Fig 1.
Distribution of Semimytilus algosus in Angola and Namibia by 1969.
Broad direction of coastal currents, the Angola Current (pink arrow) and the Benguela Current (blue arrow) are indicated on the map. Data can be found in S1 Appendix.
Fig 2.
Distribution of Semimytilus algosus in Angola and Namibia by 2019 showing (1) a recent detection in northern Angola, (2) historical spread in northern Namibia (ranging from central Namibia to southern Angola), (3) records from a previously unsurveyed region consisting of relatively established populations, (4) records from Lüderitz and vicinity consisting of small transient populations, and (5) a recent introduction to southern Namibia and local spread (e.g., spreading as far south as Alexanderbaai in northern South Africa). Years mark temporal changes in distribution. Broad direction of coastal currents, the Angola Current (pink arrow) and the Benguela Current (blue arrow) are indicated on the map. Data from Angola and Namibia can be found in S1 Appendix; data from northern South Africa were extracted Ma et al. [36].
Table 1.
Increase in the distributional range (spread) and the estimated rate of spread of Semimytilus algosus in Angola and Namibia.