Feeding growth experiments on black porgy, Sparus macrocephalus , were carried out at four ration levels from starvation to satiation and four temperatures ranging from 14.8° to 26.8℃. The energy budget was used...Feeding growth experiments on black porgy, Sparus macrocephalus , were carried out at four ration levels from starvation to satiation and four temperatures ranging from 14.8° to 26.8℃. The energy budget was used to calculate the metabolism in black porgy. Resting metabolism correlated significantly with body weight in power function at 24.4°, 20.1° and 14.8℃ ( R S=aW b ). The model predicting resting metabolism was obtained as: R S=0.0834W 0.8763 ·e 0.0319T . The feeding metabolism correlated linearly with ration level and food consumption. The predicting model of feeding metabolism is: R F=0.5631+0.0341·T-0.0013C·W·T+0.0010W ·T+0.0219C ·W-0.3335C. Using ln( RL+1 ), ln W , ln T and their interaction terms as independent variables, the prediction model of total daily metabolism was obtained by stepwise regression as: ln R T =-1.7328+0.3936ln W +1.1882ln( RL +1)-0.2823ln( RL +1)ln T +0.1555ln W ln T .展开更多
Due to the decreasing resources of both inshore and offshore fisheries, many organizations have released fry to enhance their stock in recent years. The discrimination between wild and hatchery-reared individuals must...Due to the decreasing resources of both inshore and offshore fisheries, many organizations have released fry to enhance their stock in recent years. The discrimination between wild and hatchery-reared individuals must be performed to assess the efficiency of the release. Fresh groundwater is generally used by hatchers in southwesternTaiwanto decrease salinity and to promote the growth of larvae prior to feeding;thus, the elemental composition of the otolith may be different in stocks, and this difference may be used for identification. This study used Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) to analyze the trace elements in the nuclei of otoliths from black porgy Acanthopagrus schlegelii, including six hatchery reared specimens from the Tainan County, three recaptured marked and ten captured unmarked specimens from the Miaoli County in Northwestern coast of Taiwan. Among the six hatchery and three recaptured marked specimens, which ranged from 4.9 to23.4 cmin body length, the nucleus zone (relative to within5 cmin size growth) of the otoliths showed higher magnesium concentrations than that observed on both edges. The distribution was similar to an inverse “V” shape. The otoliths also showed lower manganese concentrations near the nucleus and had higher values near the edges, resulting in a distribution similar to a “U” shape. According to the appeared shape of Mg2+/Ca2+ and Mn2+/Ca2+ ratio in the central area of the nucleus zone, this study determined six specimens which were from hatchery reared and three specimens were from wild among ten unmarked specimens captured from the Northwestern coast of Taiwan. Under the conditions used in this study, the absorption of calcium into the otolith was active and required energy in the seawater and freshwater, while the incorporation of magnesium and manganese was passive and was primarily affected by diffusion.展开更多
Transmission electron microscopy of the yellowfin porgy (Sparus latus Houttuyn) spermatozoa ultrastructure showed the spermatozoon as a primitive type made up of the acrosomeless head , the flagellum , and the midpiec...Transmission electron microscopy of the yellowfin porgy (Sparus latus Houttuyn) spermatozoa ultrastructure showed the spermatozoon as a primitive type made up of the acrosomeless head , the flagellum , and the midpiece , at the periphery of which was a relatively big mitochondrion with more complex structure . It was found that during spermiogenesis, only one relatively big mitochondrion occurred in both the spermatid and the spermatozoon . This is different from other teleost fishes . During spermiogenesis, the mitochondria number is one, and morphology did not change . All these are different fromthose of other fishes .展开更多
文摘Feeding growth experiments on black porgy, Sparus macrocephalus , were carried out at four ration levels from starvation to satiation and four temperatures ranging from 14.8° to 26.8℃. The energy budget was used to calculate the metabolism in black porgy. Resting metabolism correlated significantly with body weight in power function at 24.4°, 20.1° and 14.8℃ ( R S=aW b ). The model predicting resting metabolism was obtained as: R S=0.0834W 0.8763 ·e 0.0319T . The feeding metabolism correlated linearly with ration level and food consumption. The predicting model of feeding metabolism is: R F=0.5631+0.0341·T-0.0013C·W·T+0.0010W ·T+0.0219C ·W-0.3335C. Using ln( RL+1 ), ln W , ln T and their interaction terms as independent variables, the prediction model of total daily metabolism was obtained by stepwise regression as: ln R T =-1.7328+0.3936ln W +1.1882ln( RL +1)-0.2823ln( RL +1)ln T +0.1555ln W ln T .
文摘Due to the decreasing resources of both inshore and offshore fisheries, many organizations have released fry to enhance their stock in recent years. The discrimination between wild and hatchery-reared individuals must be performed to assess the efficiency of the release. Fresh groundwater is generally used by hatchers in southwesternTaiwanto decrease salinity and to promote the growth of larvae prior to feeding;thus, the elemental composition of the otolith may be different in stocks, and this difference may be used for identification. This study used Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) to analyze the trace elements in the nuclei of otoliths from black porgy Acanthopagrus schlegelii, including six hatchery reared specimens from the Tainan County, three recaptured marked and ten captured unmarked specimens from the Miaoli County in Northwestern coast of Taiwan. Among the six hatchery and three recaptured marked specimens, which ranged from 4.9 to23.4 cmin body length, the nucleus zone (relative to within5 cmin size growth) of the otoliths showed higher magnesium concentrations than that observed on both edges. The distribution was similar to an inverse “V” shape. The otoliths also showed lower manganese concentrations near the nucleus and had higher values near the edges, resulting in a distribution similar to a “U” shape. According to the appeared shape of Mg2+/Ca2+ and Mn2+/Ca2+ ratio in the central area of the nucleus zone, this study determined six specimens which were from hatchery reared and three specimens were from wild among ten unmarked specimens captured from the Northwestern coast of Taiwan. Under the conditions used in this study, the absorption of calcium into the otolith was active and required energy in the seawater and freshwater, while the incorporation of magnesium and manganese was passive and was primarily affected by diffusion.
文摘Transmission electron microscopy of the yellowfin porgy (Sparus latus Houttuyn) spermatozoa ultrastructure showed the spermatozoon as a primitive type made up of the acrosomeless head , the flagellum , and the midpiece , at the periphery of which was a relatively big mitochondrion with more complex structure . It was found that during spermiogenesis, only one relatively big mitochondrion occurred in both the spermatid and the spermatozoon . This is different from other teleost fishes . During spermiogenesis, the mitochondria number is one, and morphology did not change . All these are different fromthose of other fishes .
