European Sprat

The European sprat is a small fish growing to a maximum length of 16 cm (6.3 in), but more often in the 8–12 cm (3.1–4.7 in) range. It is fairly elongate and rather laterally compressed, with a keel-like row of sharp scales along the belly. The lower jaw projects slightly, there are rarely any vomerine teeth on the roof of the mouth and the hind edge of the gill covers is smoothly rounded, without any fleshy protuberances. The dorsal and anal fins have no spines, and contains 13-21 and 12-23 soft rays respectively. The origin of the pelvic fins, which have 7 (occasionally 8) soft rays, is immediately below or in front of the dorsal-fin origin. This fish has a bluish or greenish back and silvery flanks, with no dark spotting.

The European sprat is native to the northeastern Atlantic Ocean. Its range includes the Baltic Sea, the North Sea, southern Norway and Sweden, the coasts of the British Isles, the Iberian Peninsula, Morocco, the Mediterranean Sea (including the Adriatic Sea) and the Black Sea. It occurs both in open water well away from the coast and in bays and estuaries, being able to tolerate salinities as low as 4 parts per thousand. It is a schooling fish (like many other species in its family) and migrates between its winter feeding grounds and its summer breeding grounds. The European sprat also makes vertical migrations, rising to near the surface at night to feed.

Adult European sprats feed on copepods, such as species in the genera Calanus, Pseudocalanus and Temora; on the other hand, juveniles feed on the eggs and larvae of these crustaceans, and on diatoms. Breeding takes place at any time of the year, but peaks between December and April in the Mediterranean and between April and August in the Baltic Sea and northeastern Atlantic. Spawning may take place in inshore waters or up to 100 km (60 mi) off the coast. This fish is sometimes parasitised by the copepod Lernaeenicus sprattae. That animal burrows into the eyes of the European sprat, causing loss of visual acuity or even blindness. Heavy infestations can even result in death.