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Comparison of methods for hatchery‐scale triploidization of European catfish ( Silurus glanis L.)
Author(s) -
Linhart O.,
Haffray P.,
OzoufCostaz C.,
Flajšhans M.,
Vandeputte M.
Publication year - 2001
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1046/j.1439-0426.2001.00299.x
Subject(s) - biology , catfish , gamete , gametogenesis , zoology , hatchery , hydrostatic pressure , ploidy , andrology , botany , horticulture , sperm , fish <actinopterygii> , embryo , fishery , cryopreservation , biochemistry , medicine , physics , gene , thermodynamics
Heat‐, cold‐ and hydrostatic pressure shocks were applied in order to improve triploidy induction in European catfish ( Silurus glanis L . ). A 41°C heat shock (45 s, starting 9 min after gamete activation) provided 88% triploids and a high percentage of malformation (38.8 ± 4.1%). The superior 6°C cold shock (20 min, starting 9 min after gamete activation) gave 100% triploids and a 33.4 ± 3.8% triploid yield. The earliest hydrostatic treatments (600 kg cm 2 ), lasting 4 min and starting 3 min after gamete activation, gave 97.8 ± 1.8% triploids and a 33.7 ± 16.9% triploid yield. The ploidy level was investigated using four approaches: karyotyping, quantification of Ag‐stained nucleoli per cell, flow cytometry, and erythrocyte nuclear sizing by computer‐assisted image analysis. Induction of triploidy under mass conditions in three experiments gave triploid percentages of 74%, 83% and 66%. Five months later, the percentage of triploids significantly decreased to 12.4%, 8.2% and 21.4%. The growth performance of yearlings was better in diploids than in triploids. Differences between diploids and triploids were 13.5% (NS), 27.6% (P < 0.001) and 25.4% (P < 0.05) in the three experiments. Analysis of variance showed the influence of ploidy (P < 0.001) on growth rate, and multiple range analysis (LSD) assessed differences between total diploids (12.6 g) and total triploids (9.5 g) at the P < 0.01 level.