First evidence of ganoin-scaled Halecomorphi (Neopterygii) in the Lower Jurassic of Holzmaden and Ohmden, Germany

2020 ◽  
Vol 295 (3) ◽  
pp. 307-326
Author(s):  
Martin Ebert ◽  
Detlev Thies ◽  
Rolf B. Hauff

The Posidonienschiefer Formation (lower Toarcian) of the Holzmaden region, Baden-Württemberg, in southwestern Germany is world- famous for its marine fossils, including excellently preserved fossil vertebrates, especially ichthyosaurs and plesiosaurs, but also fossil fishes. The study of the diversity and palaeoecology of fish within these deposits gives us further hints to understand the corresponding ecosystem. With Holzmadenfuro rebmanni new gen. et sp. and Ohmdenfuro bodmani new gen. et sp., both curated at the Urweltmuseum Hauff in Holzmaden, we now describe the first ganoin-scaled Halecomorphi from the Posidonienschiefer of Germany. These new taxa are characterized by a specific combination of features, including body shape; number of parietals, extrascapulars, infraorbitals, dorsal and caudal fin rays, and vertical scale rows; number and shape of maxillary teeth; number and arrangement of supraorbitals; ornamentation of skull bones; insertion of dorsal, pelvic, and anal fins; position of lateral line in caudal fin area; shape and distribution of scales; and number and shape of serrations on scales. The more basal Halecomorphi with ganoid scales (Parasemionoti- formes, Panxianichthyformes, and Ophiopsiformes) remain poorly known, compared with the more advanced halecomorph group of the Amiiformes (especially the Amiidae). Closer investigation of their taxonomic relationships is therefore important for understanding broader patterns of haleco- morph evolution, especially the origin of the Jurassic Ophiopsiformes.

2021 ◽  
Vol 19 (4) ◽  
Author(s):  
Cárlison Silva-Oliveira ◽  
Rafaela P. Ota ◽  
Flávio C. T. Lima ◽  
Lúcia Rapp Py-Daniel

ABSTRACT A redescription of Bryconops gracilis is provided, a species poorly known for more than a century. Bryconops gracilis differs from all congeners by having the following combination of features: eight branched pelvic-fin rays, 31-36 anal-fin rays, 15-17 predorsal scales arranged in a regular series, two rows of premaxillary teeth, and 53-60 lateral-line scales. The species was often misidentified as B. alburnoides by sharing an overall elongated body shape, caudal fin yellowish in life, and a high number of lateral-line scales. A diagnosis between B. alburnoides and B. gracilis is provided. The holotype of B. gracilis which for many years had whereabouts unknown, was recovered, examined and illustrated by CT-Scan. Additionally, more detailed information about the type locality, morphology, color pattern (including in living specimens), habitat and distribution pattern of species are provided.


2009 ◽  
Vol 7 (3) ◽  
pp. 371-376 ◽  
Author(s):  
Valdener Garutti ◽  
Francisco Langeani

Astyanax goyacensis Eigenmann, 1908 is redescribed based on the holotype and 25 topotypes. The species belongs to the A. bimaculatus species complex, sharing with those species a black, horizontally ovate, humeral spot (the most conspicuous feature of this complex), two diffuse vertical brown bars in the humeral area (the first through humeral spot and the second 2-3 scales behind), and black medium caudal-fin rays. Furthermore, A. goyacensis possesses a black stripe extending along midlateral body portion, more conspicuous in alcohol preserved specimens. These characteristics allow its inclusion in the putative "black lateral stripe" sub-group of A. bimaculatus species complex. From the species of this complex it differs by the black lateral stripe shape, pattern of chromatophores on the flank, coloration of the caudal fin, scales on the lateral line, branched rays on anal fin, eye diameter, and caudal peduncle depth. Comments about the color pattern in Astyanax bimaculatus species complex are added.


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.


2005 ◽  
Vol 3 (3) ◽  
pp. 383-388 ◽  
Author(s):  
Carolina Ferreira Haluch ◽  
Vinícius Abilhoa

A new species of characid fish, Astyanax totae, is described from a small tributary in the upper drainage of the rio Iguaçu, Paraná basin, Brazil. The new species is distinct from most species of Astyanax by the vertically elongated humeral spot, slightly expanded above the lateral line to posterodorsal margin of opercle, followed by a midlateral dark stripe expanded from the humeral region to the median caudal-fin rays, maxilla with 2 to 5 teeth (usually 3) and 15 to 18 branched anal-fin rays.


2010 ◽  
Vol 8 (4) ◽  
pp. 673-706 ◽  
Author(s):  
Flávio A. Bockmann ◽  
Ricardo M. C. Castro

Rhamdiopsis krugi, a new troglobitic heptapterid catfish, is described from the caves of Chapada Diamantina, State of Bahia, northeastern Brazil. This species, although frequently cited in the scientific literature along the last seventeen years, remained undescribed largely due to its uncertain phylogenetic affinities. The generic assignment of R. krugi was clouded largely by its high number of unusual morphological features (some related to cave life), for instance: absence of eyes and body pigmentation; presence of a widely exposed pseudotympanum; posterior border of the anterior branch and anterior margin of the arborescent portion of the posterior branch of the transverse process of fourth vertebra joined; dorsal hypural plate commonly with seven rays; ventral caudal plate usually with six rays; dorsal and ventral caudal-fin lobes typically with six branched fin rays each; 38-39 vertebrae; anal fin with 14-17 rays; and lateral line very short. Rhamdiopsis krugi can be easily distinguished from its congeners, R. microcephala and R. moreirai, by its troglomorphic features and by the presence of a shorter lateral line, fewer vertebrae and anal-fin rays, pattern of branching of caudal-fin rays, and several attributes of skeletal system. The affinities of this new species are discussed in light of current phylogenetic knowledge of the family Heptapteridae. Incongruent derived characters do not allow selection of a particular hypothesis of sister group relationships among species of Rhamdiopsis. The occurrence of R. krugi in the rio Paraguaçu basin is possibly due to an event of hydrological capture from a section of the middle portion of the rio São Francisco basin, caused by tectonic events. The semi-arid region where R. krugi presently lives was probably covered by a wide forested area during a humid cycle in Quaternary. A summary of natural history and ecology data of R. krugi, as well as notes on its conservation, are provided. We also offer comments on the morphological plasticity of R. krugi.


Zootaxa ◽  
2008 ◽  
Vol 1813 (1) ◽  
pp. 42 ◽  
Author(s):  
CARLOS A. GARCÍA-ALZATE ◽  
CÉSAR ROMÁN-VALENCIA ◽  
DONALD C. TAPHORN

Hyphessobrycon oritoensis (Characiformes: Characidae) is described from the Putumayo River drainage of the Colombian Amazon. The new species belongs to the H. heterorhabdus group and is distinguished from all other known species by the following combination of characters: iii,8 dorsal–fin rays, iv, 26–27 anal–fin rays, 19 teeth on dentary, 35 scales in longitudinal series, 10–11 perforated scales in lateral line, 7 scales between lateral line and dorsal–fin origin, 14 predorsal scales and a dark lateral band that extends from the posterior border of the humeral spot to the tips of the middle caudal fin rays.


Zootaxa ◽  
2020 ◽  
Vol 4755 (2) ◽  
pp. 365-374
Author(s):  
JUAN G. ALBORNOZ-GARZÓN ◽  
ASTRID ACOSTA-SANTOS ◽  
JUAN D. BOGOTÁ-GREGORY ◽  
EDWIN AGUDELO-CÓRDOBA

A new species of Creagrutus is described from the Amazonian Piedmont, Colombia. The new species can be distinguished from congeners by presenting the following unique combination of characters: a dark mid-lateral stripe starting at anteriormost scale of lateral line, a vertically elongated humeral blotch, absence of dark blotches on dorsal fin and at base of middle caudal-fin rays, a triangular dentigerous surface of the premaxilla, 5–6 dentary teeth, and 11–12 predorsal scales. Comparisons with congeners distributed in the piedmont region of Río Caquetá basin are presented and its relationships among species of Creagrutus is inferred from the available phylogenetic framework. 


Zootaxa ◽  
2019 ◽  
Vol 4555 (3) ◽  
pp. 407 ◽  
Author(s):  
LAIS REIA ◽  
RICARDO C. BENINE

A new species of Hemigrammus is described from the upper Rio Negro, Amazon basin, Brazil. The new species is distinguished from all congeners by its unique color pattern consisting of a single humeral blotch clearly spaced from a conspicuous midlateral dark stripe, which extends from fifth or sixth anteriormost vertical scale row to the basis of the middle caudal-fin rays. Comments on its putative relationships are provided. 


Zootaxa ◽  
2017 ◽  
Vol 4306 (2) ◽  
pp. 291 ◽  
Author(s):  
HIROYUKI MOTOMURA ◽  
TOMOHIRO YOSHIDA ◽  
VEERA VILASRI

Sacura sanguinea n. sp. (Serranidae: Anthiadinae) is described on the basis of two male and one female specimens from the Andaman Sea. The new species is characterized by the following characters: dorsal-fin rays X, 15; pored lateral-line scales 34; gill rakers 8 + 23 = 31; body depth 42.6–44.7% of SL; head length 39.5–41.4% of SL; pectoral-fin length 32.4–33.1% of SL; poorly defined broad yellow band from anterior profile of head to middle of body, the band gradually becoming red around middle of body and ending at caudal-fin base; caudal fin with distinct red spots centrally; and large dark red blotch posteriorly on spinous portion of dorsal fin in females. 


Zootaxa ◽  
2021 ◽  
Vol 4903 (3) ◽  
pp. 419-429
Author(s):  
PETER N. PSOMADAKIS ◽  
TATSUKI YOSHINAGA ◽  
ZI ZA WAH ◽  
HITOSHI IDA

Two new species of Bleekeria Günther, 1862 are described from specimens collected in the Andaman Sea off the coast of Myanmar during bottom surveys conducted by the R/V Dr Fridtjof Nansen in 2015 and 2018. They are distinguished from each other and from congeners by a combination of morphological and meristic characters as well as fin coloration and genetic variance. Bleekeria albicauda sp. nov. has pelvic fins, 40–41 dorsal-fin rays, 54–55 total vertebrae, no teeth in jaws, 4 scale rows between dorsal-fin origin and lateral line, a single row of about 10 scales on mid-upper part of opercle, scales on central part of body clearly shorter than their height, caudal fin with white upper and lower lobes when fresh (unique within the genus). Bleekeria nigrilinea sp. nov. has no pelvic fins, 37–39 dorsal-fin rays, 49–50 total vertebrae, 2½ scale rows between dorsal-fin origin and lateral line (the smallest count within the genus with B. estuaria of Mozambique brackish water), 5–6 scales on mid-upper part of opercle arranged in a single row, scales on central part of body clearly longer than their height, upper and lower margins of caudal fin black when fresh (unique within the genus). The COI gene sequences of the two new species showed clear genetic divergence (pairwise K2P, >10 %) from Bleekeria estuaria Randall & Ida, 2014 and Bleekeria mitsukurii (Jordan & Evermann, 1902). A key to the species of Bleekeria is provided. 


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