| Gymnocypris potanini firmispinatus is a subspecies of Gymnocypris potanini. Them belongs to the genus of Gymnocypris, the subfamily of schizothoracinae, the family of Cpyrinidae and the order of Cypriniformes. G. potanini firmispinatus and G. potanini are endemic species in china. During February 2014 to September 2015, 1244 individuals of G. potanini firmispinatus and 13 individuals of G. potanini were collected from Anning River and Minjiang River respectively. Based on surveys, the complete mitochondrial DNA and genetic diversity of G. potanini firmispinatus and G. potanini were analyzed, In addition, the reproductive biology of G. potanini firmispinatus was studied. The main results are as follows:1 The complete mitochondrial genome of G. potanini firmispinatus and G. potanini were respectively 16680bp and 16749bp. They both form closed loop and similar to the sequence of Gymnocypris which have been reported. The orientation and arrangement of genes on the DNA chain are similar to most other sequenced fish mitochondrial DNAs. The mitochondrial genome of G. potanini firmispinatus and G. potanini are composed of 13 proteincoding genes,2 ribosomal RNAs,22 transfer RNAs and a noncoding control region.A total of 3800 and 3790 amino acids were identified in the mitogenome of G. potanini firmispinatus and G. potanini respectively. In these mt genome, all genes use ATG as start codon, except col use GTG. Most open reading frames ended with two types of complete stop codons TAA and TAG, whereas few genes (including coll, nd4 and cytb) had an incomplete stop codon:T.A total of 22 tRNA and two rRNA genes were identified in the G. potanini firmispinatus and G. potanini mt genome. The tRNA sequences were ranged from 68-76 bp, and all of them can be folded into typical cloverleaf secondary structures. The rrnS of G. potanini firmispinatus and G. potanini are located between tRNA-Phe and tRNA-Val, and rrnL is located between tRNA-Val and tRNA-LeuUUR. The length of the rrnS gene of G. potanini firmispinatus is 957 bp and rrnL gene is 1681 bp. The length of the rrnS gene of G. potanini is 958 bp and rrnL gene is 1681 bp.Based on combined nucleotide sequence, phylogenetic trees were constructed using the ME, NJ, MP and UPMGA methods. Throughout the phylogenetic analysis, all Gymnocypris species had close relationship, G. potanini firmispinatus and G. potanini clusrered into one chade, had close relationship.2. Accroding to the genetic structure and diversity analysis of cyt b, col and control region, the average content of A+T exceed C+G, from which five population of G.potanini firmispinatus in An'ning river and two populations of G.potanini in the the Minjiang River, which shows up anti-G-bias. All of the variation sites conversion rate is greater than transversion rate. Respectively each of cytb,coI and control region is 43,28 and 18.We find that cytb has the maximum haplotypes in cytb, col and control region, whose number is 21,13 and 6 respectively. Accroding to the sequence analysis of the cytb and col G.potanini irmispinatus, the index of the G.potanini firmispinatus''s diversity of haplotype and nucleotide are greater than G.potanini's, which is oppsite with the control region.Genetic distance shown that the distance of the G.potanini firmispinatus and G.potanini are longer than other species in the inner-population, but it is less than the Gymnocypris. Based on the analysis of the cytb?col and control region's phylogenetic relationship, we find that G.potanini firmispinatus is closer with G.potanini, which proves that G.potanini firmispinatus is the subspecies of the G.potanini.3. The standard length(SL) of G. potanini firmispinatus ranged 3.6-18.8cm (7.86±1.52cm). The relationship between total length(TL) and body weight(BW) of G. potanini firmispinatus was described as:BW= 0.0025TL3.3943(n=1244), it showed a power function significantly. The relationship between total length(TL) and daily age(D) of G. potanini firmispinatus was described as:TL=0.7574+0.03184D (n=280), it showed a linearly related. The BW-D relationship of G. potanini firmispinatus was described as:BW=-0.03901+5.4383D(n=280), it showed a linear correlation.The range of G. potanini firmispinatus absolute individual fecundity was 1244-1656 eggs (1467.77±121.88 eggs), From the view of G. potanini firmispinatus's gonadal tissue sections in February and April,2014, we found that the stage of ovarian is III ovarian, but oocytes of I and II stages of G.potanini firmispinatus still possess definite proportion. And IV ovarian also exists III oocyte, which showed that it is a batch spawning species.The fertilized eggs of G. potanini firmispinatus are canary yellow, sinking, as well as mild adhesive, and the diameter were 3.01±0.24mm. At the temperature of 12.4± 0.7?, The embryonic developmental stage completed at 269.5 hpf, which included cleavage stage, blastula stage, gastrulation stage, neurula stage, somite apparition stage, heart beats stage and broken shell stage. The newly hatched larvae were 8.41±0.24mm in mean total length (TL). The yolk had been exhausted completely at 15 dph (14.9±0.9?)and 18 dph (12.1±0.2?). At the temperature of 12.4±0.7?, the larvae of G. potanini firmispinatus dorsal fin, anal fin, and forked tail fin formed at 27,40, and 62 dph, respectively. The metamorphosis completed basically and the larvae transformed into juveniles at 113 dph.According to the relationship of incresaing numbers of otolith, combining with the daily age of wild samples and sampling time to calculate the breeding time. The hatching period of juvenile of G. potanini firmispinatus collected in February were from April to September, The hatching period of juvenile of G. potanini firmispinatus collected in April were from May to December, The hatching period of juvenile of G. potanini firmispinatus collected in September were from early December to early April. The peak period were respectively in February, June to July and September to November, which showed that G.potanini firmispinatus is batch spawning species. |
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