A non-native macroalga is less attractive for herbivores but more susceptible to light limitation and grazing stress than a comparable native species

Table 2 Effects of grazing and light intensity on the consumption of the native Stypopodium zonale and the non-native Grateloupia imbricata by Paracentrotus lividus as assessed in no-choice feeding assays

Source of variation	SS	df	MS	F	p
Stypopodium zonale
Grazing	<0.001	1	<0.001	15.302	<0.001
Light	<0.001	5	<0.001	1.856	0.111
Light × Grazing	<0.001	5	<0.001	2.451	0.040
Grateloupia imbricata
Grazing	<0.002	1	<0.002	6.130	0.015
Light	<0.002	5	<0.001	1.102	0.365
Light × Grazing	0.002	5	<0.001	1.610	0.166

ISSN: 1438-3888