Publication abstract

Growth and reproduction of native crucian carp Carassius carassius in small ponds of Epping Forest, southeast England

 A.S. Tarkan, G.H. Copp*, G. Zieba*, M.J. Godard* and J. Cucherousset 

Crucian carp Carassius carassius is native to southeast England, but few studies exist on its growth and reproduction in England, and the species is threatened by introductions of its Asiatic congener, goldfish Carassius auratus. To increase our knowledge of the crucian carp as a means of aiding in its conservation, the present study assesses the growth (back-calculated length at age, body condition) and reproduction (fecundity, egg size, length and age at maturity) of crucian carp in small ponds of Epping Forest (northeast London, England). Evaluation of our growth and reproduction data with published data for populations from Northern Europe (i.e. latitude ≥ 50°) suggest that growth is very variable, even within the same area, and that data on reproductive indices, in particular length and age at maturity, are scarce. In the England, somatic growth and body condition were greatest in the crucian carp population living in sympatry with feral goldfish Carassius auratus, where crucian carp relative fecundity (eggs per body weight) was also significantly higher (though length and age at maturity were similar in all populations). This suggests a possible maximization of somatic growth and reproductive output in crucian carp when confronted by coexistence with feral goldfish. However, data from a larger number of populations, both in allopatry and sympatry with feral goldfish, are required to determine

Reference:
A.S. Tarkan, G.H. Copp*, G. Zieba*, M.J. Godard* and J. Cucherousset  (2009)  Growth and reproduction of native crucian carp Carassius carassius in small ponds of Epping Forest, southeast England. Aquatic Conservation: Marine & Freshwater Ecosystems, 19; 797-805