Table 1. Generalized environmental conditions at the sampling (specimen collection) sites.

Sample code	Country	Region	First report	Location	Coordinates	Temperature	Sunlight	Rainfall	Habitat	Salinity	Pollution
Xenostrobus securis
XCant	Spain	South Bay of Biscay	201426	Aviles estuary	43° 33′ 22″N, 5° 55′ 20″W	9.6 (6.8–19.8)	1,670	1,048	Marina, international port	29.3 (17.9–35.8)	Urban, industrial
XAtl	Spain	Northwest Spain	200253	Pontevedra estuary	42° 26′ 7.6″N, −8° 38′ 56″W	14.8 (10.4–19.2)	2,247	1,613	Marina, international port	33 (31.5–35)57	Urban, industrial
XMed	France	Mediterranean Sea	199254	Vidourle Lagoon	43°34′42.14″N 4°02′34.98″E	15.1 (10.4–19.9)	2,668.2	629.1	Lagoon/Natura 2000 Network	23.9 (20.4–27.3)58	Urban, eutrophication
Ficopomatus enigmaticus
FCant	Spain	South Bay of Biscay	1920s30	Llanes	43°25′16″N, 4°45′11″W	13.5 (9.9–17.1)	1,756	1,062	Marina, small fishing port	25.2 (21.4–29.5)	Urban, small village
FMed	France	Mediterranean Sea	194759	Saint-Nazaire Lagoon	42°38′49.25″ N 3°01′27.75″ E	15.7 (11.4–20.1)	2,464.9	557.6	Lagoon/Natura 2000 Network	20.4 (5.55–35.2)60	Urban, eutrophication61
FNZ	New Zealand	South Pacific Ocean	196762	Napier, Hawke’s Bay	39°29′S 176°55′E	16.4 (12.2–22.1)	2,281	809.7	Marina, international port	34–3563	Urban, industrial

In the sample code ‘X’ refers to X. securis samples and ‘F’ to F. enigmaticus samples. International ports receive >one million annual cargo tons. Temperature, average annual temperature in °C (min-max); sunlight, average sunlight hours per year; rainfall, annual rainfall in mm; salinity in ppm (min-max).