The History of Crucian Carp in the UK

The History of the Crucian Carp in the UK

Most writers on the subject up to quite modern times assumed that the comparative rarity of the fish and its then limited distribution indicated that it was an introduced species.

However, Jonathan Newdick, in The Complete Freshwater Fishes of the British Isles (1979), states that the Crucian Carp “was considered to be a fairly recently introduced species until 1975, when the discovery of a Crucian Carp bone among Roman remains in London pointed to the fact that it is an indigenous species or at least a very early introduction.” And A. Wheeler, in his paper on The Status of the Crucian Carp, Carassius carassius (L), in the UK (2000), argues that the Crucian Carp in this country is similar in its distribution to certain other species and therefore is probably a native.

I cannot comment on the fossil bone beyond asking why only one was found and wondering about accuracy of identification. Without wishing to be dismissive, I suggest that this does seem rather flimsy evidence. I’ve read it nowhere else.

Although Alwyne Wheeler’s conclusion seems to have been generally accepted, I’m not sure that the argument is completely convincing. I wonder, too, why he doesn’t mention the fossil bone “proof”.

‘Elongated’ crucian from Marsh Farm

The high-backed form of crucian carp

The fish that Wheeler identifies as originally having had the same range as Carassius carassius are Burbot, Silver Bream, Spined Loach and Ruffe. The first of these is now extinct in this country, but it and the other three species appear to have been fish that in the course of time adapted to life in stillwater as well as continuing to inhabit their original slow-flowing rivers. Silver Bream, Spined Loach and Ruffe are still to be found in rivers in this country; the Crucian Carp is not, except rarely as an escapee.

Why then, if it colonised England via the same ancient river system as those four species, is the Crucian Carp not found in rivers today, as they are? Where it has occurred in rivers, as anecdotally in the Thames, its extreme rarity suggests an escapee population rather than a self-maintaining one.

Admittedly, in a comment on the extreme rarity (my italics) of the Crucian Carp, Yarrell (3) stated that he had never seen the fish “except from the Thames, between Hammersmith and Windsor, where it attains considerable size, sometimes weighing a pound and a half; and in one instance a specimen brought me in October 1829, weighed two pounds eleven ounces.” Succeeding writers took this statement as evidence that there was a wild population of crucian carp in that river. Yet if that was so, why was the fish caught so very rarely, bearing in mind that the crucian is a prolific breeder? Juvenile Roach, Chub, Bream were and are commonplace. Why not juvenile Crucian Carp?

Patrick Chalmers in his famous book on the fish of the Thames and the fishing for them (10), does not mention Crucian Carp, though every other fish you might expect is featured. Wheeler himself states in his excellent book on the fish of that river, The Tidal Thames, A History of a River and its Fishes (1979) (11) that Crucian Carp have been caught less frequently in the Thames than the exotic Goldfish.

Personally, I believe it more likely that the Crucian was imported from Europe, probably Germany as its traditional, familiar names of “German Carp”, “Prussian Carp” and “Hamburgh Carp” suggest, and that its presence in the Thames can most convincingly be explained its escape from fish ponds in the neighbourhood of the river.

As for the reasons for the Crucian Carp’s introduction, again we can only speculate. It seems unlikely that it was introduced as a sporting fish. Indeed the old angling authors that I have read, including Isaac Walton himself, ignore the species, possibly because they didn’t know about it. Equally, in this country it seems unlikely to have been raised for food. Compared with the Common Carp, the Crucian is a relatively slow-growing species except under the most advantageous conditions. Its capacity to put on some weight in impoverished waters would not seem to be an attraction in an island where fish-rearing would have been concentrated in specially dug stew ponds and where sea fish were becoming more and more widely available as transport efficiency improved.

The most likely reason for the Crucian’s importation would seem to be that it is a decorative fish, almost as attractive as the more dramatically coloured goldfish, and that land owners and fish enthusiasts would have been eager to add it to their list of species. Rev. Houghton (1876) (6) writes that “It has been introduced into fishponds by various gentlemen interested in pisciculture….” He thanks “Mr Masefield of Ellerton Hall” for the specimen he examined for his book. Donald F. Leney FZS, in his contribution to a scientific paper by E.W.Swanton (9) states that “the Crucian Carp sometimes called Prussian carp do not occur in the wild state but are acclimatised in the Haslemere district” and were to be found with other exotics like Golden Carp, Goldfish, Golden Rudd and Golden Tench in a nameless pisciculturalist’s ponds at Shottermill. Incidentally, Haslemere is close to Godalming (Marsh Farm) and Yateley, famous now for their populations of big, true – and arguably introduced – Crucian Carp.

Another less obvious reason for the fish’s introduction into this country is the suitability of the Crucian for scientific experimentation, a tradition that exists today. The hardiness of the crucian carp is legendary and there is an account in Couch (1865) (5) of the importation by Jethro Tull in the early eighteenth century of “eight Carrushens (a kind of small carp lately brought into England from Hamburgh (my italics) – the Cyprinus carassius of Linnaeus”) for an experiment involving the castration of carp in order to improve the quality of their flesh. The experiment was to impress Sir Hans Sloane, the famous scientist and philanthropist. Presumably it was because the Crucian is one of the toughest of fish that it was used in the first place.

Jethro Tull, of course, would not have needed to send to Germany in the early 18th century for Crucian Carp had they been readily available in this country. Even later, in Victorian times, the fish was described as very rare, in its deep bodied form at any rate. Couch (1865) (5) wrote that so little was formerly known of this fish in early days that Gesner said that he could not find any mention of it by any writer before Dubravius. I have looked at Willughby’s De Historia Piscium of 1685 and could not find the Crucian listed as native to this country. The native fish have roughly contemporary English sub-titles in the edition that I consulted; Carassius pinna dorsi ossiculorum viginti, however, is called just that, suggesting that it was not considered a native of this country at that time. Pennant (1812) in British Zoology (2) describes the Crucian low-backed form (Gibele, as he called it) as “common in many of the fishponds (my italics) about London and other parts of the south of England” but did not believe it and the much rarer deep-bodied form to be a native fish.

My own theory, for what it’s worth, is that the crucian carp was introduced here, most likely from Germany, as an ornamental fish, a curiosity if you like, at the end of the C17th or beginning of the C18th, possibly at the same sort of time as the goldfish, though fish historians still cannot agree when the latter did arrive here. It seems likely that the initial stockings would have been in the wealthy and fashionable London area and the south east, spreading from there to estate lakes and fishponds elsewhere in the country.

Many of these stockings would have come to nothing if the Crucians were introduced into waters containing substantial numbers of pike or big perch (see later comments on predation and stocking). Where predator numbers were limited, or in bigger estate lakes with a mixed population, the high-backed form would have remained. In smaller, predator-free waters, prolific spawning would have led eventually to big populations of the lower-backed form known as Prussian Carp. I believe that this explanation best fits the few facts that we have about the crucian carp’s origins in this country.

The situation would have been bedevilled from the beginning by the commonness of the Goldfish in similar waters, leading to a failure to recognise hybrids, or escapee brown Goldfish, and the variable body profile of the Crucian Carp.