Nothing is known about the TMRCA between Sprattus and Clupea, thus a uniform prior between 60 and 10 millions of years ago (Mya) was chosen, with an initial value of 30 Mya.
Clupea pallasii (GenBank accession number NC009578) was used as an outgroup to root all trees.
Clupea pallasii (GenBank accession number NC009578) was used as an outgroup to root the tree.
Clupea pallasii (GenBank accession number NC009578) was used as an outgroup to root both types of tree.
- Several species of fish (sprat Sprattus sprattus, sardine Sardina pilchardus, and herring Clupea harengus) have similar cell structures: broadband guanine-cytoplasm 'silver' multilayer reflectors, which make, however, the reflected light non-polarized and provide a sort of cryptic camouflage for the situation.
The Siberian shad (Alosa saposhnikovi), the Baltic sprat (Sprattus sprattus balticus), and the Clupeonella engrauliformis all mature at two to three years of age but at lengths of 160 to 200 mm (roughly 6.25 to 8 inches), 120 to 130 mm (4.75 to 5 inches), and 85 to 100 mm (3.3 to 4 inches), respectively.
One of the smaller sprats (Sprattus sprattus phalericus), with a maximum size of 8 cm (about 3 inches), produces about 2,000 eggs; one of the biggest shads, Alosa kessleri kessleri, can produce more than 300,000 eggs; and menhaden (several species of Brevoortia) produce more than 500,000.
If a herring (Clupetta), a pilchard (Sardinops), and a sprat (Sprattus) are held by the leading edge of their dorsal fins, the herring's body orientation is approximately horizontal, because the fin is located at the centre of the back.
Some forms (Clupea, Pomolobus) have sticky eggs with an adhesive secretion, so they stick to stones, gravel, or plants shortly after being released.
Few clupeiform species spawn far from shore or in the open sea, except, notably, the Atlantic herring (Clupea harengus harengus), which spawns on offshore banks.
The name herring refers to either the Atlantic herring (Clupea harengus harengus) or the Pacific herring (C. harengus pallasii); although once considered separate species, they are now believed to be only subspecifically distinct.
