Horizontal starch gel electrophoresis was used to investigate the biochemical genetic structure of Chinese mitten crab Eriocheir sinensis and Hepu mitten crab E.hepuensis. Sixteen putative enzyme-coding loci were exam...Horizontal starch gel electrophoresis was used to investigate the biochemical genetic structure of Chinese mitten crab Eriocheir sinensis and Hepu mitten crab E.hepuensis. Sixteen putative enzyme-coding loci were examined for forty-nine Chinese mitten crabs and thirty-eight Hepu mitten crabs. Nine loci, AAT-1 *, AAT-2 *, G3PDH *, GPI *, IDHP-1 *, IDHP-2 *, MDH-1 *, MDH-2 * and PGM *, are polymorphic in Chinese mitten crab, and seven, AAT-1 *, AAT-2 *, GPI *, IDHP-1 *, MDH-1 *, MDH-2 * and PGM *, are polymorphic in Hepu mitten crab. The proportion of polymorphic loci and the expected heterozygosity are 0.562 5 and 0.080 3 for Chinese mitten crab, and 0.437 5 and 0.075 4 for Hepu mitten crab. The Nei’s genetic distance between two species is 0.002 4.展开更多
Mesocosm hatcheries using semi-intensive culture methodologies are characterized by large tanks （40 m3） for fish larvae production at low densities （2-8 larvae/L）, with live prey production within the tank supplem...Mesocosm hatcheries using semi-intensive culture methodologies are characterized by large tanks （40 m3） for fish larvae production at low densities （2-8 larvae/L）, with live prey production within the tank supplemented by exogenous sources of feed. Due to the high biological quality of larvae produced and low level of technological input, these methodologies are regarded as an interesting option to meet the increasing fry demand from the aquaculture industry. This study aimed to describe the experience at Centro de Maricultura da Calheta, Madeira Island, Portugal, with the establishment of a mesocosm hatchery for the production of marine fish larvae. Production trials were initiated with gilthead seabream Sparus aurata. This larval species presented faster growth in total body length （TL） per day （TL = 3.7516e~ ~293day, R2 = 0.9404）, higher survival rate （SR = 31.9%） and comparable swimbladder inflation rates （SB = 90%） to those of larvae reared with intensive methodologies. High larval performance was obtained with two candidate species for aquaculture： the red porgy Pagruspagrus （TL = 3.212e~~39day, R2 = 0.995; SR = 15.3%; SB = 95.7%） and the white seabream Diplodus sargus （TL = 3.6355e~~413day, R2= 0.9824; SR = 25%; SB --- 100%）. Testing ofa 110 m3 mesocosm rearing tank with white seabream larvae revealed limitations associated to larger tanks namely, the amount and quality of live feed required daily. First trials with striped jack （Pseudocararoc dentex） larvae resulted in low larval survival （0.04%）, but the use of a white tank avoided culture management constraints related to positive phototropism. The present results suggest that a mesocosm using semi-intensive methodologies may contribute to species diversification and consequently, to the sustainable development of aquaculture.展开更多
文摘Horizontal starch gel electrophoresis was used to investigate the biochemical genetic structure of Chinese mitten crab Eriocheir sinensis and Hepu mitten crab E.hepuensis. Sixteen putative enzyme-coding loci were examined for forty-nine Chinese mitten crabs and thirty-eight Hepu mitten crabs. Nine loci, AAT-1 *, AAT-2 *, G3PDH *, GPI *, IDHP-1 *, IDHP-2 *, MDH-1 *, MDH-2 * and PGM *, are polymorphic in Chinese mitten crab, and seven, AAT-1 *, AAT-2 *, GPI *, IDHP-1 *, MDH-1 *, MDH-2 * and PGM *, are polymorphic in Hepu mitten crab. The proportion of polymorphic loci and the expected heterozygosity are 0.562 5 and 0.080 3 for Chinese mitten crab, and 0.437 5 and 0.075 4 for Hepu mitten crab. The Nei’s genetic distance between two species is 0.002 4.
文摘Mesocosm hatcheries using semi-intensive culture methodologies are characterized by large tanks （40 m3） for fish larvae production at low densities （2-8 larvae/L）, with live prey production within the tank supplemented by exogenous sources of feed. Due to the high biological quality of larvae produced and low level of technological input, these methodologies are regarded as an interesting option to meet the increasing fry demand from the aquaculture industry. This study aimed to describe the experience at Centro de Maricultura da Calheta, Madeira Island, Portugal, with the establishment of a mesocosm hatchery for the production of marine fish larvae. Production trials were initiated with gilthead seabream Sparus aurata. This larval species presented faster growth in total body length （TL） per day （TL = 3.7516e~ ~293day, R2 = 0.9404）, higher survival rate （SR = 31.9%） and comparable swimbladder inflation rates （SB = 90%） to those of larvae reared with intensive methodologies. High larval performance was obtained with two candidate species for aquaculture： the red porgy Pagruspagrus （TL = 3.212e~~39day, R2 = 0.995; SR = 15.3%; SB = 95.7%） and the white seabream Diplodus sargus （TL = 3.6355e~~413day, R2= 0.9824; SR = 25%; SB --- 100%）. Testing ofa 110 m3 mesocosm rearing tank with white seabream larvae revealed limitations associated to larger tanks namely, the amount and quality of live feed required daily. First trials with striped jack （Pseudocararoc dentex） larvae resulted in low larval survival （0.04%）, but the use of a white tank avoided culture management constraints related to positive phototropism. The present results suggest that a mesocosm using semi-intensive methodologies may contribute to species diversification and consequently, to the sustainable development of aquaculture.
