Research Article |
Corresponding author: Wagner Franco Molina ( molinawf@yahoo.com.br ) Academic editor: Petr Rab
© 2021 Rodrigo Xavier Soares, Clóvis Coutinho da Motta-Neto, Gideão Wagner Werneck Félix da Costa, Marcelo de Bello Cioffi, Luiz Antonio Carlos Bertollo, Amanda Torres Borges, Wagner Franco Molina.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Soares RX, Motta-Neto CC, Costa GWWF, Cioffi MB, Bertollo LAC, Borges AT, Molina WF (2021) Comparative cytogenetic patterns in Carangidae fishes in association with their distribution range. Comparative Cytogenetics 15(4): 429-445. https://doi.org/10.3897/CompCytogen.v15.i4.69638
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Carangidae are an important and widespreaded family of pelagic predatory fishes that inhabit reef regions or open ocean areas, some species occupying a vast circumglobal distribution. Cytogenetic comparisons among representatives of its different tribes help to understand the process of karyotype divergence in marine ecosystems due to the variable migratory ability of species. In this sense, conventional cytogenetic investigations (Giemsa staining, Ag-NORs, and C-banding), GC base-specific fluorochrome staining and FISH mapping of ribosomal DNAs were performed. Four species, Elagatis bipinnulata (Quoy et Gaimard, 1825) and Seriola rivoliana (Valenciennes, 1883) (Naucratini), with circumtropical distributions, Gnathanodon speciosus (Forsskål, 1775) (Carangini), widely distributed in the tropical and subtropical waters of the Indian and Pacific oceans, and Trachinotus carolinus (Linnaeus, 1766) (Trachinotini), distributed along the western Atlantic Ocean, were analyzed, thus encompassing representatives of three out its four tribes. All species have diploid chromosome number 2n = 48, with karyotypes composed mainly by acrocentric chromosomes (NF = 50–56). The 18S rDNA/Ag-NORs/GC+ and 5S rDNA loci were located on chromosomes likely homeologs. Karyotypes showed a pattern considered basal for the family or with small variations in their structures, apparently due to pericentric inversions. The migratory capacity of large pelagic swimmers, in large distribution areas, likely restricts the fixation of chromosome changes in Carangidae responsible for a low level of karyotype diversification.
Conservative karyotype, Fish cytogenetics, karyotype evolution, pelagic fishes
The spatial distribution of biodiversity is related to the existing or past physical and environmental conditions. In this context, fishes provide good models for investigating the association between chromosome diversity and environmental characteristics of different regions and ecosystems (
The marine environment is both extensive and multidimensional due to its varied ecological patterns, thus providing complex evolutionary conditions that impacts the genetic structure of species (
The investigation of environmental effects on the genetic diversity of marine fish species depends on favorable spatial models, which have been used to identify causes and factors that promote their karyotype differentiation (
A negative correlation was found when associating the dispersive potential of the pelagic larvae with the karyotype diversification in reef fish (
Carangidae are pelagic fishes with high swimming capacity, composed of 31 genera and 150 presently recognized species (
In view of the environmental complexity to which the marine fish groups are subjected, the investigation of their chromosome change patterns must consider wide taxonomic, biogeographic, and different biological models. In the context of the marine environment, cytogenetic analyses in groups with a wide geographic distribution, such as Carangidae, provide an understanding of the role of biogeographic barriers and the dispersive potential on karyotype changes. Therefore, we performed cytogenetic analyses using conventional and molecular protocols in Elagatis bipinnulata (Quoy et Gaimard, 1825) (Rainbow runner), Seriola rivoliana (Valenciennes, 1883) (Greater amberjack), Gnathanodon speciosus (Forsskål, 1775) (Golden trevally), and Trachinotus carolinus (Linnaeus, 1766) (Florida pompano), which have extensive geographical distribution. The patterns of their karyotype evolution were discussed in relation with the dispersive potential estimated by their geographic distribution.
Cytogenetic analyses were performed on the species Elagatis bipinnulata (n = 15; 10 males; 5 females), and Seriola rivoliana (n = 4; 1 male; 3 females), both from off the São Pedro and São Paulo archipelago (00°56'N, 29°22'W) located in the Meso-Atlantic region; in Gnathanodon speciosus (n = 2; juveniles), from the Pacific and Indo-Pacific, obtained through ornamental fish traders, and Trachinotus carolinus (n = 10; 4 males; 6 females), from cultivated stock of the coast of Florida (USA). The samples were collected with the authorization of the Brazilian environmental agency ICMBio/ SISBIO (License #19135-4, #131360-1 and #27027-2).
The individuals were subjected to in vivo mitotic stimulation according to Molina et al. (2010). Chromosome preparations were obtained from short-term culture (
The nucleolus organizing regions (NORs) and the chromosomal heterochromatin content were analyzed according to the C-banding and Ag-NOR methods, reported by
FISH was performed according to
At least 30 metaphase spreads per individual were analyzed to confirm the chromosome number, karyotype structure, and FISH results. Images were photographed using an Olympus BX51 epifluorescence microscope coupled to an Olympus DP73 digital image capture system (Olympus Corporation, Ishikawa, Japan) with the cellSens (Version 1.9 Digital, Tokyo, Kanto, Japan) software. Chromosomes were classified as metacentric (m), submetacentric (sm), subtelocentric (st), and acrocentric (a) according to their arm ratios (
The maximum linear geographic distribution distance (MLD) and the occupied area by each species (OA) were obtained through the Ocean Biogeographic Information System (
The descriptive statistical analysis (Table
Cytogenetic data from species of the family Carangidae and their maximum linear geographic distribution (MLD) and occupied area (OA) and ratio with the maximum distribution values defined for the family. Vertical bars represent the set of parameters available to the species.
Species | MLD Km × 104 | % LGDmax | OA Km2 × 104 | % OAmax | 2n | Karyotype | NF | Ref. |
---|---|---|---|---|---|---|---|---|
Naucratini | ||||||||
Elagatis bipinnulata (Quoy et Gaimard, 1825) | 3.80 | 100 | 977.05 | 100 | 48 | 2st+46a | 50 | 1 |
Seriolina nigrofasciata (Rüppell, 1829) | 1.34 | 40 | 213.16 | 30 | 48 | 48a | 48 | 2 |
Seriola rivoliana Valenciennes, 1833 | 3.14 | 90 | 446.50 | 50 | 48 | 2sm+2st+44a | 52 | 1 |
Seriola dumerili (Risso, 1810) | 2.05 | 60 | 526.26 | 60 | 48 | 2sm+46a | 50 | 3 |
48 | 2sm+2st+44a | 52 | 4 | |||||
Seriola quinqueradiata Temminck et Schlegel, 1845 | 0.13 | 10 | 18.54 | 20 | 48 | 2sm+2st+44a | 52 | 5 |
Seriola lalandi Valenciennes, 1833 | 1.43 | 40 | 454.94 | 50 | 48 | 2m+2sm+6st+38a | 58 | 6 |
Average values | 1.98 | 60 | 439.41 | 50 | 51.7 | |||
Scomberoidini | ||||||||
Scomberoides lysan (Forsskål, 1775) | 2.15 | 60 | 523.60 | 60 | 48 | 4m/sm+44a | 52 | 7 |
Oligoplites saliens (Bloch, 1793) | 0.60 | 20 | 36.95 | 10 | 48 | 4m/sm+44st/a | 52 | 8 |
Average values | 1.37 | 40 | 280.28 | 30 | 52 | |||
Carangini | ||||||||
Alectis ciliaris (Bloch, 1787) | 2.75 | 80 | 579.72 | 60 | 48 | 48a | 48 | 9 |
Alepes djedaba (Forsskål, 1775) | 1.33 | 40 | 161.50 | 20 | 56 | 56a | 56 | 10 |
Alepes melanoptera (Swainson, 1839) | 0.83 | 30 | 122.57 | 20 | 48 | 2sm+46a | 50 | 10 |
Atropus atropos (Bloch et Schneider, 1801) | 0.71 | 20 | 43.83 | 10 | 48 | 48a | 48 | 7 |
Atule mate (Cuvier, 1833) | 1.48 | 40 | 483.84 | 50 | 50 | 14sm+36a | 64 | 11 |
Carangoides armatus (Rüppell, 1830) | 0.99 | 30 | 197.62 | 30 | 48 | 2st+46a | 50 | 7 |
Carangoides equula (Temminck et Schlegel, 1844) | 1.48 | 40 | 221.06 | 30 | 48 | 2st+46a | 50 | 9 |
Carangoides bartholomaei (Cuvier, 1833) | 0.73 | 20 | 219.65 | 30 | 48 | 6sm+42a | 54 | 12 |
Caranx praeustus Anonymous (Bennett), 1830 | 0.67 | 20 | 41.97 | 10 | 48 | 10m/sm+28a | 58 | 7 |
Caranx latus Agassiz, 1831 | 1.14 | 40 | 212.55 | 30 | 48 | 2sm+46a | 50 | 12 |
Caranx lugubris Poey, 1860 | 3.59 | 100 | 379.16 | 40 | 48 | 2sm+46a | 50 | 13 |
Caranx ignobilis (Forsskål, 1775) | 2.21 | 60 | 590.42 | 70 | 48 | 2sm+46a | 50 | 14 |
Caranx sexfasciatus Quoy et Gaimard, 1825 | 2.48 | 70 | 875.01 | 90 | 48 | 2st+46a | 50 | 9 |
Chloroscombrus chrysurus (Linnaeus, 1766) | 1.33 | 40 | 422.56 | 50 | 48 | 48a | 48 | 15 |
Gnathanodon speciosus (Forsskål, 1775) | 2.47 | 70 | 615.10 | 70 | 48 | 2st+46a | 50 | 1 |
Megalaspis cordyla (Linnaeus, 1758) | 1.06 | 30 | 336.44 | 40 | 50 | 2st+48a | 50 | 10 |
Selene setapinnis (Mitchill, 1815) | 1.23 | 40 | 298.39 | 40 | 46 | 2sm+44a/2m+44a | 48 | 16 |
Selene vomer (Linnaeus, 1758) | 0.69 | 20 | 289.54 | 30 | 48 | 2st+46a | 50 | 16 |
Selene brownii (Cuvier, 1816) | 0.40 | 20 | 46.20 | 10 | 48 | 48a | 48 | 16 |
Trachurus japonicus (Temminck et Schlegel, 1844) | 0.23 | 10 | 40.34 | 10 | 48 | 4m+14sm+12st+18a | 78 | 9 |
T. mediterraneus (Steindachner, 1868) | 0.58 | 20 | 122.38 | 20 | 48 | 4m+6sm+38st/a | 58 | 17 |
0.69 | 48 | 4m+4sm+14st+26a | 70 | 18 | ||||
T. trachurus (Linnaeus, 1758) | 1.32 | 20 | 423.31 | 50 | 48 | 2sm+46a | 50 | 18 |
Average values | 2.75 | 40 | 327.54 | 40 | 53.4 | |||
Trachinotini | ||||||||
Trachinotus goodei Jordan et Evermann, 1896 | 0.67 | 20 | 89.73 | 10 | 48 | 4m/sm+44a | 52 | 19 |
T. carolinus (Linnaeus, 1766) | 0.69 0.19 |
20 10 |
122.06 | 20 | 48 | 8m/sm+40a | 56 | 19 |
25.22 | 10 | 48 | 4m+4sm+40a | 56 | 1 | |||
T. falcatus (Linnaeus, 1758) | 1.30 | 40 | 265.56 | 30 | 48 | 10m/sm+38a | 58 | 19 |
125.64 | 20 | 48 | 2m+2st+44a | 52 | 20 | |||
T. ovatus (Linnaeus, 1758) | 0.67 | 20 | 89.73 | 10 | 48 | 2m+4sm+42st/a | 54 | 10 |
Average values | 0.69 | 20 | 122.06 | 20 | 54.4 |
All species had 2n = 48, but with different karyotypes. While E. bipinnulata and G. speciosus shared karyotypes with 2st+46a (NF = 50), S. rivoliana has 2sm+2st+44a (NF = 52), and T. carolinus has 4m+4sm+40a (NF = 56). No evidence of the presence of differentiated sex chromosomes was found.
C-positive heterochromatic blocks were located mainly in the pericentromeric regions and in the terminal regions of some chromosome pairs to a lesser extent (Fig.
Karyotypes of Elagatis bipinnulata, Seriola rivoliana, Gnathanodon speciosus, and Trachinotus carolinus arranged after Giemsa staining (Ag-NORs and MM+/DAPI- sites, highlighted), C- banding, and double-FISH with 18S rDNA (red) and 5S rDNA (green) probes. The chromosome pairs were tentatively numbered. Scale bar: 5 μm.
The 5S rDNA loci were also unique, but with an interstitial or terminal distribution in a pairs of similar size among the species, and non-syntenic with the 18S ones. In E. bipinnulata and S. rivoliana, they were interstitially located in the q arms of the pair labelled as No. 6; in the terminal region of the short arms of the pair labelled as No. 6 in T. carolinus, and in the pericentromeric region of the smallest chromosome pair No. 24 in G. speciosus (Fig.
The average number of the chromosome arms (NF average) showed an negative correlation with the averages of linear distances of distribution and areas occupied for each tribe. In fact, the NF average showed be progressively divergent on the NF considered as basal for the family (NF = 50) in Naucratini (51.7), that encompass an average linear distribution distance equivalent to 60% of the greatest distance established for the family (LD), and 50% concerning the largest occupied area (LOA); Scomberoidini (52), with 40% (LD) and 30% (LOA), Carangini (53.4), with 40% (LD) and 40% (LOA) and Trachinotini (54.4), with 20% (LD) and 20% (LOA) (Table
The average of the two distribution measures (MLD and OA) and NF values showed evidences on an statistically supported relationship between karyotype and geographic distribution, that encompass a synergic set of ecological, adaptive, and migratory characteristics. The variables MLD (p = 0.001), OA (p = 0.001), and NF (p < 3.097e-07) did not present a normal distribution (Shapiro-Wilk test). The analysis revealed a high correlation between the MLD and OA (Pearson’s correlation r = 0.829, p ≤ 0.05). The NF values showed a moderate negative Pearson’s correlation coefficient with the MLD (r = -0.419, p = 0.0144) and modest negative correlation with OA (r = -0.876, p = 0.043).
In contrast to other marine fish groups, Carangidae have a representative set of cytogenetic data (Table
Pericentric inversions are predominant changes in the order, but to a lesser extent in the syntenic composition of gene groups. If so, the chromosome conservation evidenced among the four Carangidae genera could encompass a wide shared synteny among the species. Indeed, genetic maps of Seriola species evidenced a high collinearity among their linkage groups (
If pericentric inversions are the most common rearrangements in Carangidae, and if they are equally likely to occur in all tribes, a similar level of karyotype divergence among them would be expected. However, this does not occur, as seen by cytogenetic data covering representative species from most genera of each tribe (Table
The geographic variables MLD and OA showed a high positive correlation with each other and both showed a negative correlation with the NF (p ≤ 0.05). In fact, the data set revealed that the probability of chromosomal variations decreases as the geographical distribution of the species expands. Between the two distribution variables, MLD exhibited a more pronounced negative correlation with the NF. Although both parameters are negatively associated with chromosomal variation, they have different prediction intervals. The modest correlation between OA and NF, was statistically significant, and probably related to lower precision in the definition of the ecological areas occupied by the species. In contrast, MLD, despite being a simpler parameter, proved to be a more effective predictor of differences in the dispersive potential of migratory species.
Large pelagic fish populations, whose life histories include migratory behavior, planktonic larval stages, and broadcast spawning, maintain high levels of gene flow among vast oceanic areas (
Karyotype index of chromosomal similarity (orange) and divergence (blue) regarding the probable basal karyotype for Carangidae studied species. Maps show the magnitude of the geographic distribution of Elagatis bipinnulata, Seriola rivoliana, Gnathanodon speciosus, and Trachinotus carolinus (top to bottom).
Significantly, a conservatism pattern can also be seen at microstructural cytogenetic level. For example, the 18S rDNA sites, that are usually characterized by a high evolutionary dynamism among fishes (
The distribution of some Trachinotus species in the Western Atlantic is subdivided by the Amazonas and Orinoco rivers barrier. In this context, T. carolinus from Caribbean, first analyzed here, shows no variable karyotypes compared to those previously reported for populations from the southeast and northeast Brazilian coasts (
Biogeographic barriers in marine oceans affect the karyotype diversification (
Carangidae constitute a marine fish group in which many species are vagrant/nomadic pelagic swimmers, ranging from a single ocean to circumglobal distributions. Gene flow among marine fish populations with significant population sizes and extensive distributions can mitigate genetic differentiation. The cytogenetical/geographical approach suggest negative correlation between active migratory capacity and cytogenetic divergence in marine fish. This genetic context could restrains evolutionary diversification and speciation, in the Carangidae, a clade in which many genera are monotypic or formed by a few species. As a whole, our data provide preliminary data of high gene flow in minimize chromosomal rearrangements in large oceanic spaces, highlighting new scenarios of the karyotype evolution in pelagic species.
Rodrigo Xavier Soares: Conceptualization, Methodology, Writing – Original draft preparation, Data curation. Gideão Wagner Werneck Félix da Costa: Investigation, Validation. Clóvis Coutinho da Motta-Neto, Amanda Torres Borges: Supervision, Visualization. Marcelo de Bello Cioffi, Luiz Antônio Carlos Bertollo: Writing – Reviewing and Editing. Wagner Franco Molina: Conceptualization, Methodology, Writing – Original draft preparation, Funding acquisition, Project administration. Writing – Reviewing and Editing.
The data that support the findings of this study are available from the corresponding author upon reasonable request.
The authors thank to the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for financial support (#442664/2015-0; #442626/2019-3 and #301458/2019-7 to WFM), to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) to scholarship grant to RXS, and to ICMBio/SISBIO (#19135-4, #131360-1 and #27027-2) for the authorization in collecting specimens. We also thank to Dr. José Garcia Júnior for the taxonomic identification of the specimens and the University of Miami’s RSMAS (Rosenstiel School of Marine and Atmosferic Science) for the partnership and for making available the specimens of Trachinotus carolinus used in this study.
Wagner Franco Molina https://orcid.org/0000-0002-6695-0952
Marcelo de Bello Cioffi https://orcid.org/0000-0003-4340-1464
Clóvis Coutinho da Motta-Neto https://orcid.org/0000-0002-0592-6131
Rodrigo Xavier Soares https://orcid.org/0000-0002-3735-3649