scholarly journals The origin of a new fin skeleton through tinkering

2015 ◽  
Vol 11 (7) ◽  
pp. 20150415 ◽  
Author(s):  
Thomas A. Stewart
Keyword(s):  
Teleost Fishes ◽  
Regular Pattern ◽  
Developmental Context ◽  
Fin Rays ◽  
Adipose Fin ◽  
Developmental Programme

Adipose fins are positioned between the dorsal and caudal fins of many teleost fishes and primitively lack skeleton. In at least four lineages, adipose fins have evolved lepidotrichia (bony fin rays), co-opting the developmental programme for the dermal skeleton of other fins into this new territory. Here I provide, to my knowledge, the first description of lepidotrichia development in an adipose fin, characterizing the ontogeny of the redtail catfish, Phractocephalus hemioliopterus . Development of these fin rays differs from canonical lepidotrich development in the following four ways: skeleton begins developing in adults, not in larvae; rays begin developing at the fin's distal tip, not proximally; the order in which rays ossify is variable, not fixed; and lepidotrichia appear to grow both proximally and distally, not exclusively proximodistally. Lepidotrichia are often wavy, of irregular thickness and exhibit no regular pattern of segmentation or branching. This skeleton is among the most variable observed in a vertebrate appendage, offering a unique opportunity to explore the basis of hypervariation, which is generally assumed to reflect an absence of function. I argue that this variation reflects a lack of canalization as compared with other, more ancient lepidotrichs and suggest developmental context can affect the morphology of serial homologues.

scholarly journals New species of Cyphocharax (Characiformes: Curimatidae) from the upper rio Negro, Amazon basin

2014 ◽  
Vol 12 (2) ◽  
pp. 327-332 ◽  
Author(s):  
Bruno F. Melo ◽  
Richard P. Vari
Keyword(s):  
New Species ◽  
Amazon Basin ◽  
Caudal Peduncle ◽  
Caudal Fin ◽  
Rio Negro ◽  
Fin Rays ◽  
Dark Pigmentation ◽  
Northern Brazil ◽  
Adipose Fin ◽  
A New Species

A new species of Cyphocharax, Curimatidae, apparently endemic to the blackwater upper rio Negro of the Amazon basin in northern Brazil, is described.The new species is readily distinguished from its congeners by the presence of a distinctly longitudinally elongate, posteriorly vertically expanding patch of dark pigmentation along the midlateral surface of the caudal peduncle, with the patch extending from the base of the middle caudal-fin rays anteriorly past the vertical through the posterior terminus of the adipose fin. The new species additionally differs from all congeners in details of body and fin pigmentation and meristic and morphometric ratios. Evidence for the assignment of the species to Cyphocharax and the occurrence of other species of the Curimatidae apparently endemic to the upper rio Negro catchment is discussed.

scholarly journals A new miniature of Xenurobryconini (Characiformes: Characidae) from the rio Tapajós basin, Brazil

2016 ◽  
Vol 14 (1) ◽  
Author(s):  
Marina Barreira Mendonça ◽  
Luiz Antônio Wanderley Peixoto ◽  
Guilherme Moreira Dutra ◽  
André Luiz Netto-Ferreira
Keyword(s):  
New Species ◽  
Posterior Half ◽  
Caudal Fin ◽  
Number Of Species ◽  
Fin Ray ◽  
Fin Rays ◽  
Dark Color ◽  
Adipose Fin ◽  
A New Species

Abstract A new species of Xenurobrycon isdescribed from tributaries of the rio Tapajós, Pará, Brazil. It is diagnosed from all congeners by the dark color of the posterior half of both caudal-fin lobes, the presence of infraorbitals one, two, and three, the presence of a set of lamellar processes on eighth principal caudal-fin ray of mature males, the presence of bony hooks similar in size or decreasing posteriorly on last unbranched and first 9-12 branched anal-fin rays of mature males, the presence of only conical teeth on both jaws, the lack of the adipose fin and the presence of 15-18 predorsal scales. The description of the new species increases the number of species in Xenurobrycon to six. An updated key to the species of the genus is provided.

scholarly journals A new species of Tyttocharax (Characiformes: Characidae: Stevardiinae) from the Güejar river, Orinoco river Basin, Colombia

2012 ◽  
Vol 10 (3) ◽  
pp. 519-525 ◽  
Author(s):  
César Román-Valencia ◽  
Carlos A. García-Alzate ◽  
Raquel I Ruiz-C ◽  
C Donald ◽  
B Taphorn
Keyword(s):  
New Species ◽  
Lateral Line ◽  
River System ◽  
First Record ◽  
Dorsal Fin ◽  
Fin Rays ◽  
Adipose Fin ◽  
A New Species ◽  
Pectoral Fin Rays ◽  
Pelvic Fin

A new Tyttocharax species from the Güejar River system, near the Macarena Mountains in Colombia is described. This is the first record for the genus from the Orinoco basin. The combination of the following characters distinguish Tyttocharax metae from its congeners: presence of bony hooks on the pectoral and caudal-fin rays; bony hooks on the anal-fin rays larger than those on the pelvic-fin rays; pectoral-fin rays i,5-6,i; presence of three unbranched dorsal-fin rays; absence of an adipose fin; four scales rows between the anal-fin origin and the lateral line; and four scale rows between the pelvic-fin and the lateral line. Ecological characteristics of the habitat of the new species are also presented.

scholarly journals The origins of adipose fins: an analysis of homoplasy and the serial homology of vertebrate appendages

2014 ◽  
Vol 281 (1781) ◽  
pp. 20133120 ◽  
Author(s):  
Thomas A. Stewart ◽  
W. Leo Smith ◽  
Michael I. Coates
Keyword(s):  
De Novo ◽  
Morphological Evolution ◽  
Structural Complexity ◽  
Teleost Fishes ◽  
Dorsal Midline ◽  
Fin Rays ◽  
Limited Function ◽  
Repeated Evolution ◽  
Living Species ◽  
Anatomical Evidence

Adipose fins are appendages found on the dorsal midline between the dorsal and caudal fins in more than 6000 living species of teleost fishes. It has been consistently argued that adipose fins evolved once and have been lost repeatedly across teleosts owing to limited function. Here, we demonstrate that adipose fins originated repeatedly by using phylogenetic and anatomical evidence. This suggests that adipose fins are adaptive, although their function remains undetermined. To test for generalities in the evolution of form in de novo vertebrate fins, we studied the skeletal anatomy of adipose fins across 620 species belonging to 186 genera and 55 families. Adipose fins have repeatedly evolved endoskeletal plates, anterior dermal spines and fin rays. The repeated evolution of fin rays in adipose fins suggests that these fins can evolve new tissue types and increased structural complexity by expressing fin-associated developmental modules in these new territories. Patterns of skeletal elaboration differ between the various occurrences of adipose fins and challenge prevailing hypotheses for vertebrate fin origin. Adipose fins represent a powerful and, thus far, barely studied model for exploring the evolution of vertebrate limbs and the roles of adaptation and generative biases in morphological evolution.

scholarly journals Chrysobrycon yoliae, a new species of stevardiin (Characiformes: Characidae) from the Ucayali basin, Peru

2014 ◽  
Vol 12 (2) ◽  
pp. 291-300 ◽  
Author(s):  
James Anyelo Vanegas-Ríos ◽  
María de las Mercedes Azpelicueta ◽  
Hernán Ortega
Keyword(s):  
New Species ◽  
Posterior Margin ◽  
The Body ◽  
Pelvic Bone ◽  
Body Depth ◽  
Dorsal Fin ◽  
Fin Rays ◽  
Adipose Fin ◽  
Fin Length ◽  
A New Species

Chrysobrycon yoliae, new species, is described from a drainage flowing into the río Yucamia basin, río Ucayali basin, Peru. Chrysobrycon yoliaeis readily distinguished from its congeners by the anterior tip of pelvic bone situated anterior to the fifth rib (vs. situated posterior to the fifth rib), the presence of 20-26 dentary teeth (vs. 11-19), and the possession of a terminal lateral-line tube between caudal-fin rays 10 and 11 (vs. the absence of this tube, except in C. eliasi). The new species differs from C. eliasiand C. myersiby the presence of teeth on third pharyngobranchial (vs. the absence of teeth on this bone) and also differs from C. eliasiby the dorsal-fin origin situated at vertical through anal-fin rays 5 to 7 (vs. located at vertical through anal-fin rays 8 to 10), the posterior extent of the ventral process of quadrate reaching the vertical through posterior margin of symplectic (vs. not reaching the vertical through posterior margin of symplectic), the dorsal-fin to adipose-fin length 26.8-28.8% SL (vs. 23.9-26.8% SL), and the body depth at dorsal-fin origin 34.4-42.2% SL (vs. 24.1-34.5% SL). A key for the identification of Chrysobryconspecies is provided.

scholarly journals Functional morphology of the fin rays of teleost fishes

2013 ◽  
Vol 274 (9) ◽  
pp. 1044-1059 ◽  
Author(s):  
Brooke E. Flammang ◽  
Silas Alben ◽  
Peter G.A. Madden ◽  
George V. Lauder
Keyword(s):  
Functional Morphology ◽  
Teleost Fishes ◽  
Fin Rays

scholarly journals Gephyrocharax torresi (Characiformes: Characidae: Stevardiinae), a new species from the río Cascajales basin, río Magdalena system, Colombia

2013 ◽  
Vol 11 (2) ◽  
pp. 275-284 ◽  
Author(s):  
James Anyelo Vanegas-Ríos ◽  
María de las Mercedes Azpelicueta ◽  
Juan Marcos Mirande ◽  
María Dolly García Gonzales
Keyword(s):  
New Species ◽  
The Body ◽  
Pectoral Fin ◽  
Caudal Peduncle ◽  
Caudal Fin ◽  
Fin Ray ◽  
Fin Rays ◽  
Adipose Fin ◽  
Black Pigmentation ◽  
A New Species

A new species of Gephyrocharax is described from the río Cascajales basin, a tributary of the río La Colorada, río Magdalena system, Colombia. The new species is distinguished from its congeners, exceptG. melanocheir, by the absence of an adipose fin in most specimens and by the possession of a lateral branched pectoral-fin ray in males with a distal fan-shaped structure with minute bony hooks and a dark blotch or a few scattered dark brown chromatophores along its branches. The new species differs from G.melanocheir by the absence of an intense black pigmentation at the base of the anterior five dorsal-fin rays, the number of vertebrae (40-41vs. 38-39), the frontals contacting each other anterior to the epiphyseal bar in adults (vs. the absence of contact), the posterior margin of the mesethmoid straight in its central portion (vs. strongly concave at this point), the pouch scale of mature males reaching caudal-fin ray 11 or the area between caudal-fin rays 11 and 12 (vs. reaching only to caudal-fin ray 10 or the area between caudal-fin rays 9 and 10), the number of minute terminal branches of the lateral branched pectoral-fin ray of mature males (60-88 vs. 28-54), a longer black lateral stripe along the body in males (reaching to the base of the caudal-fin rays vs. reaching the middle of the length of the caudal peduncle), and the snout length (28.3-31.8% HLvs. 22.2-28.0% HL). The diagnosis ofGephyrocharax is modified to include species with the adipose fin variably present

Morphology of Abnormal Columns of Mesenchyme Cells in the Channel Catfish, Ictalurus Punctatus.

1976 ◽  
Vol 34 ◽  
pp. 182-183
Author(s):  
Vernon Henderson
Keyword(s):  
Ictalurus Punctatus ◽  
Channel Catfish ◽  
Structural Changes ◽  
Microscopic Analysis ◽  
Common Source ◽  
Brood Stock ◽  
Electron Microscopic ◽  
Fin Ray ◽  
Fin Rays ◽  
Adipose Fin

During recent years , I have utilized several thousand young channel catfish or fry for several different studies. A few years ago, I noticed an increase in the number of adipose fins which showed fin ray-like structures. Fin rays in adipose fin of fish are rare. Assuming that the said structures were fin rays, I proceeded to study them, histologically. Upon microscopic examination, it was discovered that there was a complete absence of fin ray elements. In an effort to understand the structural changes responsible for the appearance of the ray-like elements , an electron microscopic analysis was undertaken.Fish used in this study were secured from several different catfish farms located in the Grambling area; however, all seem to be linked to a common source from which brood stock had been purchased. The specimen used in this study ranged in length from 7.5 centimeters to 15.0 centimeters and were approximately four to six months in age.

A new species of Heptapterus Bleeker 1858 (Siluriformes, Heptapteridae) from the Uruguay River Basin in Misiones, Northeastern Argentina

Zootaxa ◽  
2017 ◽  
Vol 4299 (4) ◽  
pp. 572 ◽  
Author(s):  
GASTÓN AGUILERA ◽  
MAURICIO BENITEZ ◽  
GUILLERMO ENRIQUE TERÁN ◽  
FELIPE ALONSO ◽  
JUAN MARCOS MIRANDE
Keyword(s):  
New Species ◽  
River Basin ◽  
Coloration Pattern ◽  
Fin Rays ◽  
Adipose Fin ◽  
Uruguay River ◽  
Northeastern Argentina ◽  
A New Species ◽  
Size Variable ◽  
Small Tributary

In this paper we describe Heptapterus mandimbusu sp. n., a new species of heptapterid catfish from a small tributary of the Uruguay River Basin in Misiones-Argentina. This new species is distinguished from all other congeners by the unique coloration pattern with aggregated melanophores scattered on dorsal and lateral surface of body, forming conspicuous size-variable blotches, and the combination of a long interdorsal distance (13.8–18.9 % SL), 14–18 anal-fin rays, short maxillary barbels (52.2–74.5 % HL), and the adipose fin confluent with caudal fin. 

scholarly journals A new species of the characid genus Hollandichthys Eigenmann from coastal rivers of southern Brazil (Teleostei: Characiformes) with a discussion on the diagnosis of the genus

2013 ◽  
Vol 11 (4) ◽  
pp. 767-778 ◽  
Author(s):  
Vinicius A. Bertaco ◽  
Luiz R. Malabarba
Keyword(s):  
New Species ◽  
Black Spot ◽  
Lower Number ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Caudal Fin ◽  
Coastal Rivers ◽  
Fin Rays ◽  
Adipose Fin ◽  
A New Species

Hollandichthys taramandahy, new species, is described from the rio Tramandaí, rio Mampituba, and rio Araranguá basins, coastal drainages of Rio Grande do Sul and Santa Catarina States, Brazil. The new species is distinguished from H. multifasciatus, the single recognized species of the genus, by the presence of a small black spot covering the base of median caudal-fin rays, by the lower number of dorsal and ventral procurrent caudal-fin rays, by the absence of a black spot located along anterior half of adipose-fin, and by the absence of humeral spot in specimens larger than 60 mm of standard length. Comments about the geographic distribution and diagnosis are provided for the genus.

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