teeth types in adults of 2 fish species (the baracouda, Sphyraena barracuda, and the Nile Tilapia, Oreochromis niloticus). Also, it investigates the relationship between teeth types in fish and its feeding habits, where tilapia is an herbivore while barracuda is a carnivore. The present work has applied the anatomy of barracuda and tilapia and analyzed the types of teeth and how they work. The teeth were investigated by binocular microscope and scanning electron microscopy to determine the shape of teeth in both barracuda and tilapia and determine the method of using these teeth in feeding. The results indicated that there is a difference between barracuda and tilapia teeth in structural morphology and type. This difference was demonstrated by virtual and microscopic examination, and this is due to the different feeding habits of both barracuda and tilapia.

Is NGC 5824 the Core of the Progenitor of the Cetus Stream?

Abstract The complicated story of the Cetus Stream (CS) is recently revealed by its newly discovered ∼150 members with 6D kinematics from the cross-matched catalog of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) DR5 K giants and Gaia DR2. It exhibits a very diffuse structure at heliocentric distances between 20 and 50 kpc, extending over at least 100°, and crossing the Galactic plane. Interestingly, The CS is dynamically linked to a massive globular cluster, NGC 5824. A suggestive scenario is that NGC 5824 was the nuclear star cluster of the dwarf progenitor of the CS. We explore this scenario by modeling the disruption process of a dwarf galaxy in the Milky Way potential, on the orbit of NGC 5824, using a suite of N-body simulations. Our results show that the simulated stream can marginally recover the main component of the CS, which is the densest part of the observed stream. Inspired by this mismatch, we use a dwarf progenitor following the representative orbit of the main component members, and find it can reproduce the general morphology of the CS. This gives us a more favorable scenario of the CS progenitor, in which NGC 5824 was not the core, but located off-center. Our fiducial model also predicts a vast extension of the CS in the South, surprisingly coincident with a newly discovered wide southern stream “Palca.” Another more diffuse substructure, the Eridanus–Phoenix overdensity is also likely to be related to the CS progenitor.

New findings of the coelacanth Mawsonia Woodward (Actinistia, Latimerioidei) from the Late Jurassic – Early Cretaceous of Uruguay: Novel anatomical and taxonomic considerations and an emended diagnosis for the genus

New findings of Mawsonia from the Juro-Cretaceous Tacuarembó Formation (Uruguay) are presented. The new materials have taphonomic and anatomic significance, considering the biofabric and state of preservation of most of the bones. The most complete specimen studied is represented by several cranial and postcranial remains found in spatial association, including skull roof, cheek bones and opercula, neurocranium, palate, lower jaw, branchial and hyoid apparatuses; and also part of the shoulder and pelvic girdles. The present record is also complemented through the finding of several isolated bones from other individuals. General morphology of the bones, postparietal shield configuration and external ornamentation of dermic bones, allow to refer all the specimens to the species Mawsonia gigas. It is considered that the most complete specimen studied in this work constitutes one of the anatomically most informative records referable to this species, and to the genus, considering the following arguments: The presence of complete bones scarcely represented in previous records due to its delicate configuration, and the fact that all the remains are three-dimensionally preserved (being completely released from their sedimentary matrix). The new information provided by the comparative analyses is used for the following purposes: Bring a critical anatomical description, complement the diagnosis of the genus, and discuss previous taxonomic and ontogenetic hypotheses. The comparative analyses support previous taxonomic proposals, regarding the existence of morphological, size and ornamental variabilities, which as a whole characterize M. gigas and place it as the only recognizable species referable to this genus in South America.

New insights into the systematics and phylogeny of the genus Fouragea (Arthoniales, Opegraphaceae)

The foliicolous lichen-forming fungus Opegrapha vegae was collected on the French island of Mayotte (Comoros archipelago). Phylogenetic analyses using nuLSU and RPB2 sequences place this species in the genus Fouragea (Opegraphaceae). Opegrapha alba, O. heliabravoa, O. tuxtlensis and O. vegae are newly combined in the genus Fouragea because of their foliicolous habit, their general morphology and their ascomata and ascospores types. Fouragea vegae is reported as new for the Comoros archipelago.

Morphology of Stephanella hina (Bryozoa, Phylactolaemata): common phylactolaemate and unexpected, unique characters

Stephanella hina is a little studied freshwater bryozoan belonging to Phylactolaemata. It is currently the only representative of the family Stephanellidae, which in most reconstructions is early branching, sometimes even sister group to the remaining phylactolaemate families. The morphological and histological details of this species are entirely unknown. Consequently, the main aim of this study was to conduct a detailed morphological analysis of S. hina using histological serial sections, 3D reconstruction, immunocytochemical staining and confocal laser scanning microscopy techniques. The general morphology is reminiscent of other phylactolaemates; however, there are several, probably apomorphic, details characteristic of S. hina. The most evident difference lies in the lophophoral base, where the ganglionic horns/extensions do not follow the traverse of the lophophoral arms but bend medially inwards towards the mouth opening. Likewise, the paired forked canal does not fuse medially in the lophophoral concavity as found in all other phylactolaemates. Additional smaller differences are also found in the neuro-muscular system: the rooting of the tentacle muscle is less complex than in other phylactolaemates, the funiculus lacks longitudinal muscles, the caecum has smooth muscle fibres, latero-abfrontal tentacle nerves are not detected and the medio-frontal nerves mostly emerge directly from the circum-oral nerve ring. In the apertural area, several neurite bundles extend into the vestibular wall and probably innervate neurosecretory cells surrounding the orifice. These morphological characteristics support the distinct placement of this species in a separate family. Whether these characteristics are apomorphic or possibly shared with other phylactolaemates will require the study of the early branching Lophopodidae, which remains one of the least studied taxa to date.

La ceinture scapulaire Homo naledi : une adaptation à l’escalade de bloc

Homo naledi, a recently discovered hominin species from the Rising Star cave complex in Gauteng Province, South Africa, is a surprising species in more ways than one. The conditions of accumulation, as well as the location of these remains in the cave are intriguing, as is their age of approximately 300,000 years. Likewise, the number of remains as well as their state of preservation are exceptional. But the most astonishing discovery of all is represented by the general morphology of this new species, with an upper body adapted to climbing and the lower body presenting important adaptations to bipedalism. The shoulder joint, in conjunction with the overall morphology of the upper limb, indicates the ability to move on vertical supports. These characteristics have been interpreted as being the hallmark of arboreal behavior; however, the tree cover in the region 300,000 years ago was very similar to that of today that is to say, very sparse. Thus, we suggest that the morphology of the pectoral girdle and upper limb in H. naledi represents adaptations not to arboreal behavior, but to behavior related to movement across and climbing on rocky walls.

A 3D-CT Analysis of Femoral Symmetry-Surgical Implications.

Background: Mirroring the image of the affected side is a widely used technique for surgical planning in orthopedic surgery, especially for fractures and custom-made prostheses. Our objective is to evaluate the three-dimensional symmetry of the femurs using finite element analysis and manual alignment. Methods: Using the computed tomography of 15 patients without lower limb pathology, 30 3D biomodels of their femurs were obtained. The error obtained through image manipulation was calculated and broken down into a rendering error and a manual overlay error. The Hausdorff–Besicovitch method was applied to obtain the total asymmetry. The manipulation error was theb subtracted from it to obtain the intrapersonal asymmetry. Results: The mean intrapersonal asymmetry was 0.93 mm. It was obtained by subtracting the error derived from rendering and alignment of 0.59 mm (SD 0.17 mm) from the overall mean error of 1.52 mm (SD 1.45). Conclusions: Intrapersonal femoral asymmetry is low enough to use the mirror image of the healthy side as a reference for three-dimensional surgical planning. This type of planning is especially useful in deformity surgery when the objective of the surgery is not to restore only one specific parameter but to obtain a general functional morphology when a healthy contralateral femur is available.

New record of podocopid ostracods from Cretaceous amber.

Burmese Cretaceous amber (∼99 Ma, Myanmar) is famous for the preservation of a wide range of fauna and flora, including representatives of marine, freshwater and terrestrial groups. Here, we report on three ostracod specimens, that came visible as syninclusions to an aquatic isopod. The three specimens represent three different taxa, that were found preserved in a single piece of amber. One of the described specimens was studied using µCT scanning data. On the basis of general carapace morphology we assign all three to the group Podocopida, and (tentatively) its ingroup Cypridocopina. A lack of visibility of more particular diagnostic features such as adductor muscle scars and details of the marginal zone precludes a further identification, but we discuss possible affinities with either the marine-brackish group Pontocypridoidea or the non-marine group Cypridoidea. The taphonomy indicates that the studied ostracods had been subject to limited (if any) post-mortem transport, which could be consistent with marginal marine environments.

A new species of dartfish of the genus Ptereleotris (Teleostei: Gobiidae) from the East Coast of India.

Ptereleotris cyanops n. sp. is described from five specimens collected in trawl landings at Chennai, Tamil Nadu, East Coast of India. The new species is unusual among congeners in possessing a wide interdorsal space, its width 2.5-3.2% in SL. The new species resembles P. microlepis in general morphology and coloration, but is readily distinguished from it in lacking a black bar at base of pectoral fin, in having a slightly truncate caudal fin with the 5th and 13th branched rays prolonged as filaments (vs. emarginated caudal fin with absence of any caudal filaments), and in having the second dorsal and anal fin not elevated anteriorly (vs. elevated). Ptereleotris cyanops differs from caudal filaments bearing congeners viz., P. arabica and P. hanae, by the absence of chin barbel (vs. present in both); in having a longer pelvic fin (17.7-18.8 vs. 13.1-15.5% SL in P. arabica), and more anal rays (27 vs. 22-25 in P. hanae).

Phenotypic and transcriptomic consequences in zebrafish early-life stages following exposure to crude oil and chemical dispersant at sublethal concentrations

To further understand the underlying mechanisms involved in the developmental toxicity of crude oil and chemically dispersed crude oil on fish early-life stages (ELS), zebrafish (Danio rerio) embryos were exposed to GM-2 chemical dispersant (DISP), low-energy water-accommodated fractions (LEWAF), and chemically enhanced WAF (CEWAF) of Merey crude oil at sublethal concentrations for 120 h. We employed the General Morphology Score (GMS) and General Teratogenic Score (GTS) systems in conjunction with high-throughput RNA-Seq analysis to evaluate the phenotypic and transcriptomic responses in zebrafish ELS. Results showed that ΣPAHs concentrations in LEWAF and CEWAF solutions were 507.63 ± 80.95 ng·L−1 and 4039.51 ± 241.26 ng·L−1, respectively. The GMS and GTS values indicated that CEWAF exposure caused more severe developmental delay and higher frequencies of teratogenic effects than LEWAF exposure. Moreover, no significant change in heart rate was observed in LEWAF treatment, while CEWAF exposure caused a significant reduction in heart rate. LEWAF and CEWAF exposure exhibited an overt change in eye area, with a reduction of 4.0% and 25.3% (relative to the control), respectively. Additionally, no obvious impact on phenotypic development was observed in zebrafish embryo-larvae following DISP exposure. Significant changes in gene expression were detected in LEWAF and CEWAF treatments, with a total of 957 and 2062 differentially expressed genes (DEGs), respectively, while DISP exposure altered only 91 DEGs. Functional enrichment analysis revealed that LEWAF and CEWAF exposure caused significant perturbations in the pathways associated with phototransduction, retinol metabolism, metabolism of xenobiotics by cytochrome P450, and immune response-related pathways. Our results provide more valid evidence to corroborate the previous suggestion that ocular impairment is an equal or possibly more sensitive biomarker than cardiotoxicity in fish ELS exposed to oil-derived PAHs. All these findings could gain further mechanistic insights into the effects of crude oil and chemical dispersant on fish ELS.

Effects of environmental cocaine concentrations on COX and caspase-3 activity, GRP-78, ALT, CRP and blood glucose levels in the liver and kidney of the European eel (Anguilla anguilla)

Cocaine is one of the most widely used illicit drugs in the world, and as a result of incomplete removal by sewage treatment plants it is found in surface waters, where it represents a new potential risk for aquatic organisms. In this study we evaluated the influence of environmental concentrations of cocaine on the liver and the kidney of the European eel (Anguilla anguilla). The eels were exposed to 20 ng L−1 of cocaine for fifty days, after which, three and ten days after the interruption of cocaine exposure their livers and kidneys were compared to controls. The general morphology of the two organs was evaluated, as well as the following parameters: cytochrome oxidase (COX) and caspase-3 activities, as markers of oxidative metabolism and apoptosis activation, respectively; glucose-regulated protein (GRP)78 levels, as a marker of endoplasmic reticulum (ER)-stress; blood glucose level, as stress marker; serum levels of alanine aminotransferase (ALT), as a marker of liver injury and serum levels of C-reactive protein (CRP), as a marker of the inflammatory process. The liver showed morphologic alterations such as necrotic areas, karyolysis and pyknotic nuclei, while the kidneys had dilated glomeruli and the renal tubules showed pyknotic nuclei and karyolysis. In the kidney, the alterations persisted after the interruption of cocaine exposure. In the liver, COX and caspase-3 activities increased (COX: P = 0.01; caspase-3: P = 0.032); ten days after the interruption of cocaine exposure, COX activity returned to control levels (P = 0.06) whereas caspase-3 activity decreased further (P = 0.012); GRP78 expression increased only in post-exposure recovery specimens (three days: P = 0.007 and ten days: P = 0.008 after the interruption of cocaine exposure, respectively). In the kidney, COX and caspase-3 activities increased (COX: P = 0.02; caspase-3: P = 0.019); after the interruption of cocaine exposure, COX activity remained high (three days: P = 0.02 and ten days: P = 0.029 after the interruption of cocaine exposure, respectively) whereas caspase-3 activity returned to control values (three days: P = 0.69 and ten days: P = 0.67 after the interruption of cocaine exposure, respectively). Blood glucose and serum ALT and CRP levels increased (blood glucose: P = 0.01; ALT: P = 0.001; CRP: 0.015) and remained high also ten days after the interruption of cocaine exposure (blood glucose: P = 0.009; ALT: P = 0.0031; CRP: 0.036). These results suggest that environmental cocaine concentrations adversely affected liver and kidney of this species.

Functional morphology and post-larval development of the buccal complex in Eubranchus rupium (Nudibranchia: Aeolidida: Fionidae)

Nudibranch molluscs represent an interesting model group to study the evolution of feeding apparatus and feeding modes, being characterized by specialized buccal complex in combination with extremely diverse dietary preferences and multiply prey shifts in evolutionary history. However, the plasticity of the buccal complex morphology in response to diet and specific feeding modes remains understudied. Here we study the general morphology and ontogenesis of the buccal complex in Eubranchus rupium (Nudibranchia: Fionidae). Specific goals are to provide a detailed description of buccal structures morphology in post-larval stages, suggest the feeding mechanism and discuss the phylogenetic value of the morphological characteristics of buccal armature within the genus Eubranchus. Methods included in vivo observations of the feeding process for E. rupium, light microscopic methods, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and confocal laser scanning microscopy (cLSM). According to our results, E. rupium is a mechanical driller, boring holes in hydrozoan perisarc and sucking internal content. The mechanical drilling is supplied by functionally uniserial radula with plate-like laterals teeth of exclusively supportive function and by massive buccal musculature. Comparative phylogeny-based analysis suggests that the drilling feeding mode is common for the genus Eubranchus and indicates radular characters may have a high phylogenetic signal. The buccal complex morphology and feeding mode were found to be similar in both adults and post-metamorphic specimens, its general structures occur even in settled veligers. Juveniles and adults compete for food source, but the competition is smoothed due to characteristics of prey species growth and life cycle.