| From July 2013 to September 2014 in Jiangsu Marine Fisheries Research Institute Lusi Mariculture Center,we proceed Cereus sinensis cultivation experiments. In this paper, anemone individuals of Cereus sinensis were cultivated from the parental nurturing, spawning, hatching, breeding, to the anemone adult harvest in the second year. We observed the sea anemone spawning rhythms, characteristic of embryonic development, larval morphology and growth characters, the influence of temperature and food intake during the anemone growth progress, and the foster type of sediment and the bait feeding mode. And a more detailed description was introduced of the anemone Cereus sinensis cultivation points. Refer to look forward to providing basic information for the study of early developmental biology of Cereus sinensis and artificial cultivation.1. Spawning rhythm and characteristics of embryonic development of Cereus sinensisThe anemones were dioecious, the gonad maturation then ruptured, gamete cells excreted from the mouth through the pharynx, complete fertilization in seawater. Through 2013 and 2014 for two years in a row experimentally observed spawning, anemone spawning was found staggering gap type, there were two peak spawning. Cereus sinensis annually spawned in mid-June to mid-August, the total spawning cycle for 50 to 60 days. Spawning water temperature is at 25~30℃. The first peak and the second peak spawning peak interval of 8 to 10 days around.The anemone fertilized egg shape is spherical, egg diameter is about 150~200μm. The fertilized egg was full equality cleavage, by experimental observation, the first division were observed after 20 min, then by 4 cells, 8 cells, 16 cells, 32 cells, 64 cells and multi-cells stage, about 3h anemone eggs developed into the blastocyst stage. Internal blastocyst cell retraction develop into gastrulation. At the bottom end of gastrulation there were 8 to 12 flagellum, and length is about half the original embryo intestine. The early planula individual is about 260 μm. The late planula is about 380~450μm, Eight mesenteries emerge around the mouth correspondence within planula and small intestine eight membrane protrusions primordia become eight tentacles, eight tentacle primordia differentiate eight tentacles. The new eight tentacles primordia grow after the gap between the first row tentacles, followed a new round of tentacles. Cereus sinensis anemone embryos grow 4~5d then attachment, juvenile can move freely in the substrate surface by the contraction of the foot plate. Cereus sinensis anemone larvae do not metamorphosis, after attachment anemone develop into young anemone.2. The growth characters of anemone individualsObserved experimentally, Cereus sinensis anemone larvae oral disc diameter grow up from 3~4 mm to 38~40 mm, anemones individual oral disc grow 1.22 ㎜ daily. By calculating the anemone individual oral disc diameter growth rate η = 5.65%. Fitting anemone oral disc diameter(y) and incubation time(x) of the equation exponentially: y=3.4292x0.723, where R2 = 0.991. By fitting the weight(y) with the oral disc diameter(x) equation for exponential growth relationship, fitting equation: y=0.0064x2.2403, where R2 = 0.7583. Feeding anemone Artemia nauplii, the newborn anemone take in less than 8000ug/d with oral disc diameter less than 10 mm. With the growth of the oral disc diameter, anemone larval food intake significantly increased. With oral diameter about 20 mm, its food intake is maintained at 17000~40000ug/d. By fitting the daily food consumption(y) and oral disc diameter(x) of the equation shows that food intake and outlet plate diameter grow exponentially relationship, the equation is: y=423.3x1.2841, where R2 = 0.7362.At temperature conditions of 16℃, 19℃, 22℃, 25℃, 28℃, 31℃ and 34℃, continuously culture anemone individuals for 22 d, to study the effects of water temperature on the growth of sea anemone larvae. The results show that: anemone oral disc diameter growth rates were 3.87%, 3.64%, 4.76%, 5.34%, 5.28%, 4.53% and 3.22%, and which was 4.21% in the control group. SPSS analysis shows oral disc diameter growth rate of group 25℃ is significantly different(P<0.05) from 16℃, 19℃, 31℃, 34℃ and the control group. And the experimental group of 22℃, 28℃ and 31℃ were not significant different(P> 0.05); the experimental group 34℃ was significantly different(P<0.05) to other groups. Experimental results show that the difference of temperature conditions significantly affected the growth of anemone individuals.3. Effects of substrates and baits feeding on grow of sea anemoneUnder the water temperature conditions at 24~26℃ to study the effects of sandy sediments and free sediment on the growth rate of sea anemones. Sandy sediment anemone oral disc diameter growth rate is 1.71%, and free sediment group growth rate is 1.53%, SPSS analysis shows no significant difference(P> 0.05). Setting the culture density at 33.3ind/m, 50.0ind/m, 66.7ind/m, 88.3ind/m and 100.0ind/m, the experimental results show that anemone oral disc diameter growth rates were 1.73%, 1.66%, 1.55%, 1.43% and 1.29%. SPSS analysis shows no significant difference(P> 0.05). Setting bait feeding frequency at 1.00 time/d, 0.50 time/d, 0.33 time/d, 0.25 time/d and 0.20 time/d, anemone individuals oral disc diameter growth rates are 1.51%, 1.16%, 1.30%, 0.84% and 0.82%. SPSS analysis shows that there is significant difference(P<0.05), in which the group 1.00 time/d and the group 0.25 time/d and group 0.20 time/d, group 0.33 time/d and group 0.20 time/d were significant difference(P<0.01). Bait feeding level are at 0.5g/d, 1.0g/d, 1.5g/d, 2.0g/d and 2.5g/d. SPSS analysis showed that feeding level at 2.5g/d and level at 1.0g/d and 0.5g/d are significant difference(P <0.05). |
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