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As a powerful and attractive method for detecting gene expression, qRT-PCR has been broadly used in aquacultural research. Understanding the biology of taimen (Hucho taimen) has attracted increased interest because of its ecological and economic values. Stable reference genes are required for the reliable quantification of gene expression, but such genes have not yet been optimised for taimen. In this study, the stability levels of 10 commonly used candidate reference genes were evaluated using four methods, geNorm, NormFinder, BestKeeper and RefFinder. The expression levels of the 10 genes were detected using samples from 48 experimental groups that consisted of six tissues (blood, heart, brain, gill, skin and liver) collected under five heat-stress conditions (18, 20, 22, 24 and 26°C) and four heat-stress processing times (4, 24, 48 and 96 h). RPS29 and RPL19 were the most stable genes among all the samples, whereas 28S rRNA, ARBPR and 18S rRNA were the least stable. These results were verified by an expression analysis of the heat-stress genes (hsp60 and hsp70) of taimen. In conclusion, RPS29 and RPL19 are the optimal reference genes for qRT-PCR analyses of taimen, irrespective of the tissue and experimental conditions, and these results allow the reliable study of gene expression in taimen.

The complete mitochondrial genome of Rhynchocinetes durbanensis (Rhynchocinetidae: Rhynchocinetes) was sequenced in this study. The genome sequence was 17,695 bp in size, with the base composition of 35.14% A, 32.98% T, 20.34% G and 11.55% C of the light strand. The gene order and genes were the same as that found in other previously reported shrimps, including 13 protein-coding genes, 24 transfer RNA genes and two ribosomal RNA genes. Except for ND5, ND4, ND4L, ND1 genes and eight tRNA genes and two ribosomal RNA genes, all other mitochondrial genes were encoded on the heavy strand. The start codon of COX1 gene was not determined. These complete mitogenome data provide the basis for taxonomic and conservation research of Rhynchocinetes durbanensis, and closely related species.