What does dab eat?

A dab hunts by lying still and taking what crosses it, and almost everything it takes is small, slow and at least partly buried.

The verified relationships are three groups: polychaete worms, thin-shelled bivalve and gastropod molluscs, and small decapod crustaceans. All three are creatures of clean sand and fine gravel, and none of them is chased. Brittlestars are a further substantial component in many areas, and fish eggs and very small fish are taken opportunistically.

The shell point matters. A dab is not equipped to crush heavy shell, so the molluscs it takes are the thin-shelled species a soft-bottomed flatfish can manage. That constrains the diet more than abundance does: a ground rich in thick-shelled bivalves is not necessarily a rich ground for dabs.

Detection is chemical as much as visual. The eyes sit on the upper surface where a buried fish can still see, and vision contributes, but a dab will track a scent trail across open sand to a food source it has not seen. That combination — a visual bottom-dweller with a working sense of smell — is why dabs feed as effectively in the coloured water of a moderate surf as in clear conditions, and why they go on feeding through the winter when many inshore species have gone quiet.

Feeding is close to year-round and intensifies in autumn and winter. Condition follows spawning rather than temperature: fish are heaviest before spawning in late autumn and thin immediately after it in late spring.

There is a size shift, though a modest one. Small dabs take proportionally more small crustaceans and amphipods; larger fish take a greater share of worms, molluscs and brittlestars. It is a change of proportion rather than a change of strategy.

The scent-led half of the sensory profile is the basis of almost everything dab anglers do, and it is practitioner reasoning rather than an established consequence.

The convention is fresh worm — lugworm or ragworm — on small hooks, and the argument for freshness is that a bait which has stopped leaking has stopped doing the thing the fish responds to. Anglers commonly re-bait far more often than the bait's physical condition would suggest, on exactly that reasoning.

Tipping a worm with a small piece of squid is widely used and is defended on two grounds: it holds a soft bait together on the cast, and it adds a second scent source. Both are plausible and neither is established.

The visual half supports the traditional use of beads and a small spoon above the hook, borrowed from plaice fishing. A slowly worked bait is generally held to do better than a static one, which fits a fish that detects movement and disturbance as well as scent.

The welfare consequence is not interpretation. Small hooks and soft worm baits produce deep-hooked fish when a bait is left out too long, and dabs are very often caught by anglers whose attention is elsewhere. Strike the bite rather than let it develop, and cut the trace rather than dig for a hook you cannot see.

All three verified relationships are group-level and none establishes proportions. Diet composition varies substantially between grounds according to what the sediment holds, and the brittlestar component — significant in some areas — rests on no modelled relationship because the catalogue holds no record to point at. Nothing here establishes seasonal proportions, and the size-related shift is a change of emphasis reported in general terms rather than a quantified transition.