EPS eLibrary: HERMAPHRODITISM IN GREY MULLET (MUGIL CEPHALUS) ALONG THE BULGARIAN BLACK SEA COAST: POTENTIAL CONNECTIONS TO ECOLOGICAL FACTORS

Peer-reviewed articles 17,970 +

Proceedings Cover

Title: HERMAPHRODITISM IN GREY MULLET (MUGIL CEPHALUS) ALONG THE BULGARIAN BLACK SEA COAST: POTENTIAL CONNECTIONS TO ECOLOGICAL FACTORS

Year

2025

BibTex Views:

338

Peer Reviewed

Open this article in the author's DB

<< Back to list

Title

HERMAPHRODITISM IN GREY MULLET (MUGIL CEPHALUS) ALONG THE BULGARIAN BLACK SEA COAST: POTENTIAL CONNECTIONS TO ECOLOGICAL FACTORS

PlumX Article Metrics by Elsevier

Authors

Radoslava Bekova; Viktoriya Vachkova; Borislava Margaritova; Bogdan Prodanov

DOI

10.5593/sgem2025/5.1/s19.017

DOI Issue

10.5593/sgem2025/5.1

ISSN

1314-2704

ISBN

978-619-7603-85-9

Language

English

Volume

Issue

5.1

Editor

• Prof. Dr. hab. oec. Baiba Rivza, LATVIA• Prof. DSc. Ildiko Tulbure, GERMANY• Prof. DSc. Oleksandr Trofymchuk, UKRAINE

Scientific Area

Ecology, Biodiversity, and Environmental Protection

Abstract/ Foreword

Hermaphroditism in the flathead grey mullet (Mugil cephalus), manifested as intersex conditions, is linked to various environmental factors and anthropogenic pressures. Key contributors include exposure to endocrine-disrupting compounds (EDCs), heavy metals, and pollutants that disrupt hormonal regulation, leading to sexual development abnormalities. Research indicates that Mugil cephalus is particularly sensitive to EDCs in coastal and brackish ecosystems. Our findings reveal that 19% of male individuals from the Varna-Beloslav Lakes and the brackish waters at the mouths of the Kamchia, Ropotamo, Karaagach and Veleka Rivers exhibited intersex gonads correlated with elevated levels of organochlorine contaminants in their tissues. Laboratory experiments have shown that exposure to 17ß-estradiol (E2) and ethinylestradiol (EE2) during sexual differentiation can induce feminisation and intersex conditions. In addition to EDCs, heavy metals pose significant genotoxic risks. A study in the Varna-Beloslav Lakes demonstrated that mullets exposed to high concentrations of metals such as Cu²?, Zn²?, and Pb²? exhibited increased frequencies of micronuclei and nuclear anomalies, indicating DNA damage. Climate change further impacts migratory behaviour and reproductive biology, mainly through rising sea surface temperatures. Our study along the Bulgarian Black Sea coast identified warming waters as a significant factor contributing to the decline in Mugil cephalus catches between 2010 and 2024.
The combined effects of pollution and climate change synergistically enhance toxicity and increase contaminant sensitivity, amplifying reproductive risks for Mugil cephalus populations along the Bulgarian Black Sea coast.

References (click to open)

[1] Jobling, S., Nolan, M., Tyler, C.R., Brighty, G. and Sumpter, J.P., (1998). Widespread sexual disruption in wild fish. Environmental Science & Technology, 32(17), pp. 2498–2506. DOI: 10.1021/es980465j
[2] Kidd, K.A., Blanchfield, P.J., Mills, K.H., Palace, V.P., Evans, R.E., Lazorchak, J.M. and Flick, R.W., (2007). Collapse of a fish population after exposure to a synthetic estrogen. Proceedings of the National Academy of Sciences, 104(21), pp. 8897–8901. DOI: 10.1073/pnas.0609568104
[3] Sumpter, J.P. and Johnson, A.C., (2005). Lessons from endocrine disruption and their application to other issues concerning trace organics in the aquatic environment. Environmental Science & Technology, 39(12), pp. 4321–4332. DOI: 10.1021/es048963j
[4] Hinck, J.E., Blazer, V.S., Schmitt, C.J., Papoulias, D.M. and Tillitt, D.E., (2006). Widespread occurrence of intersex in black basses (Micropterus spp.) from U.S. rivers, 1995–2004. Environmental Science & Technology, 40(21), pp. 7551–7558. DOI: 10.1021/es062066m
[5] Blaber, S.J.M., (2000). Tropical estuarine fishes: Ecology, exploitation and conservation. Oxford: Blackwell Science, 384 pp. ISBN: 9780632051759
[6] Guidetti, P., Magnelli, F. and Gramigni, E., (2004). Effects of coastal bottom trawling on the size structure of fish assemblages in the Southern Adriatic Sea (central Mediterranean). Aquatic Conservation: Marine and Freshwater Ecosystems, 14(6), pp. 575–589. DOI: 10.1002/aqc.636
[7] Orlando, E.F., Kolok, A.S., Binzcik, G.A., Gates, J.L., Horton, M.K., Lambright, C.S., Gray Jr., L.E. and Soto, A.M., (2007). Endocrine-disrupting effects of cattle feedlot effluent on an aquatic sentinel species, the fathead minnow. Environmental Health Perspectives, 112(3), pp. 353–358. DOI: 10.1289/ehp.6575
[8] Blasco, J., Muse, J., Ruiz, F., Sáenz, J. and González de Canales, M., (2011). Intersex condition in Mugil cephalus from estuarine areas of the southwestern Spanish coast. Marine Environmental Research, 72(2), pp. 100–105. DOI: 10.1016/j. marenvres.2011.06.002
[9] Zhou, Y., Chen, Y., Hu, Y., Yang, J. and Liu, L., (2014). Effects of 17ß-estradiol and 17a-ethinylestradiol on gonadal development and reproduction in juvenile Mugil cephalus. Environmental Toxicology and Chemistry, 33(5), pp. 1157–1164. DOI: 10.1002/etc.2542
[10] Bologa, A.S., Petranu, A., Gâstescu, P., Dorogan, L., & Tiganov, G., (2000). Environmental state of the Romanian Black Sea coastal zone. Geo-Eco-Marina, 5–6, pp. 145–164.
[11] Kideys, A.E., (2002). Fall and rise of the Black Sea ecosystem. Science, 297(5586), pp. 1482–1484. DOI: 10.1126/science.1073002
[12] Topcuoglu, S., Ergül, H.A., Esen, N. and Kut, D., (2002). Heavy metal and radionuclide levels in fish samples collected from the eastern Black Sea. Marine Pollution Bulletin, 44(10), pp. 1026–1030. DOI: 10.1016/S0025-326X(02)00135-4
[13] Oros, A., Török, Z., Navodaru, I. and Placinta, S., (2010). Mercury, cadmium and lead concentrations in fish from Danube Delta lakes. Environmental Engineering and Management Journal, 9(3), pp. 399–403. [ISSN: 1582-9596]
[14] McDonough, C.J., Roumillat, W.A. and Wenner, C.A., (2003). Fecundity and spawning season of striped mullet (Mugil cephalus L.) in South Carolina estuaries. Fishery Bulletin, 101(4), pp. 822–834.
[15] Bruslé, J., (1981). Sexuality and biology of reproduction of grey mullets. In: O.H. Oren (Ed.), Aquaculture of Grey Mullets, Cambridge University Press, Cambridge, pp. 99–154. ISBN: 9780521228473
[16] Bahamonde, P.A., Munkittrick, K.R. and Martyniuk, C.J., (2013). Intersex in teleost fish: Are we distinguishing endocrine disruption from natural phenomena? General and Comparative Endocrinology, 192, pp. 25–35. DOI: 10.1016/j. ygcen.2013.04.005
[17] Ferreira, M., Moradas-Ferreira, P. and Reis-Henriques, M.A., (2004). The effect of estrogenic compounds on the development of juvenile sea bass (Dicentrarchus labrax L.). Aquatic Toxicology, 68(4), pp. 385–398. DOI: 10.1016/j.aquatox.2004.04.004
[18] Abdelhakim, N.T., El Sayed, A.M., Abdelaziz, M.E., Mekkawy, I.A. and Hegazy, R.E., (2020). Reproductive biology of the flathead grey mullet (Mugil cephalus, Linnaeus 1758) from Bardawil Lagoon, Egypt. The Egyptian Journal of Aquatic Research, 46(1), pp. 11–19. DOI: 10.1016/j.ejar.2019.10.001
[19] Basusta, N., Demirel, N. and Akyol, O., (2021). Age, growth and reproduction of flathead grey mullet (Mugil cephalus) in the eastern Mediterranean Sea (Turkey). Journal of Applied Ichthyology, 37(1), pp. 34–41. DOI: 10.1111/jai.14137
[20] Morozov, A.A., (1964). Biologicheskie osnovy promysla ryb Chernogo morya. Trudy VNIRO, 52, pp. 3–214. (In Russian)
[21] Zhang, Y., Xu, H., Zhao, Y., Wang, X. and Lin, H., (2022). Gonadosomatic indices and seasonal reproductive dynamics in mullet species: Revisiting classical maturity models with updated biometric approaches. Fisheries Research, 253, 106347.DOI: 10.1016/j.fishres.2022.106347
[22] Alonso-Fernández, A., Domínguez-Petit, R., Saborido-Rey, F., (2021). Thermal sensitivity of reproductive timing in marine fish: insights from gonadal development and spawning phenology. Marine Environmental Research, 168, 105307. DOI: 10.1016/j.marenvres.2021.105307
[23] Nikolopoulou, M., Tsiaras, K.P., Triantafyllou, G., Petihakis, G., (2020). Sea surface temperature trends in the eastern Mediterranean and the Black Sea: A 35-year satellite-based perspective. Remote Sensing, 12(10), 1597. DOI: 10.3390/rs12101597
[24] Copernicus Marine Service, (2023). Sea surface temperature anomaly data for the Black Sea (1982–2023). Retrieved from: https://marine.copernicus.eu
[25] Petric, M., Glamuzina, B., Kožul, V., Tutman, P., Skaramuca, B. and Franicevic, M., (2021). Reproductive dynamics of flathead grey mullet (Mugil cephalus) in the southeastern Adriatic Sea. Journal of Sea Research, 169, 102005. DOI: 10.1016/j.seares.2020.102005
[26] Abdelhakim, N.T., El Sayed, A.M., Abdelaziz, M.E., Mekkawy, I.A. and Hegazy, R.E., (2020). Reproductive biology of the flathead grey mullet (Mugil cephalus, Linnaeus 1758) from Bardawil Lagoon, Egypt. The Egyptian Journal of Aquatic Research, 46(1), pp. 11–19. DOI: 10.1016/j.ejar.2019.10.001
[27] Nikolopoulou, M., Tsiaras, K.P., Triantafyllou, G. and Petihakis, G., (2020). Sea surface temperature trends in the eastern Mediterranean and the Black Sea: A 35-year satellite-based perspective. Remote Sensing, 12(10), 1597. DOI: 10.3390/rs12101597
[28] Miladinova, S., Stips, A., Garcia-Gorriz, E. and Macias, D., (2018). Black Sea thermohaline properties: Long-term trends and variations. Journal of Marine Systems, 180, pp. 17–28. DOI: 10.1016/j.jmarsys.2018.01.005
[29] Alonso-Fernández, A., Domínguez-Petit, R. and Saborido-Rey, F., (2021). Thermal sensitivity of reproductive timing in marine fish: Insights from gonadal development and spawning phenology. Marine Environmental Research, 168, 105307. DOI: 10.1016/j.marenvres.2021.105307
[30] Dufour, S., Weltzien, F.A., Sebert, M.E., Le Belle, N. and Vidal, B., (2010). Seasonal control of reproduction in teleosts: lessons from the female European eel (Anguilla anguilla). Annals of the New York Academy of Sciences, 1200(1), pp. 105–115. DOI: 10.1111/j.1749-6632.2010.05556.x
[31] Blazer, V.S., Iwanowicz, L.R., Iwanowicz, D.D., Smith, D.R., Young, J.A., Hedrick, J.D. and Reeser, S.J., (2007). Intersex (testicular oocytes) in smallmouth bass from the Potomac River and selected nearby drainages. Journal of Aquatic Animal Health, 19(4), pp. 242–253. DOI: 10.1577/H07-031.1
[32] Barone, G., Gioia, I., Storelli, M.M. and Garofalo, R., (2020). Occurrence of endocrine-disrupting compounds in fish from Apulia (Southern Italy) and their potential risk. Environmental Science and Pollution Research, 27, pp. 34591–34601.DOI: 10.1007/s11356-020-09569-2
[33] Jobling, S., Beresford, N., Nolan, M., Rodgers-Gray, T., Brighty, G.C., Sumpter, J.P. and Tyler, C.R., (2009). Altered sexual maturation and gamete production in wild roach (Rutilus rutilus) living in rivers that receive treated sewage effluents. Biology of Reproduction, 79(5), pp. 831–841. DOI: 10.1095/biolreprod.108.074674
[34] Hinfray, N., Palluel, O., Piccini, B., Sanchez, W., Aït-Aïssa, S., Noury, P., Gomez, E. and Brion, F., (2010). Endocrine disruption in wild populations of chub (Leuciscus cephalus) in contaminated French streams. Science of The Total Environment, 408(9), pp. 2146–2154. DOI: 10.1016/j.scitotenv.2009.12.045
[35] Scholz, S. and Klüver, N., (2009). Effects of endocrine disrupters on sexual, gonadal development in fish. Sexual Development, 3(2–3), pp. 136–151. DOI: 10.1159/000223077

Acknowledgements (click to open)

The presented surveys discussed herein were supported financially by the project “Citizen Science for Reducing Anthropogenic Litter on the Seabed, Beaches, and Dunes along the Bulgarian Black Sea Coast”, part of the scientific research program of the DERTOUR FOUNDATION, Germany.

Type

conference

Url

https://doi.org/10.5593/sgem2025/5.1/s19.017

Full manuscript

Download PDF

HERMAPHRODITISM IN GREY MULLET (MUGIL CEPHALUS) ALONG THE BULGARIAN BLACK SEA COAST: POTENTIAL CONNECTIONS TO ECOLOGICAL FACTORS

Proceedings Тitle

Proceedings of 25th International Multidisciplinary Scientific GeoConference SGEM 2025, Volume 25, Issue 5.1

Note

25th International Multidisciplinary Scientific GeoConference SGEM 2025, Volume 25, Issue 5.1, 29 June - 6 July, 2025

Type

Proceedings Paper

Publisher

STEF92 Technology

Series

International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM

Organization

SWS Scholarly Society; Acad Sci Czech Republ; Latvian Acad Sci; Polish Acad Sci; Russian Acad Sci; Serbian Acad Sci and Arts; Natl Acad Sci Ukraine; Natl Acad Sci Armenia; Sci Council Japan; European Acad Sci, Arts and Letters; Acad Fine Arts Zagreb Croatia; Croatian Acad Sci and Arts; Acad Sci Moldova; Montenegrin Acad Sci and Arts; Georgian Acad Sci; Acad Fine Arts and Design Bratislava; Russian Acad Arts; Turkish Acad Sci.

Pages

139-154

Date

29 June - 6 July, 2025

Online Source Type

website

Digital Source Type

10459

Keywords

Mugil cephalus, reproductive biology, Black Sea, gonadosomatic index, intersex, SST, endocrine disruption