Image: João Pedro Marques ©
Species description and status: The meagre, Argyrosomus regius (Asso, 1801), is one of the largest members of the Sciaenidae taxonomic family (257 sp.), growing up to 2 meters and commonly over 50 kg1,2. Visual identification is easily possible through simple morphological characteristics. The coloration is silver to golden brown with violet reflections further in the dorsal region. The lateral line scales are very conspicuous standing out from the remainder of lateral scales and extends from the head to the end of the truncated caudal fin. Dorsal fins base is black. The mouth is yellow, with two or three lines of sharp and irregularly sized teeth, adapted to capture and hold difficult prey. A remarkable aspect in this species and taxonomic family is the well-developed set of sonic muscles and gas bladder, usually larger in males, allowing the production of very intense sounds during spawning season or stressful circumstances3,4.
The meagre is a long-lived species, with high fecundity, high recruitment variation and multiple spawning events, following a “periodic strategist” life-history5. It is a marine migratory species with a wide distribution range encompassing the NE Atlantic Ocean, the Mediterranean Sea, and the western Black Sea and migrated to the Red Sea via the Suez Canal (Figure 1)3,6,7 . In European waters, meagre is mostly observed in estuaries and adjacent coastal areas. Adults congregate in specific estuaries during the spawning season from late spring to mid-summer, returning to offshore habitats for feeding and overwintering. Juveniles grow on the spawning grounds until autumn and are thought to migrate to near-shore waters, occasionally visiting nursery sites. Much of the current knowledge on the migratory behavior and distribution of the meagre is derived from commercial and recreational fisheries catches3,8,9,10.
Figure 1. Distribution of the meagre, Argyrosomus regius, in the East Atlantic and Mediterranean Sea (From:11).
Despite a successful life-history strategy, the reproductive aggregations, together with high economical value and large size of the meagre, are leading to a dedicated fishing effort in spawning and nursery areas1. IUCN status for the meagre is “Least Concern”, but spawning adults are in decline. Other Sciaenidae with similar life-history strategy and migratory behavior face serious decline due to persistent fishing effort on estuaries (spawning and nursery sites), e.g. Bahaba taipigensis, Totoaba macdonaldi and A. japonicus “Critically endangered”12,13,14. The seeming risks of vulnerability, together with the paucity of current data and difficulties in applying analytical stock assessment models underscore an urgency to search for innovative alternatives that can inform management and safeguard the species sustainability1.
- Population structure and connectivity across the distribution range;
- Determination of estuarine recruitment contribution to adult populations and to the species success;
- Data-poor on adults’ habitat distribution during the overwintering period;
- Data-poor on the overlapping habitat-use of estuaries and nearshore coastal waters by juvenile meagre;
Regions of interest: Spawning and nursery habitats of Europe (e.g. France, Spain and Portugal), North Africa (e.g. Morocco and Mauritania), and Mediterranean Sea (e.g. Egypt).
Telemetry tools: Different telemetry tools such as acoustic telemetry, data storage tags (DST) and pop-up satellite archival tags, are being applied to study juvenile and adult meagre migrations.
Benefits within ETN: Studies targeting meagre migrations are being developed in Portugal in the framework of ongoing projects (MIGRACORV, BECORV and FISHNOISE). The Portuguese Tracking Network, deployed in the framework of the CoastNet infrastructure (https://coastnet.pt/), a national network which is part of ETN, will allow the evaluation of the areas used by juveniles as nursery habitats, and by adults spawning habitat, including the movements between estuaries and adjacent coastal areas. The ETN infrastructure covers the European distribution range of the species. Moreover, previous studies have identified a population cluster in European waters, and uncommon segregation for a marine large-bodied long-lived species. Therefore, ETN is considered a very promising tool to clarify meagre population structure and connectivity between regions.
1 Maigret J. & Ly B. (1986). Les poissons de mer de Mauritanie. Science Nat, Compiègne. 213 p.
2 Prista N. (2013). Argyrosomus regius (Asso, 1801) fishery and ecology in Portuguese waters, with reference to its relationships to other European and African populations. Doctoral Thesis, University of Lisbon, Lisbon. 257p.
3 Quéméner L. (2002). Le Maigre Commun (Argyrosomus regius) - Biologie, Pêche, Marché et Potentiel Aquacole. IFREMER, Plouzané, France. [In French.].
4 Pereira B.P., Vieira M., Pousão-Ferreira P., Candeias-Mendes A., Barata M., Fonseca P.J. & Amorim M.C.P. (2020). Sound production in the Meagre, Argyrosomus regius (Asso, 1801): intraspecific variability associated with size, sex and context. PeerJ 8, e8559.
5 Cheung W. W. L., Watson R., Morato T., Pitcher T. J. & Pauly D. (2007). Intrinsic vulnerability in the global fish catch. Marine Ecology Progress Series 333, 1-12.
6 Quéro J-C. & Vayne J-J. (1987). Le maigre, Argyrosomus regius (Asso, 1801) (Pisces, Perciformes, Sciaenidae) du Golfe de Gascogne et des eaux plus septentrionales. Revue des Travaux de l'Institut des Peches Maritimes 49, 35-66.
7 Quéro J. C. (1989). Sur la piste des maigres Argyrosomus regius (Pisces, Sciaenidae) du Golfe de Gascogne et de Mauritanie. Océanis 15, 161-170.
8 Prista N., Jones C. M., Costa J. L. & Costa M. J. (2008). Inferring fish movements from small-scale fisheries data: the case of Argyrosomus regius (Sciaenidae) in Portugal, 19 p. ICES CM/K-19, Copenhagen, Denmark.
9 González-Quirós R., del Árbol J., García-Pacheco M. M., Silva A., Naranjo J. M. & Morales-Nin B. (2011). Life history of the meagre Argyrosomus regius in the Gulf of Cádiz (SW Iberian Peninsula). Fisheries Research 109, 140-149.
10 Morales-Nin B., Geffen A. J., Pérez-Mayol S., Palmer M., González-Quirós R., & Grau A. (2012). Seasonal and ontogenic migrations of meagre (Argyrosomus regius) determined by otolith geochemical signatures. Fisheries Research 127–128, 154-165.
11 Pollard, D.A., Yokes, B., Kara, M., Bizsel, K. & Quignard, J.P. (2015). Argyrosomus regius. The IUCN Red List of Threatened Species 2015: e.T198706A49227019. http://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T198706A49227019.en
12 Sadovy Y. & Cheung W. L. (2003). Near extinction of a highly fecund fish: The one that nearly got away. Fish and Fisheries 4, 86-99.
13 Valenzuela-Quiñonez F., Arreguín-Sánchez F., Salas-Márquez S., García-De León F., Garza J., Román-Rodríguez M. & De-Anda-Montañez J. (2016). Critically endangered totoaba Totoaba macdonaldi: signs of recovery and potential threats after a population collapse. Endangered Species Research 29, 1-11.
14 Mirimin L., Macey B., Kerwath S., Lamberth S., Bester-van der Merwe A., Cowley P., Bloomer P., Roodt-Wilding R. (2015) Genetic analyses reveal declining trends and low effective population size in an overfished South African sciaenid species, the dusky kob (Argyrosomus japonicus). Marine and Freshwater Research 67, 266-276.