Cod-fish are sorely attacked by dog and cuttle-fish. The latter, with their hard mouths, resembling parrots' bills, cut up the mackerel and herrings with great adroitness. The cuttle-fish are, in their turn, sometimes attacked by the dog-fish; but they generally escape, by ejecting a liquid resembling ink, which renders the water dark and turbid.
MACKEREL.
When red mullet are abundant in fishmongers' shops, a fine mackerel season may be expected. The early mackerel are frequently attended by a few mullet; and whenever they nearly, if not altogether, equal the mackerel in number, the circumstance is generally the presage of the approach of great shoals of mackerel.
The course of herrings and mackerel is traced by their eggs, which, during a calm, may be seen floating on the surface of the water, like saw-dust, amidst an appearance like the wake or track of a vessel.
SPRATS AND WHITE BAIT.
Mr. Yarrell has recently shown that the sprat is not the young of the herring and pilchard, as has been generally supposed. One of the most material differences is, that the vertebrae in the sprat are forty-eight in number, while in the herring there are fifty-six. The same gentleman has also proved that white bait are not the young of the shad, or mother of herrings; but that they are a well-marked and distinct species.