Latest Articles from Zoosystematics and Evolution Latest 9 Articles from Zoosystematics and Evolution https://zse.pensoft.net/ Fri, 29 Mar 2024 01:05:56 +0200 Pensoft FeedCreator https://zse.pensoft.net/i/logo.jpg Latest Articles from Zoosystematics and Evolution https://zse.pensoft.net/ Relationships and description of a new catfish species from Chapada Diamantina, the northernmost record of Trichomycterus s.s. (Siluriformes, Trichomycteridae) https://zse.pensoft.net/article/115564/ Zoosystematics and Evolution 100(1): 223-231

DOI: 10.3897/zse.100.115564

Authors: Wilson J. E. M. Costa, Caio R. M. Feltrin, José L. O. Mattos, Axel M. Katz

Abstract: Psammocambeva exhibits the largest geographical distribution amongst the subgenera of Trichomycterus s.s., with its present northernmost represented by Trichomycterus tete, endemic to the upper Rio de Contas Basin in the Chapada Diamantina Region, north-eastern Brazil. Herein, we describe a new species recently collected in the Chapada Diamantina Region, but in the Rio Paraguaçu Basin, about 100 km north of the area inhabited by T. tete. A molecular phylogeny using one nuclear and two mitochondrial genes (2430 bp) supported the new species as sister to T. tete; both species are distinguished by colour patterns, morphometric data, relative position of dorsal and anal fins and osteological character states. The clade comprising the new species and T. tete, endemic to the semi-arid Caatinga biogeographical province, is supported as sister to a clade comprising species from the Rio Doce and Rio Paraíba do Sul Basins, in the Atlantic Forest biogeographical province. This study corroborated the Chapada Diamantina Region, a well-known mountainous biodiversity centre, as an important centre of endemism for trichomycterid catfishes.

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Research Article Wed, 6 Mar 2024 10:14:03 +0200
Chromatic polymorphism in Trichomycterus albinotatus (Siluriformes, Trichomycteridae), a mountain catfish from south-eastern Brazil and the role of colouration characters in trichomycterine taxonomy https://zse.pensoft.net/article/98341/ Zoosystematics and Evolution 99(1): 161-171

DOI: 10.3897/zse.99.98341

Authors: Wilson J. E. M. Costa, José Leonardo O. Mattos, Pedro F. Amorim, Beatrizz O. Mesquita, Axel M. Katz

Abstract: Colouration is an important tool for systematists inferring species limits and phylogenetic relationships of teleost fishes, but the use of colouration variation in trichomycterine catfish systematics has generated some controversy. We first report and describe the occurrence of four, geographically disjunct colour morphs in Trichomycterus albinotatus, endemic to south-eastern Brazil, as well as ontogenetic colouration change in each morph. A phylogenetic analysis using a cytb fragment (1098 bp) for 23 specimens representing all colour morphs and four outgroups did not support any correlation between colour morphs and lineages, with different colour morphs sharing identical haplotypes. This study indicated that young adult specimens found in lighter habitats had white and brown to black spots on the flank, whereas similar-sized specimens inhabiting darker habitats had white spots inconspicuous or absent and dark brown or black spots expanded. Individuals above about 65 mm SL of all populations had flank white marks less conspicuous or absent and cryptic habits during daylight, contrasting with smaller individuals with white marks and actively swimming above the substrate. Literature data indicate that ontogenetic colouration and habit changes occur in different trichomycterid lineages. Our data thus show that colouration may be problematic in taxonomical studies, although often being consistently used to diagnose species and clades. We conclude that colouration should not be discarded a priori as evidence of trichomycterine relationships and species limits, but should be used with caution in systematic studies, being necessary additional evidence, such as osteological characters or molecular data.

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Research Article Thu, 23 Feb 2023 11:14:36 +0200
Redefinition of Heptapterus (Heptapteridae) and description of Heptapterus carmelitanorum, a new species from the upper Paraná River basin in Brazil https://zse.pensoft.net/article/89413/ Zoosystematics and Evolution 98(2): 327-343

DOI: 10.3897/zse.98.89413

Authors: Gabriel de Carvalho Deprá, Gastón Aguilera, Dario R. Faustino-Fuster, Axel M. Katz, Valter M. Azevedo-Santos

Abstract: A new diagnosis and a new classification of Heptapterus are provided and a new species, H. carmelitanorum, is described. Heptapterus is diagnosed by the following character combination: adipose fin confluent with the caudal fin; non-bifurcate caudal fin; anal-fin insertion posterior to vertical through adipose-fin insertion; 10–23 anal-fin rays; anal fin not confluent with caudal fin; and extremely elongate body, with a head length of 16.1–24.9%SL. Species included in Heptapterus are H. borodini, H. carmelitanorum, H. carnatus, H. exilis, H. hollandi, H. mandimbusu, H. mbya, H. mustelinus, H. ornaticeps, and H. qenqo. Some of the character states diagnosing H. carmelitanorum among its congeners are the anal-fin insertion less than one eye diameter posterior to a vertical through the adipose-fin insertion (vs. more than one eye diameter in all congeners); the isognathous mouth (vs. slightly to moderately retrognathous, except H. borodini); and the keel formed by ventral procurrent caudal-fin rays shallow, far from reaching anal-fin base (vs. keel formed by ventral procurrent caudal-fin rays deep, continuing almost to the anal-fin base, except in H. borodini and H. hollandi).

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Research Article Thu, 8 Sep 2022 10:46:06 +0300
Phylogenetic relationships of a new catfish of the genus Trichomycterus (Siluriformes, Trichomycteridae) from the Brazilian Cerrado, and the role of Cenozoic events in the diversification of mountain catfishes https://zse.pensoft.net/article/83109/ Zoosystematics and Evolution 98(1): 151-164

DOI: 10.3897/zse.98.83109

Authors: Wilson J. E. M. Costa, José Leonardo O. Mattos, Wagner M. S. Sampaio, Patrícia Giongo, Frederico B. de Almeida, Axel M. Katz

Abstract: The Brazilian Cerrado highlands shelter the headwaters of the three largest South American hydrographic basins, where a great species diversity is concentrated, but some biological groups are still insufficiently known. The focal taxa of this study are trichomycterid catfishes of the subgenus Cryptocambeva, genus Trichomycterus, endemic to mountain areas of south-eastern Brazil. The primary objective of this study is to test through a molecular phylogeny if a new species collected in streams of the upper Rio Paraná basin draining the Serra da Canastra is sister to T. macrotrichopterus, endemic to the upper Rio São Francisco at another facet of the Serra da Canastra, as suggested by morphological data. The analysis corroborated sister group relationships between these two species, besides supporting four main clades in Cryptocambeva, each of them endemic to distinct mountain regions. A time-calibrated analysis supported the divergence timing between the new species and T. macrotrichopterus at the Pliocene, which is chronologically compatible with the final period of intense fluvial configuration re-arrangement, when São Francisco headwater streams were captured by the Paraná basin. The new species herein described is similar to T. macrotrichopterus and distinguished from all other species of Cryptocambeva by having a long pectoral-fin filament. These two species are distinguished from each other by characteristics of the latero-sensory system, colour pattern and bone morphology.

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Research Article Mon, 23 May 2022 12:07:58 +0300
A new catfish of the genus Trichomycterus from the Rio Paraíba do Sul Basin, south-eastern Brazil, a supposedly migrating species (Siluriformes, Trichomycteridae) https://zse.pensoft.net/article/72392/ Zoosystematics and Evolution 98(1): 13-21

DOI: 10.3897/zse.98.72392

Authors: Wilson J. E. M. Costa, Axel M. Katz

Abstract: A new species of the catfish genus Trichomycterus is described from the Rio Paraíba do Sul, south-eastern Brazil. This species exhibits some morphological character states that are unique amongst congeners, including a robust opercle and a long interopercle with numerous odontodes (50–60 opercular and 90–100 interopercular), a black bar on the basal portion of the caudal fin and a dark brown flank with a well delimited dorsal yellow stripe. It also exhibits some morphological traits that are uncommon amongst congeners, such as the presence of nine pectoral-fin rays. The presence of a shallow hyomandibular outgrowth and a ventrally expanded pre-opercular ventral flap suggests that this species is closely related to T. melanopygius, T. pradensis and T. tete. The new species also differs from T. melanopygius, T. pradensis and T. tete by having an emarginate caudal fin and a single median supra-orbital pore S6. Anecdotal evidence suggests that T. largoperculatus and T. pradensis have migratory habits, a condition not previously reported for eastern South American trichomycterines.

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Research Article Fri, 14 Jan 2022 11:05:05 +0200
Filling distribution gaps: Two new species of the catfish genus Cambeva from southern Brazilian Atlantic Forest (Siluriformes, Trichomycteridae) https://zse.pensoft.net/article/61006/ Zoosystematics and Evolution 97(1): 147-159

DOI: 10.3897/zse.97.61006

Authors: Wilson J. E. M. Costa, Caio R. M. Feltrin, Axel M. Katz

Abstract: The fauna and flora of the Brazilian Atlantic Forest have been intensively inventoried since the 19th century, but some components of this rich biota are still poorly known, and some areas have been poorly sampled. Recent studies on a rich collection of mountain catfishes of the genus Cambeva have revealed a high diversity of species still undescribed in the region. Here we provide formal descriptions for two of these species, found in areas inserted in a broad gap of the presently known genus distribution. The first one is endemic to small coastal river basins of Santa Catarina state, southern Brazil; it is tentatively placed in an intrageneric clade, also including C. castroi, C. davisi, C. guareiensis and C. zonata, by all sharing the presence of a flat small process on the dorsal margin of the quadrate, laterally overlapping metapterygoid and situated just posterior to the syncondrial joint between the metapterygoid and the quadrate. Phylogenetic relationships of the second new species, endemic to the Rio Itajaí-Mirim basin, are still obscure, but it shares a derived morphology of the mesethmoid with some species of the C. balios group. Although species of Cambeva have little external morphological variation when compared to other trichomycterine groups, the present study once more shows the importance of recording and using osteological characters to diagnose externally similar trichomycterine species.

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Research Article Tue, 2 Mar 2021 13:27:31 +0200
A new species from subtropical Brazil and evidence of multiple pelvic fin losses in catfishes of the genus Cambeva (Siluriformes, Trichomycteridae) https://zse.pensoft.net/article/56247/ Zoosystematics and Evolution 96(2): 715-722

DOI: 10.3897/zse.96.56247

Authors: Wilson J. E. M. Costa, Caio R. M. Feltrin, Axel M. Katz

Abstract: A third pelvic-less species of Cambeva from river basins draining the Geral mountain range in southern Brazil is described. It is distinguished from other congeners lacking pelvic fin and girdle, C. pascuali and C. tropeiro, by having six pectoral-fin rays, 20–23 dorsal procurrent caudal-fin rays, 15–20 opercular and 25–30 interopercular odontodes and a different colour pattern consisting of flank dark brownish-grey with two irregular horizontal rows of small pale yellow grey marks. Whereas available molecular evidence indicates that C. pascuali is more closely related to C. zonata, a species with well-developed pelvic fin, and C. tropeiro is more closely related to C. balios, another species also with well-developed pelvic fin; osteological data strongly suggest that the new species herein described is more closely related to C. diatropoporos than to other congeners. Therefore, this study indicates that the pelvic fin and pelvic-fin support have been lost independently in each of these three species of Cambeva, which corresponds to 11% of all describe species. This result highly contrasts with the closely-related trichomycterine genera Trichomycterus, in which only one in 50 species lost pelvic fin and girdle (0.2%) and Scleronema with all the nine included species having well-developed pelvic fin. These data suggest a stronger tendency to losing pelvic fin in Cambeva, but factors favouring this evolutionary event are still unknown.

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Research Article Wed, 11 Nov 2020 08:43:16 +0200
A new psammophilic species of the catfish genus Ammoglanis (Siluriformes, Trichomycteridae) from the Amazon River basin, northern Brazil https://zse.pensoft.net/article/48952/ Zoosystematics and Evolution 96(1): 67-72

DOI: 10.3897/zse.96.48952

Authors: Elisabeth Henschel, Pedro H. N. Bragança, Filipe Rangel-Pereira, Wilson J. E. M. Costa

Abstract: Ammoglanis obliquus sp. nov., a minute catfish species reaching a maximum adult size of 15.5 mm, is described from the Rio Preto da Eva drainage in the central Brazilian Amazon. It is distinguished from all of its congeners in possessing an exclusive combination of character states, including the presence and number of premaxillary and dentary teeth, number of interopercular and opercular odontodes, presence of cranial fontanel, number of dorsal-fin rays, number of anal-fin rays, number of caudal-fin rays, number of pelvic-fin rays, number of pectoral-fin rays, absence of pelvic splint, antorbital morphology, and absence of supraorbital and autopalatine morphology. It is considered to be a member of a clade also including A. pulex and A. amapaensis due to the unique oral, antorbital, and autopalatine morphology. Ammoglanis obliquus is regarded as more closely related to A. pulex than to any other congener, as both species exhibit a similar colour pattern, an absence of the metapterygoid, and the presence of two finger-like projections on the chin region.

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Research Article Tue, 18 Feb 2020 08:52:32 +0200
Multigene analysis of the catfish genus Trichomycterus and description of a new South American trichomycterine genus (Siluriformes, Trichomycteridae) https://zse.pensoft.net/article/29872/ Zoosystematics and Evolution 94(2): 557-566

DOI: 10.3897/zse.94.29872

Authors: Axel Makay Katz, Maria Anais Barbosa, José Leonardo de Oliveira Mattos, Wilson José Eduardo Moreira da Costa

Abstract: Trichomycterus comprises about 170 valid species, but its monophyly has been challenged in the last decades. Bayesian Inference and Maximum Likelihood analyses comprehending mitochondrial genes COI and CYTB and nuclear genes GLYT, MYH6 and RAG2 from 71 Trichomycterinae terminal taxa and eight outgroups were performed. The analyses highly supports a clade containing Trichomycterus nigricans, the type species of the genus, and several other congeners endemic to eastern and northeastern Brazil, herein considered as the genus Trichomycterus, the sister clade the southern Brazil and adjacent areas clade; the latter clade comprises two subclades, one comprising species of the genus Scleronema and another comprising species previously placed in Trichomycterus, herein described as a new genus. Cambeva gen. n. is distinguished from all other trichomycterines by the presence of a bony flap on the channel of the maxillo-dentary ligament, the interopercle shorter than the opercle, a deep constriction on the basal portion of the antero-dorsal arm of the quadrate, absence of teeth in the coronoid process of the dentary, the maxilla shorter than the premaxilla, the cranial fontanel extending from the the medial posterior of frontal to the medial region of supraoccipital, and absence of the postorbital process of the sphenotic-prootic-pterosphenoid.

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Research Article Thu, 22 Nov 2018 10:11:41 +0200