Nasal Pores Research Articles

Revisionary study of the armored catfish Corydoras paleatus (Jenyns, 1842) (Siluriformes: Callichthyidae) over 180 years after its discovery by Darwin, with description of a new species

ABSTRACT The taxon known as Corydoras paleatus carries one of the most complex taxonomic histories among Corydoradinae catfishes. A comprehensive review of specimens attributed to that species from several localities was carried out, allowing the clear recognition of C. paleatus and also of a new species previously misidentified as C. paleatus , described herein. Corydoras paleatus can be distinguished from its congeners by presenting the following unique combination of features: perpendicularly directed serrations along entire posterior margin of the pectoral spine; three large black blotches along midline of flank; hyaline or black pectoral fin; and transversal black bars on caudal-fin lobes. Corydoras paleatus is known from the lower rio Paraná basin, coastal rivers from Southern Brazil and Uruguay and rio Uruguai basin. The new species can be distinguished from its congeners by having the following unique combination of features: three large black blotches along midline of flank; three nasal pores; mesethmoid short; infraorbital 2 not in contact with compound pterotic; striated black spots from the snout tip to nuchal plate region; markedly rounded snout; and anterior portion of dorsal fin spotted. The new species is known from the upper rio Uruguai basin, from the rivers Canoas, do Peixe and Pelotas.

A new species of the clingfish genus Kopua (Gobiesociformes: Gobiesocidae) from Japan

A new clingfish, Kopuavermiculata, is described on the basis of a single specimen collected from ca. 100 m depth off the Pacific coast of Honshu Island, Japan. The new species is distinguished from its congeners by having the following characters: dorsal fin rays 7; anal fin rays 6; segmented caudal fin rays 15; upper procurrent caudal rays associated with both neural spine of second preural centrum and epural; vertebrae 35; nasal pores 1; lacrymal pores 3; mandibular pores 3; predorsal length about 60 % of standard length; body whitish with distinct reddish-orange blotches on body; no reddish-orange stripes on cheek; belly whitish. A key to the species of Kopua is provided.

A new species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the upper rio Paraná basin, Brazil

A new species of Corydorasis described from three tributaries of the rio Ivaí drainage, upper rio Paraná basin, Paraná State, Brazil. The new species can be distinguished from most of its congeners by the presence of three nasal pores. Other diagnostic features are the lower number of serrations in posterior margin of pectoral and dorsal spines and presence of four to six small black blotches along the midline of the flank. The possible mimetic relationship between the new species and Characidium heirmostigmatais discussed.

Description of two new species of Santelmoa (Teleostei, Zoarcidae) from the Southern Ocean

Detailed examination of eelpouts in collected material from the Gerlache Strait and the Bellingshausen Sea, during the Spanish Antarctic Expeditions Bentart 03 and Bentart 06, and from the Bransfield Strait, during the Danish Galathea 3 Expedition, at depths between 1,056 and 1,837 m, revealed two undescribed species of Santelmoa Matallanas 2010. Herein, Santelmoa fusca sp. nov. and Santelmoa antarctica sp. nov. are described on the basis of twelve specimens. Santelmoa fusca can be separated from all other Santelmoa species by the following characters: mouth terminal; two posterior nasal pores; lateral line double; two irregular rows of palatine teeth; dorsal fin rays 109–113; anal fin rays 88–94; vertebrae 27–29 + 87–91 = 114–118; two pyloric caeca well developed; scales reduced to tail; pelvic fins and vomerine teeth present. Santelmoa antarctica can be separated from all other Santelmoa species by the following characters: mouth subterminal; two posterior nasal pores; suborbital pores seven (6 + 1); lateral line double; single row of palatine teeth; supraoccipital dividing the posterior end of frontals; central radials notched; dorsal fin rays 109–112; anal fin rays 89–93; vertebrae 27 + 89–92 = 116–119; two pyloric caeca well developed; scales, ventral fins and vomerine teeth present. Santelmoa fusca and S. antarctica can readily be separated from each other by squamation (reduced to tail vs. on the tail and on the posterior part of body); suborbital pore pattern (6 + 0 vs. 6 + 1), as well as several morphometric characters. The relationships of the two new species with congeners are discussed.

Description ofSantelmoa elviraesp. nov. (Teleostei: Zoarcidae) from the Southern Ocean

Santelmoais diagnosed by the following characters: anterior portion of frontals fused; scapular foramen open; anterior ceratohyal–posterior ceratohyal (=epihyal) articulation interdigitating; cranium narrowed; supratemporal commissure and occipital pores absent; intercalar reaching the prootic; ascending rami of the parasphenoid wing high; palatal arch well developed; posterior hyomandibular ramus short; post-temporal ventral ramus well developed; six branchiostegal rays; vertebrae asymmetrical; pelvic fin rays ensheathed; scales, lateral line, pyloric caeca, palatine and vomerine teeth present. A new species ofSantelmoa, Santelmoa elviraesp. nov., is described on the basis of four specimens collected from the Bellingshausen Sea, Southern Ocean, at a depth of 1837 m. The new species can be distinguished fromSantelmoa carmenae, the type species of the genus and the sole knownSantelmoaspecies, by the following characters: mouth inferior; vertical folds on posterior end of the upper lip and on the lower lip lobe; oral valve nearly reaching the anterior edge of vomer; two posterior nasal pores; lateral line double with ventral and medio-lateral branches; single row of palatine teeth; dorsal fin rays 108–111; anal fin rays 93–94; pectoral fin rays 18–19 and vertebrae asymmetrical, 26–27 + 90–93 = 116–119.

Coptobrycon bilineatus (Ellis, 1911) (Characiformes: Characidae): redescription and comments on its phylogenetic relationships

Coptobrycon bilineatus (Ellis, 1911) is redescribed on the basis of specimens from the District of Paranapiacaba, Municipality of Santo André, upper rio Tietê, and additional ones recently collected in a small coastal river system of Serra do Mar, very near the headwaters of the rio Tietê. The genus was compared to other Characidae lacking a supraorbital, and it seems to be more phylogenetically related to Grundulus based on the possession of various putative apomorphic character states related to: the absence of a rhinosphenoid and fourth, fifth (sometimes) and sixth infraorbitals; nasal pores separated; nares with up to six nasal lamellae; cephalic laterosensory system poorly developed on supraorbital and infraorbital series; and a globose scapula. Furthermore, Coptobrycon and Grundulus are characterized by the absence of the adipose fin, of the supraorbital laterosensory series on the parietal, and of the humeral spot, and by the reduction of lateral musculature in front of the first pleural rib and between the first and second pleural ribs. Biogeographic comments are also provided.

Description of two new genera, Santelmoa and Bentartia and two new species of Zoarcidae (Teleostei, Perciformes) from the Southern Ocean

Two new genera of lycodine zoarcid fish, Santelmoa and Bentartia, and two new species, Santelmoa carmenae and Bentartia cinerea, are described from 13 specimens collected from the Gerlache Strait, Southern Ocean, at 1,056-m depth. Santelmoa can be distinguished from all other lycodine genera by the combination of the following characters: anterior portion of frontals fused; scapular foramen open; ceratohyal–epihyal articulation interdigitating; cranium narrowed; supratemporal commissure and occipital pores absent; intercalar reaching the prootic; parasphenoid wing well developed; palatal arch well developed; posterior hyomandibular ramus short; post-temporal ventral ramus well developed; six branchiostegal rays; vertebrae asymmetrical; pelvic fin rays ensheathed; scales, lateral line, pyloric caeca, palatine and vomerine teeth present. Bentartia differs from the remaining lycodine genera by the following combination of characters: basioccipital and exoccipitals fused; supraoccipital–exoccipital articulation broadly contacting; ceratohyal–epihyal articulation interdigitating; post-temporal ventral ramus weak; two posterior nasal pores; cranium narrowed; supratemporal commissure and occipital pores absent; intercalar set posteriorly; palatal arch well developed; posterior hyomandibular ramus not elongate; parasphenoid wing high; six branchiostegal rays; vertebrae asymmetrical; pelvic fin rays ensheathed; scales, lateral line, pyloric caeca, palatine and vomerine teeth present. The relationships of the two new genera are discussed.

Retinoid-Induced Nasal Malformations

Treatment of pregnant Sprague-Dawley rats with etretinate or retinoic acid on pregnancy days 8.5-9.0 resulted in craniofacial defects in all embryos. A morphological investigation of the malformations occurring in the nasal region is described. The external nose was deformed with a depressed nasal bridge and pronounced hump. Fusion between nasal processes was defective, resulting in fistulas and clefts. The nasal septal cartilage was reduced in size, the paranasal cartilage was missing, the parietothecal cartilage was deformed and the paraseptal cartilage was dislocated. Aberrant vessels were seen on the external nose in combination with underdevelopment of the vibrissae. The distance between the outer nasal pores was reduced after administration of retinoids.