Complete mitochodrial genome of the redlip loach Leptobotia rubrilaris (Teleostei, Cypriniformes: Cobitidae).

In this study, the complete mitochondrial genome sequence of the Leptobotia rubrilaris has been obtained. The genome includes 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and a non-coding control region with the total length of 16,585 bp. The gene arrangement and composition were identical to other vertebrate. Most of the genes are encoded on heavy strand, except for eight tRNA and ND6 genes. The complete mitochondrial genome sequence of L. rubrilaris would contribute to better understand population genetics and protect its genetic diversity.

The mitochondrial genome of Mystacoleucus marginatus (Cypriniformes, Cyprinidae).

The mitochondrial genome of Mystacoleucus marginatus (Cypriniformes, Cyprinidae) has been sequenced. The total sequence is 16,611 bp in size with 56.67% AT content. It contains 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs and 1 putative control region. The gene content and organization are similar to that of most other vertebrates. Most genes are encoded on the heavy strand except ND6 and eight tRNA genes on light strand. This molecular information will contribute to better understand its evolution and population genetics.

[Effects of surgically implanted dummy ultrasonic transmitters on grass carp Ctenopharyngodon idella].

In order to study the effects of surgically implanted dummy ultrasonic transmitters on grass carp Ctenopharyngodon idella, two experiments were conducted from October 2010 to December 2010 and November 2010 to October 2011. The results showed that surgical implantation of dummy ultrasonic transmitters had a significant negative influence on the growth of grass carp within 30 days following the surgery. However, the negative influence after 30 days faded away. One and two fish died during the 60-day and 360-day experiments, equivalent to the mortalities of 4.2% and 6.7%, respectively. All fish incisions were completely healed in 30 days after surgery, and all sutures were lost in 360 days after surgery. Two and one fish expelled the transmitters through the unclosed wound during the 60 days and 360 days, and the discharges were 8.7% and 3.3%, respectively. All the remaining transmitters were encapsulated in fibrous capsules and adhered to body wall, intestinal tract or viscera multiply. The result suggested that surgical implantation of ultrasonic transmitters could be applied to the ultrasonic telemetry research on grass carp. Nevertheless, the grass carp should be given for at least 30 days with the purpose of incision healing and growth recovery from the surgical procedure.

The mitogenome of Leptobotia microphthalma (Teleostei, Cypriniformes: Cobitidae).

The Leptobotia microphthalma belongs to family Cobitidae, which is endemic to the upper reaches of the Yangtze River in China. In this studying, the complete mitochondrial genome sequence of L. microphthalma has been obtained with PCR, which contains 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and a non-coding control region with the total length of 16,512 bp. The gene arrangement and composition are similar to that of other vertebrates. Most of the genes are encoded on heavy strand, except for eight tRNA and ND6 genes. The complete mitochondrial genome sequence of L. microphthalma would contribute to better understand population genetics and protect its genetic diversity.

[Age structure and genetic diversity of Homatula pycnolepis in the Nujiang River basin].

This study examined the age structure of the Loach, Homatula pycnolepis through the otolith growth rings in 204 individual specimens collected from the Xiaomengtong River of the Nujiang River (Salween River) basin in April, 2008. There were only two different age classes, 1 and 2 years of age-no 3 year olds were detected. The age structure of H. pycnolepis was simple. The complete mitochondrial DNA cytochrome b gene sequences (1140) of 80 individuals from 4 populations collected in the Nujiang River drainage were sequenced and a total of 44 variable sites were found among 4 different haplotypes. The global haplotype diversity (Hd) and nucleotide diversity (Pi) were calculated at 0.7595, 0.0151 respectively, and 0, 0 in each population, indicating a consistent lack of genetic diversity in each small population. There was obvious geographic structure in both the Nujiang River basin (NJB) group, and the Nanding River (NDR) group. The genetic distance between NJB and NDR was calculated at 0.0356, suggesting that genetic divergence resulted from long-term isolation of individual population. Such a simple age structure and a lack of genetic diversity in H. pycnolepis may potentially be due to small populations and locale fishing pressures. Accordingly, the results of this study prompt us to recommend that the NJB, NDR and Lancang River populations should be protected as three different evolutionary significant units or separated management units.

[Effects of transmitter's surgical implantation on fish: research progress].

Surgical implantation is generally accepted as the preferred attachment method for longterm fish telemetry study, but the negative effects of this surgical implantation on fish should not be ignored. The key for the successful fish telemetry study is that the existence and attachment of the transmitters in the experimental fish would not have negative effects on the normal fish physiology or behavior. Therefore, it is necessary to assess the potential negative effects of surgical implantation of transmitter on experimental fish prior to telemetry monitoring. This paper reviewed the overseas research progress in the effects of surgical implantation of transmitter on fish, and discussed the possible negative effects and affecting degrees of transmitters, surgical procedure, environmental factors, ad anthropogenic factors in the process of transmitter' s surgical implantation in fish. Some suggestions were put forward to reduce the potential negative effects, and the research directions of surgically implanted transmitters in fish in China were prospected.