Some biological aspects of marbled spinefoot (Siganus rivulatus) were determined from a southern Aegean Sea small-scale fishery. A total of 721 individuals were captured (335 females, 279 males and 87 immature) and sex ratio was found to be 1:1.27, female to male. Total lengths and ages of individuals ranged between 9.0–26.1 cm and 1–9 years. Asymptotic length (L∞), growth coefficient (K) and the theoretical age at zero length (t0) were estimated to be 27.7 cm, K = 0.162 y−1 and t0 = −1.87 y. Length at maturity value was determined as 16.6 cm for females and 16.84 cm for males. Although S. rivulatus is one of the target species for small-scale and recreational fishery in the Turkish coast of the southern Aegean Sea, especially in Gökova Bay, official landing data is lacking for Turkey. Results of the present study are of crucial importance for further fisheries management of this invasive species.

Although both Siganus luridus and Siganus rivulatus have been reported from the Maltese Islands in the literature, and on internet sites and databases, there do not seem to be any specific records of S. rivulatus from these islands. In order to address the question whether both or only one of these alien siganids occur in the Maltese Islands, all records of siganids collected or photographed in Maltese waters were evaluated. Thirteen records comprising at least 33 specimens supported by photographs or specimens and 25 records of 48 individual rabbitfish identified in the field were all S. luridus. This suggests that S. rivulatus does not occur in Maltese waters.