GB/T 21441-2018 in English

1. Background and significance of the standard

As an important marine aquaculture fish, Paralichthys olivaceus occupies an important position in my country's aquatic industry. GB/T 21441—2018 replaces the original GB/T 21441—2008, and comprehensively revises and improves the scientific name and classification, morphological characteristics, growth and reproduction characteristics, and molecular biological characteristics of Paralichthys olivaceus.

2. The scientific name and classification of the olivaceous flounder

olivaceous flounder belongs to the class Actinopterygi, order Pleuronectiformes, family Paralichthyidae and genus Paralichthys. Its scientific name is Paralichthys olivaceus Tmminck & Schlegel.

3. Morphological characteristics of the Japanese flounder

The body of the Japanese flounder is long and oval, flat, with two eyes on the left side of the head. The side with eyes is covered with small ctenoid scales, which are brown, yellowish brown or grayish yellow, usually with three dark black spots, and the side without eyes is covered with round scales, which are white.

4. Growth and Reproductive Characteristics

The relationship between body length and weight of Japanese flounder is in the form of power function growth, and the regression equation is as follows:

5. Cytogenetic Characteristics

The number of chromosomes of Japanese flounder is 2n=48, and the karyotype formula is 48 t, NF=48。

6. Molecular genetic characteristics

The COI gene sequence fragment is as follows (partial): GGATAGTGGG GACAGCCCTA AGCCTCCTCA TTCGGGCAGA ACTCAGCCA

7. Implementation recommendations

To ensure the effective implementation of the standard, it is recommended that:

• Strictly carry out sampling and testing in accordance with the standard (see 8.1-8.5).
• Regularly monitor the full length and weight of different age groups (see Appendix A).
• Establish a germplasm identification database to ensure genetic diversity and purity.