Revision of the fish family Euclichthyidae (Pisces: Gadiformes) with the description of two new species from the Western Pacific

Members of the benthopelagic fish family Euclichthyidae, also known as the Eucla cods, occur on the upper continental slopes off Australasia at 220–1040 m depths. Euclichthyids essentially differ from other gadiform fishes in a combination of two almost contiguous dorsal fins with the second much longer based, a deeply notched anal fin with its anterior portion greatly elevated, jugular pelvic fins consisting of 3 partly united filiform upper rays and 3 free filamentous lower rays, an asymmetrical caudal fin with 5 hypurals fused into two plates, and no chin barbel, or vomerine and palatine tooth patches. Additional characters attributed to the group by other published studies include: no horizontal diaphragm within the posterior chamber of the swim bladder, no swim bladder-auditory capsule connection, presence of a luminous organ, and cranial muscle adductor arcus palatini divided by a strong ligament running from the lateral ethmoid and palatine to the medial face of the hyomandibular. Widely considered to be monotypic since its erection in 1984, the group consists of a single genus and three allopatric species, Euclichthys polynemus McCulloch, 1926 (Western and southern Australia, New Zealand), and two new taxa, E. microdorsalis sp. nov. (northeastern Australia) and E. robertsi sp. nov. (eastern Australia and New Caledonia). Eucla cods are morphologically conservative with both new species superficially resembling the type species, E. polynemus. Euclichthys microdorsalis sp. nov. is the most anatomically and morphologically divergent member of the group in having a shorter first dorsal fin, longer snout, relatively small eye compared to its interorbital width, and fewer caudal-fin rays and primary rakers on the outer gill arch than its congeners. Euclichthys robersti sp. nov. differs from E. polynemus in being smaller with a more slender head, and having a smaller eye, longer anal-fin base and tail, smaller scales, fewer primary rakers on the outer gill arch, more elongate oval otoliths, and usually having a X and/or Y bone in the caudal skeleton (both absent in other Euclichthys). Little is known of their biology but available material suggest that early juveniles remain pelagic in the open ocean with adults benthopelagic near the sea floor. Diagnoses and a key are provided for the three species.

Phylogenetic Systematics of the Family Pentacerotidae(Actinopterygii: Order Perciformes)

The osteologic and myologic characteristics of the family Pentacerotidae are described in detail. The family Pentaceroti-dae is a monophyletic group supported by 11 synapomorphies found in all family members. Of their synapomorphies, two(the second infraorbital and endopterygoid articulate with lateral ethmoid conditions) are considerably rare in percoidsand strongly support the monophyly of the family. A comparison of 44 transformation series among all species revealedfour equally parsimonious trees, and a strict consensus tree was adopted. On the basis of the inferred phylogenetic rela-tionships of the Pentacerotidae, this family was cladistically classified into two subfamilies and seven genera: Histiopter-inae (Histiopterus, Evistias, Zanclistius, Pentaceropsis, Paristiopterus, and Parazanclistius) and Pentacerotinae(Pentaceros). The center of origin of pentacerotids was inferred to be the Southern Australian region. I propose that the two families, Ostracoberycidae and Chaetodontidae, are closely related with Pentacerotidae.

A fossil loricariid catfish (Siluriformes: Loricarioidea) from the Taubaté Basin, eastern Brazil

A new loricariid catfish is described from the Tremembé Formation (Late Oligocene to Early Miocene) sediments of the Taubaté Basin in eastern São Paulo State, Brazil. Taubateia paraiba, new genus and species, is based on a single specimen preserved as a ventral-side impression of an articulated partial neurocranium, dorsal elements of the pectoral girdle and anterior vertebrae. The fossil is identified as belonging to family Loricariidae based on obvious overall similarity and the presence of diagnostic derived characters such as: odontodes, dorsal margin of metapterygoid contacting lateral ethmoid, presence of mesethmoid disk (condyle), and compound pterotic-supracleithrum bone. Also, as in most loricariids, the ossified transcapular (Baudelot's) ligament plus basiocciptal lateral process form a prominent transverse wall at the occiput. Other derived characters preserved in Taubateia are synapomorphies at different levels within Loricariidae, including a wide and low parasphenoid, form of pterotic-supracleithrum, shape and position of the mesethmoid disk, a triangular lateral ethmoid with expanded posterolateral corner and a rounded and low ridge articulating with the metapterygoid, and a pointed distal margin of transverse process of the Weberian compound centrum. The derived characters recognized in this fossil are a distinctive combination for diagnosing a new genus and species but not for its unambiguous placements in any of the currently recognized loricariid subfamilies.

Evaluation of mucosal surface reduction after ethmoidal surgery in nasal polyposis

Objectives: To assess the reduction of mucosal surface after total sphenoethmoidectomy.Study design: Prospective study.Methods: Twelve normal, consecutive computed tomography scans were used. Computed tomography measurements were made at two different levels: the cribriform plate, and the upper level of the maxillary antrum. The length of the lateral wall of the ethmoid sinus and the perimeter of each ethmoid cell were measured at each level and on each side. The whole perimeter of the ethmoid sinus was evaluated for each CT scan level. For each side and each level, the ratio between the ethmoid sinus perimeter and the lateral ethmoid wall length was calculated.Results: The mean length of the lateral ethmoid sinus wall was 61.7±1.3 mm and 59.9±1.6 mm at the upper and lower parts of the ethmoid sinus, respectively. The mean ethmoid sinus perimeter was 263.2±11.5 mm and 250.4±11.1 mm at the upper and lower parts of the ethmoid sinus, respectively. No significant statistical difference was observed between measurements as a function of side (right or left) or level (upper or lower). The mean ratio between the ethmoid sinus perimeter and the lateral ethmoid wall length was 4.2.Conclusion: After total sphenoethmoidectomy, the mucosal surface of the ethmoid sinuses is reduced by a factor of 4.2; about 76 per cent of the mucosa is removed during total sphenoethmoidectomy.

Merodoras nheco, new genus and species from Rio Paraguay basin, Brazil (Siluriformes, Doradidae), and nomination of the new subfamily Astrodoradinae

Merodoras nheco, new genus and species of Doradidae (Siluriformes) is described from Rio Paraguay basin, Brazil. The new genus belongs to the new subfamily Astrodoradinae, a monophyletic group formally named herein that includes, besides Merodoras, Amblydoras, Anadoras, Astrodoras, Hypodoras, Physopyxis, and Scorpiodoras. This group is diagnosed by the possession of: lacrimal serrated and participating in the orbital margin, four to seven pleural ribs; spines on the postcleithral process; postero-inferior portion of the coracoid exposed. Merodoras nheco, new species, is distinguished from other doradids by the unique combination of the following characteristics: 1) tips of retrorse spines on the midlateral scutes ventrally oriented in adults; 2) incomplete lateral line, with only a few midlateral scutes anteriorly; 3) pectoral girdle entirely exposed ventrally, with the opening of the arrector ventralis inferior reduced to a small fossae on the anterior edge of the coracoid; 4) caudal fin truncate; 5) dorsal-fin spine smooth, without serrae on both faces; 5) lacrimal serrated; 6) lateral ethmoid serrated. Merodoras nheco inhabits the “Pantanal Matogrossense,” a flooded portion of the upper Rio Paraguay basin in western Brazil.

Description of a new species of Parancistrus (Siluriformes: Loricariidae) from the rio Xingu, Brazil

Parancistrus nudiventris, new species, is described and compared with the congener P. aurantiacus. The new species has only been recorded from rio Xingu and can be distinguished from P. aurantiacus by having a naked abdomen (plated in P. aurantiacus), the presence of bluish dots in living specimens or spotted in preserved specimens (uniformly dark or clear brown or mottled, never spotted in P. aurantiacus), larger interbranchial distance (39-56% in HL vs. 24.9-39.5% in P. aurantiacus), narrower interorbital distance (26.8-38% in HL vs. 38.5-43.1% in P. aurantiacus). Parancistrus nudiventris also has buccal teeth more conspicuous than in P. aurantiacus. Main skeletal differences include the presence of a strong condyle on the lateral ethmoid for articulation with the metapterygoid in P. nudiventris (not seen in P. aurantiacus); anguloarticular processes short in P. nudiventris (long in P. aurantiacus); opercle with odontodes, partly exposed in P. nudiventris (completely embedded in skin in P. aurantiacus).

Lacantunia enigmatica (Teleostei: Siluriformes) a new and phylogenetically puzzling freshwater fish from Mesoamerica

A new family (Lacantuniidae), genus and species of catfish, Lacantunia enigmatica, is described from the Río Usumacinta basin of Chiapas, México. This odd siluriform is diagnosed by five distinctively autapomorphic and anatomically complex structures. The fifth (last) infraorbital bone is relatively large, anteriorly convex and remote from a prominent sphenotic process. The lateral margin of the frontal, lateral ethmoid and sphenotic bones are thick at the origins of much enlarged adductor mandibulae and levator arcus palatini muscles; otherwise the skull roof is constricted and flat. One pair of cone-shaped "pseudo-pharyngobranchial" bones is present at the anterior tips of enlarged cartilages medial to the first epibranchial. A hypertrophied, axe-shaped uncinate process emerges dorsally from the third epibranchial. The gas bladder has paired spherical, unencapsulated diverticulae protruding from its anterodorsal wall. Lacantunia enigmatica cannot be placed within or as a basal sister lineage to any known catfish family or multifamily clade except Siluroidei. This species may represent an ancient group, perhaps of early Tertiary age or older, and it adds another biogeographic puzzle to the historically complex Mesoamerican biota.

The late Miocene Phractocephalus catfish (Siluriformes: Pimelodidae) from Urumaco, Venezuela: additional specimens and reinterpretation as a distinct species

Based on additional specimens the fossil pimelodid catfish from the upper Miocene Urumaco Formation, Falcón State, Venezuela originally assigned to the extant species Phractocephalus hemioliopterus is described as a new, extinct species. †Phractocephalus nassi n. sp. is diagnosed by the following combination of characters: 1) posterior half of frontals and anterior half of supraoccipital with elongate, coarse ridges and sulci in addition to reticulating ridges and subcircular pits; 2) very broad and ornamented mesethmoid bone; 3) lateral ethmoid margin convex and eliminating orbital notch but not projecting far anteriorly over palatine condyle; 4) anterior cranial fontanelle closed or represented by a small pit; 5) supraoccipital process rounded laterally and posterolaterally, concave posteriorly and completely concealing Weberian complex in dorsal view; 6) opercle covered with reticulating ridges and pits; 7) cleithrum coarsely ornamented along ventral edge and bulging outward lateral to spine articulation; 8) pectoral spine mostly ornamented with coarse ridges and sulci. †Phractocephalus nassi is compared to modern P. hemioliopterus and an undescribed extinct species from the upper Miocene Solimões Formation, Acre, Brazil. New diagnostic characters of Phractocephalus are presented that apply to the modern and fossil species, including: 1) ornamentation of skull, pectoral girdle and fin spines comprising a coarse meshwork of reticulating ridges surrounding rounded pits plus some elongate ridges and sulci; 2) supraoccipital posterior process greatly expanded laterally and posteriorly behind occipital wall; 3) lateral ethmoid and sphenotic broadly sutured behind eye; 4) anterior cranial fontanelle reduced or completely closed and posterior cranial fontanelle closed; 5) vomerine tooth plate large, roughly pentagonal to triangular in form, and with fine teeth. Today Phractocephalus ranges widely throughout the lowland Orinoco, Amazon and Essequibo basins. However, the genus does not occur west or north of the Andes or Venezuelan coastal ranges. Recognizing the Urumaco Phractocephalus as a distinct species does not alter the obvious conclusion that this catfish marks a large river connection between the Caribbean coastal region and the Orinoco system during at least part of the Neogene. Other Urumaco fossils show this same biogeographic relationship.

Cranial Osteology of Brosme brosme with Notes on its Position Within the Subfamily Lotinae (Gadidae)

The cranial skeleton of Brosme brosme is described in detail. It differs from Urophycis and Gadus in that its lateral ethmoid surrounds the nasal capsule from all sides and the winglike flanges of the parasphenoid take part in the formation of the trigemino-facial foramen. The trigemino-facial foramen of Brosme is not homologous with that of Merluccius. So B. brosme probably represents a third line of evolution within Lotinae.