Notes on the occurrence and ecology of Saduriella losadai (Isopoda: Chaetiliidae) in the Minho River estuary (NW Iberian Peninsula)

Nuno Gomes; Carlos Antunes

doi:10.3989/graellsia.2025.v81.792

Authors

Nuno Gomes Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto - Faculdade de Ciências, Universidade do Porto (FCUP) https://orcid.org/0000-0002-5513-6875
Carlos Antunes Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto - Aquamuseu do Rio Minho https://orcid.org/0000-0003-3736-5743

DOI:

https://doi.org/10.3989/graellsia.2025.v81.792

Keywords:

Isopoda, Saduriella losadai, estuaries, environmental factors, migration

Abstract

Ecological aspects, habitat preferences, demographic structure, migration patterns and productivity of the isopod Saduriella losadai were analysed from monthly sediment samples and by-catch in glass eel fishery in the Minho River estuary. This species is typically distributed within the mesohaline-oligohaline boundary, so salinity plays a large role in the distribution of this species within the estuary, with sandy sediments having higher densities. High temperatures and saline intrusion have been shown to hinder the population growth. Adult populations were strongly female-biased. Two peaks in juvenile recruitment have been recorded with higher densities occurring in the spring-summer season. Tidal drift during flood tides is used as a mean of migration. Juvenile migrations to freshwater environments occur in late spring and summer seasons and are dependent on salinity increases. Juvenile migrations to the lower estuary occur in the autumn and mature adults migrate back in the winter before the reproductive season. There was a sharp decline in abundance compared with data collected 40 years ago for the same study area, but further studies are needed to confirm the trend.

Downloads

Download data is not yet available.

References

Baldó, F., Megina, C. & Cuesta, J.A., 2000. Saduriella losadai Holthuis, 1964 (Isopoda, Valvifera) in the Guadalquivir Estuary (S.W. Spain). Crustaceana 73 (8): 1015-1017. https://doi.org/10.1163/156854000504921

Bowman, T.E., 1955. The isopod genus Chiridotea Harger, with a description of an new species from brackish waters. Journal of the Washington Academy of Science, 45: 224-229.

Cabral, H.N., 2000. Comparative feeding ecology of sympatric Solea solea and S. senegalensis, within the nursery areas of the Tagus estuary, Portugal. Journal of Fish Biology, 57: 1550-1562. https://doi.org/10.1111/j.1095-8649.2000.tb02231.x

Chainho, P., Costa, J.L., Chaves, M.L., Lane, M.F., Dauer, D.M. & Costa, M.J., 2006. Seasonal and spatial patterns of distribution of subtidal benthic invertebrate communities in the Mondego River, Portugal - a poikilohaline estuary. In: Martens, K. et al. (Eds.), Marine Biodiversity. Developments in Hydrobiology, vol 183, Springer, Dordrecht. https://doi.org/10.1007/1-4020-4697-9_6

Costa, J.L., Assis, C.A., Almeida, P.R., Moreira, F.M. & Costa, M.J., 1992. On the food of the European eel, Anguilla anguilla (L.), in the upper zone of the Tagus estuary, Portugal. Journal of Fish Biology, 41: 841-850. https://doi.org/10.1111/j.1095-8649.1992.tb02712.x

Cunha, M., Sorbe, J. & Moreira, M., 1999. Spatial and seasonal changes of brackish peracaridan assemblages and their relation to some environmental variables in two tidal channels of the Ria de Aveiro (NW Portugal). Marine Ecology Progress Series 190: 69-87. https://doi.org/10.3354/meps190069

Hammer, Ø., Harper, D.A.T. & Ryan, P.D., 2001. PAST: Paleontological statistics software package for education and data analysis. Palaeontologia Electronica 4 (1): 1-9.

Holthuis L.B., 1964. Saduriella, a new genus of Isopoda Valvifera from northwestern Spain. Zoologische Mededelingen, 40 (6): 29-35. Available from https://repository.naturalis.nl/pub/319060 [accessed 16 Oct. 2025].

Ilarri, M.I., Souza, A.T., Antunes, C., Guilhermino, L. & Sousa, R., 2014. Influence of the invasive Asian clam Corbicula fluminea (Bivalvia: Corbiculidae) on estuarine epibenthic assemblages. Estuarine, Coastal and Shelf Science 143: 12-19. https://doi.org/10.1016/j.ecss.2014.03.017

King, R.A. & Cawood, A.M., 2007. A Revision of the genus Chiridotea (Isopoda: Chaetiliidae) with species Rredescriptions and a ley. Journal of Crustacean Biology, 27 (1): 121-139. https://doi.org/10.1651/S-2708.1

Kuris, A.M. 1991. A review of patterns and causes of crustacean brood mortality. In: Wenner & Kuris (Eds.), Crustacean Issues Vol. 7. Crustacean egg production, ed. Wenner and Kuris, Balkema, Rotterdam, Netherlands.

Martins, I., Dias, E., Ilarri, M.I., Campuzano, F.J., Pinto, L., Santos, M.M. & Antunes, C., 2019. Antagonistic effects of multiple stressors on macroinvertebrate biomass from a temperate estuary (Minho estuary, NW Iberian Peninsula). Ecological Indicators 101: 792-803. https://doi.org/10.1016/j.ecolind.2019.01.065

Mazé, R.A., Lastra, M. & Mora, J., 1993. Macrozoobentos del estuario del Miño (NO de España). Publicaciones Especiales, Instituto Español de Oceanografía 11: 283-290.

Morin, A. & Bourassa, N., 1992. Modèles empiriques de la production annuelle et du rapport P/B dʼinvertébrés benthiques dʼeau courante. Canadian Journal of Fisheries and Aquatic Sciences 49: 532-539. https://doi.org/10.1139/f92-063

Rodrigues, A.M., Meireles, S., Pereira, T., Gama, A. and Quintino, V. 2006. Spatial patterns of benthic macroinvertebrates in intertidal areas of a Southern European estuary: the Tagus, Portugal. In: Martens, K. (Ed.), Marine Biodiversity. Developments in Hydrobiology, 183. Springer, Dordrecht. https://doi.org/10.1007/s10750-005-1109-1

Sánchez-Moyano, J.E. & García-Asencio, I., 2011. Crustacean assemblages along the Guadiana River estuary (south-western Iberian Peninsula). Journal of the Marine Biological Association of the United Kingdom 91 (1): 127-138. https://doi.org/10.1017/S0025315410001074

Sousa, R., Guilhermino, L. & Antunes, C., 2005. Molluscan fauna in the freshwater tidal area of the Minho River estuary, NW of Iberian Peninsula. Annales de Limnologie-International Journal of Limnology 41: 141-147. https://doi.org/10.1051/limn/2005009

Weber, M., 1985. Zur Ökosystemstruktur des Minhoästuars, Iberische Westküste. PhD thesis. University of Kiel.

Weber, M., 1986. Fishing method and seasonal occurrence of glass eels (Anguilla anguilla L.) in the Rio Minho, west coast of the Iberian Peninsula. Vie et Milieu, 36: 243-250.