Research Article |
Corresponding author: Maria Yankova ( maria_y@abv.bg ) Academic editor: Snejana Moncheva
© 2023 Maria Yankova, Violin Raykov, Petya Ivanova, Nina Dzhembekova, Cemal Turan, Yordan Raev.
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:
Yankova M, Raykov V, Ivanova P, Dzhembekova N, Turan C, Raev Y (2023) Morphological and genetic characteristics of garfish Belone belone (L., 1760) (Belonidae, Teleostei) population from the southern Bulgarian Black Sea coast. Nature Conservation 54: 1-12. https://doi.org/10.3897/natureconservation.54.113071
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This study was conducted to investigate genetic and some morphometric and meristic characteristics of garfish Belone belone from Nesebar in the Bulgarian Black Sea coast. Twelve morphometric characters were measured, and six meristic characters were counted for each individual. Based on both sexes’ morphological and meristic analyses, no statistically significant sexual differences were observed. Additionally, DNA barcoding was done. The fragment of the cytochrome oxidase subunit I (COI) gene of mitochondrial DNA was sequenced to supplement the species identification and population diversity study. Two haplotypes were found out of 39 sequences, indicating a low level of haplotype diversity (0.146±0.072). Nucleotide diversity was also found to be low (0.00023±0.00011). The Nesebar population of B. belone requires conservation efforts, due to the highly decreased mtDNA genetic diversity.
Belone belone, Bulgarian Black Sea coast, genetic, meristic analysis, morphometric
The Belonidae family, represented by a total of 10 genera and 44 nominal species in marine and freshwater ecosystems, constitutes one of the important groups of the ichthyofauna of the Eastern Atlantic, the Mediterranean and the Black Sea (
Morphometrics and meristics characters are the two types of morphologic characters that have been most frequently used to describe populations of exploited marine fish species (
Genetic diversity is the basis of species adaptability and evolution, and there is a positive linear relationship between intraspecific genetic diversity and the adaptability of the species to the environment (
The aim of this paper is to represent for the first time the morphological and genetic diversity of one Belone belone population along the Bulgarian Black Sea coast, which as a commercially important fish species could aid in its conservation.
B. belone specimens were collected in December 2022 from the Bulgarian Black Sea coast (Nesebar) (Fig.
Relative relationships of measured body proportions of Belone belone in the Bulgarian Black Sea coast. n-number of fish studied, X̄ -mean value, SD-standard deviation; SE-standard error of mean value; CV-coefficient of variation.
Relation | Sex | n | Range | X̄ ±SD | X̄ ±SE | CV (%) |
---|---|---|---|---|---|---|
FL/TL | ♀ | 26 | 32.7±39.9 | 35.3±1.79 | 35.3±0.35 | 5.08 |
♂ | 14 | 30.0±37.8 | 34.7±2.15 | 34.7±0.57 | 6.21 | |
Total | 40 | 30.0±39.9 | 35.1±1.91 | 35.1±0.30 | 5.46 | |
SL/TL | ♀ | 26 | 31.1± 39.4 | 34.1±1.80 | 34.1±0.35 | 5.29 |
♂ | 14 | 25.8± 36.6 | 33.2±2.88 | 33.2±1.80 | 8.69 | |
Total | 40 | 25.8±39.4 | 33.8±2.25 | 33.8±0.35 | 6.65 | |
PA/TL | ♀ | 26 | 24.1±30.3 | 48.9±1.32 | 48.9±0.26 | 5.01 |
♂ | 14 | 23.2±28.0 | 26.2±1.24 | 26.2±0.33 | 4.72 | |
Total | 40 | 23.2±30.3 | 26.3±1.28 | 26.3±0.20 | 4.86 | |
HL/TL | ♀ | 26 | 10.1±11.5 | 19.5±0.39 | 19.5±0.07 | 3.73 |
♂ | 14 | 9.5±10.9 | 10.3±0.33 | 10.3±0.09 | 3.25 | |
Total | 40 | 9.5±11.5 | 10.4±0.37 | 10.4±0.06 | 3.60 | |
O/LH | ♀ | 26 | 0.8±1.0 | 0.9±0.06 | 0.9±0.01 | 7.03 |
♂ | 14 | 0.7±0.9 | 0.9±0.06 | 0.9±0.02 | 7.01 | |
Total | 40 | 0.7±1.0 | 0.9±0.06 | 0.9±0.01 | 7.19 | |
H/TL | ♀ | 26 | 1.5±1.9 | 1.7±0.12 | 1.7±0.02 | 7.02 |
♂ | 14 | 1.5±1.9 | 1.7±0.12 | 1.7±0.03 | 7.18 | |
Total | 40 | 1.5±1.9 | 1.7±0.12 | 1.7±0.02 | 6.99 | |
h/H | ♀ | 26 | 0.7±0.8 | 0.7±0.04 | 0.7±0.01 | 5.59 |
♂ | 14 | 0.7±0.8 | 0.7±0.03 | 0.7±0.01 | 3.78 | |
Total | 40 | 0.7±0.8 | 0.7±0.04 | 0.7±0.01 | 5.53 | |
LD/TL | ♀ | 26 | 4.3±5.3 | 4.8±0.03 | 4.8±0.06 | 6.93 |
♂ | 14 | 4.3±5.1 | 4.2±0.03 | 4.7±0.08 | 6.44 | |
Total | 40 | 4.3±5.3 | 4.7±0.32 | 4.7±0.05 | 6.94 | |
LP/TL | ♀ | 26 | 1.8±2.4 | 2.2±0.13 | 2.2±0.02 | 5.89 |
♂ | 14 | 2.0±2.4 | 2.2±0.11 | 2.2±0.03 | 4.96 | |
Total | 40 | 1.8±2.4 | 2.2±0.12 | 2.2±0.02 | 5.55 | |
LA/TL | ♀ | 26 | 5.2±6.3 | 6.1±0.36 | 6.1±0.07 | 5.84 |
♂ | 14 | 5.1±6.2 | 6.4±0.37 | 6.4±0.10 | 5.78 | |
Total | 40 | 5.1±6.3 | 6.2±0.36 | 6.2±0.06 | 5.82 | |
LV/TL | ♀ | 26 | 1.4±1.9 | 1.7±0.10 | 1.6±0.02 | 6.19 |
♂ | 14 | 1.4±1.9 | 1.7±0.12 | 1.7±0.03 | 6.91 | |
Total | 40 | 1.4±1.9 | 1.7±0.11 | 1.7±0.02 | 6.37 |
Meristic characteristic of garfish from Bulgarian Black Sea. n-number of fish studied, X̄ -mean value, SD-standard deviation; SE-standard error of mean value; CV-coefficient of variation.
Meristic characteristic | Sex | n | Range | X̄ ± SD (%) | X̄ ±SE (%) | CV (%) |
---|---|---|---|---|---|---|
No rays in dorsal fin (D) | ♀ | 26 | 16–19 | 17.8±0.65 | 17.8±0.13 | 3.67 |
♂ | 14 | 16–19 | 17.6±0.75 | 17.6±0.20 | 4.30 | |
Total | 40 | 16–19 | 17.7±0.68 | 17.7±0.11 | 3.88 | |
No rays in pectoral fin (P) | ♀ | 26 | 12–19 | 13.0±0.20 | 13.0±0.04 | 1.51 |
♂ | 14 | 13–19 | 13.0±0.01 | 13.0±0.01 | 0.01 | |
Total | 40 | 12–19 | 13.0±0.16 | 13.0±0.03 | 1.22 | |
No ray in anal fin (A) | ♀ | 26 | 19–23 | 21.9±1.02 | 21.9±0.20 | 4.64 |
♂ | 14 | 19–23 | 21.6±1.01 | 21.6±0.27 | 4.66 | |
Total | 40 | 19–23 | 21.8±1.01 | 21.8±0.16 | 4.63 | |
Upper teeth | ♀ | 26 | 13–15 | 14.0±0.28 | 14.0±0.05 | 2.02 |
♂ | 14 | 14–14 | 14.0±0.01 | 14.0±0.00 | 0.01 | |
Total | 40 | 13–15 | 14.0±0.23 | 14.0±0.03 | 1.62 | |
Gill | ♀ | 26 | 31–34 | 33.1±0.88 | 33.2±0.17 | 2.65 |
♂ | 14 | 31–34 | 32.9±0.83 | 32.9±0.22 | 2.52 | |
Total | 40 | 31–34 | 33.1±0.86 | 33.1±0.14 | 2.60 | |
Vert. | ♀ | 26 | 80–81 | 80.0±0.20 | 80.0±0.04 | 0.24 |
♂ | 14 | 80–81 | 80.2±0.36 | 80.2±0.10 | 0.45 | |
Total | 40 | 80–81 | 80.1±0.27 | 80.1±0.04 | 0.33 |
Tissue sample from the pectoral fin was cut and preserved in 96% ethanol at 4 °C. The genomic DNA was isolated using the DNeasy Blood & Tissue Kit (QIAGEN), and the target DNA was amplified with universal set of mitochondrial primers – cytochrome c oxidase subunit I (COI) FishF2: 5’TCGACTAATCATAAAGATATCGGCAC3’ and FishR2: 5’ACTTCAGGGTGACCGAAGAATCAG AA3’ (
The total length of female varied between 30.0 cm±37.8 cm (TLmin-TLmax) and 32.7 cm± 39.9 cm for males. No statistically significant difference was noted between sexes (KOLMOGOROV-SMIRNOV Test, P<0.05) for all morphometric characters: total length P (T<=t) =0.54, fork length P (T<=t) =0.50, standard length P (T<=t) =0.29, pre-anal distance P (T<=t) =0.74, head length P (T<=t) =0.29, eye diameter P (T<=t) =0.18, maximum body height T<=t) =0.81, minimum body height P (T<=t) =0.24, length of the dorsal fin basis base P (T<=t) =0.63, length of anal fin basis P (T<=t) =0.75, length of pectoral fin P (T<=t) =0.44, length of pelvic fin P (T<=t) =0.82. The fork length, standard length, pre-anal distance, length of anal fin, length of dorsal fin, maximum body height, length of pelvic fin, minimum body height was found as 87.5%, 84.4%, 65.8%, 14.5%, 11.9%, 4.3%, 4.1% and 1.8% of the total length of the fish respectively (Fig.
Morphometric measures of garfish in relation to the A total length and B head length of the fish in percentage.
The coefficient of variation CV was relatively low (CV<9%) for all morphometric measured body proportions of Belone belone. The lowest value was recorded for the relationship of length head and total length (LH/TL) in male (CV= 3.25%), while the highest value was registered for relationship (SL/TL) of standard and total length in male (CV= 8.69%) (Table
The dorsal fin is long, unbranched with 16–19 spiny rays. The pectoral and anal fin comprised of 13–19 and 19–23 fin rays respectively. The coefficients of variation CV were relatively low for all meristic characteristics. The lowest value was recorded for the pectoral fin rays in total (CV= 0.01%), while the highest value was registered for anal fin rays in male (CV= 4.66%). No statistical difference was observed between sexes (Table
Some length-length relationships (FL/TL, PA/TL, SL/FL, SL/TL, LH/TL) were fitted well by linear regression and show high determination (R2) with the exception of the relationships:
(H/TL, LV/TL, LD/TL, h/H, LP/TL, LH/ O), which displayed very small values of R2 (Fig.
The obtained COI gene fragment (633 bp) showed high percent identity (100% for haplotype 1 and 99.84% for haplotype 2) with B. belone sequences deposited in GenBank (KJ204729 North Sea, KJ128428 Sweden), supporting the species identification. From the 39 garfish samples analyzed, only two haplotypes were found, indicating low level of haplotype (0.146 ±0.072) diversity. The first haplotype (H1) was dominant, presented in 36 of the samples, whereas the second one (H2) was found only in 3 of them. Low nucleotide diversity (0.00023 ±0.00011) was also found.
The range of TL observed in the present study (31–39.90 cm) was generally congruent with results from Bosphorus area (31–59 cm,
Area | Authors | Length (cm) | Length type | Fishing gear |
---|---|---|---|---|
Black Sea, Turkey | Bilgin et al. 2014 | 65.1 | TL | Surrounding net |
Black Sea, Turkey |
|
60.3 | TL | Surrounding net |
Black Sea, Turkey |
|
58.0 | TL | Purse seine, Surrounding net |
Black Sea, Turkey |
|
58.0 | TL | Purse seine, Surrounding net |
Black Sea, Turkey |
|
52.2 | TL | Surrounding net |
Black Sea, Turkey | Kalayci and Yeşilcicek 2012 | 50.5 | TL | Purse seine, Gillnet |
Black Sea, Turkey |
|
49.5 | TL | Trammel net |
Bosporus, Turkey | Yuce 1975 | 57.5 | FL | Unknown |
Aegean Sea, Greece |
|
27.0 | TL | Beach seine |
Mediterranean Sea, Tunisia |
|
40.1 | TL | Unknown |
Black Sea, Bulgaria |
|
57.9 | TL | Unknown |
Black Sea, Bulgaria | Present Study | 39.9 | TL | Trammel net |
The observation of infrequent growth in total length could be a result of hereditary factors (
The feminine rate of garfish population is dominant with 65% and was higher than that reported for southern Ireland (58.3%:
It was noted that R2 values from the trends (Fig.
Data from the literatures on morphometric relations are comparable since they refer to total body length. However, a study carried out by
Area | Authors | No rays in Dorsal fin (D) | No rays in Pectoral fin (P) | No rays in Anal fin (A) | Vert. |
---|---|---|---|---|---|
Black Sea |
|
14–16 | II/18–20 | ||
Black Sea |
|
II/14–16 | 9–11 | II/18–20 | |
Black Sea |
|
II/14–18 | II/11–12 | II/17–21 | 74–81 |
Mediterranean, Atlantic, Black Sea | Colette and Parin (1986) | 16–20 | 11–14 | 19–23 | 75–84 |
Adriatic Sea |
|
16–19 | 11–14 | 19–23 | 80–81 |
Present study | II/16–19 | I/13–19 | II/19–23 | 80–81 |
Genetic diversity is an important part of biodiversity, and its level reflects the environmental adaptability, evolutionary potential, and viability of species. Haplotype and nucleotide diversity are two important indicators for evaluating population genetic diversity. Low haplotype (0.146) and nucleotide (0.00023) diversity of COI found in Nesebar population could be a result of population decline, probably caused by overfishing. The results indicated that some measures should be taken to protect the resources of Belone belone along the Bulgarian Black Sea coast. The information on genetic diversity and population structure of B. belone are critical for phylogenetic relationships, resource conservation and fisheries management. Suggesting future studies, the genetic diversity analysis of other genetic markers should be supplemented.
The authors have declared that no competing interests exist.
No ethical statement was reported.
This research was supported by the grants: IC-TR/1/2022-2023, Bulgarian Academy of Sciences, TUBITAK-121N777, Scientific & Technological Research Council of Turkey and MASRI (project of the National roadmap for scientific Infrastructure (2020–2027) of Republic of Bulgaria).
Data curation: YR. Formal analysis: PI, MY, ND. Investigation: ND, MY, PI, VR. Methodology: VR, PI, MY, ND. Software: MY. Visualization: MY. Writing - original draft: ND, PI, VR, MY. Writing - review and editing: MY, VR, PI, CT, ND.
Maria Yankova https://orcid.org/0000-0002-3333-7131
Violin Raykov https://orcid.org/0000-0003-4322-6352
Petya Ivanova https://orcid.org/0000-0002-7487-9033
Nina Dzhembekova https://orcid.org/0000-0001-9620-6422
Cemal Turan https://orcid.org/0000-0001-9584-0261
All of the data that support the findings of this study are available in the main text.