The evolution of the monkfish has given it characteristics closer to a ray than a shark and rendered it frankly grotesque. But its looks mask a well adapted, efficient, seabed predator.
Of all our large sea fishes the monkfish, Squatina squatina, is possibly the least known. To some extent this is due to its rather localized distribution, but mostly it is because it falls into that category of fishes which have neither direct commercial importance nor are prime angling species. Despite this, it has much to offer the sea angler. It is a dogged fighter which uses all its considerable weight to resist pressure. When firmly clamped to the bottom, it takes a lot of shifting as its flat-bellied skate-like shape allows it to suction itself to the sea- bed. As specimens of 50 lb are not uncommon, the study of its habits and distribution could well be worthwhile for anyone tempted to try for a relatively unusual catch.
In outward appearance, the monkfish seems halfway between a skate and a shark. Its body is flattened from above, its eyes and spiracles (respiratory openings) are set on the topside, its pectoral fins are large and almost wing-like, and its pelvic fins broad – all ray-like characteristics. But the gill slits are on the side of the head, the tail fin seems typically shark-like, and the pectorals are not fused with the head. For these reasons scientists have classed the monkfishes (there are about 11 species worldwide) with the sharks, and they are closest related to the spurdog family.
Adapted for life on the seabed
The monkfish is well adapted for bottom-living. Its flattened shape and eyes on top of the head, both suggest this. So do the large spiracles which, like those of a skate, enable it to pump water into the gill chamber so that it can breathe while clamped to the seabed. Yet it can swim actively and, as it seems to make regular migrations and often turns up in out-of-the-way places, it must also be capable of sustained swimming. It propels itself by its tail, making powerful side-to-side strokes, while its dorsal fins and the paddle-like tail fin give it ample hold on the water.
Looking at a monkfish swimming, one is impressed by its efficiency. The compressed head and wide pectorals produce enough uplift to counter the tendency to nosedive caused by the dorsals and tail fin. Yet it is not a fast swimmer – rather, a steady one that can achieve long distances. This is not to say, however, that it cannot accelerate. It certainly does when occasion demands, diving and darting with considerable agility. Probably its normal lifestyle involves swimming for a short while, then resting on the bottom – although there are no published observations available to confirm this.
The monkfish’s food
The mouth of the monkfish is fringed with quite elaborate flattened and branched barbules which extend to the edge of the nostrils. These barbules act as food finders, for analysis of the food of the monkfish shows that it eats bottom-living animals almost exclusively. Flatfishes seem to be the major food – plaice, dab, sole, brill and small turbot have all been found in the stomachs of monkfishes.
Squatina squatina bottom-living fishes, such as rays and gobies, as well as whelks and crabs may be eaten on occasions, but flatfish seem to be the staple diet. No doubt, however, given the opportunity, other fish are taken. The often-referred-to historical report of a cormorant seized by the wing by a 3ft monkfish off the Cornish coast suggests that large monkfish might attack all kinds of potential food.
When feeding, the monkfish cruises gently over the seabed with its extended barbules sweeping the sand as it goes. The barbules are densely packed with taste buds which assess the edibility of any item they contact. Interestingly too, the nostrils are large, with a well-developed sensory surface and, being placed virtually on the extreme edge of the head, are ideal for picking up the scent of foods. Any odour particles from food fish or bait, carried by tidal currents to the monkfish, will be detected by the nostrils, but at close range the barbules take over.
Diet of flatfish
Considering how well such fish as plaice and dabs hide themselves on a sandy bottom, it is obvious that the monkfish has a highly sensitive nose to find them so efficiently. It is not just the odd flatfish that one finds in a monkfish’s stomach, but sometimes as many as six. There is a 19th century record of more than five dabs and plaice of 5£in-8in in one fish and the author himself has found four plaice and dab in the stomach of a 45 lb fish. Even though partially digested, they weighed nearly 3 lb in total and were packed into the stomach as neatly as fish in a fish merchant’s box.
The monkfish is, so far as the literature shows, the only fish to prey almost exclusively on flatfishes, which in general manage to escape the attention of most predatory fishes. For the angler who is setting out to catch a monkfish, the inference is obvious: there is no better bait you can use than a half-pound dab or plaice.
As with all other sharks, the eggs are fertilized internally, the male monkfish having the typical pair of copulatory claspers, more prominent in mature specimens, on the inside of its pelvic fins. However, mature males seem to be less common around our coasts than females. After copulation, development of the eggs continues within the body of the female – the young develop inside the fish but are not connected to it by a placenta.
The size of a monkfish’s litter varies with the size of the mother; a small female may produce only ten pups, large ones twice that number. The minimum size of the litter seems to be seven, and the maximum 25. The young fish is about 10in at birth, and very new young retain traces of the yolk sac, which before birth is very prominent.
Very few newly born fish are caught in British seas although, occasionally, young specimens are taken in seines and shrimp trawls on the south western coasts. Females with large eggs inside them are more often reported; but these may be several months away from giving birth. Although no studies have been made of the breeding cycle of this species in North European waters, information from the Mediterranean suggests that gestation may last for six months. It may be longer in our cooler seas, and as the monkfish’s nearest relative, the spurdog, has a gestation period of two years, there is no reason why it should not be much longer.
The few records there are of young British fish suggest that the pups are dropped in June and July, although in the Mediterranean the fish is thought to give birth in December. Clearly, there remains much more to learn about the basic biology of the monkfish.
Fishing for monkfish
Over the years, monkfish have been caught all round the coasts of the British Isles, even as far north as Orkney, but it is far from common in the north or anywhere on the east coast. On southern and western coasts it is moderately frequent, but the only area where it is at all com-mon, and can be fished for with a fair certainty of success, is on the west and south western coasts of Ireland. Here, as elsewhere, it lives on sand, or sand and gravel bottoms, in depths of 20ft-100ft, occasionally coming closer inshore.
Almost all monkfish captures are made in summertime, but it is not proven that the fish are absent from our seas in winter. Various sugges-tions have been made to account for this. Some have claimed that the fish moves into shallower water during the warm season having over-wintered offshore; others suggest that there is a northward migration in spring which brings the fish into our seas, perhaps from the region of Biscay. Without intensive tagging, the true explanation is not likely to be established, but from the evidence of their seasonal occur-rence and distribution along the western coasts of Great Britain, as well as on the Dutch and Belgian coasts in summer, the more likely explanation is that monkfish over-winter in the south and make a northward migration to the richer feeding of the wide Continental Shelf around Britain in the summer. Their distribution in summer is very similar to that of a number of other kinds of fish which are known with greater certainty to migrate from the south.
The current British record fish weighed 66 lb and was caught off Shoreham in 1965. The shore-caught record stands at exactly 50 lb and was taken off Monknash Beach in Wales in 1974. This was an extremely good weight for shallow water and can be expected to stand for some time. The boat record, on the other hand, could be bettered at any time. The heaviest specimens are females; males seem not to get much heavier than 40 lb.
There is considerable uncertainty among scientists as to the maximum weight for the species. Many text-books cite a maximum of 80kg (176 lb) but this figure originated from the Mediterranean and seems suspiciously round. It is unlikely that it came from an angling source, and as Mediterranean fishes are usually smaller than those from the Atlantic, it seems too large to be true. Once again, this is an aspect of the monkfish about which little is known. How big it grows is one of the greatest of the many puzzles which still remain about this fish.
On the kitchen table – and the arguments in favour of their use are thoroughly convincing.
Spinning flights are designed to impart a pure spinning action to the lure, not a wobble or side swoop.