| Based on the survey in the waters near Dongying and Xiaying on July 1 and July 2, 2015. This thesis studied the phytoplankton community composition, cell abundance, dominant species, diversities in the survey area and diet composition of juvenile Konosirus punctatus and Liza haematocheila by using conventional method(microscope). Discussing the diet composition of larval and juvenile of Liza haematocheila and Konosirus punctatus and its relationship with phytoplankton.A total of 2 phyla, 23 genera and 28 species of phytoplankton were identified from the water near Xiaying by using microscope, which included 17 genera and 20 species of diatom, 6 genera and 8 species of Pyrrophyta. Dominant species were Thalassiosira rotula, Lithodesmium undulatum, Leptocylindrus danicus, Guinardia delicatula, Surirella sp., Stephanopyxis palmeriana, Cerataulina pelagica, Thalassiosira sp., Licmophora abbreviate, Gymnodinium sp., Karenia mikimotoi.A total of 2 phyla, 30 genera and 44 species of phytoplankton were identified from the stomach of the juvenile Liza haematocheila(near Xiaying) by using microscope, which included 21 genera and 28 species of Bacillariophyta, 9 genera and 16 species of Pyrrophyta. Number percentage and appear frequency percentage of diatom were 92.38% and 73.40%. Number percentage and appear frequency percentage of dinoflagellate were 7.59% and 25.96%. We also found the occurrence of Protozoa but few in number. Liza haematocheila whose body length range from 2.6 cm to5.0 cm divided into 8 individual groups with 2mm intervals. Total cell abundance of each group changed in 175-1303 cells. Total diatom cells abundance changed in 163-1088 cells. Total dinoflagellate cells abundance changed in 4-215 cells. Number percentage of diatom changed in 80.8-94.8%, and the average was 89.1%. Number percentage of dinoflagellate changed in 5.2-19.1%, and the average was 10.8%. The percentage of diatom and dinoflagellate cells abundance were small amplitude variation. Dominant species were Thalassiosira sp., Thalassiosira rotula, Leptocylindrus danicus, Cerataulina pelagica, Lithodesmium undulatum, Surirella sp. and so on. Each length group had different dominant species of phytoplankton. But Thalassiosira sp., Thalassiosira rotula and Lithodesmium undulatum were dominant species in each individual group. The phytoplankton composition similarity between stomach and survey area was high, and the similarity coefficient was more than 60%. The similarity coefficient had no significant change in each individual group. This study showed that the juvenile Liza haematocheila selected dinoflagellate actively and selected diatom randomly.A total of 3 phyla, 41 genera and 65 species of phytoplankton were identified from the stomach of the juvenile Konosirus punctatus(near Dongying) by using microscope, which included 26 genera and 36 species of Bacillariophyta, 14 genera and 28 species of Pyrrophyta, 1 genera and 1 species of chrysophyte. We also found the occurrence of Protozoa but few in number. Number percentage and appear frequency percentage of diatom were 23.17% and 43.38%. Number percentage and appear frequency percentage of dinoflagellates were 70.65% and 49.16%. Number percentage and appear frequency percentage of Protozoa were 6.16% and 7.20%. Konosirus punctatus whose body length range from 2.2 cm to 6.6cm divided into 17 individual groups with 2mm intervals. Total cell abundance of each group changed in 22-346 cells. Total diatom cells abundance changed in 9-56 cells. Total dinoflagellates cell abundance changed in 6-294 cells. Total Protozoa cell abundance changed in 0-42 cells. Number percentage of diatom changed in 5.9%-69.0%, and the average was 41.3%. Number percentage of dinoflagellate changed in 25.0%- 84.2%, and the average was 54.5%. Diatom cell abundance was higher than dinoflagellate in the stomach of Konosirus punctatus whose body length ranged from 2.2 cm to 4.0 cm. Diatom and dinoflagellate cell abundance has been greatly changed in 4.0-5.6 cm length range and dinoflagellate cell abundance was higher than diatom cell abundance. Diatom cell abundance was higher than dinoflagellate in 5.6-6.6 cm length range. Number percentage of Protozoa changed in 0-18.3%, and the average was 4.1%. Protozoa cell abundance was higher than diatom in 4.4-4.6 cm and 4.6-4.8 cm length range. Dominant species were Thalassiosira sp., Gymnodinium sp., Thalassiosira rotula, Coscinodiscus spp., Actinocyclus octonarius, Prorocentrum dentatum, Prorocentrum triestinum, Gymnodinium simplex. |
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