Could the small size of sunbleak, Leucaspius delineatus (Pisces, Cyprinidae) be an ecological advantage in invading British waterbodies?
Journal: Folia Zoologica
Since the introduction of sunbleak (Leucaspius delineatus) to southern England in 1986, its life history characteristics (such as reproductive behaviour, early sexual maturity and an unusually small adult size) have contributed to its rapid dispersal. This study examines the length-weight relationships and age of this non-indigenous cyprinid to highlight the potential throat to native 0+ cyprinids. Sunbleak populations demonstrated an unusual growth pattern for a cyprinid, with an average of 42% of its maximum growth occurring in the first year, followed by extremely low annual growth until death. Very few significant differences were found between the mean length of several sunbleak age groups and the length of native 0+ bream Abramis brama, roach Rutilus rutilus, bleak Alburnus alburnus and rudd Scardinius erythrophthalmus. We have also found that young-of-the-year of these cyprinids share the same food and habitat with all sunbleak year class, which in some places has had a detrimental impact on the recruitment of native species.