Direct comparison of six methods to induce triploidy in bivalves

Effect of three triploidy induction methods on the growth and survival of larvae and post-larvae of the Caribbean scallopArgopecten nucleus

“…The higher percentage of triploid larvae of A. nucleus obtained with chemical stimuli (27%) in comparison to that obtained with thermal shock (14%) is in agreement with the results reported for other bivalves, such as Mytilus galloprovincialis (Scarpa, Toro, & Wada, ) and Ostrea cucullata (Zeng et al., ). Both chemical treatments (CB and 6‐DMAP) and thermal induction affect the polymerization of structural proteins, inhibiting the cytokinesis or the meiosis and, therefore, the formation of the polar body (Allen et al., ; Beaumont & Fairbrother, ).…”

Induction of triploid embryos by heat shock in the Chilean northern scallopArgopecten purpuratusLamarck, 1819

“…The optimal procedure for triploidy induction and percentage survival at 3 h and at 18 days of culture was 31°C for 10 min and applied 10 min after insemination (meiosis I). The highest levels of triploidy (65.3-66.7 %) obtained with the highest temperature tested in the present study are comparable with those reported for other bivalve species, C. gigas (51-64 %, Quillet & Panelay 1986), T. semidecussatus (56 %, Gosling & Nolan 1989) and Mytilus galloprovincialis (81.2 %, Scarpa et al 1994), but less effective compared with chemical (CB) treatment in other species of scallops with percentage of triploids ranging from 66 to 94% in Argopecten irradians (Tabarini 1984), 88.2% in Chlamys nobilis (Komaru et al 1988); 78.5% in Chlamys varia (Baron et al 1989). According to Allen (1987) one reason for these differences in ploidy production is that heat shocks inhibit all development and only those eggs that were in a specifc stage of cell division will be affected by the high temperature-whereas CB does not appear to arrest development of eggs; so as they reach the vulnerable stage of cell divison they are affected by the chemical.…”

“…The results obtained from this preliminary study show that all the treatments were effective in producing triploid embryos in A. purpuratus, reconfirming the effectiveness of heat shock to induce triploidy in bivalve molluscs (Scarpa et al 1994). Longer treatment times (15 min) produced higher percentages of triploids in the present study; several authors using heat treatment have also found an increased production of triploids with longer times of induction (Quillet & Panelay 1986;Yamamoto et al 1990).…”

“…To induce triploidy in bivalves, heat shock treatments at meiosis I or II are advantageous because of the low cost, the safe handling, and the large amount of eggs that can be treated (Thorgaard 1986;Gosling & Nolan 1989). Heat has been used successfully to induce triploidy in Crassostrea gigas (Quillet & Panelay 1986;, Tapes semidecussatus (Gosling & Nolan 1989), Mytilus edulis Beaumont & Kelly 1989) and Mytilus galloprovincialis (Scarpa et al 1994). Among the species of scallops that have been induced by cytochalasin B (CB) treatment to produce triploids are Argopecten irradians (Tabarini 1984), Chamys nobilis (Komaru et al 1988), and Chlamys varia (Baron et al 1989).…”

Abnormal Gametogenesis, Male Dominant Sex Ratio, and Sertoli Cell Morphology in Induced Triploid Mussels, Mytilus galloprowincialis

“…Triploidy was induced in mussels, Mytilus galloprovincialis, using cytochalasin B (CB) to prevent polar body II formation of fertilized eggs (Scarpa et al, 1994). Briefly, natural mussels were collected in January 1992 from Gokasho Bay, Mie Prefecture, Japan and induced to spawn the same day by air exposure and thermal stimulation.…”