Branchial Arches Research Articles

Single-cell reconstruction with spatial context of migrating neural crest cells and their microenvironments during vertebrate head and neck formation.

The dynamics of multipotent neural crest cell differentiation and invasion as cells travel throughout the vertebrate embryo remain unclear. Here, we preserve spatial information to derive the transcriptional states of migrating neural crest cells and the cellular landscape of the first four chick cranial to cardiac branchial arches (BA1-4) using label-free, unsorted single-cell RNA sequencing. The faithful capture of branchial arch-specific genes led to identification of novel markers of migrating neural crest cells and 266 invasion genes common to all BA1-4 streams. Perturbation analysis of a small subset of invasion genes and time-lapse imaging identified their functional role to regulate neural crest cell behaviors. Comparison of the neural crest invasion signature to other cell invasion phenomena revealed a shared set of 45 genes, a subset of which showed direct relevance to human neuroblastoma cell lines analyzed after exposure to the in vivo chick embryonic neural crest microenvironment. Our data define an important spatio-temporal reference resource to address patterning of the vertebrate head and neck, and previously unidentified cell invasion genes with the potential for broad impact.

Trichlorfon is effective against Dawestrema cycloancistrium and does not alter the physiological parameters of arapaima (Arapaima gigas): A large Neotropical fish from the Amazon.

This study investigated the in vitro and in vivo efficacy of trichlorfon against Dawestremacycloancistrium, as well as its physiological effects on arapaima. Naturally parasitized arapaima gill arches were exposed in vitro to 100, 250, 500 and 750mg/L of trichlorfon and a control group (only distilled water), in triplicate. Parasites were monitored, and mortality was used to determine the median effective concentration (EC50 ). The 750mg/L concentration demonstrated 100% in vitro efficacy against D.cycloancistrium after 60min, while the intermediate (500mg/L) and the lowest (100 and 250mg/L) tested concentrations were completely efficient after 90 and 130min, respectively. The EC50-1h of trichlorfon for D.cycloancistrium was determined at 171.73mg/L. Parasitized arapaima juveniles were exposed to a control group and 150mg/L of trichlorfon in triplicate. Fish were exposed to two therapeutic baths for 60min with 24-h intervals between treatments. Therapeutic baths with 150mg/L of trichlorfon were 92.99% effective against D.cycloancistrium and did not bring about haematological alterations (erythrogram, white blood cell count, thrombogram, plasma glucose and total proteins). Therefore, 150mg/L of trichlorfon can be used in therapeutic baths to control and treat D.cycloancistrium infestations with no physiological impairments for arapaima.

Loss of iqgap1 (IQ Motif Containing GTPase Activating Protein 1) in Zebrafish Leads to Intracerebellar Hemorrhage, Morphological Abnormalities and Activates Hematopoietic Response

Defects in multiple cell signaling molecules lead to disruptions of vascular integrity given the need for fine-tuned regulation of the cell adhesion complexes. These genetic defects have been linked to the development of intracerebral hemorrhage (ICH). There is genetic evidence in humans for ICH due to some genetic variants, while other variants have been identified in preclinical animal models. Signaling adaptor proteins play a crucial role in cell signaling by promoting interactions between effector proteins and even enabling integration of different pathways. IQGAP1 is a conserved signaling adaptor known for its roles in cell adhesion, cancer and for other cell biological effects. We engineered a zebrafish null mutant in the zebrafish iqgap1 gene by introducing an 11-bp deletion using a CRISPR/Cas9 genome editing method and characterized its phenotype. Homozygous mutants exhibit severe brain hemorrhage and morphological abnormalities, which are ultimately lethal, in about 30-40% of cases, whereas the other embryos survive to adulthood. We visualized the expression pattern of iqgap1 relative to the established fli1a vascular marker and found that iqgap1 strongly overlapped with fli1a expression, but was expressed much more broadly in tissues, such as muscle, branchial arches, and the caudal hematopoietic tissue (equivalent to the mammalian fetal liver).Critically, iqgap1 exhibited co-localization with fli1a in the blood vessels of the central nervous system, whose disruption is likely responsible for the brain hemorrhage. Whole embryo RNA sequencing-based comparison of hemorrhage-positive iqgap1-/- embryo pools with wild-type embryos at 52 hours post-fertilization (hpf) shortly after the onset of hemorrhage identified approximately 800 differentially regulated genes. The most striking feature of this dataset was up-regulation of hematopoietic markers especially those of erythrocytes, neutrophils, mast cells and HSPCs (hematopoietic stem and progenitor cells), but not macrophages. We have confirmed by in situ hybridization with marker gene probes that erythrocyte and neutrophil production is up-regulated most strongly in iqgap1-/- embryos undergoing some level of hemorrhage. By contrast, fli1a endothelial and stem cell marker was downregulated. This animal model provides a compelling genotype-phenotype correlation, implicating IQGAP1 as a new player in vascular disorders such as ICH and identifying a previously unrecognized relationship between IQGAP and regulation of hematopoiesis. Furthermore, this model is now poised to identify ameliorating and exacerbating modifier lesions and potential therapeutic agents that restore normal vascular integrity and prevent ICH. DisclosuresRobitaille: Novartis: Consultancy. Berman: Oxford Immune Algorithmics: Membership on an entity's Board of Directors or advisory committees.

Histological Morphology of Gill, Skin and Liver of Nile Tilapia Oreochromis Niloticus Fingerling Exposed to Jatropha Curcas (Linnaeus I779) Seed Powder

The effect of Jatropha curcas seed powder on the histopathology of selected organs of Oreochromis niloticus fingerlings was investigated. O. niloticus fingerlings of 6.5cm-10cm in length and 14.7g-18g in weight were exposed to different concentrations of J.curcas seed powder at 133.3mg/l, 200mg/l, 266.7mg/l, 333.3mg/land 400mg/l. The acute toxicity of the toxicant to O. niloticusfingerlings was carried out using bioassay method under laboratory condition and the 96h LC 50 was 439.23mg/l with maximum admissible concentration of the toxicant to be 4.3923mg/l – 43.923mg/l which is derived by multiplying the 96h LC 50 with an application factor of 0.01 – 0.1 . After 96hr of exposure, Histopathological changes of gill, liver and skin were observed. In the gill there was Degeneration of the gill arch,Lamellae are severely stunted,Shortened and High degeneration of gill arch, filament & lamellae and Severe submucosal congestion, secondary lamellae are absent at the highest concentration. In the skin there wasNecrosis of the skinandHypertrophy, Necrosis and erosion of dermal cell. In the liver Disorientation of the liver parenchyma structures, Hyperplasia and disorientation of hepatic cells and marked sinusoidal congestion was observed. The pattern of response of O. niloticus fingerlings at the various concentration of J. curcas seed powder varied widely at the exposure duration. The observable effect of the toxicant on the examined organs could be could serve as a baseline information needed to develop models of J. curcas seed effects on ecological systems.

Palato-Pharyngo-Laryngeal Myoclonus with Facial Involvement After an Ischemic Stroke.

Palatal myoclonus, also described as palatal tremor, is characterized by rhythmic continuous 0.5 to 5 Hz movements of the soft palate and pharynx.1 There are two categories described: symptomatic palatal tremor, because of a brainstem or cerebellar lesion, and essential palatal tremor, with no associated structural lesion.2, 3 Palatal myoclonus can rarely be associated with synchronous myoclonus of other branchial arch muscles, the diaphragm, facial muscles, or even the extremities.2 One specific variant is termed palato-pharyngo-laryngeal myoclonus, which can result in dysphagia, dysphonia, and dysarthria.4 A 56-year-old woman awoke from sleep with new right-sided weakness and dizziness. Magnetic resonance imaging (MRI) of the brain showed restricted diffusion in the right superomedial cerebellum consistent with an acute infarct (Fig. 1). The etiology of stroke was atheroembolism from an aortic arch plaque atheroma, for which she was started on aspirin. The follow-up MRI of the brain 4 months later showed a new fluid-attenuated inversion recovery (FLAIR) signal abnormality in the left medulla involving the left inferior olivary nucleus, reflecting hypertrophic olivary degeneration related to the chronic cerebellar infarct in the proximity of the contralateral dentate nucleus (Fig. 2). Ten months after the stroke, the patient reported a subjective, rhythmic, non-suppressible “whooshing” sound in her right ear that did not correspond to her heart rate and persisted during sleep. A computed tomography (CT) angiogram of the head and neck ruled out any vascular abnormalities. Nasopharyngolaryngoscopy showed spasm of the hypopharyngeal musculature and larynx. The patient returned to clinic to report new involuntary twitching of the right lower face. On examination, she had ~2 Hz rhythmic myoclonus of the right lip, chin, and throat (Video 1) as well as the palate (Video 2). There was no evidence of facial weakness, ocular motility problems, dysarthria, or dysphagia. She was prescribed a trial of carbamazepine 200 mg twice daily for palatal tremor followed by baclofen 5 mg twice daily with mild relief. She declined to try clonazepam or botulinum toxin injections. Palato-pharyngo-laryngeal myoclonus is a rare condition that can be idiopathic or lesional. Symptoms of palatal tremor are usually delayed 6 to 9 months after the initial injury, but can be delayed up to 30 months.1 The etiology of palatal tremor is disruption of the dento-rubro-olivary pathway, known as the Guillain Mollaret triangle. A lesion in this pathway causes denervation of olivary neurons from inhibitory cerebellar inputs, leading to hypertrophy and sustained synchronized oscillations causing tremor.2, 3 We present a unique case of palato-pharyngo-laryngeal and facial myoclonus caused by an ischemic stroke of the cerebellum. The patient also had pulsatile tinnitus, which correlated with direct visualization of spasms of the palate, hypopharyngeal musculature, and larynx via nasopharyngolaryngoscopy. Pulsatile tinnitus is most common in essential palatal tremor because of contraction of the tensor veli palatini on the eustachian tube. Although symptomatic palatal tremor affects the levator veli palatini, it can also rarely cause subjective auditory phenomena, likely because of some fibers inserting on the eustachian tube.1, 5 The patient's mild improvement in symptoms with the combination of baclofen and carbamazepine suggest a potential therapeutic option that warrants further investigation. (1) Research project: A. Conception, B. Organization, C. Execution; (2) Statistical Analysis: A. Design, B. Execution, C. Review and Critique; (3) Manuscript Preparation: A. Writing of the First Draft, B. Review and Critique. C.L.N.: 1B, 1C, 3A S.Q.: 1B, 1C, 3A M.S.: 1A, 3B Per the University of Pennsylvania Institutional Review Board, “a single retrospective case report is a medical/educational activity and does not meet the Federal Policy for the Protection of Human Subjects definition of research which is a systematic investigation, including research development, testing and evaluation, designed to develop or contribute to generalizable knowledge. Therefore, the activity does not require review by the IRB. Under HIPAA, a single case report is an activity to develop information to be shared for medical/educational purposes. Therefore, the use of protected health information to prepare a paper for publication of a single case report does not require IRB review for HIPAA purposes.” The patient provided verbal consent while at a clinic visit. The patient also provided signed/written consent which was mailed to the Neurology office. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this work is consistent with those guidelines. No specific funding was received for this work. The authors declare that there are no conflicts of interest relevant to this work. M.S. has received clinical trial support from AbbVie, Abbott, United States (US) World Meds, and Sanofi. C.L.N. and S.Q. have no other financial disclosures to report.

Deletion of Nf2 in neural crest-derived tongue mesenchyme alters tongue shape and size, Hippo signalling and cell proliferation in a region- and stage-specific manner.

ObjectivesThe mammalian tongue develops from the branchial arches (1–4) and comprises highly organized tissues compartmentalized by mesenchyme/connective tissue that is largely derived from neural crest (NC). This study aimed to understand the roles of tumour suppressor Neurofibromin 2 (Nf2) in NC‐derived tongue mesenchyme in regulating Hippo signalling and cell proliferation for the proper development of tongue shape and size.Materials and methodsConditional knockout (cKO) of Nf2 in NC cell lineage was generated using Wnt1‐Cre (Wnt1‐Cre/Nf2cKO ). Nf2 expression, Hippo signalling activities, cell proliferation and tongue shape and size were thoroughly analysed in different tongue regions and tissue types of Wnt1‐Cre/Nf2cKO and Cre ‐/Nf2 fx/fx littermates at various stages (E10.5–E18.5).ResultsIn contrast to many other organs in which the Nf2/Hippo pathway activity restrains growth and cell proliferation and as a result, loss of Nf2 decreases Hippo pathway activity and promotes an enlarged organ development, here we report our observations of distinct, tongue region‐ and stage‐specific alterations of Hippo signalling activity and cell proliferation in Nf2cKO in NC‐derived tongue mesenchyme. Compared to Cre −/Nf2fx / fx littermates, Wnt1‐Cre/Nf2cKO depicted a non‐proportionally enlarged tongue (macroglossia) at E12.5–E13.5 and microglossia at later stages (E15.5–E18.5). Specifically, at E12.5 Nf2cKO mutants had a decreased level of Hippo signalling transcription factor Yes‐associated protein (Yap), Yap target genes and cell proliferation anteriorly, while having an increased Yap, Yap target genes and cell proliferation posteriorly, which lead to a tip‐pointed and posteriorly widened tongue. At E15.5, loss of Nf2 in the NC lineage resulted in distinct changes in cell proliferation in different regions, that is, high in epithelium and mesenchyme subjacent to the epithelium, and lower in deeper layers of the mesenchyme. At E18.5, cell proliferation was reduced throughout the Nf2cKO tongue.

Generation of a new six1-null line in Xenopus tropicalis for study of development and congenital disease.

The vertebrate Six (Sine oculis homeobox) family of homeodomain transcription factors plays critical roles in the development of several organs. Six1 plays a central role in cranial placode development, including the precursor tissues of the inner ear, as well as other cranial sensory organs and the kidney. In humans, mutations in SIX1 underlie some cases of Branchio-oto-renal (BOR) syndrome, which is characterized by moderate-to-severe hearing loss. We utilized CRISPR/Cas9 technology to establish a six1 mutant line in Xenopus tropicalis that is available to the research community. We demonstrate that at larval stages, the six1-null animals show severe disruptions in gene expression of putative Six1 target genes in the otic vesicle, cranial ganglia, branchial arch, and neural tube. At tadpole stages, six1-null animals display dysmorphic Meckel's, ceratohyal, and otic capsule cartilage morphology. This mutant line will be of value for the study of the development of several organs as well as congenital syndromes that involve these tissues.

THE CLINICAL CASE OF HEMIFACIAL MICROSOMIA IN THE NEWBORN BOY FROM MOTHER WITH Z-21

Hemifacial Microsomia (HFM) is a term used to identify facial deformities associated with the development ofthe first and second pairs of branchial arches, characterized by underdevelopment of one half of the face. One typeof hemifacial microsomia is oculo-auriculo-vertebral dysplasia or Goldenhar syndrome.The incidence of HFM is 1:3500-1:7000 of live births and occurs in 1 case per 1000 children with congenitaldeafness. The ratio of boys to girls is 3:2. The etiology and type of inheritance is studied insufficiently. There are threepossible pathogenetic models: vascular abnormalities and hemorrhages in the craniofacial region, damage of Meckel'scartilage, and abnormal cell development of the cranial nerve crest. Environmental factors, maternal internal factors,and genetic factors (OTX2, PLCD3, and MYT1 mutations) may also cause the development of hemifacial microsomia.The article demonstrates a clinical case of hemifacial microsomia in a newborn boy from a mother with Z-21 inthe form of deformation of the left auricle with atresia of the auditory canal and "false" ears on the right, combinedwith congenital anomaly of heart (atrial septal defect) and brain (hypoplasia of the corpus callosum).Emphasis is placed on the need of involving a multidisciplinary team of specialists in the management of thispatient both in the neonatal period and in the system of subsequent follow-up.

Description of a new codling species of Physiculus from Taiwan (Gadiformes: Moridae).

A new species of codling Physiculus megastomus sp. nov. is described based on the holotype and a subadult paratype collected from northern and eastern Taiwan. The new species is classified in Physiculus by the presence of a ventral light organ on the abdomen and a chin barbel, and the absence of vomerine teeth. It is distinguished from congeners in having a large mouth with the posterior end of the maxilla extending well behind the level of the posterior margin of the orbit, its length 57.8‒60.7% in head length (HL) and the combination of the following characters: both jaws bearing caniniform teeth; snout, suborbital area, and gular region fully scaled; ventral light organ small, its length 5.5‒6.7% of distance from the interventral line to the origin of the anal fin (InV-af), located approximately at the mid-point of InV-af; five gill rakers on the upper limb of the first gill arch. DNA barcoding supported the establishment of the new species.

Gross morphological and surface ultrastructural investigation on the gills of the European barracuda Sphyraena sphyraena.

The present work examined 10 gill systems of European barracuda grossly and by scanning electron microscopy (SEM). Grossly, there were four pairs of the gill arches. The convex border of the gill arch carried the gills filaments, but there were abundance of spines near to its concave border and the gill rakers were absent. Laterally near to the convex border of the gill arch, SEM observations revealed that the first gill arch carried small elliptical, oval, cuboidal, and triangular groups of two shapes of spines; spearhead-like spines and canine-like spines, but the other three gill arches carried larger groups of the same shaped spines with the appearance of waterfalls. Medially near to the convex border of the first gill arch, the canine-like spines were observed only in the form of vertical rectangular groups that adhered in some areas. Laterally near to the concave border, the two shapes of spines were present in the form of longitudinal groups separated by spaces at the first gill arch, but these spaces were absent in the other three gill arches. Medially near to the concave border of the first gill arch, the two shapes of spines were presented in oval groups, while the other three gill arches were covered entirely by cuboidal groups of the two shapes of spines. The absence of the gill rakers in conjunction with an abundance of spines helps the European barracuda to control the food particles from escaping to the gill filaments to prevent its suffocation.

Identification and characterization of hybrids of Acipenser ruthenus and Acipenser baerii (Actinopterygii, Acipenseriformes) from the Irtysh River

Two sturgeon species, Acipenser ruthenus (Linnaeus, 1758) and Acipenser baerii (Brandt, 1869), inhabit the Irtysh basin. In 2018, we received some “atypical” specimens of sturgeon, which were similar to A. ruthenus but had a number of pronounced external differences. The hybrids A. ruthenus × A. baerii, named “oster”, can sometimes be caught in natural habitats in the Ob and the Yenisei rivers. Despite the development of methods for the genetic identification of sturgeons, the molecular genetic characteristics of the hybrids of A. baerii and A. ruthenus have not been carried out. The purpose of this study is to develop a complex of morphological and genetic characters to identify the hybrid of A. ruthenus and A. baerii from the Irtysh River. We used a complex of morphological and genetic methods to compare the putative hybrids with parental species The putative hybrids were similar to A. ruthenus in the number of dorsal scutes, the number of rays in the dorsal and anal fins, the structure of stamens on the first gill arch, and the presence of fringe on the tendrils. The hybrids were similar to A. baerii in size and weight values, the structure of dorsal scutes, the number of lateral and ventral scutes, and the number of gill rakers on the first gill arch. Genotyping of putative hybrids by using the Inter Simple Sequence Repeat (ISSR) markers revealed the presence of sites characteristic of both parental species. The fragment of the control region of mitochondrial DNA in the hybrids matched to that of A. baerii that allowed us to identify females of A. baerii as maternal individuals of the hybrids. Possible causes and factors promoting interspecific hybridization of A. ruthenus and A. baerii were studied. This is the first described fact of the appearance of sturgeon hybrids in the Ob-Irtysh basin. It is necessary to continue monitoring studies to identify the number of these hybrids in the ecological system of the Irtysh River. The data set of morphological characters and genetic methods can be used to identify the hybrids of A. ruthenus and A. baerii.

Epidemiology of Gill Monogenean Parasites Infections in Nile Tilapia Oreochromis Niloticus (Teleostei: Cichlidae) from Agneby River, Côte d’Ivoire

The Nile tilapia, Oreochromis niloticus is a fast growing fish and has a great importance for fisheries, aquaculture, and screen aquarium in Côte d’Ivoire. Parasitic infections constitute significant economic loss in fish production. The work based on Epidemiology of gill Monogenean parasites of O. niloticus from the Agneby River between August to December 2020, for the first time, was aimed to characterize the physicochemical parameters of this River, to inventory the gill Monogenean species in Nile tilapia, to analyze the parasitism as a function study areas and to highlight the parasite species’ distribution on the gill. A total of 102 specimens of fishes was sampled and examined for parasites. Gill helminthofauna of this fish consisted of Cichlidogyrus cirratus, C. tilapiae, C. halli and Scutogyrus longicornis. Fishes of the Agneby River at Agboville are more infested than the other ones due to environmental conditions. The examination of the two sides of the fish revealed that parasites species have the same affinity for the both sides of the fish. In contrast, at the level of the gill arch, these parasites preferred median gill arches (arches II and III).

AN INSIGHT INTO - HEMIFACIAL MICROSOMIA

Hemifacial microsomia is a common birth defect involving first and second branchial arch derivatives. The phenotype is highly variable. In addition to craniofacial anomalies, there may be cardiac, vertebral, and central nervous system defects. Most cases are sporadic, but there are rare familial cases that exhibit autosomal dominant inheritance.

Goldenhar syndrome

Goldenhar syndrome is a rare congenital disease that originates from the abnormal development of the first and second branchial arches. It is characterized by a classical triad: vertebral anomalies, mandibular hypoplasia and ocular and auricular malformations.

Review of the cardinalfishes of the genus Cercamia (Percomorpha: Apogonidae) of the Red Sea and Indian Ocean with descriptions of three new species.

The representatives of Cercamia from the Indian Ocean including Red Sea are reviewed and three new species are described: Cercamia spio n. sp., formerly known as C. eremia (Allen, 1987), is described from 14 specimens, 1733 mm SL, collected in 1015 meters from northern (Duba) to central (Jeddah) Saudi Arabia and from Jezirat Faraun, Egypt. It also has been photographed from the Gulf of Aqaba (Dahab, Egypt) and El Quseir (Mangrove Bay, Egypt). The new species is distinguished from other Indian Ocean Cercamia in having fewer developed gill rakers on lower limb (usually 11 versus usually 1213) and fewer anal-fin rays (11 versus usually 1213). Another new species, Cercamia laamu, n. sp., is described only from the Maldives and Chagos Archipelago based on five specimens 16.030.5 mm SL. It differs from all Indian Ocean Cercamia in having more greater number of the second dorsal-fin rays (10 versus usually 9), and a translucent body devoid of reddish marks versus small reddish dots and crisscross lines. The third new species, Cercamia mascarene, n. sp., is described from 40 specimens 1936 mm SL, from Rodrigues Island, Mauritius. It differs from Cercamia eremia in having a greater number of developed gill rakers on the lower limb of the first gill arch (usually 13 versus usually 12). Free neuromasts and cephalic pores are illustrated for Cercamia mascarene and free neuromasts on the body and caudal fin are illustrated for Japanese specimens of C. cf. eremia. New diagnoses are provided for Cercamia cladara, the type species of the genus, and C. eremia. A map of collection locations for species of Cercamia is presented to show the breath of known occurrences in the Red Sea and Indian Ocean. A new morphologic diagnosis is provided for Cercamia. A phylogenetic analysis of the barcoding portion of the mitochondrial COI gene, including all available sequences from members of the genus Cercamia, displays a much higher species diversity than expected, with high levels of divergence among recognized and undescribed species. A key to the described Indian Ocean species is provided.

Turcichondrostoma, a new genus for the Leuciscidae (Teleostei: Cypriniformes) from Southwestern Anatolia.

Turcichondrostoma, a new genus, from the Southwestern Anatolia is distinguished by having fewer gill rakers on first gill arch and morphologies of premaxilla and dentary bones. In addition, as a result of the phylogenetic analyses based on combine data set (mtDNA COI + Cytb) sequences (1706 bp.), Turcichondrostoma genus was recovered with high posterior probability value (BI PP:1.0) and strong-supported bootstrap value (ML BP: 100%) among the former Chondrostoma groups. Also, high K2P mean genetic distance values (more than 7.84%) differentiated genus Turcichondrostoma from the other genera of former Chondrostoma group. The results of both morphological-osteological and molecular analyses are congruent with each other. The results of this study revealed that the genus Turcichondrostoma is easily distinguished from the genera in Chondrostoma group.

Description of a New Genus and Two New Species of Indo-Pacific Clingfishes (Gobiesocidae: Diademichthyinae) with Redescription and Reassignment of Two Species Previously Assigned to Lepadichthys Waite, 1904

A new genus and two new species of Indo-Pacific clingfishes are described in this study. The new genus, Flabellicauda, belongs to the Diademichthyinae and can be distinguished from other genera currently placed in this subfamily by the following combination of characters: snout moderate in length and slightly pointed, not extremely long or strongly rounded; oral cleft very small, restricted to anterior tip of snout, posterior portion of both jaws covered by thick skin of snout; gill opening a tiny, narrow slit, dorsalmost point level with base of 9th to 14th (usually 12th, rarely 9th) pectoral-fin ray in lateral view; gill membrane attached to isthmus; two rows of gill filaments on gill arches 1–3; extremely small “single” adhesive disc, its length 8.1–13.5% SL; center of disc flat, without cavity; disc papillae flattened, similar in size across disc surface; preopercular lateral-line canal and associated pores absent; dorsal, anal, and caudal fins connected via thin membrane, giving appearance of single, continuous median fin around posterior part of body; and upper and lower hypural plates completely fused, forming large fan-like hypural complex. Two new species are described and assigned to Flabellicauda, new genus, including F. alleni, new species (type species of Flabellicauda, new genus), and F. cometes, new species. Two additional species previously assigned to Lepadichthys are transferred to Flabellicauda, new genus, including F. bolini, new combination, and F. akiko, new combination. Among species of Flabellicauda, new genus, F. akiko is unique in having the following characters: head sensory canal pores poorly developed, including 1 nasal and 1 postorbital pore (vs. usually 2 nasal, 2 lacrimal, and 2 postorbital pores in F. alleni, new species, and F. bolini; 2 nasal pores in F. cometes, new species); upper end of gill opening level with base of 9th or 10th pectoral-fin ray in lateral view (vs. 12th to 14th); disc region A with papillae at center (vs. disc region A without papillae at center); and body background color red in life, with white stripes along body (vs. body background color black or maroon in life, with white stripes along body). Although F. alleni, new species, is very similar to F. bolini, the former differs from the latter in having a higher number of gill rakers (viz., 5–8 [modally 6, rarely 5], 6–8 [6], and 6–8 [7] on the first, second, and third gill arch, respectively, and 18–24 [19] total gill rakers [first + second + third arch] in F. alleni, new species, vs. 4–6 [5] on the first, second, and third arch, respectively, and 12–17 [14] total gill rakers in F. bolini). In addition to the meristic difference, head length, pre-disc length, orbit diameter, and caudal-peduncle length and width proportions further aid to distinguish F. alleni, new species, from F. bolini. Examined specimens of F. alleni, new species, were collected from Sri Lanka and southeast Asia, whereas those of F. bolini were collected from Papua New Guinea, Vanuatu, and Fiji; the range of the two species are not known to overlap. Flabellicauda cometes, new species, can be easily distinguished from F. alleni, new species, and F. bolini in having the following characters: 10–12 dorsal-fin rays (vs. 12–15 [13]); 9–11 anal-fin rays (vs. 10–13 [11], rarely 10); head sensory canal pores poorly developed, including 2 nasal and 1 postorbital pores. Notes on the ecology of each of the four species of Flabellicauda, new genus, are also provided.

OCORRÊNCIA DE Therodomas elongatus (COPEPODA) EM Pterygoplichthys pardalis (LORICARIIDAE) NA AMAZÔNIA BRASILEIRA

The presente study report the first occurrence of T. elongatus in P. pardalis, a fish of the order Siluriformes. Were analyzed 44 individuals of P. pardalis caught in Lake Araca (Amazon state, Brazil). The mean fish standard length was 24.5cm ± 8.8 and the mean weight was 213.9g ± 102.6. The specimen found a postmetamorphic female, penetrated deep into the gill arch. Until the present moment there was the registration of T. elongatus only for fish of order Perciformes and Cichliformes, thus this is the first records for host of order Siluriformes. Keywords: Amazonian; Copepoda; fish; freshwater.

English

Prosthodontists usually stick to the dictum by MM Devan, “preservation of what remains than meticulous replacement of what has been lost.1” “Microtia” is a term used to describe congenital anomaly of the external ear. It is a combination of the words “micro” and “otia” each of the term denoting small and ear respectively. It includes a range of deformities which may consist of presence of a rudimentary ear, a grossly normal or smaller ear or complete absence of the entire external ear. These deformities usually account for 3 in every ten thousand births, with less than 10 % of all the cases showing bilaterally missing ears.2-4 Facial deformities are common for the microtia patient as the auricle develops from tissues of the branchial arches. Figure 1 describes the patient having congenitally missing unilateral ear. Maxillofacial prosthodontics deals with prosthetic rehabilitation of disfigured or missing parts of head and neck. Prosthetic replacement of the exterior part (Epithesis) can be related to as old as civilization. References to it are available in Indian, Greek, Roman, Egyptian Civilizations.5 Ambroise Pare is credited with making various contributions to the materials and techniques in facial prosthetics. Fabrication of an extra-oral prosthesis is probably more of an art than science. Throughout the recorded history, humans have attempted to restore missing parts of the body by using various artificial materials. MPF materials have evolved since centuries right from metals, ivory, porcelain, waxes, natural rubber, gelatin, and latex to modern day materials such as methacrylate or acrylic resins, polyurethane elastomers, and silicone elastomers each having their own set of advantages and disadvantages. But silicone is most commonly used because of its assorted benefits over other MFP materials. This case report describes an auricular prosthesis for the patient with congenital ear deformity using an acrylic template for colour depiction and room temperature volcanizing (RTV) silicone.6

Gill morphology and morphometry of the facultative air-breathing armoured catfish, Corydoras paleatus, in relation on aquatic respiration.

The Neotropical armoured catfish Corydoras paleatus is a facultative air-breathing teleost commonly exported as ornamental fish. In this species, air breathing enables it to survive and inhabit freshwater environments with low oxygen levels. Therefore, it is important to analyse the gills from a morphological aspect and its dimensions in relation to body mass with reference to aquatic respiration. For that, the gills were analysed using a stereoscopic microscope for morphometric studies, and structural and ultrastructural studies were carried out to compare the four branchial arches. Furthermore, two immunohistochemical techniques were used to locate and identify the presence of a Na+ /K+ pump. The characterization of the potential for cell proliferation of this organ was assessed using an anti-PCNA antibody. The results show that gills of C. paleatus present some characteristics related to its diet and lifestyle, such as the limited development of gill rakers and the abundance of taste buds. In addition, other special features associated with the environment and bimodal breathing were observed: scarce and absent mucous cells (MCs) in the gill filaments and branchial lamellae, respectively, and the localization of mitochondria-rich cells (MRCs) covering the basal third of the branchial lamellae, which reduces the gill respiratory area. A peculiar finding in the gill epithelium of this armoured catfish was the presence of mononuclear cells with sarcomeres similar to myoid cells, whose functional importance should be determined in future studies. Finally, in C. paleatus, the interlamellar space of gill filaments is an important site for cell turnover and ionoregulation; the latter function is also performed by the branchial lamellae.