The genus Spongites (Corallinales, Rhodophyta) in South Africa

Abstract

Coralline red algae (Corallinales, Hapalidiales, Sporolithales: Corallinophycidae, Rhodophyta) are widespread and common in all the world’s oceans (Adey & McIntyre 1973; Johansen 1981; Littler et al. 1985; Björk et al. 1995; Aguirre et al. 2007; Harvey & Woelkerling 2007; Littler & Littler 2013). They achieve their highest diversity in the tropics and subtropics (Björk et al. 1995; Littler & Littler 2013; Riosmena-Rodríguez et al. 2017), and within the photic zone of rocky shores (Lee 1967; Littler 1973; Adey 1978; Adey et al. 1982; Steneck 1986; Kendrick 1991; Kaehler & Williams 1996; Gattuso et al. 2006; van der Heijden & Kamenos 2015; Riosmena-Rodríguez et al. 2017) where they serve as important carbonate structures (Adey et al. 1982; Littler & Littler 1994, 1997; Vermeij et al. 2011) and habitats for a host of marine species (Foster 2001; Amado-Filho et al. 2010; Foster et al. 2013; Littler & Littler 2013; Riosmena-Rodríguez et al. 2017). Coralline algae are resilient, inhabiting extreme conditions that include: low temperatures (Adey 1970, 1973; Freiwald & Hendrich 1994; Barnes et al. 1996; Freiwald 1996; Aguirre et al. 2000; Roberts et al. 2002; Björk et al. 2005; Martone et al. 2010); limited light exposures (Adey 1970; Littler & Littler 1985; Littler et al. 1985; Liddell & Ohlhorst 1988; Dullo et al. 1990; Littler & Littler 1994; Iryu et al. 1995; Stellar and Foster 1995; Gattuso et al. 2006; Aguirre et al. 2007; Littler & Littler 2013); severe wave action (Steneck 1989; Littler & Littler 2013); intense grazing pressures (Steneck 1989; Steneck & Dethier 1994; Maneveldt & Keats 2008; Littler & Littler 2013), highly fluctuating salinities (Harlin et al. 1985; Barry & Woelkerling 1995; Barnes et al. 1996; Wilson et al. 2004); including occurring in freshwater (Žuljevic et al. 2016), and constant sand scouring (Littler & Littler 1984; D’Antonio 1986; Kendrick 1991; Chamberlain 1993; Dethier 1994).