Inter-specific hybridization between Black Sea trout (Salmo labrax Pallas, 1814) and rainbow trout (Oncorhynchus mykiss Walbaum, 1792)

Abstract

Thermal shock-induced triploid and unshocked control hybrids between rainbow trout (Oncorhynchus mykiss) and Black Sea trout (Salmo labrax) and their parental species were produced under hatchery condition by using heat shocks. Triploidization reduced eyed egg rate and alevin yield in all groups. Low survival rate was observed in both shock-induced triploid hybrid and non-shock-induced control hybrids. Although hybrids demonstrated low body weight during the ¢rst feeding stage, they reached higher body weight by day 200 when compared with Black Sea trout and rainbow trout. A higher speci¢c growth rate was calculated as 3.60 in the triploid hybrid groups,1.41in the triploid Black Sea trout groups and 2.27 in the triploid rainbow trout groups between days 110 and 200. A lower condition factor was determined in the hybrid than in the diploid parental species. A negative value of mid-parent heterosis (MPH) performance was deected for condition factor, and a favourable MPH was detected for speci¢c growth rate and weight in hybrids.

The physiological stress response to acute thermal exposure inBlack Sea trout (Salmo trutta labrax Pallas, 1814)

“…Currently, the Black Sea trout is potentially important for the Turkish aquaculture industry and has been cultured on a small scale in almost all trout farms operating in the Black Sea region (2). Free-swimming Black Sea trout are known to move to preferred temperatures due to the constant changes in water temperature.…”

“…The Black Sea trout (Salmo trutta labrax Pallas, 1814) is an endemic trout species inhabiting coastal Black Sea waters and streams that drain into the Black Sea coast of Turkey (1). Currently, the Black Sea trout is potentially important for the Turkish aquaculture industry and has been cultured on a small scale in almost all trout farms operating in the Black Sea region (2). Free-swimming Black Sea trout are known to move to preferred temperatures due to the constant changes in water temperature.…”

Genetic differentiation among distinct karyomorphs of the wolf fish Hoplias malabaricus species complex (Characiformes, Erythrinidae) and report of unusual hybridization with natural triploidy

“…Therefore, triploidization in H. malabaricus is probably associated with disturbance of the process of second polar-body extrusion, induced by natural causes. Few previous studies reported the occurrence of spontaneous triploidization among interspecies hybrids (Beck et al, 1984;Akhan et al, 2010;He et al, 2013). In general, the main cause for natural triploidization in fishes was attributed to the retention of the second polar body, possibly caused by post-ovulatory oocyte ageing (Thorgaard & Gall, 1979;Beck et al, 1984;Flajšhans et al, 1993).…”

Comparative ontogeny of the digestive tract ofOncorhynchus mykiss♀ xSalmo trutta caspius♂ triploid hybrids to their parental species

“…For example, Salmo trutta x Salvelinus fontinalis hybrids are sterile (Scheerer & Thorgaard, 1983). The hybrids of Salvelinus namaycush x S. fontinalis (maintained at low pH, 5.5–7.2) and Salmo labrax x Oncorhynchus mykiss have increased growth rates relative to the parental species by day 200 post‐hatch (Akhan et al., 2011), while O. mykiss x Salvelinus sp. and S .…”