Belg. J. Zool., 139 (1) : 70-78 January 2009 The Holocene occurrence of the European catfish ( Silurus glanis ) in Belgium: the archaeozoological evidence Wim Van Neer 1 & Anton Ervynck 2 1 Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, Belgium and Katholieke Universiteit Leuven, Laboratory of Animal Biodiversity and Systematics, Ch. Deberiotstraat 32, B-3000 Leuven, Belgium 2 Flemish Heritage Institute, Phoenix-building, Koning Albert II-laan 19 box 5, B-1210 Brussels, Belgium Corresponding author : e-mail: [email protected] ABSTRACT. An overview is given of the skeletal remains of the European catfish Silurus glanis found thus far in Belgian archae- ological sites. These finds demonstrate that the species is autochthonous and allow documenting its occurrence and disappearance during the Holocene in the Scheldt and Meuse basins. Possible causes for the local extinction of this catfish are discussed. KEY WORDS : archaeozoology, extinction, overfishing, Meuse, Scheldt INTRODUCTION explicitly that the species is unknown in Belgium. In more recent fishery surveys, the status of the species is Well-dated skeletal remains of fish species found dur- considered to be doubtful or is not clearly evaluated ing archaeological excavations can help to reconstruct the (B RUYLANTS et al., 1989; V ANDELANNOOTTE et al., 1998). composition of ancient fish faunas and thus allow estab- Confusion also arises from more popular accounts. The lishing the distribution of certain species before the start ‘silures’ mentioned from the Demer river, a tributary of of human disturbance, such as overfishing or habitat deg- the Scheldt, in the Belgian fishery bulletin Pêche et Pisci- radation. In this paper, the contribution of archaeozoolog- culture (A NONYMOUS , 1926) was considered to be evi- ical finds to the evaluation of the status of the European dence for the occurrence of the species in that river (D E catfish Silurus glanis Linnaeus, 1758 in Belgian waters is CHARLEROY & B EYENS , 1998). However, this record no documented. Because of its large size and the robustness doubt refers to the brown bullhead Ameiurus nebulosus of its skeleton, Silurus glanis is a relatively good prospect (Lesueur, 1819) (V RIELYNCK et al., 2003), a north-Ameri- for representation in the archaeological and palaeontolog- can silurid that became acclimated to Belgian rivers and ical record. Its remains have a fair chance of being pre- pools since 1901 (R OUSSEAU , 1915). The postglacial dis- served and can rather easily be retrieved during excava- tribution of Silurus glanis includes Central and Eastern tion, whereas smaller fish species have a tendency to be Europe, northern Anatolia and goes as far east as the Aral overlooked when no sediment sieving is practiced. The Sea and the Ural mountains ( DE N IE , 1996). Towards the European fossil record of this catfish is poor with few west, the natural distribution stops at the Elbe, but there pre-Holocene finds, which are usually only identified at are populations in the northern part of The Netherlands genus level. Miocene records of Silurus exist for Ukraine and in southern Sweden that are believed to represent relic populations (H EINRICH , 2007). (B ELYAEVA , 1948) and Turkey (P IVETEAU , 1978) and Pliocene finds have been reported from Russia, near the Recently, a number of specimens of the European cat- Sea of Azov (B AIGUSHEVA , 1971) and from southern fish have been recorded from Belgian waters. A first Silu- France (D EPÉRET , 1885). Middle Pleistocene records of rus glanis was captured in 1984 in the Meuse basin near Silurus exist for three different sites in Turkmenistan Lanaye, but nowadays it is abundant in the entire river (D UBROVO & N IGAROV , 1990). Holocene finds of Silurus and it lives also in the Sambre river and some canals glanis , from archaeological sites, are more numerous and (P HILIPPART , 2007). The species has recently also been have been used in neighbouring countries to reconstruct reported from the Scheldt and some of its tributaries (the the zoogeography of the species during the last 10,000 Rupel, the Grote Nete and the Kleine Nete) (B REINE et al., years. This is the case for the Netherlands (B RINKHUIZEN , 2007). All these recent records, however, should be con- 1979; H EINRICH , 1994; 2007), northern Germany and sidered to represent exotic specimens (cf. V RIELYNCK et southern Scandinavia (H EINRICH , 1994; 2007). However, al., 2003). Similarly, Dutch records since 1972 in the area the available evidence for Belgium has thus far never of the IJsselmeer and in the Rhine and Waal basins are been compiled. In what follows, all known finds of Silu- regarded as escaped or stocked specimens derived from rus glanis from Belgian prehistoric and historic archaeo- breeding experiments with animals imported from the logical sites is presented and discussed from a palaeo- Donau (N IJSSEN & DE G ROOT , 1987). The catfish’s occur- zoogeographical point of view. rence in the Dutch part of the Meuse basin since 1985 is In the older Belgian fishery literature (e.g., DE S ELYS - explained in a similar way, and chronologically coincides LONGCHAMPS , 1842; L AMEERE , 1895 or M AES , 1898), the well with the aforementioned observations made in the European catfish is not mentioned at all, whereas on one Belgian part of the Meuse. Records of Silurus glanis west occasion (R AVERET -W ATTEL , 1900) it is even stated of the Elbe, in the Weser and Ems basins, are also Holocene occurrence of Silurus glanis in Belgium 71 believed to represent escaped or stocked fish (H EINRICH , Brussels). On well-preserved remains a reconstruction of 1994; 2007). body size was carried out through comparison with skele- tal elements of modern fish of known length. The size reconstructions are given in centimetres standard length MATERIALS AND METHODS (SL: the distance from the snout of the animal to the base of its tail). The skeletal remains mentioned in the following sur- vey were found during archaeological excavations and RESULTS were dated through the characteristics of the context in which they were found, i.e. stratigraphical position and association with datable archaeological finds (lithics, The various catfish finds known to date in Belgium are ceramics, or coins, depending on the period). It was also presented in a more or less chronological order, for sites always checked to ensure the finds did not represent located along the Meuse and the Scheldt basins sepa- residual or intrusive material (i.e. older or younger than rately. Because of the geographic proximity to the Bel- the context in which they were found). Unless specified gian territory, finds from Maastricht are also included. otherwise, the bones have been identified or re-analyzed The localities mentioned in the text are indicated on Fig. by the first author. Identification was carried out by com- 1. A chronological, cultural and biostratigraphical frame- parison with modern reference skeletons housed at the work for the archaeozoological evidence is summarised Royal Belgian Institute of National Sciences (RBINS, in Fig. 2. Fig. 1. – Map with the location of Belgian archaeological sites mentioned in the text. Those that yielded Silurus glanis are indi- cated with an asterisk. 1: Oudenaarde-Donk; 2: Tournai; 3: Ename; 4: Grimbergen; 5: Aalst; 6: Néviau; 7: Walou; 8: Trou de Chaleux; 9: Trou du Frontal; 10: Trou du Sureau; 11: Bois Laiterie; 12: Trou de Pont-à-Lesse; 13: Abri du Pape; 14: Maastricht; 15: Namur; 16: Montaigle. 72 Wim Van Neer & Anton Ervynck Fig. 2. – Schematic overview of the biozonation (after V ERBRUGGEN et al., 1996) and succession of cultural periods (after S LECHTEN , 2004) for Belgium during the Holocene (Preboreal to Subatlantic) and Late Glacial Period. Holocene occurrence of Silurus glanis in Belgium 73 Scheldt basin dating to the end of the 12 th -first half of the 13 th century AD (D E G ROOTE , 2007, pers. comm.). Oudenaarde-Donk : 7 vertebrae and 6 pectoral spines of individuals between 150 and 200cm SL were found dur- Meuse basin ing rescue excavations of a waterlogged site near the Scheldt. Identifications were carried out by the first Néviau : a precaudal vertebra has been reported from author in 1985 and were briefly mentioned in V AN DER this rock shelter on the left bank of the Meuse, 5km south PLAETSEN et al. (1986) and P ARENT et al. (1987). The site of Namur (G ILTAY , 1931). The photographs of the speci- yielded evidence for occupation by mesolithic hunter- men in the publication allow us to confirm the identifica- gatherers and subsequently by neolithic people belonging tion and show that also the estimated total length of 1.50 to the Michelsberg culture. The catfish remains were meters is correct. The bone reportedly derives from a con- found in unspecified Michelberg contexts that were radio- text that also comprised remains of Equus sp ., Cervus carbon dated between 5240+ 70 BP (IRPA-743) and elaphus and lithic material typical for an Upper Magdale- 4990+ 70 BP (IRPA-667). These dates were calibrated to nian (Late and Final Palaeolithic) occupation. calendar ages using the Calib. Rev 5.0.1 program S TUIVER Trou de Pont-à-Lesse : the faunal remains from this site, & R EIMER (1986-2005), in conjunction with S TUIVER & excavated in 1866 by E. Dupont, are stored at the RBINS. REIMER (1993). The 2- ranges are 4261-3943cal BC for The fish bones were recently analyzed for the first time, the oldest date and to 3945-3656cal BC for the youngest. by the first author. Trou de Pont-à-Lesse yielded 8 skele- Tournai-Cloître : one pectoral spine of an individual tal remains of Silurus glanis , derived from layers dating measuring about 140cm SL was found in a destruction to the Neolithic (D UPONT , 1905).