Grey mullet are shoal fish which can be found all around our coasts. The most common member of the family is the thick-lipped, which is extremely hardy and infuriatingly elusive.
The three species of grey mullet found in Britain—golden, thin-lipped and thick-lipped—are very similar, and although a novice may confuse them with bass, there are several ways of distinguishing them. Mullet have large scales on both their gill-covers and cheeks, as well as over their bodies, and grey mullet have several distinct lines running along their flanks.
The importance of the lips
Thin-lipped grey mullet have noticeably smaller fins than the bass, particularly the two dorsals, and the name ‘thin-lipped’ is derived from the fact that the top lip does not measure more than half the diameter of its eye. In the thick-lipped grey mullet, the top lip is thicker than half the diameter of its eye. Comparing the thickness of the upper lip with the diameter of the creature’s eye is relatively straightforward. Both the thin and thick-lipped grey mullets are quite widely distributed throughout British waters, although the thick-lipped is more common.
Golden grey mullet, as the name would suggest, are distinguished by their well defined gold spots: a comparatively large one on each gill-cover, and another, smaller one, just to the rear of each eye. The upper lip is distinctly thin, and the pectoral fins about half the length of the pelvic fins. It is smaller in size—growing to lWin—than either the thin or thick-lipped variety.
Mullet can tolerate and thrive in conditions which would be lethal to many other species. They revel in brackish water, and often swim long distances upriver. For example, mullet are often caught as far up the River Arun as Pulborough, about 20 miles from the river’s mouth.
Murky water with a low oxygen content holds no terrors for these fish, and it is believed that they are able to gulp in and absorb an amount of air from the atmosphere through their gills.
Exceptions to the rule
Grey mullet are shoal fish, and although generally considered to be an inshore or coastal species, they retire into deeper water during the winter months. There are, however, exceptions to this general rule. Where there are special cir-cumstances, such as cooling water from a power station flowing into a harbour, or where the fish have become virtually land-locked as a result of penetrating into a dock system, mullet will be seen virtually all year round.
Grey mullet feed on a variety of both vegetable matter and small animals such as crustaceans and molluscs. Soft mud, weed-laced rocks and pier supports as well as boat hulls often provide rich pickings for them—a fact which should not be overlooked.
Although mullet do not possess powerful teeth to crush the harder items of food (their teeth are in fact rather feeble), they do have a pharyngeal structure which acts like a ‘filter’ and are equipped with an almost ‘gizzard-like’ organ in their gut, which normally contains an amount of grit to aid digestion. This organ acts like a chicken’s gizzard in that it crushes the harder items of food, and passes it on until finally the food is digested in the rear of the intestine.
Although their natural diet consists of the items already mentioned, the mullet will also eat all kinds of waste thrown overboard from sea craft. In harbours where private cruising boats are moored, or even around ocean-going ships, mullet will often shoal, just waiting for the scraps or leftovers.
The wary mullet
Although as a general rule mullet appear indolent, seeming to spend much of their time lazing on or close to the surface, they are in fact surprisingly wary creatures. Mullet have the ability to fade from sight, and indeed, when frightened they show considerable speed.
A shadow suddenly falling across their line of vision, or the noise of a reel or rod clattering on to the bottom boards of the fishing boat is quite sufficient to scare them, and this is a point well worth remembering, particularly if you are to spend the night on a boat with the intention of fishing for mullet at first light—which is one of the best times ___ , _ _.-_.- -— mtmmm to lure these fish. Although there are always exceptions created by weather and other factors beyond the angler’s control, mullet have always seemed to be far more susceptible to a surface-fished bait between first light and sunrise, and also during the evening.
Are mullet uncatchable?
It would seem that the environment in which these fish settle has a great bearing on the way in which they react to various circumstances. For example, a shoal of mullet in the open sea will bite quite hard and often at red ragworm presented on ledger tackle, but once the fish move into the quieter or more sheltered waters of a harbour their nature appears to undergo a change, and they become considerably more wary and generally more difficult to catch, so much so that in many places even the local anglers class them as ‘uncatchable’ and not worth fishing for.
It is generally thought that mullet spawn during the spring and early summer in the relatively sheltered waters of the coastal zone, which include the various natural harbours around Britain’s shoreline. However, although adult mullet will inhabit brackish and even completely fresh water, there is no evidence to suggest that they will spawn in these areas. Even if they did young mullet released into fresh water would certainly die, as experiments carried out in Israel indicate.
There are indeed some authorites who believe that mullet reproduce much later in the year—during August and September.
No doubt water temperature has a great bearing on the actual time that they do spawn, but I have never caught a mullet during the late summer that appeared to be in a condition to spawn.
The various species reach sexual maturity at different ages. In the case of the thin-lipped mullet, they mature from 3 to 5 years and the thick-lipped from 2 to 4 years. The striped mullet, a fish which may very occasionally turn up in the warmer waters of the far south-west, matures from 6 to 8 years.
Mullet are a fairly prolific species; a female thin-lipped sheds some1 million eggs, and the thick-lipped a similar number. Golden mullet may lay up to 2 million, but the striped is probably the most prolific of all—the female of this species can lay up to 7 million eggs.
Mullet spawn would normally drift with the current, fairly close to the surface, where it is vulnerable to various predators. The survival of both spawn and young fish is dependent to a very large extent on the general condition of the water. It is impossible to estimate how many are lost through pollution. Mullet which live all year round in docks and similar restricted areas also spawn at comparable times, but the mortality rate is high, particularly if the water is not sufficiently saline, as the spawn then sinks and becomes lost in the mud.
Mullets are reared, artificially, in a number of countries for food. As it has proved so difficult to hatch and rear the fry under artificial conditions, it is usual to net the young fish when they are about 20mm long and transfer them from the sea into nursery pools, where they are held for about two months. They are then moved into larger ponds to grow. As their capacity to forage is high, they are a relatively cheap fish to raise. During the early days of captivity they are gradually acclimatized to water which is only slightly saline.
The growth rate of these fish depends upon the particular species. The thin-lipped grows more slowly than the thick-lipped, but the striped shows an even faster growth rate. However, although the British rod-caught shore record stands at just over 14lb (a thick-lipped mullet caught off The Leys, Aberthaw in 1952) fish between 5 and 6lb can be considered a good catch.