[3][4] This common species is found in the northeast Atlantic, the Mediterranean, and the Black Sea at depths of 10–100 m (33–328 ft).

Its range extends from Iceland and the southern part of Norway and Sweden southwards to Senegal in West Africa.

Under this genus, Gunther (1868) gave a general description of a terminal mouth, minute or absent teeth, a complete midventral series of scutes, and an anal fin.

This role is particularly noticeable in the Adriatic Sea where the water is shallow, the food chain is shorter and energy is retained within the basin; overfishing of pilchard and anchovy can thus cause dramatic changes in the ecosystem.

A study by Fuentes et al. (2022) show that the consumption of S. pilchardus poses an unlikely health hazard for parasite infection of Anisakis spp., even when consumed raw or lack of adequate preparation through freezing.

But as with all fish consumed raw, proper precautions should be taken, such as consumption of sardines caught in the Mediterranean and smaller specimens.

[11] Little is known about status of the stock of S. pilchardus despite the economic dependency on the surrounding nations, particularly in the West African region [9].

According to Baldé et al. (2022), "plasticity in the growth performance, survival, and other life-history characteristics […] is the key to their dynamics."

The United Kingdom's Sea Fish Industry Authority, for example, classifies sardines as young pilchards.

[19] However, this has been challenging for researchers to definitively claim due to large population sizes and the sardine’s high dispersal ability.

[20] Due to possible homozygote excess and null alleles, most loci showed differences from the Hardy-Weinberg Equilibrium.

Further tests showed that the S. pilchardus populations from across nine locations over the Atlantic Ocean and Mediterranean Sea act as one evolutionary unit.

[19] Mitochondrial and micro-satellite analyses of the Sp2, Sp7, Sp8 and Sp15 loci with biologic parameter and genetic analysis show homogeneity in the Atlantic Moroccan coast population of S. pilchardus.

In Baibai et al. (2017)’s biologic and morphometric analysis, they found high variability within the stocks of the Moroccan Atlantic, with two distinct morphological groups that are geographically separated in the Northwest African Coast and South region of Morocco.

Of note, loci Sp2 and Sp8 carried a high number of private alleles, although this is consistent with other marine fishes.

Due to homozygote excess and null alleles, significant values of the inbreeding coefficient, Fis, was found in Safi, Malaga, and Cadiz.

This subarea has also had a decline in older fish which limits the plasticity of sardines to environmental changes and thus affects spawn quality.

The study found that because reproduction is dependent availability of resources, the Northern Adriatic population’s storage period is not as distinctive as other stocks.

[21] Northern Alboran stock was recorded to show earlier gonad maturation in the summer than their Atlantic neighbors.

The authors speculate individuals from the Atlantic swim into the Mediterranean, spawn, and the drop in temperature along the Alboran coast favors sardine nursery grounds.

The authors urge for close monitoring of the Northern Spain sardine population due to rapid environmental change vulnerability and heavy fishing pressures.

[21] In a more recent study, analysis of the genome of the European sardine S. pilchardus and mitochondrial data revealed evidence of at least three genetic clusters within the natural range (Eastern Mediterranean to the Azores archipelago).