Differences in the macrozoobenthic fauna colonising empty bivalve shells before and after invasion by Corbicula fluminea

Abstract

Bivalve shells can potentially alter the structure of aquatic benthic communities. However, little is known about the effect that different shell morphologies have on their associated fauna. This study aimed to understand how empty shells, from four different freshwater bivalve species, affect macrozoobenthic communities, using the River Minho (Iberian Peninsula) as a study area. Three native (Anodonta anatina, Potomida littoralis, Unio delphinus) and one non-indigenous (Corbicula fluminea) species were used for this research. Comparisons among species and between scenarios (i.e. before and after invasion by C. fluminea) were performed. Our results suggest that macrozoobenthic community structure did not vary among treatments, with the exception of species richness, which was higher on shells of native species. Furthermore, little difference was detected when comparing scenarios with and without C. fluminea shells, despite dissimilarities in size and morphology between species. The empty shells of C. fluminea partially (in terms of density and biomass, but not in species richness) replaced the role of empty shells of native species as a physical substratum for the associated macrozoobenthic community.

Decay and persistence of empty bivalve shells in a temperate riverine system

“…However, the water flow differs between sites, with L1 located in the main canal of the Minho River and being characterized by a fastflowing (lotic) water regime during the entire year with the exception of summer and early autumn and L2 located in a side arm of the Minho River and being characterized by a slow-flowing (lentic) water regime throughout the entire year. The classification of sites according to the water flow conditions was done qualitatively, based on previous studies performed in the study area (Sousa et al, 2007(Sousa et al, , 2008Ilarri et al, 2015aIlarri et al, , 2015bIlarri et al, , 2018Novais et al, 2017) and on empirical evidence of the water regime throughout the study period (authors personal observations).…”

“…They provide suitable substrate for attachment and refuge for many species, reduction of the physical and/or physiological stress, and also as reservoirs of nutrients to the benthic compartment (Gutiérrez et al, 2003;Ilarri et al, 2012Ilarri et al, , 2015bIlarri et al, , 2018Wenger et al, 2019). In fact, in previous studies performed in the Minho River it was possible to observe that the shells of the selected species attracted a relevant and similar macrozoobenthic community (Ilarri et al, 2015b). As showed by the results of the present study, shell decays can be context dependent being important the study of the factors that influence their availability in the ecosystems.…”

Physical legacy of freshwater bivalves: Effects of habitat complexity on the taxonomical and functional diversity of invertebrates

“…They can alter the physical structure of the benthic environment through their shells in creating colonizable biogenic substrate for several species (Gutiérrez et al, 2003;Bódis et al, 2014;Burdon et al, 2014). The substratum provided by the presence of bivalve shells are used by the associated fauna to avoid predators and competitors (Ilarri et al, 2012(Ilarri et al, , 2014(Ilarri et al, , 2015a, as well as to reduce the physical and/or physiological stress as they can be responsible for changes in the current velocity (Gutiérrez et al, 2003;Erwin, 2008).…”

Assessing the effects of temperature and salinity oscillations on a key mesopredator fish from European coastal systems

“…The estuarine fauna is dominated by the European green crab (Carcinus maenas) and the common goby on the epibenthic compartment (Dias et al, 2010;Dolbeth et al, 2010;Souza et al, 2014;Mota et al, 2014), while two non-indigenous species (NIS), the Asian clam (Corbicula fluminea) and the red swamp crayfish (Procambarus clarkii), are the dominant macroinvertebrates in the study area (Sousa et al, 2008a;. In fact, Minho estuary have been invaded by several aquatic NIS in the last decades, which impacted the system in various ways (Sousa et al, 2008b;Mota et al, 2014;Novais et al, 2015;, Ilarri et al, 2015a).…”