scholarly journals Osteological characters of the axial skeleton and pectoral girdles in some species of the Euroasian freshwater fishes of the family Cottidae

2016 ◽  
Vol 320 (1) ◽  
pp. 71-83
Author(s):  
V.P. Prirodina ◽  
I.B. Tsvetkov

The structure of the pectoral fin, its girdle and osteological details of the axial skeleton and a skeleton of the caudal fin, including the structure of unpaired fins were studied in three species of three genera of the family Cottidae: the genus Cottus: European species C. koshewnikowi Gratzianov, 1907 and two species of Fareastern monotypic genera: Trachidermus fasciatus Heckel, 1837 and Mesocottus haitej (Dybowsky, 1869). The species well differ in structure of the pectoral girdles and pleural ribs. Mesocottus haitej is characterized by absence of the interradial and coracoid fenestrae and by considerable reduction of pleural ribs in the abdomen part of the vertebral column. Сottus koshewnikowi and T. fasciatus have backwardly directed pleural ribs (3 pairs of ribs in M. haitej). Trachidermus fasciatus is characterized with the most number of plesiomorphic features: the presence of branched rays in the pectoral fin, greater numbers of vertebrae, rays in the second dorsal, anal and pectoral fins, big anteanal distance and by number of preural vertebrae, supporting the procurrent rays. In C. koshewnikowi, the first dorsal fin occupies the most anterior position: aID 32.6–38.0% SL vs 35.7–38.7% SL in T. fasciatus and 36.4–40.8% SL in M. haitej.

1994 ◽  
Vol 85 (3) ◽  
pp. 159-175 ◽  
Author(s):  
Per Erik Ahlberg ◽  
Nigel H. Trewin

AbstractThe axial skeleton and fin supports of the Middle Devonian lungfish Dipterus are described from a range of specimens from the Orcadian Basin of Scotland. The axial skeleton of the trunk region consists of intercentra, relatively short ribs, and neural arches bearing two rows of supraneural spines; posteriorly, the intercentra are replaced by haemal arches. The notochord seems to have been essentially unconstricted. There may have been two pairs of cranial ribs. In general terms the vertebral column resembles that of Neoceratodus but is more fully ossified. The only known paired fin support of Dipterus is an archipterygial structure resembling those of Neoceratodus, with at least seven mesomeres and jointed pre- and postaxial radials. The pectoral fin is rotated as in modern lungfishes. The median fin supports all consist of basal plates supporting radials. In the posterior dorsal fin support the posterior radials form a branched structure. The heterocercal tail is supported by segmental radials. A new body reconstruction is presented.The characters possessed by Dipterus offer support for a lungfish–porolepiform sistergroup relationship. All known lungfishes fit into a single cumulative series of postcranial morphologies. The evidence for a paedomorphic trend in lungfish phylogeny is interesting but inconclusive.


2020 ◽  
Vol 95 (1) ◽  
pp. 170-183
Author(s):  
Eric J. Hilton ◽  
Lance Grande ◽  
Fan Jin

AbstractThe family †Peipiaosteidae contains the genera †Peipiaosteus, †Stichopterus, †Spherosteus, †Yanosteus, and †Liaosteus, all from Late Jurassic to Early Cretaceous deposits of China, Russia, Kazakhstan, and Mongolia. Although the family has taxonomically expanded since it was first established for †P. pani Liu and Zhou, 1965, the amount of detailed comparative data for many of the taxa involved is lacking. In this paper, we describe the osteology of the monotypic genus †Yanosteus from the Yixian Formation (Early Cretaceous) of China largely on the basis of a newly prepared, well-preserved specimen. †Yanosteus is characterized by a series of infraorbital ossicles (a characteristic of the family), a broad, rounded palatopterygoid, a robust dentary, an extremely small opercle and a subopercle with distinctly long and rounded anterior process and a posteriorly scalloped margin, a broad and weakly forked caudal fin, an elongate dorsal fin with more than 160–178 fin rays (diagnostic for the genus), and a short but well-formed pectoral fin spine. We use the results of this study to discuss the characters of the †Peipiaosteioidei and the diversity of †peipiaosteioids.


2017 ◽  
Vol 5 (4) ◽  
pp. 434-441
Author(s):  
Asha Rayamajhi ◽  
M. Arunachalam

In this study, we describe a miniature sisorid catfish of the family Erethistidae, as a new distributional record of Pseudolaguvia nubila from the Baandhkhola (stream), a tributary of Narayani River inCentral Nepal. Pseudolaguvia nubila shows its distribution to Nepal is distinguished from its congeners by combination of characters, such as- two broad and distinct yellowish vertical bands at the origin of dorsal fin and anal fin, smooth outer edge of the dorsal fin spine, dorsal fin spine length 13.23-17.60 % SL, pectoral fin length 24.89-26.27 % SL, pectoral fin spine length 18.39-19.48 % SL and body depth at anus 17.22-18.69 % SL.Int. J. Appl. Sci. Biotechnol. Vol 5(4): 434-441


Author(s):  
Laith A. Jawad ◽  
Liu Jig

Seven osteological characters of the axial skeleton are studied in the eight species of the genus Pampus. The characters include: pattern of interdigitation of the dorsal- and anal-fin pterygiophores with the neural and haemal spines of the vertebrae, structure of the vertebral column, distribution of the dorsal- and ventral- procurrent caudal-fin rays, distribution of the principal caudal-fin rays and the morphology of the caudal-fin skeleton. All these features appear to be useful in the characterization of the eight species of the genus Pampus. Formulae for the structure of the vertebral column, the dorsal- and anal-fin pterygiophores’ interdigitation with the neural and haemal spines of the vertebrae, distribution of the dorsal and ventral procurrent caudal-fin rays, and distribution of the principal caudal-fin rays were developed. Pampus nozawae was recently considered a synonym of P. argenteus. However, according to the characters used in the present study, this species is notably distinct from P. argenteus.


Zootaxa ◽  
2020 ◽  
Vol 4750 (1) ◽  
pp. 31-48
Author(s):  
JOHN E. McCOSKER ◽  
SERGEY V. BOGORODSKY ◽  
AHMAD O. MAL ◽  
TILMAN J. ALPERMANN

A new species of snake eel Ophichthus olivaceus is described based on two specimens trawled from a depth of 35–63 m from a soft substratum off Jizan, Red Sea coast of southern Saudi Arabia. It differs from its congeners by the following combination of characters: vertebrae 141–145; tail moderately short (2.15 in TL); head short (9.6–11.1 in TL); uniserial teeth in jaws and on vomer; pectoral fins slightly elongate, not lanceolate, upper rays longer than the lower; dorsal-fin origin above middle of pectoral fin; and a generally uniform, dark tan body with an olivaceous hue shading to tan or pale orange ventrally, with two pale yellow blotches above pectoral-fin base, snout and lower jaw dark brown, and olivaceous median fins. Its divergence from other mitochondrial-analyzed species is shown by phylogenetic analysis of the mitochondrial COI barcoding region. A key to the Indian Ocean species is provided. 


2017 ◽  
Vol 98 (6) ◽  
pp. 1487-1511 ◽  
Author(s):  
Laith A. Jawad ◽  
Ronald Fricke ◽  
Joacim Näslund

This paper presents the results of a comparative study of five osteological complexes, the infraorbital bones, branchial arches, urohyal bone, interdigitation of the median fins, and the caudal fin skeleton, of some members of the fish family Tripterygiidae. Osteological characters that may prove valuable for taxonomic purposes are described, and on the basis of the material handled, their use to separate species within the family is discussed. Several formulae were developed for the distribution of the osteological complexes of the dorsal fin, dorsal and ventral caudal procurrent ray distribution, and caudal fin in the different tripterygiid species studied.


2021 ◽  
Vol 80 ◽  
pp. 1-41
Author(s):  
Martin Gomon ◽  
Carl Struthers ◽  
Jodie Kemp

Gomon, M.F., Struthers, C.D. and Kemp, J. 2021. A review of the Australasian genus Pseudophycis (Gadiformes: Moridae), redescribing its four species and resurrecting the name Physiculus palmatus Klunzinger, 1872, for the Australian Red Cod. Memoirs of Museum Victoria 80: 103–143. The commercially fished Red Cod Pseudophycis bachus Forster in Bloch and Schneider, 1801, is shown on the basis of both morphological and genetic evidence to be confined to New Zealand waters. The separation of the closely related but distinct Australian cognate brings the number of species in the Australasian genus Pseudophycis to four. The name Physiculus palmatus Klunzinger, 1872, which was long thought to be a junior synonym of Pseudophycis barbata Günther, 1862, is demonstrated to have been originally proposed for the Australian endemic. Pseudophycis palmata (new combination) differs from P. bachus in having a prominent black blotch or spot basally on the pectoral fin that does not extend dorsally onto the body, in contrast to distinctly extending onto body, the second dorsal fin with 47–56 rather than 40–45 rays, the anal fin with 50–57 rather than 42–48 rays and the vertebral column with 47–50 rather than 44–46 total vertebrae. Diagnoses, colour descriptions, images and distributions for all four species and a key to members of the genus are provided.


2014 ◽  
Vol 12 (4) ◽  
pp. 747-753 ◽  
Author(s):  
Daniel Pires Coutinho ◽  
Wolmar Benjamin Wosiacki

A new species of Polycentrusis described from the rio Negro, in Brazil. It is distinguished from P. schomburgkii by the presence of two dark postocular and one subocular band, all smaller than orbital diameter, blunt snout, isognathous mouth, reduction of the serrations on the lower edge of the lacrimal-spines ranging from zero to two tiny spines at the posterior end, intensely serrated edge of the interopercle, fully serrated posterior edge of the vertical arm of the preopercle, presence of five pungent opercular spines, subopercle broadly serrated along most of its posterior ventral edge, presence of serrations dorsally on the posterior margin of the cleithrum, fourth ray of pectoral fin reaching the vertical through the anal-fin origin, 19-21 predorsal scales, 19-20 scales on dorsal-fin base, 12-14 scales on anal-fin base, and absence of a median opercular blotch.


Zootaxa ◽  
2012 ◽  
Vol 3586 (1) ◽  
pp. 329 ◽  
Author(s):  
ZACHARY S. RANDALL ◽  
LAWRENCE M. PAGE

The genus Homalopteroides Fowler 1905 is resurrected and distinguished from the genus Homaloptera van Hasselt 1823based on a combination of characters including a unique mouth morphology, dorsal-fin origin over pelvic fin,≤60 lateral-line scales, and≤30 predorsal scales. Species included in Homalopteroides are H. wassinkii (Bleeker 1853), H. modestus(Vinciguerra 1890), H. rupicola (Prashad & Mukerji 1929), H. smithi (Hora 1932), H. stephensoni (Hora 1932), H. weberi(Hora 1932), H. tweediei (Herre 1940), H. indochinensis (Silas 1953), H. nebulosus (Alfred 1969), H. yuwonoi (Kottelat1998), and possibly H. manipurensis (Arunkumar 1999). Homalopteroides modestus (Vinciguerra 1890) is a poorlyknown species that was originally described from the Meekalan and Meetan rivers of southern Myanmar. It occurs in theSalween, Mae Khlong, and Tenasserim basins, and can be distinguished from all other species of Homalopteroides by thecombination of caudal-fin pattern (black proximal and distal bars, median blotch), 15 pectoral-fin rays, pectoral-fin lengthgreater than head length, 5½–6½ scales above and 5–6 scales below the lateral line (to the pelvic fin), 39–44 total lateral-line pores, no axillary pelvic-fin lobe, pelvic fin not reaching anus, orbital length less than interorbital width in adult, and maxillary barbel reaching to or slightly past the anterior orbital rim.


Author(s):  
Sanaz Bazaz Behbahani ◽  
Xiaobo Tan

In this paper, we propose a novel design for a pectoral fin joint of a robotic fish. This joint uses a flexible part to enable the rowing pectoral fin to feather passively and thus reduce the hydrodynamic drag in the recovery stroke. On the other hand, a mechanical stopper allows the fin to maintain its motion prescribed by the servomotor in the power stroke. The design results in net thrust even when the fin is actuated symmetrically for the power and recovery strokes. A dynamic model for this joint and for a pectoral fin-actuated robotic fish involving such joints is presented. The pectoral fin is modeled as a rigid plate connected to the servo arm through a pair of torsional spring and damper that describes the flexible joint. The hydrodynamic force on the fin is evaluated with blade element theory, where all three components of the force are considered due to the feathering degree of freedom of the fin. Experimental results on robotic fish prototype are provided to support the effectiveness of the design and the presented dynamic model. We utilize three different joints (with different sizes and different flexible materials), produced with a multi-material 3D printer, and measure the feathering angles of the joints and the forward swimming velocities of the robotic fish. Good match between the model predictions and experimental data is achieved, and the advantage of the proposed flexible joint over a rigid joint, where the power and recovery strokes have to be actuated at different speeds to produce thrust, is demonstrated.


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