Hybridization behaviour between two common European cyprinid fish species – silver bream, Blicca bjoerkna and common bream, Abramis brama – in a controlled environment

Abstract

Th e egg release-mating comparison, heterospecifi c matings and mating success under two hybridization conditions -(i) mixing one sex per species and (ii) mixing both sexes from each species -were investigated to determine whether silver bream Blicca bjoerkna and common bream Abramis brama can hybridize in nature.Th e results revealed that non-matings in hybridization experiments of silver bream females × common bream males can be explained by territorial and aggressiveness activities observed in common bream. In common bream females × silver bream males, heterospecifi c matings were observed but their numbers were signifi cantly lower than the spawning numbers, and in this experiment, a female mated with one to four heterospecifi c males. In mixing both sexes from both species, similar spawning -mating numbers were observed but heterospecifi c matings accounted for only 27% of the total matings, with 24% accounting for heterospecifi c matings between common bream females and silver bream males, directly or by opportunism. Mating success was characterized by the occurrence of fertilized eggs after matings.Natural hybridization occurred preferentially between common bream females and silver bream males. © Koninklijke Brill NV, Leiden, 2009.

Behavioural Study of Polyandrous Spawning inBlicca bjoerknaUnder a Controlled Environment

“…The main trend shown was greater mating activity observed in conjunction with greater following behaviour. The absence of aggressiveness and territoriality in silver bream males observed during these reproduction experiments is consistent with the behaviour of the species and the results of Poncin et al (2004) and Nzau Matondo et al (2008Matondo et al ( , 2009 obtained in experimental environments. Between males, interactions consisted of the fact that when the males do not follow a female, they are resting or swimming one behind the other calmly and ready to rush toward her at the slightest movement.…”

“…Fish were injected the day after their capture. According to Poncin et al (1994) and Nzau Matondo et al (2009), hormonal injection was used to synchronise the spawning activity and to reduce experimental time to 2 days only. The time between the hormonal treatment and the first spawning attempt varied between 190 and 330°h (number of hours × temperature in degrees).…”

“…Investigating the reproductive behaviour of the silver bream would increase the knowledge on this poorly studied species in terms of its reproductive strategies and tactics. It is known that sexual behaviours are involved in the success of intra-species genetic diversity that are useful for the survival of the offspring in the wild (Becher & Magurran 2004, Barbosa & Magurran 2006, Nzau Matondo et al 2007, and the hybridisation processes of silver bream with other sympatric cyprinid fish such as the roach Rutilus rutilus and the common bream Abramis brama (Nzau Matondo et al 2009). Therefore, this study aims (1) to describe the reproductive activity of the silver bream with precise data, including the behaviour of the male following Introduction Silver bream Blicca bjoerkna is a common cyprinid fish species in European waters (Spillmann 1961, Wheeler 1969).…”

Spawning behaviour and mating success in hybrids of silver bream (Blicca bjoerkna L.) and rudd (Scardinius erythrophthalmus L.) in an experimental environment

“…The female ready to release eggs moved to the spawning substrate, and in a successful spawning act, female and males with gaping mouths and pectoral fins deployed, released eggs and sperm in a twisting movement of the body signaled by trembling movements and violent splashing. Spawning takes place only on spawning substrate, confirming the phytophilous of the parental species (Philippart and Vranken, 1983;Nzau Matondo et al, 2009). The mating combination of the female hybrid and its three corresponding males most frequently observed, indicates that these hybrids have a polyandrous mating system which could give as in no hybrids fish species many advantages useful for the survival of offspring such as high fertility, prevention of inbreeding and maintenance genetic diversity (Kellogg et al, 1998;Arnqvist and Nilsson, 2000;Becher and Magurran, 2004;Ivy and Sakaluk, 2005).…”

Dynamics of indices of metabolism in muscle tissue, liver and gonads of Abramis brama in different periods of the annual cycle

“…In the muscular tissue of females of Teleostei, including Cyprinidae, during spawning, decrease in lipids was seen (Wallace & Selman, 1981;Guijarro et al, 2003). The main expenditure of carbohydrates in the organism of male bream in this period is probably associated with the reproductive behaviour regulated by hormones: individuals become aggressive and their moving activity increases (Diamond, 1985;Zaboukas et al, 2006;Matondo et al, 2009;Munakataa & Kobayashib, 2010;Poncin et al, 2011). For the gonadal products of fish, some part of proteins, further transported to the gonads of the serum blood, synthesizes directly in the liver (Plack et al, 1971).…”