Evolutionary Tracks of Chromosomal Diversification in Surgeonfishes (Acanthuridae: Acanthurus) Along the World’s Biogeographic Domains

Fishes of the genus Acanthurus (Acanthuridae) are strongly related to reef environments, in a broad biogeographic context worldwide. Although their biological aspects are well known, cytogenetic information related to this genus remains incipient. In this study, Acanthurus species from populations inhabiting coastal regions of the Southwest Atlantic (SWA), South Atlantic oceanic islands (Fernando de Noronha Archipelago and Trindade Island), Greater Caribbean (GC), and Indo-Pacific Ocean (the center of the origin of the group) were analyzed to investigate their evolutionary differentiation. For this purpose, we employed conventional cytogenetic procedures and fluorescence in situ hybridization of 18S rDNA, 5S rDNA, and H3 and H2B-H2A histone sequences. The Atlantic species (A. coeruleus, A. chirurgus, and A. bahianus) did not show variations among them, despite their vast continental and insular distribution. In contrast, A. coeruleus from SWA and GC diverged from each other in the number of 18S rDNA sites, a condition likely associated with the barrier created by the outflows of the Amazonas/Orinoco rivers. The geminate species A. tractus had a cytogenetic profile similar to that of A. bahianus. However, the chromosomal macrostructures and the distribution of rDNA and hisDNA sequences revealed moderate to higher rates of diversification when Acanthurus species from recently colonized areas (Atlantic Ocean) were compared to A. triostegus, a representative species from the Indian Ocean. Our cytogenetic data covered all Acanthurus species from the Western Atlantic, tracked phylogenetic diversification throughout the dispersive process of the genus, and highlighted the probable diversifying role of ocean barriers in this process.

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Taxonomy and phylogeny of calcareous sponges (Porifera: Calcarea: Calcinea) from Brazilian mid-shelf and oceanic islands

Zootaxa ◽

10.11646/zootaxa.4311.3.1 ◽

2017 ◽

Vol 4311 (3) ◽

pp. 301 ◽

Cited By ~ 4

Author(s):

FERNANDA AZEVEDO ◽

ANDRÉ PADUA ◽

FERNANDO MORAES ◽

ANDRÉ ROSSI ◽

GUILHERME MURICY ◽

...

Keyword(s):

Species Richness ◽

Morphological Characters ◽

Oceanic Islands ◽

Biological Communities ◽

Calcareous Sponges ◽

Molecular Approaches ◽

Strategic Value ◽

Molecular Tree ◽

Trindade Island ◽

Fernando De Noronha

Despite the enormous economic, scientific and strategic value of the Brazilian oceanic and mid-shelf islands (BOMIs), the biological communities of these islands are still poorly known. An example is their fauna of calcareous sponges (Porifera: Calcarea), with only six species described up to date. In the present study, we analysed the Calcinean sponges from the mid-shelf Abrolhos Archipelago and four of the five Brazilian oceanic islands (São Pedro e São Paulo Archipelago, Fernando de Noronha Archipelago, Rocas Atoll, and Trindade Island), using both morphological and molecular approaches for taxonomy. Fourteen species were found, of which 12 are new to science: Arturia trindadensis sp. nov., Borojevia tenuispinata sp. nov., B. trispinata sp. nov., Clathrina insularis sp. nov., C. lutea sp. nov., C. mutabilis sp. nov., C. zelinhae sp. nov., Ernstia citrea sp. nov., E. multispiculata sp. nov., E. rocasensis sp. nov., E. sanctipauli sp. nov., and E. solaris sp. nov. These results raised in 63% the species richness of calcareous sponges from the BOMIs. Clathrina aurea and Leucetta floridana were recollected and the former had its geographical distribution expanded. The molecular tree obtained confirmed the morphological identifications and allowed a discussion about the evolution of morphological characters, and the usefulness of some of those characters in the taxonomy of Calcinea.

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Evolution of Bird Sex Chromosomes Narrated by Repetitive Sequences: Unusual W Chromosome Enlargement in Gallinula melanops (Aves: Gruiformes: Rallidae)

Cytogenetic and Genome Research ◽

10.1159/000501381 ◽

2019 ◽

Vol 158 (3) ◽

pp. 152-159 ◽

Cited By ~ 5

Author(s):

Ricardo J. Gunski ◽

Rafael Kretschmer ◽

Marcelo Santos de Souza ◽

Ivanete de Oliveira Furo ◽

Suziane A. Barcellos ◽

...

Keyword(s):

Sex Chromosomes ◽

18S Rdna ◽

Organizer Region ◽

Repetitive Sequences ◽

Nucleolar Organizer Region ◽

Molecular Cytogenetics ◽

5S Rdna ◽

Nucleolar Organizer ◽

W Chromosome ◽

Rdna Sites

Among birds, species with the ZZ/ZW sex determination system generally show significant differences in morphology and size between the Z and W chromosomes (with the W usually being smaller than the Z). In the present study, we report for the first time the karyotype of the spot-flanked gallinule (Gallinula melanops) by means of classical and molecular cytogenetics. The spot-flanked gallinule has 2n = 80 (11 pairs of macrochromosomes and 29 pairs of microchromosomes) with an unusual W chromosome that is larger than the Z. Besides being totally heterochromatic, it has a secondary constriction in its long arm corresponding to the nucleolar organizer region, as confirmed by both silver staining and mapping of 18S rDNA probes. This is an unprecedented fact among birds. Additionally, 18S rDNA sites were also observed in 6 microchromosomes, while 5S rDNA was found in just 1 microchromosomal pair. Seven out of the 11 used microsatellite sequences were found to be accumulated in microchromosomes, and 6 microsatellite sequences were found in the W chromosome. In addition to the involvement of heterochromatin and repetitive DNAs in the differentiation of the large W chromosome, the results also show an alternative scenario that highlights the plasticity that shapes the evolutionary history of bird sex chromosomes.

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Axiidean ghost shrimps (Decapoda: Axiidae, Callianassidae, Callichiridae, Micheleidae) of the Trindade and Martin Vaz Archipelago, Vitória-Trindade Seamounts Chain and Abrolhos, off southeastern Brazil

Zootaxa ◽

10.11646/zootaxa.4758.1.4 ◽

2020 ◽

Vol 4758 (1) ◽

pp. 103-126

Author(s):

PAULO P.G. PACHELLE ◽

MARCOS TAVARES

Keyword(s):

Oceanic Islands ◽

Southeastern Brazil ◽

Brazilian Coast ◽

Western Atlantic ◽

African Coast ◽

Fernando De Noronha ◽

Southern Central ◽

Insular Fauna ◽

Central Atlantic ◽

A New Species

The Trindade and Martin Vaz (TMV) volcanic archipelago is highly isolated, being located some 1200 km off the Brazilian coast and about 4200 km away from the nearest African coast. The only axiidean known from the archipelago is Coralaxius nodulosus (Meinert, 1877), a species extensively reported in the western Atlantic. From 2012 to 2018, 263 SCUBA diving and intertidal samplings were conducted at TMV and yielded 46 axiidean specimens in three species, one of which is a new species: Corallianassa longiventris (A. Milne-Edwards, 1870), Neocallichirus grandimana (Gibbes, 1850), and Fragillianassa joeli sp. nov., a species closely related to F. fragilis (Biffar, 1970). Hitherto unreported specimens from along the Vitória-Trindade Seamounts Chain (VTSC) and the Abrolhos Bank were also included in this report, namely C. nodulosus and Michelea vandoverae (Gore, 1987). The occurrence of M. vandoverae at the Abrolhos Bank extends its range into the southwestern Atlantic. Coralaxius abelei Kensley & Gore, 1981 is herein considered a junior synonym of Coralaxius nodulosus (Meinert, 1877). Meinertaxius Sakai, 2011, therefore becomes a subjective synonym of Coralaxius Kensley & Gore, 1981. Axiideans from the tropical southern-central Atlantic oceanic islands (Ascension, Fernando de Noronha, Rocas Atoll, Saint Helena, Trindade and Martin Vaz) are listed with their gross distribution in the Atlantic Ocean revealing a strongly depauperate axiidean insular fauna, totaling six species. Except for Axiopsis serratifrons (A. Milne-Edwards, 1873), a pantropical species, the insular southwestern-central Atlantic axiideans are entirely of western Atlantic affinities, with F. joeli sp. nov. being the only endemic so far.

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Contributions to the systematic of Pimelodidae (Osteichthyes, Siluriformes): basic and molecular cytogenetics on seven species of Pimelodus from three Brazilian hydrographic systems

Neotropical Ichthyology ◽

10.1590/1982-0224-20170148 ◽

2018 ◽

Vol 16 (2) ◽

Cited By ~ 2

Author(s):

Simone C. Girardi ◽

Carla S. Pavanelli ◽

Vladimir P. Margarido

Keyword(s):

18S Rdna ◽

Molecular Cytogenetics ◽

5S Rdna ◽

Neotropical Region ◽

Valid Species ◽

Rdna Sites ◽

The Family ◽

Rdna Fish ◽

Pimelodus Maculatus ◽

Cytogenetic Methods

ABSTRACT Pimelodidae harbors several species and is widely distributed throughout the Neotropical region. Pimelodus is the genus with the largest number of species, however it is a polyphyletic group. Cytogenetic analyzes of the valid species still covers less than half of them. Herein, seven Pimelodus species from three Brazilian hydrographic systems were analyzed through basic (Giemsa, AgNORs and C banding) and molecular (5S and 18S rDNA-FISH) cytogenetic methods. All species had 2n=56 chromosomes with different karyotype formulas observed among the species. AgNORs were corresponding to 18S rDNA and localized on long arm of one chromosome pair in all species. Heterochromatin distribution follows the pattern commonly verified in the family and allows to identify each one of the studied species. 5S rDNA marker was interspecifically variable in number and position of cistrons. Pimelodus ortmanni had B chromosomes varying intra and inter-individually. We performed a discussion on our own and available cytogenetic data for Pimelodidae, and the associating of them with available phylogeny enable us identifying features that distinguish subgroups within Pimelodidae, such as NORs location (terminal/long arm for species belonging to “Iheringichthys-Parapimelodus” and “Pimelodus maculatus” subclades) and location of 5S rDNA sites (pericentromeric/interstitial/ long arm for species belonging to Pimelodus group).

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Taxonomy of Plakortis and Plakinastrella (Demospongiae: Plakinidae) from oceanic islands off north-eastern Brazil, with description of three new species

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315403007239h ◽

2003 ◽

Vol 83 (2) ◽

pp. 385-397 ◽

Cited By ~ 8

Author(s):

Fernando C. Moraes ◽

Guilherme Muricy

Keyword(s):

New Species ◽

Morphological Characters ◽

Oceanic Islands ◽

Western Atlantic ◽

Eastern Brazil ◽

North Eastern ◽

Fernando De Noronha ◽

Plakortis Angulospiculatus ◽

Three New Species ◽

Shape And Size

Three species of Plakortis and one of Plakinastrella (Demospongiae: Homosclerophorida) collected mostly at oceanic islands off north-eastern Brazil (Atol das Rocas, Fernando de Noronha and São Pedro e São Paulo Archipelago) are described, three of which are new to science: Plakortis angulospiculatus, P. insularis sp. nov., P. microrhabdifera sp. nov, and Plakinastrella microspiculifera sp. nov. External morphological characters such as colour, oscules, and consistency are sufficient to discriminate all the four species in the field, except Plakortis angulospiculatus from P. microrhabdifera. Internal features such as skeletal arrangement, shape and size of diods, and presence of microrhabds and calthrops are also important taxonomic characters for western Atlantic Plakortis and Plakinastrella. We consider as valid only five species of Plakortis in the western Atlantic: the three species described here plus P. halichondrioides and P. zyggompha. All these species except P. zyggompha have been recorded from Brazil. Plakinastrella has now two species in the western Atlantic, P. onkodes and P. microspiculifera sp. nov. The generic distinction between Plakortis and Plakinastrella is tenuous, based only on the presence of spicule size-classes and of deformed vs normal calthrops, and both genera need detailed revision.

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B chromosome and NORs polymorphism in Callichthys callichthys (Linnaeus, 1758) (Siluriformes: Callichthyidae) from upper Paraná River, Brazil

Neotropical Ichthyology ◽

10.1590/1982-0224-20130189 ◽

2014 ◽

Vol 12 (3) ◽

pp. 603-609 ◽

Cited By ~ 2

Author(s):

Jocicléia Thums Konerat ◽

Vanessa Bueno ◽

Lucas Baumgartner ◽

Isabel Cristina Martins-Santos ◽

Vladimir Pavan Margarido

Keyword(s):

Physical Mapping ◽

18S Rdna ◽

Diploid Number ◽

5S Rdna ◽

B Chromosome ◽

Paraná River ◽

Rdna Genes ◽

Parana River ◽

Rdna Sites ◽

Upper Paraná River

B chromosomes are extra chromosomes from the normal chromosomal set, found in different organisms, highlighting their presence on the group of fishes. Callichthys callichthys from the upper Paraná River has a diploid number of 56 chromosomes (26 m-sm + 30 st-a) for both sexes, with the presence of a sporadically acrocentric B chromosome. Moreover, one individual presented a diploid number of 57 chromosomes, with the presence of a morphologically ill-defined acrocentric B chromosome in all analyzed cells. The physical mapping of 5S and 18S rDNA shows multiple 5S rDNA sites and only one pair of chromosomes with 18S sites in C. callichthys, except for two individuals. These two individuals presented a third chromosome bearing NORs (Ag-staining and 18S rDNA) where 5S and 18S rDNA genes are syntenic, differing only in position. The dispersion of the 18S rDNA genes from the main st-achromosome pair 25 to one of the chromosomes from the m-sm pair 4 would have originated two variant individuals, one of which with the ill-defined acrocentric B chromosome. Mechanisms to justify the suggested hypothesis about this B chromosome origin are discussed in the present study.

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Paguroids (Decapoda: Anomura: Diogenidae and Paguridae) of the remote oceanic Archipelago Trindade and Martin Vaz, off southeast Brazil, with new records, description of three new species and zoogeographical notes

Zootaxa ◽

10.11646/zootaxa.4694.1.1 ◽

2019 ◽

Vol 4694 (1) ◽

pp. 1-63 ◽

Cited By ~ 1

Author(s):

DANIEL LIMA ◽

MARCOS TAVARES ◽

JOEL BRAGA JR. DE MENDONÇA

Keyword(s):

New Species ◽

Oceanic Islands ◽

Brazilian Coast ◽

Western Atlantic ◽

Fernando De Noronha ◽

Southern Central ◽

Seamount Chain ◽

Three New Species ◽

Central Atlantic ◽

First Time

Trindade and Martin Vaz (TMV) is a highly isolated, oceanic volcanic archipelago located some 1200 km off the Brazilian coast and about 4200 km away from the nearest African coast. For almost 100 years Calcinus tibicen (Herbst, 1791) was the only hermit crab species known from TMV. From 2012 to 2018, 263 daytime SCUBA diving and intertidal samplings conducted at TMV yielded 1075 paguroid specimens in 10 species, three of which are established herein as new species: Iridopagurus martinvaz sp. nov., Nematopagurus micheleae sp. nov., and Pagurus carmineus sp. nov. Iridopagurus margaritensis García-Gómez, 1983, and Phimochirus leurocarpus McLaughlin, 1981, both only known from the northern hemisphere, are recorded for the first time from the southwestern Atlantic. Opportunity was taken herein to include hitherto unreported or little known specimens from along the Vitória-Trindade Seamount Chain, namely, Dardanus venosus H. Milne Edwards, 1848, Nematopaguroides pusillus Forest & de Saint Laurent, 1968, Pagurus provenzanoi Forest & de Saint Laurent, 1968, and Phimochirus holthuisi (Provenzano, 1961). The lectotype of Pagurus venosus H. Milne Edwards, 1848 is designated as the neotype for the obscure Pagurus arrosor divergens Moreira, 1905, which thus becomes an objective junior synonym of the former. A list of all paguroid species known from the tropical southern-central Atlantic oceanic archipelagoes and islands (Ascension, Cape Verde, Fernando de Noronha, Gulf of Guinea, Rocas Atoll, Saint Helena, Trindade and Martin Vaz) with their gross distribution in the Atlantic Ocean is provided. Investigation on the existence of patterns of geographic distribution for the paguroid fauna of the tropical southern-central Atlantic oceanic islands showed that 70% percent of the paguroids from TMV are western Atlantic in origin and 30% endemic. No amphi-Atlantic paguroid species are known from TMV. Conversely, the affinity of Ascension’s (33%) and Saint Helena’s (50%) paguroids is with the eastern Atlantic; no western Atlantic paguroids have been reported from these two islands so far. Exploration on the existence of trends of correlation between islands area and species richness through the Spearman’s coefficient of correlation showed that the patterns in the number of paguroid species cannot be explained by variation in island area alone (rs = 0.4728; p = 0.28571).

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Physical Mapping of the 5S and 18S rDNA in Ten Species ofHypostomusLacépède 1803 (Siluriformes: Loricariidae): Evolutionary Tendencies in the Genus

The Scientific World JOURNAL ◽

10.1155/2014/943825 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 17

Author(s):

Vanessa Bueno ◽

Paulo César Venere ◽

Jocicléia Thums Konerat ◽

Cláudio Henrique Zawadzki ◽

Marcelo Ricardo Vicari ◽

...

Keyword(s):

18S Rdna ◽

Chromosome Pair ◽

5S Rdna ◽

Pericentromeric Region ◽

Telomeric Region ◽

Diverse Group ◽

Rdna Genes ◽

Rdna Sites ◽

Metacentric Pair

Hypostomusis a diverse group with unclear aspects regarding its biology, including the mechanisms that led to chromosome diversification within the group. Fluorescencein situhybridization (FISH) with 5S and 18S rDNA probes was performed on ten Hypostomini species.Hypostomus faveolus,H. cochliodon,H. albopunctatus,H.aff.paulinus,andH. topavaehad only one chromosome pair with 18S rDNA sites, whileH. ancistroides,H. commersoni,H. hermanni,H. regani,andH. strigaticepshad multiple 18S rDNA sites. Regarding the 5S rDNA genes,H. ancistroides,H. regani,H. albopunctatus,H.aff.paulinus,andH. topavaehad 5S rDNA sites on only one chromosome pair andH. faveolus,H. cochliodon,H. commersoni,H. hermanni,andH. strigaticepshad multiple 5S rDNA sites. Most species had 18S rDNA sites in the telomeric region of the chromosomes. All species butH. cochliodonhad 5S rDNA in the centromeric/pericentromeric region of one metacentric pair. Obtained results are discussed based on existent phylogenies for the genus, with comments on possible dispersion mechanisms to justify the variability of the rDNA sites inHypostomus.

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Genetic Multipartitions Based on D-Loop Sequences and Chromosomal Patterns in Brown Chromis,Chromis multilineata(Pomacentridae), in the Western Atlantic

BioMed Research International ◽

10.1155/2014/254698 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11 ◽

Cited By ~ 3

Author(s):

Inailson Márcio Costa da Cunha ◽

Allyson Santos de Souza ◽

Eurico Azevedo Dias ◽

Karlla Danielle Jorge Amorim ◽

Rodrigo Xavier Soares ◽

...

Keyword(s):

Saint Paul ◽

Fish Fauna ◽

Oceanic Islands ◽

Brazilian Coast ◽

Western Atlantic ◽

Molecular Cytogenetic ◽

Mtdna Sequence ◽

Dominant Fish ◽

Fernando De Noronha ◽

D Loop

Connectivity levels among Brazilian reef fish fauna populations have attracted growing interest, mainly between mainland shores and oceanic islands. The Pomacentridae, whose phylogeographic patterns are largely unknown in the Atlantic, are a family of dominant fish in reef regions. We present data on the variability and population structure of damselfishChromis multilineatain different areas along the northeast coast of Brazil and in the waters around the oceanic islands of Fernando de Noronha (FNA) and Saint Peter and Saint Paul Archipelago (SPSPA) through analysis of the HVR1 mtDNA sequence of the control region. The remote SPSPA exhibits the highest level of genetic divergence among populations. Conventional and molecular cytogenetic analysis showed similar karyotype patterns (2n= 48 acrocentrics) between these insular areas. Our estimates reveal three genetically different population groups ofC. multilineataon the Brazilian coast. The level of genetic structure is higher than previous data suggested, indicating complex panel of interactions between the oceanic island and coastal populations of Brazil.

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A new species of Stoeba (Demospongiae: Astrophorida) from oceanic islands off north-eastern Brazil

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315407058316 ◽

2007 ◽

Vol 87 (6) ◽

pp. 1387-1393 ◽

Cited By ~ 5

Author(s):

Fernando Moraes ◽

Guilherme Muricy

Keyword(s):

New Species ◽

First Record ◽

Oceanic Islands ◽

Sao Paulo ◽

Valid Species ◽

Western Atlantic ◽

Eastern Brazil ◽

North Eastern ◽

Fernando De Noronha ◽

A New Species

The genus Stoeba has 11 recognized species. Herein we describe a new species of Stoeba endemic from two oceanic archipelagoes off north-eastern Brazil (Fernando de Noronha and São Pedro e São Paulo), constituting the first record of this genus for the western Atlantic. Stoeba latex sp. nov. is characterized by its thickly encrusting to massive shape, stretched surface, brownish-red colour, and spiculation of calthrops and sanidasters with well developed spines; dichotriaenes and oxeas are absent. Stoeba and Dercitus are very closely related genera, and should probably be merged. The genus Stoeba now contains the following valid species: S. dissimilis, S. exostotica, S. extensa, S. lesinensis, S. natalensis, S. occulta, S. pauper, S. plicata, S. reptans, S. simplex, S. syrmatita and S. latex sp. nov. Several other species still await description. A key to the valid species of Stoeba is given.

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