The role of recruitment and behaviour in the formation of mussel-dominated assemblages: an ontogenetic and taxonomic perspective

Abstract

experiments showed that recruits of all sizes responded to adult cues by movement, but that the smallest recruits showed only minimal movement and never reached adults; only large recruits of Perna responded positively to conspecific Perna adults. This study emphasises how observations made at different scales, from shore (among sites) to mussel bed (within shores), to the individual (field and laboratory), can produce different, or even contrasting, information, highlighting how behavioural traits, like attraction to conspecifics, can differ within the same group of organisms (congeneric species) and change ontogenetically within a species. Incorporating fine-scale responses makes predictions of population dynamics more complex, but identifying the relative strengths of mechanisms that lead to patterns of distribution is necessary for understanding higher-level interactions within a system.

Differential effects of adult mussels on the retention and fine-scale distribution of juvenile seed mussels and biofouling organisms in long-line aquaculture

“…Note different scales on the y-axes duction) or competition for food. Alternatively, juvenile mussels might have moved towards the adults that were mostly attached to the polypropylene rope (Porri et al 2016). Movement of juveniles towards adults would provide support for the original hypothesis that adults might have some influence on the retention of juveniles, but the number of mussels undertaking such movements was insufficient to have any effect on the number of mussels retained during the course of this experiment.…”

“…Behavioural responses to physi-cal and chemical properties of the substratum can be important determinants of secondary settlement location in mussels (Alfaro et al 2004, von der Meden et al 2010. For example, juvenile Perna perna actively seek out adult conspecifics over small (cm) scales (Cáceres-Martínez et al 1994, Erlandsson et al 2008, Porri et al 2016). The mechanisms used by juveniles to remotely locate adult mussels is unknown, but is likely to be a waterborne chemical cue, as has been observed for the primary larval settlement in a range of invertebrates, including mussels (Anderson 1996, Steinberg et al 2002, de Vooys 2003, Alfaro et al 2006, Morello & Yund 2016.…”

Species coexistence in resource-limited patterned ecosystems is facilitated by the interplay of spatial self-organisation and intraspecific competition

“…(Gravel et al 2010;Hassell et al 1994;Horn and R. H. MacArthur 1972;Levins and Culver 1971;Tilman 1994)). By contrast, the theoretical model presented in this paper captures species coexistence within single colonised patches, in agreement with field observations of different patterned ecosystems (Babarro and Comeau 2014;Bekker 2005;Porri et al 2016;Reise et al 2017;Seghieri et al 1997;Valentin et al 1999). Moreover, it also captures both the migration of consumer bands in the direction opposite to the unidirectional resource flow and the spatial species distribution within single stripes (Fig.…”

“…However, species coexistence occurs in many ecosystems despite competition for a single resource (e.g. (Babarro and Comeau 2014;Porri et al 2016;Reise et al 2017;Seghieri et al 1997;Valentin et al 1999)). Hence, this suggests that other processes prevent resource monopolisation by one species and thus enable coexistence in these ecosystems (McPeek 2012).…”

“…Moreover, despite the environmental stress associated with these ecosystems, occurrence of species coexistence on the scales of single colonised patches have been reported. In dryland vegetation patterns, herbaceous species typically coexist with shrubs or trees (Seghieri et al 1997;Valentin et al 1999); ribbon forests in the Rocky Mountains feature spruces (Picea engelmannii ) and firs (Abies lasiocarpa) (Bekker and Malanson 2008;Hiemstra et al 2006); and Pacific oysters (Magallana gigas) and blue mussels (Mytilus edulis) form mussel beds in the Wadden Sea (Reise et al 2017), with coexistence of different species being reported from other geographical locations (Babarro and Comeau 2014;Porri et al 2016).…”