Differences in the antibody response and survival of genetically different varieties of common carp (Cyprinus carpio L.) vaccinated with a commercial Aeromonas salmonicida/A. hydrophila vaccine and challenged with A. hydrophila

Males of two strains of carp, wild Duna (D), and inbred Szarvas 22 (22), were selected for high and low stress response. Two purebreds of D and 22, from randomly chosen parents and four crosses, 22 × 22-L (low stress response), 22 × 22-H (high stress response), 22 × D-L (low stress response) and 22 × D-H (high stress response) from selected stress response parents were produced and vaccinated with a commercial Aeromonas salmonicida/Aeromonas hydrophila vaccine and their circulating antibody response evaluated 1, 3, 5, and 7 weeks post-vaccination by ELISA. Significantly higher titres of circulatory antibodies against A. hydrophila were found in the families 22 and cross 22 × 22-L compared to other groups. The development of circulatory antibodies against A. hydrophila in all crosses having at least one D parent was low and remained low throughout the experiment. The level of circulatory antibodies against atypical A. salmonicida in the inbred strain increased following a booster vaccination with the highest values measured in inbred strain 22 and cross 22 × 22 L. The different varieties of carp had different levels of survival against experimental challenge with A. hydrophila. The greatest survival was obtained in strain 22 and cross 22 × 22-L, while ~90% of D wild carp and cross 22 × D (independent of their stress response) died. Survival results correlated well with the antibody response of the different groups: 22 and 22 × 22-L had the highest antibody titres against A. hydrophila and the greatest level of survival

Analysis of early growth of guppy strains, Poecilia reticulata, with different color patterns

10.1007/BF00261237Theoretical and Applied Genetics775645-650THAG

A lethal effect associated with polymorphism of the NOR-bearing chromosomes in rainbow trout (Oncorhynchus mykiss)

Cytogenetic analysis of a rainbow trout stock showed that the nucleolar organizing regions were located subterminally on the long arm of a submetacentric chromosome pair and occurred as a single chromosomal segment (phenotype N1) or as two chromosomal segments separated by a short euchromatic segment (phenotype N2). Cytogenetic analysis also showed that there were N1N1 and N1N2 individuals but no N2N2 individuals. Analysis of the different includedphenotypes incluted that the population was not in Hardy-Weinberg equilibrium (chi² = 19.333; p < 0.01), and that a higher frequency of individuals had the N1N2 phenotype. Experimental crosses involving four males (two N1N1 and two N1N2) and four females (one N1N1 and three N1N2) yielded eight broods. There were no significant differences between the expected and observed frequencies of offspring resulting from crosses involving N1N1 x N1N2 individuals. However, significant differences were seen in crosses involving N1N2 x N1N2 parents because of the a high incidence of N1N2 fishes and the absense of N2N2. The lack of N2N2 individuals in the parental sample and their absence among the offspring of the experimental crosses suggested that this genetic combination may be lethal in rainbow trout. The survival rates of embryonic "eyed egg" and fry stage individuals were not different, indicating that the possible lethal effect may occur during more advanced ontogenetic phases

Reproductive strategies and genetic variability in tropical freshwater fish

We estimated the genetic variability of nine fish species from the Brazilian upper Paraná River floodplain (Astyanax altiparanae, Hoplias malabaricus, Leporinus lacustris, Loricariichthys platymetopon, Parauchenipterus galeatus, Pimelodus maculatus, Rhaphiodon vulpinus, Roeboides paranensis and Serrasalmus marginatus) based on data for 36 putative allozyme loci obtained using corn starch gel electrophoresis of 13 enzymatic systems: aspartate aminotransferase (EC 2.6.1.1), acid phosphatase (EC 3.1.3.2), esterase (EC 3.1.1.1), glycerol-3-phosphate dehydrogenase (EC 1.1.1.8), glucose-6-phosphate dehydrogenase (EC 1.1.1.49), glucose-6-phosphate isomerase (EC 5.3.1.9), Iditol dehydrogenase (EC 1.1.1.14), isocitrate dehydrogenase - NADP+ (EC 1.1.1.42), L-lactate dehydrogenase (EC 1.1.1.27), malate dehydrogenase (EC 1.1.1.37), malate dehydrogenase-NADP+ (EC 1.1.1.40), phosphoglucomutase (EC 5.4.2.2) and superoxide dismutase, (EC 1.15.1.1). The mean expected heterozygosity varied from zero to 0.147. When data from the literature for 75 species of tropical fish were added to the nine species of this study, the heterozygosity values differed significantly among the groups of different reproductive strategies. The highest mean heterozygosity was for the non-migratory without parental care, followed by the long-distance migratory, and the lowest mean was for the non-migratory with parental care or internal fecundation