We investigated the early embryonic and larval development of the concave-eared torrent frogs, Odorrana tormota （Amphibia, Anura, Ranidae）. Embryos were derived from artificial fertilization of frogs’ eggs, and the...We investigated the early embryonic and larval development of the concave-eared torrent frogs, Odorrana tormota （Amphibia, Anura, Ranidae）. Embryos were derived from artificial fertilization of frogs’ eggs, and the staging of development was based on morphological and physiological characteristics. Two major periods of development were designated： i） early embryonic period, from fertilization to operculum completion stage, lasted for 324 h at water temperature （WT） 18 ？23℃; ii） larval period, from operculum completion stage to tail absorbed stage, took 1207 h at WT 20 ？ 24℃. Tadpoles of the concave-eared torrent frogs showed no evidence of abdominal sucker. Absence of this key characteristic supports the view from molecular systematics that concave-eared torrent frog does not belong to the genus Amolops. Two cleavage patterns were observed in embryos at 8-cell and 16-cell stages, with Pattern I2 （latitudinal cleavage at the 8-cell stage, and meridional cleavage at the 16-cell stage with two perpendicular meridional furrows） being the predominant pattern and only 1.5% belonging to Pattern II （meridional cleavage at the 8-cell stage and latitudinal cleavage at the 16-cell stage）. The factors affecting cleavage and hatching ratios, developmental speed, and ecological adaptation were discussed.展开更多
In this study, the basic composition and microbiological properties of traditional Mud （Gamur） cheese produced in Tire region of Turkey was evaluated. The total solids, fat, protein, water soluble nitrogen （WSN）, ...In this study, the basic composition and microbiological properties of traditional Mud （Gamur） cheese produced in Tire region of Turkey was evaluated. The total solids, fat, protein, water soluble nitrogen （WSN）, acid value of cheese, fat, salt, titratable acidity, pH levels in Mud cheeses were variable according to whey characteristics used in their production. Wide variations were found in the total bacteria, Coliform bacteria, Staphylococcus aureus, yeast-mould, Lactobacillus spp. and Streptococcus spp. counts of cheese samples. The presence of coliforms, Staph. aureus and yeast-moulds indicate poor hygienic conditions of cheese production.展开更多
基金supported by the National Natural Science Fundation of China(30730029)
文摘We investigated the early embryonic and larval development of the concave-eared torrent frogs, Odorrana tormota （Amphibia, Anura, Ranidae）. Embryos were derived from artificial fertilization of frogs’ eggs, and the staging of development was based on morphological and physiological characteristics. Two major periods of development were designated： i） early embryonic period, from fertilization to operculum completion stage, lasted for 324 h at water temperature （WT） 18 ？23℃; ii） larval period, from operculum completion stage to tail absorbed stage, took 1207 h at WT 20 ？ 24℃. Tadpoles of the concave-eared torrent frogs showed no evidence of abdominal sucker. Absence of this key characteristic supports the view from molecular systematics that concave-eared torrent frog does not belong to the genus Amolops. Two cleavage patterns were observed in embryos at 8-cell and 16-cell stages, with Pattern I2 （latitudinal cleavage at the 8-cell stage, and meridional cleavage at the 16-cell stage with two perpendicular meridional furrows） being the predominant pattern and only 1.5% belonging to Pattern II （meridional cleavage at the 8-cell stage and latitudinal cleavage at the 16-cell stage）. The factors affecting cleavage and hatching ratios, developmental speed, and ecological adaptation were discussed.
文摘In this study, the basic composition and microbiological properties of traditional Mud （Gamur） cheese produced in Tire region of Turkey was evaluated. The total solids, fat, protein, water soluble nitrogen （WSN）, acid value of cheese, fat, salt, titratable acidity, pH levels in Mud cheeses were variable according to whey characteristics used in their production. Wide variations were found in the total bacteria, Coliform bacteria, Staphylococcus aureus, yeast-mould, Lactobacillus spp. and Streptococcus spp. counts of cheese samples. The presence of coliforms, Staph. aureus and yeast-moulds indicate poor hygienic conditions of cheese production.
