Ubiquitous and voracious, with a truly extraordinary sex life, the black bream offers fine sport. Its numbers, however, are declining rapidly and the species is becoming scarce
The black sea bream, Spon-dyliosoma cantharus, is one of those species familiar to the angler but which have been too little studied by biologists. It shares many of the characteristics of the family Spari-dae, a group of marine fishes of worldwide distribution in tropical and temperate seas. The moderately deep, fully scaled body, a long dorsal fin with sharp spines, and a shorter anal fin with three strong spines, are common to most sea breams.
Where it differs from many others is in its dentition: the teeth are slender and pointed, only those in the outer row being larger and slightly flattened to look like in-cisors, while those all round the sides of the jaws are pointed and slim. In this relative uniformity, the black bream differs from all the other British breams, which have either large dogteeth in the front of the jaws, or rounded crushing teeth in the sides of the jaws, or, in a few cases, flattened incisors, similar in shape to human front teeth. The variation in the teeth of the sea breams is a fascinating example of adaptation to different kinds of foods and methods of feeding.
Confusion with Ray’s bream There is little chance of an angler confusing the black sea bream with any other species of sea bream, its teeth and its coloration of silver with horizontal dark lines (in breeding fish broad vertical bands and, in particular, a dusky forehead) being distinctive. Curiously, most of the identification problems that I have encountered have involved a quite unrelated fish – Ray’s bream (Brama brama), which is a member of the family Bramidae.
Despite its name, Ray’s bream is not a sea bream, although it has a superficial resemblance to them, being deep-bodied and fully scaled. It is. However, very thin in the body, and it has no separate spines in its dorsal or anal fins. The tail fin is also deeply forked, too much so to be that of a sea bream. If these points are borne in mind, there should be no confusion, but as Ray’s bream is dark-coloured and unfamiliar to most sea anglers, it is not surprising that it is sometimes thought to be a sea bream.
In British waters, the black bream is commonest in the English Channel, the southern Irish Sea, the Bristol Channel, and off South-West Ireland. Elsewhere it occurs fairly regularly, although with declining frequency the farther north and east one goes.
Dramatic decline in black bream
The large numbers of black bream that were formerly taken by anglers in the Channel during the spawning season seems to have resulted in a dramatic decline in numbers of spawning fish. If, as seems to be the case, this is the major spawning area of the species north of Biscay, then the effects will be felt far beyond the eastern Channel.
A prominent vertical white stripe runs across the back and side, ending at the vent, and there are light flecks on the head, notably one running under the eye. Individual fish vary in coloration, some spawning males being much darker than others. Female colouring too is heightened during spawning, the darkest-coloured females being almost as dark as the lightest males. These specimens may be in the process of, or only just have completed, the sex change described below.
The eggs form a single layer on the bottom of the nest, although where the bottom is irregular, two layers may be found. They form an irregular, light-coloured patch, which is guarded by the male until the eggs hatch in about nine days at 13°C (55.4°F). In addition to keeping predators away from the eggs, the male keeps the nest free of deposited silt by fanning with its tail and fins. In aquarium conditions the nest- become increasingly scarce in the North Sea and probably along the rest of the Channel coast.
The black bream spawns in April and May. Its spawning behaviour has been well described and differs in many ways from that of other sea breams. The male makes a nest on the sea bed, usually where fine graved or coarse shell grit form the surface, by sweeping the finer material away with vigorous side-to-side movements of the tail.
Separate nests may be quite close together, but their spacing probably varies with the size of the area suitable for spawning and the number of males in the breeding population. In dense populations they may be within 3ft of one another, but with lower numbers, common in nature, they are separated by 10ft-30ft of clear ground.
The male’s activities
It must be assumed that in crowded conditions the males spend more time defending their territory and nest and that survival and success of the young is lower than in less crowded situations. Normally, the males spend a considerable part of their time, once the nest is made, in pursuing females, sometimes swimming up to 30ft away from the nest in pursuit of a female and attempting to chase it towards the nest.
It is during the frenzy of nest construction and soliciting for a mate that the male’s coloration becomes most intense. The normal pale colouring changes to an intense dark violet, almost black, the head being black above the level of the mouth.
It has long been known that some sea breams, as well as various other fishes, change sex. This is the case with the black sea bream. The original observations on this subject were made in the Mediterranean but have been more recently confirmed by a French researcher working on the North African coast. He provided confirmation by ‘sexing’ and measuring the fish caught on a research cruise. He found the numbers of each sex changed with the length of the fish. Mature fish between 7in and 15in (18cm and 38cm) in length comprised 31 males and 196 females. Between 15in and 38cm and 55cm in length he found 31 males and 16 females. Two fish measuring 9.8in and 15.3in (25cm and 39cm) contained both soft roe and hard roe, and were thus bisexual. It seems therefore that the black sea bream is a protogynous hermaphrodite. This means that it starts its mature life as a female and, if it lives long enough, ends up as a functional male.
As its teeth suggest, the black bream is not a specialized feeder. Its fine, sharp teeth allow it to snap up any small soft-bodied animals it encounters. The black bream’s diet contains substantial quantities of small crustaceans and fishes, but it does not tackle the larger crustaceans nor to any great extent molluscs, both of which are a prime food for other species of bream. It also eats substantial amounts of seaweed. When feeding, a school usually congregates above a reef with a pronounced crest or on broken reefs where the groundswell causes local currents to sweep up and over the rocks, carrying planktonic organisms or other edible items with it.
While actively-feeding fish may systematically work along the ridge, the remainder hang 3 or 4ft or so above it, waiting for chance food to be swept along. Small particles of algae are quickly seized upon, but larger edible items are quickly surrounded and attacked by as many fish as can get a grip on them. This frequently happens with a baited hook, which will be the focus of attention of up to ten fish before the bait is either stripped off or a fish is hooked. This accounts for the frequency with which they are lip-hooked, and also for the ‘knocks’ and half-bites at the bait that the angler can feel in a calm sea.
British record black bream The preference of this species for broken ground and reefs no doubt explains why the great majority are taken by boat anglers. Usually only small fish are taken close inshore, but large fish taken from the beach, such as the current shore-caught British record of 4lb 14oz 4dm, taken on 5 October 1977 by R Holloway fishing the Admiralty Pier, Dover, come from relatively deep water and rough ground. The British boat record is held by a fine fish of 6 lb 14oz 4dr, caught in September 1977 by John Garlick, from a wreck in 37 fathoms off the Devon coast. Such a fish must be very close to the maximum size of the species and this record may stand for a long time.