Supraorbital Canal Research Articles

Cephalic lateral line systems in the Far Eastern species of the genus Phoxinus (Cyprinidae)

The cephalic lateral line systems of seven Far Eastern Phoxinus species (P. phoxinus, P. kumgangensis, P. semotilus, P. lagowskii, P. oxycephalus, P. perenurus, and P. czekanowskii) were investigated. In this genus, the infraorbital canal is not connected with either the supraorbital canal or the preoperculomandibular canal. Phoxinus phoxinus is unique for having an underdeveloped condition, such as canal formation or remaining as uncovered. A unified supraorbital canal was observed in all species, but the infraorbital canal of both P. perenurus and P. czekanowskii was not unified into a single canal throughout their development. Unification between both sides of the supratemporal canal occurred in larger individuals of P. lagowskii, P. oxycephalus, and P. czekanowskii. The preoperculomandibular canal of P. kumgangensis, large P. lagowskii, and large P. oxycephalus was unified. The pore number of each part of the canal system also varied depending on the species. Intraspecific variations were observed between Korean and Japanese specimens of P. lagowskii in the unification of the supratemporal canal and the preoperculomandibular canal, and the number of pores of the supratemporal canal. It was inferred that the specific characteristic patterns of their cephalic lateral line systems reflected the following two factors: different environmental requirement for their microhabitat and different maximum body size.

Microcambeva ribeirae sp. n. (Teleostei: Siluriformes: Trichomycteridae): a new sarcoglanidine catfish from the Rio Ribeira do Iguape basin, southeastern Brazil

A second species of Microcambeva, M. ribeirae, is described from the Rio Ribeira do Iguape basin, S o Paulo, southeastern Brazil, which constitutes the southernmost record for sarcoglanidine catfishes. It is distinguished from M. barbata by a series of morphological features, including nasal barbel extent, position of the eye, first pectoral-fin ray extent, position of the anal fin, position of the posterior pore of the supraorbital canal, frontal shape, cranial fontanel extent, lateral process of the sphenotic, absence of the anterior ossification of palatine, and size of the posterior process of the palatine and supraorbital bone.

Phylogeny of the subfamily Corydoradinae Hoedeman, 1952 (Siluriformes: Callichthyidae), with a definition of its genera

A phylogenetic hypothesis of relationships within the callichthyid subfamily Corydoradinae is proposed based on 83 characters. The monophyly of the subfamily is well supported, as are those of two included genera, Aspidoras and Brochis. However, the monophyly of Corydoras, as traditionally defined, is not corroborated, with some of currently included species being more closely related to Aspidoras or Brochis than to nominal congeners. These conclusions contrast with a previous hypothesis, which considered Brochis and Corydoras as forming a monophyletic assemblage, with Aspidoras as its sister-group. A clade composed of Aspidoras and the species currently assigned to Corydoras, C. barbatus, C. macropterus, C. prionotus and Corydoras sp. A, is herein recognized based on the following characters: possession of anterior portion of frontal bone long, hypobranchial 2 well ossified, free margin of opercle angulated, epiphyseal branch of the supraorbital canal long, and ossified portion of pectoral spine reduced. The remaining corydoradines are grouped in a monophyletic assemblage with complex vertebra compact, posterior expansion of ceratobranchial 3 notched, presence of triangular dorsal lamina on anguloarticular, and medial expansion of coracoid exposed. A new classification is proposed to accommodate the monophyletic groups defined in the present study. Discussions about subgroups within each major clade are provided.

A new sculpin, Microcottus matuaensis , from the central Kuril Archipelago (Scorpaeniformes: Cottidae)

A new cottid species, Microcottus matuaensis, is described on the basis of 16 specimens (27.9–81.3 mm SL) collected from tide pools of Matua Island, central Kuril Archipelago. This species is the second species of the genus Microcottus, and is distinguished from M. sellaris in having three pairs of distinct bony tubercles on the dorsal surface of occiput, a deeply concave interorbital space, and absence of the first pore of the supraorbital sensory canal.

Farinichthys gigas, a new albulid fish (Teleostei: Elopomorpha) from the Paleocene of the Pernambuco-Paraiba Basin, northeastern Brazil

ABSTRACT In Brazil, albuloid fishes have only been found in the Cretaceous of Chapada do Araripe, Northeastern Brazil, particularly in the Romualdo Member, Santana Formation. In this paper we describe †Farinichthys gigas, gen. et sp. nov., a large albuloid fish from the Paleocene of the Maria Farinha Formation, Pernambuco–Paraiba Basin, based on a large skull, disarticulated Suspensorium and isolated vertebrae. The fish is the most complete fossil vertebrate hitherto obtained from that formation and the oldest record of Albulidae in South America. It is preserved in a clay marl in association with bivalve and gastropod shells, brachyuran and echinoid carapaces, and insects, in addition to fish and reptile remains. Regarding other known albulids (e.g., Albula, †Deltaichthys and †Lebonichthys), the new genus differs mainly by the absence of contact between the epioccipital and the parietal bones, a very elongate ventral process of the quadrate, an oblique groove on the external surface of the hyomandibula, and a parietal branch of the supraorbital sensory canal directed towards the parietal without reaching it. The presence of an ossified interorbital septum, an elongate horizontal preopercular arm, and the ascending process of the subopercle reaching the articular facet for the hyomandibula define a clade formed by †Farinichthys gigas plus Albula. It suggests an extension of the minimal age of this clade to the Paleocene (Danian).

Petroleuciscus, a new genus for the Leuciscus borysthenicus species group (Teleostei: Cyprinidae)

Petroleuciscus gen. n. (type species Squalius borysthenicus Kessler, 1859) is erected for 6 species from the former subgenus Squalius of the genus Leuciscus (= Leuciscus cephalus complex sensu Bianco, 1983). It is distinguished by the reduced number of vertebrae (total vertebrae modally 34-38), few sensory cephalic pores (7-10 in the supraorbital canal), relatively small supraethmoid-mesethmoid block, narrow infraorbitals, and deep neurocranium with a normally developed interorbital septum.

Development of the supraorbital and mandibular lateral line canals in the cichlid, Archocentrus nigrofasciatus.

The development of two of the cranial lateral line canals is described in the cichlid, Archocentrus nigrofasciatus. Four stages of canal morphogenesis are defined based on histological analysis of the supraorbital and mandibular canals. "Canal enclosure" and "canal ossification" are defined as two discrete stages in lateral line canal development, which differ in duration, an observation that has interesting implications for the ontogeny of lateral line function. Canal diameter in the vicinity of individual neuromasts begins to increase before ossification of the canal roof in each canal segment; this increase in canal diameter is accompanied by an increase in canal neuromast size. The mandibular canal generally develops later than the supraorbital canal in this species, but in both of these canals development of the different canal segments contained within a single dermal bone is asynchronous. These observations suggest that a dynamic process requiring integration and interaction among different tissues, in both space and time, underlies the development of the cranial lateral line canal system. The supraorbital and mandibular canals appear to demonstrate a "one-component" pattern of development in Archocentrus nigrofasciatus, where the walls of each canal segment grow up from the underlying dermal bone and then fuse to form the bony canal roof. This is contrary to numerous published reports that describe a "two-component" pattern of development in teleosts where the bony canal ossifies separately and then fuses with an underlying dermal bone. A survey of the literature in which lateral line canal development is described using histological analysis suggests that the occurrence of two different patterns of canal morphogenesis ("one-component" and "two-component") may be due to phylogenetic variation in the pattern of the development of the lateral line canals.

Asymmetrical development of bones and soft tissues during eye migration of metamorphosing Japanese flounder, Paralichthys olivaceus.

The symmetrical body of flatfish larvae dramatically changes into an asymmetrical form after metamorphosis. Eye migration results in the most significant asymmetrical development seen in any vertebrate. To understand the mechanisms involved in eye migration, bone and cartilage formation was observed during metamorphosis in laboratory-reared Japanese flounder, Paralichthys olivaceus, by using whole-body samples and histological sections. Most of the hard tissues of the cranium (parasphenoid, trabecular cartilage, supraorbital canal, and supraorbital bar) exist symmetrically in the larval period before metamorphosis and develop by twisting in the same direction as that in which the eye migrates. An increase in skin thickness beneath the eye was observed only on the blind side at the beginning of eye migration; this was the first definitive difference between the right and left sides of the body. The pseudomesial bar, a peculiar bone present only in flatfishes, developed from this thick skin and grew dorsad. Novel sac-like structures were found and named retrorbital vesicles. The retrorbital vesicle of the blind side grew larger and faster than that of the ocular side when the right eye moved most dramatically, whereas no difference was observed between the volume of right and left connective tissue in the head. The asymmetrical presence and growth of the pseudomesial bar together with inflation of the retrorbital vesicle on the blind side may be responsible for right eye migration during metamorphosis in the Japanese flounder.

Trans-Sinusal Frontal Approach for Olfactory Groove Meningiomas

The authors report on their experience with the trans-sinusal frontal approach in removing olfactory groove meningiomas. Six tumors were operated on by the trans-sinusal frontal approach, using a bicoronal incision; two tumors developed on one side, and there were four bilateral olfactosellar tumors. Osteotomy of the anterior wall of the frontal sinus was performed with an oscillating saw without any burr hole. The posterior wall of the sinus was resected and the tumor was attacked through a real subfrontal route along the plane of the anterior skull base. Ethmoidal blood supply was controlled at the initial stages of the operation, allowing avascular tumor debulking. Olfactory nerves, invaded by the tumor, were removed along with the tumor. Tumor extensions toward the sella and the optic canals were removed without brain retraction, opening of the Sylvian fissure, or dissection of the carotid arteries. All patients made a good neurologic recovery; intellectual impairment disappeared within 1 month, and visual acuity normalized within 2 weeks. Olfactory nets were preserved on the contralateral side in unilateral tumors. The trans-sinusal frontal approach is technically easy and safe to achieve. Osteotomy and replacement of the anterior wall of the frontal sinus are rapidly performed. When the frontal sinus is small, imageguided surgery allows precise deliniation of its limits and the free bone flap, including the calvarial outer layer, tangentially cut from one supraorbital canal to the other. The cosmetic result is perfect, as the normal contour of the forehead is maintained without any scar or visible burr hole. The trans-sinusal frontal approach gives access to the orbital roofs and to the central anterior skull base from the crista galli to the tuberculum sellae and the anterior clinoid processes. The trans-sinusal frontal approach represents an alternative to conventional craniotomies for tumors developed in the central anterior skull base, especially for olfactory groove meningiomas, whatever their size.

Variations of the frontal exit of the supraorbital nerve: an anatomic study.

Until now, it has been taken for granted that the point of emergence of the supraorbital nerve is by way of a notch or a foramen at the border of the inner to the medial third of the supraorbital rim. In contrast to several anatomic textbooks, we noticed that the exit point was repeatedly not at the site where anticipated when implanting lid springs for facial palsy. This gave us the idea of investigating these variations and how big they are, because most open and recent endoscopic forehead lift techniques have relied on a constant exit point of the supraorbital nerve. A total of 507 macerated skulls (1014 orbits) from three anatomic collections in Austria and Germany were studied. All skulls were adult European skulls gathered from the prehistoric age up to the twentieth century. Additionally, 18 fixed cadavers (36 orbits) and 25 fresh cadavers (50 orbits) were studied. These data were not included in the statistical analysis but in the discussion. The anatomic measurements on the skulls were carried out with an anthropometric calliper. The examinations concentrated on the configuration (notch/foramen) and the number of exit point(s) on the supraorbital rim, the vertical distance from the supraorbital rim, and the distance from the nasion to the various exit point(s). Combining all of these parameters, 74 percent of the skulls showed asymmetric findings between the right and left orbits. In 15 percent of both orbits, the supraorbital nerve left the orbital cavity already in its two branches, the medial and lateral branch, either through a notch or a foramen, the foramen being sometimes the exit of a supraorbital canal. The average distance from the nasion to the frontal notch/foramen was 25 mm on both orbits (range 16 to 55 mm) and to the supraorbital notch/foramen 31 mm (range 20 to 49 mm). The largest vertical distance from the supraorbital rim to its farthest exit point was 19 mm. Other than what is cited in literature, the variations concerning the configuration and the distance of the exit point(s) of the supraorbital nerve were so significant that all forehead operations, especially those using endoscopic techniques, must take into account these findings.

A new porolepiform-like fish, Psarolepis romeri, gen. et sp. nov. (Sarcopterygii, Osteichthyes) from the Lower Devonian of Yunnan, China

ABSTRACT A new sarcopterygian fish, Psarolepis, gen. nov. (Sarcopterygii, Osteichthyes) is described from the Lower Devonian of Eastern Yunnan, China. The new genus manifests many porolepiform-like features that are commonly used to distinguish porolepiforms from osteolepiforms, such as internasal cavity well developed, parasphenoid not protruding forward to ethmoidal region, vomeral area rectangular in shape and not meeting at median line, dorsal part of interorbital wall broad and tectum orbitale well developed, external surface of lower jaw with three large fossae, and well developed parasymphysial plates at anterior tip of lower jaws. This new form also shares some features with Powichthys, Youngolepis and Diabolepis that are not found in typical porolepiforms, such as intracranial joint situated at the level of the trigeminal exit, posterior face of ethmosphenoid facing posteroventrally, X-type skull table, and sutures always visible between premaxilla and the rest of the frontoethmoidal shield. Unique features of the new form include: complete lack of ventral or ventrolateral endoskeletal opening of the nasal cavity; extremely short sphenoidal region; presence of postorbital pillar flanking lateral cranial wall; supraorbital sensory canal not reaching anterior part of snout; median rostral toothed and taking part in upper jaw margin; and lower jaw with five coronoids. This new form probably represents a basal member of the clade that includes Powichthys, Youngolepis, Diabolepis and Dipnoi (=Dipnoiformes of Cloutier, 1990). The unusual character combination raises interesting questions about the interrelationship of the Dipnomorpha (sensu Ahlberg, 1991) and helps to illustrate the possible character transformation sequence of the stem lineage of dipnoans.

Leuciscus torgalensis, and L. aradensis, two new cyprinids for Portuguese fresh waters

The description of two new Portuguese freshwater fish species is presented. Leuciscus torgalensis occurs in the Mira basin and Leuciscus aradensis in the Arade basin and in two other small southern basins. The type material is deposited in the collections of the Museu Bocage, Lisbon (MB). The general external similarity between L. torgalensis and L. aradensis and two further species, L. carolitertii and L. pyrenaicus is high. The main external diagnostic character for both new taxa is the lower number of scales of the lateral line, despite the slight differences between them. Head form is a distinctive character between the two new species; such that head width is greater in L. aradensis. Distinct osteological characters between both L. torgalensis and L. aradensis and the other Iberian Leuciscus species are: the supraorbital canal and the modal vertebral formula that are shorter and lower in the new species, respectively. The preopercular–mandibular canal communication exists in L. aradensis, but not in L. torgalensis. Allozyme and mitochondrial DNA data also supported a monophyletic clade of Mira and Arade and the distinction of the two new species. The differentiation of the new species occurred either by an early isolation of the Mira and the Arade basins or by ecological conditions after the disjunction of all basins in Portugal, during the early Quaternary.

The cranial lateral-line system in Clarias gariepinus (Burchell, 1822) (Siluroidei:Clariidae): morphology and development of canal related bones.

The cranial lateral-line system, as well as the canal bones are well developed in the African clariid catfish Clarias gariepinus. A generalised cranial lateral-line pattern is present (supraorbital, infraorbital, preoperculo-mandibular, otic, postotic and temporal canals). The supratemporal commissure, however, is missing, although a supraorbital commissure is present (formed through the fusion of the epiphysial branches). In addition to canals, some pit-lines are present which cover both canal regions and non-canal regions (vertical, horizontal, oral, anterior, middle and posterior pit-lines). In this paper, several ontogenetic stages of the canal related bones in C. gariepinus were studied. A description of the canal bones, as well as some considerations concerning their nomenclature are given. All canal bones develop, whereas the parietal bone seems to have fused with the supraoccipital bone during ontogeny, as has been observed in some siluroids. The extrascapulars (= supratemporals) are missing in C. gariepinus, as is the case in many siluroids. The posttemporal and supracleithral bones have fused as well. Surprisingly, some separate splenial bones, enclosing the distal part of the mandibular canal are present. Some secondary modifications indicate the apomorphic features of the Clariidae. The infraorbital bones, from which the antorbital bone has lost the antorbital commissure, and the suprapreopercular bone are enlarged, plate-like bones. The nasal bone has undergone some secondary, plate-like extensions as well.

New information on the morphology of yunnanolepid antiarchs (Placoderm fishes) from the Early Devonian of South China

ABSTRACT Skull morphology is described from acid-prepared articulated specimens of the antiarch Phymolepis cuifenshanensis from the Early Devonian of Yunnan Province, South China. The nasal and circum-orbital bones have a similar structure to the advanced antiarch Bothriolepis, but with the nasal openings bounded laterally by the sclerotic ring. Yunnanolepis parvus is reinterpreted to have the same structure, assumed primitive for antiarchs. The suborbital plates of Phymolepis meet in the midline, are crossed by a single sensory groove, and also carry possible cutaneous sensory pits as in arthrodires. Three bones (submarginal, prelateral, and infraprelateral) are identified in the cheek complex, and comparisons with Yunnanolepis suggest that they were also present in other primitive antiarchs. Traces of an opercular cartilage are described for the first time in an antiarch. The sensory canal pattern of Phymolepis differs from that of Yunnanolepis, with the supraorbital canal entering the preorbital depres...

Fine structure of the developing frontal bones and scales of the cranial vault in the cichlid fish Hemichromis bimaculatus (Teleostei, Perciformes)

The development of the frontal bone and the formation of the first head scales are described during post-embryonic ontogeny of Hemichromis bimaculatus, using light and transmission electron microscopy. The frontal bone originates close to the cartilaginous taenia marginalis in a loose mesenchymal cell condensation (=primordium) lying 1 μm from the epidermis with which it establishes no cell contacts. The anlage appears at 4.2 mm standard length (SL) in the form of the membranodermal component of the bone, and extends first over the brain and then over the eye; the neurodermal component forms later to surround the supraorbital canal. The first head scales appear at 10.0 mm SL in a dense cell condensation (papilla) adjoining the epidermal-dermal junction and, once formed, remain in this position. In both organs, the initial matrix is similarly composed of “woven-fibred” bone that soon mineralizes in a similar manner to other dermal elements. In some areas of the frontal bone, “parallel-fibred” bone is deposited unequally on both surfaces, whereas isopedine is deposited in scales on the deep surface only. Osteoblastic features confirm this eccentric growth. Differences in the shape, organization and localization of the mesenchymal condensations giving rise to the frontal bone and to the scale reflect the existence of two types of dermal cell condensations. Our data are compared with those available for the post-cranial dermal skeleton of fishes both from a developmental and structural viewpoint. Structural differences in the matrices of the frontal bone and scales are discussed in a phylogenetic perspective.

Afferent response of a head canal neuromast of the ruff ( Acerina cernua) lateral line

1. 1. The fourth neuromast of the supra-orbital canal of the ruff lateral line is innervated by 300–400 fibres. 2. 2. Afferent activity of 46 fibres was investigated as a function of stimulus amplitude and of stimulus frequency. 3. 3. The dynamic range of the fibres exceeded 30 dB. 4. 4. The gain with respect to acceleration appeared to be constant from a few Hz up to 60–80 Hz. 5. 5. At higher frequencies the gain rapidly fell off (80 dB/decade). 6. 6. Short-term (τ ≈ 100 ms) and long-term adaptation effects were observed in response to large stimulus amplitudes. 7. 7. Fibres had comparable dynamic range and sensitivity. 8. 8. Response properties at stimulus onset and offset confirmed that the neural activity encodes water acceleration in the vicinity of the fish.

Afferent bursting activity of ruff lateral line induced by background noise stimulation

Single unit resting activities were recorded from fibres innervating a neuromast of the supra-orbital canal of the lateral line system of the ruff (Acerina cernua). The interval histogram of 1 of the 4 types of resting activity had a bimodal distribution (‘bursting’ activity). The resting activity of these fibres was compared with the measured vibration of the experimental table. The conclusion that the ‘bursting’ activity is not spontaneous but is caused by small background vibrations of the table was supported by recording of extracellular hair cell responses.

Peripheral Distribution and Central Projections of the Lateral-Line Nerves in Goldfish, <i>Carasius auratus</i> (Part 2 of 2)

The lateral-line system of the goldfish, Carassius auratus, is described from the receptor distribution on the body surface to the termination of the primary afferents within the octavolateralis column. Goldfish have a continuous lateral-line canal system which consists of supraorbital, infraorbital, operculomandibular and supratemporal commissural canals on the head and a trunk canal extending the length of the trunk. There is a single neuromast between each 2 canal pores. The total number of canal neuromasts on the head ranges from 74 to 100. On the body the total number of canal neuromasts ranges from 52 to 60. Associated with each canal are populations of superficial neuromasts. There are approximately 1,000 superficial neuromasts on the head which are arranged in clusters or rows oriented perpendicular to the long axis of the associated canal. On the body there are 3–9 superficial neuromasts on each scale. Further, there is a total of 1,000 superficial neuromasts arranged in horizontal lines between the fin rays of the caudal fin. The neuromasts are innervated by branches of four lateral-line nerves. The dorsal anterior lateral-line nerve innervates the supraorbital and infraorbital canals and associated superficial neuromasts. The ventral anterior lateral-line nerve innervates the operculomandibular canal and associated superficial neuromasts, as well as superficial neuromasts on the operculum. The middle lateral-line nerve innervates the postotic canal and a cluster of associated superficial neuromasts. The posterior lateral-line nerve innervates the supratemporal commissural canal and associated superficial neuromasts, as well as the canal and superficial neuromasts on the trunk and caudal fin. Application of horseradish peroxidase to the individual branches of the lateral-line nerves shows that the posterior lateral-line nerve projects to the dorsal portion of the medial and caudal nuclei, wheras the anterior lateral-line branches project to the ventral portion. Lateral-line projections to the magnocellular and descending nuclei of the octaval column were also observed. The projections to the eminentia granularis are also segregated such that the anterior lateral-line nerves project to the anterolateral portion and the posterior lateral-line nerve to the caudal portion. Thus, there appears to be a topographic organization of the lateral-line projections to the lateralis column and eminentia granularis. However, this topography does not appear to be precise as the projections of the branches of the anterior lateral-line nerves overlap extensively, as do the branches of the posterior lateral-line nerves.

A new species of the deep‐sea eel genus Ilyophis Gilbert (Synaphobranchidae) from the eastern North Atlantic, with comments on its ecology and intrafamilial relationships

A new species of synaphobranchid eel, Ilyophis blachei, is described from the eastern North Atlantic. It is distinguished by 179–188 vertebrae, dorsal fin inserted half (or more) of the snout length posterior to extended tip of pectoral fin, gill slits obliquely inclined anteroventrally from pectoral base, rounded posterior nostril bordered anteriorly by conspicuous triangular flap, long lateral line (87–95% S.L.), supraorbital canal pores 5–6, infraorbital 7–8 and preoperculomandibular 10–11, supraorbital and supratemporal commissures with 1 and 3 pores, respectively. The diagnosis of the genus Ilyophis is extended to embrace these characters. The transitional position of the genus between the subfamilies Synaphobranchinae and Dysomminae is discussed in the light of this new evidence. Ilyophis blachei occurs on the lower continental slope (1247–2070 m soundings) within the temperature range c. 7.0−3.3°C. The first record of I. arx in the Atlantic Ocean is also reported.

The Lateral Sensory Canals of Larval Notopterus.

Summary.In larval Notopterus the latero‐sensory canals in the head are extraordinarily spacious and run through the head like huge tunnels. The canal‐system is remarkable in not possessing any opening to the exterior. The disposition of the canals follows the generalized Teleostean pattern. The cavity of the supraorbital canal is isolated from the rest of the system. There are, altogether, 36 neuromasts enclosed within the canals on each side of the head innervated in the typical Teleostean manner. The lateral canal of the body has not yet been formed, and is represented by a row of sense organs located in the epidermis and opening to the exterior. The course of the various canals, the bones associated with them, the histology of the canals and the neuromasts, and the structure of the cupulae, are described. The chemical nature of the cupulae is discussed. It has proved to be problematical. The: development of the latero‐sensory system shows some modifications in comparison to other teleosts. Primary pores are not formed, the system arises from the early stages as a closed system in the head region. The nature of the secondary association of the latero‐sensory canal system with the ear in Notopterus and Gymnarchus, and in some members of Gadidae, Muraenidae and Clupeidae is discussed. It is suggested that as a result of this association the latero‐sensory canal system tends to become modified in two ways; reduction in the external communication, ultimately in some forms leading to a total loss; and increase in the size of the canals. Notopterus shows a high degree of specialization in these directions.