Spined loach  (Cobitis taenia)

This small, bottom dwelling fish (3) has an elongate flat-sided body, which is brownish grey in colour with dark patches to the flanks (4). There are six barbels around the mouth (3), which are often difficult to see. Erectile spines below the eyes give the species its common name (4).

This loach has a wide range across Europe and Asia, and is threatened in Europe. In Britain it is restricted to five east-flowing river systems: the Trent, Welland, Witham, Nene and Great Ouse (4).

This species can occur in a variety of water bodies, such as rivers, streams, canals, ditches, drains and lakes. In the day spined loaches tend to prefer habitats dominated by submerged vegetation, which may be important for spawning (5). At night, however, they appear to venture into more open habitats, probably due to the decreased risk of predation (4).

This species has a peculiar mode of feeding in which it uses mucus to extract food particles from fine material pumped through the mouth (4). It is able to survive in low oxygen conditions because the gill area is very large. It is also thought that if oxygen levels fall drastically, spined loaches are able to gulp air from the surface of the water, and absorb oxygen through the gut wall into the blood stream (4).

This loach has an interesting courtship in which a male touches a female with his spines, and then wraps himself around her body. The female releases eggs, which are then fertilised by the male (4).

As this fish does not have commercial or angling value, it was until very recently poorly known and under-recorded; the general population trends are therefore unknown (4).

The inclusion of this species on Annex II of the EC Habitats and Species Directive has resulted in an increase in interest in its conservation, and an obligation for member states to designate Special Areas of Conservation (SACs) in key areas where the spined loach occurs (4). As yet it is unknown if a number of endemic subspecies or species of spined loach have evolved in Britain due to the reproductive isolation of different populations. If this is the case, the entire complex of species will need to be conserved. Genetic research is currently in progress. Weed cutting and dredging will have short-term negative effects on this fish, but in the longer term, dredging may create more appropriate substrate conditions. Research into more detailed habitat requirements of this species in order to guide habitat management is underway (4).

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk