摘要
本研究采用稳定同位素方法确定了克氏原螯虾在稻虾连作田地中的食物源和营养级,并分析了克氏原螯虾食性与形态学参数、质量参数和出肉率的相关性。在湛江市繁养一体的稻虾连作田地中采集克氏原螯虾正常个体62尾,螯足重生个体6尾,同时采集各类维管植物、中华圆田螺、福寿螺以及饲料样品。对所有样品进行碳、氮稳定同位素测定,采用包含浓度权重的稳定同位素混合模型计算饲料、伊乐藻和菹草对克氏原螯虾腹部肌肉生长的贡献率,通过氮稳定同位素模型计算克氏原螯虾和福寿螺的营养级,并分析克氏原螯虾肌肉碳、氮稳定同位素特征(δ^(13)C和δ^(15)N)、形态学参数(体长、全长、头胸甲长、头胸甲宽、尾扇长)、质量参数(体质量、腹肌质量、螯质量、螯体比)和出肉率的相关性。结果显示:1)采集到正常雌虾30尾、雄虾32尾,虾体质量3.40~29.35 g,均值(14.05±6.26)g。饲料为克氏原螯虾腹部肌肉生长贡献了63.40%生物量、62.28%碳源和75.15%氮源。2)本研究以中华圆田螺作为初级消费者的基线,计算出克氏原螯虾的营养级为2.20,而福寿螺的营养级为2.68。3)小于15 g的虾出肉率与螯质量和螯体比呈极显著负相关(P<0.01),说明螯足生长情况直接影响这部分虾的肌肉生长。大于15 g的虾出肉率与螯质量和螯体比无显著相关性(P>0.05),与腹肌质量和δ^(13)C值呈极显著正相关(P<0.01),说明对饲料的利用情况成为决定这部分虾出肉率的关键因素。4)所有采集的正常螯虾的螯质量与δ^(13)C值呈显著负相关(P<0.05),可以推断螯足发达的个体倾向于更多摄食δ^(13)C值较低的菹草。在饲料充足时,螯足缺失并没有显著影响螯虾的摄食和生长(P>0.05)。研究结果表明,克氏原螯虾食性与其形态学参数、质量参数和出肉率密切相关,饲料是本研究中克氏原螯虾腹部肌肉生长的主要营养源,但即便是在饲料充足的情况下,克氏原螯虾仍然会大量摄食水生植物。传统的氮同位素营养级研究方法可能不适用于受到饲料强烈影响的养殖生态系统。本研究的结果可以为克氏原螯虾选育和稻虾综合养殖模式下的生态学研究提供基础数据。
This experiment was conducted to determine the food source and trophic level of Procambarus clarkii from rice-crayfish field by stable isotope method,and to analyze the correlation between feeding habits,morphology parameters,weight parameters and abdomen meat percentage of P.clarkii.normal(62 individuals)and claw reborned(6 individuals)samples of P.clarkii were collected from the rice-crayfish continuous production field in Zhanjiang.At the same time,vascular plants,snails,as well as diet samples were collected.The stable carbon and nitrogen isotope values of all collected samples were analyzed,the contribution rate of diet,Elodea nuttallii and Potamogeton crispus to the abdomen meat growth of P.clarkii were calculated using a stable isotope mixing model including element concentration,and the trophic levels of P.clarkii and Pomacea canaliculata were calculated by stable nitrogen isotope model.The correlation between stable carbon and nitrogen isotope characteristics(δ^(13) C and δ^(15) N)of abdomen meat,morphological parameters(body length,full length,carapace length,carapace width,tail fan length)and weight parameters(body weight,abdomen meat weight,claw weight,claw body ratio)of the collected crayfish were analyzed.The results showed as follows:1)the collected crayfish included 30 female and 32 male individuals,and the body weight of these crayfish ranged from 3.40 to 29.35 g,average(14.05±6.26)g.The model calculation results showed that diet contributed 63.40% of biomass,62.28% of carbon and 75.15% of nitrogen to the abdomen meat growth of P.clarkii.2)In this study,Cipangopaludina cahayensis was used as the baseline for primary consumers,and the calculated trophic level of P.clarkii was 2.20,while the trophic level of P.canaliculata was 2.68.3)The abdomen meat percentage of P.clarkii(<15 g)collected were extremely negatively correlated with the claw weight and the claw body ratio(P<0.01),indicated that the growth of the claws directly affected the muscle growth of these crayfish.The abdomen meat percentage of P.clarkii(>15 g)were not significantly correlated with the claw weight and the claw body ratio(P>0.05),but were extremely positively correlated with the abdomen meat weight and the δ^(13) C value(P<0.01).It showed that the utilization of diet by these crayfish had become a key factor in determining their abdomen meat percentage.4)There was a significant negative correlation between the claw weight and the δ13 C value(P<0.05)in all collected normal crayfish.It could be inferred that individuals with well-developed claws tend to eat more P.crispus which with lower δ^(13) C value.When the diet was sufficient,the lack of claws did not significantly affect the feeding and growth of P.clarkii(P<0.05).It is concluded that there are significant correlation between feeding habits,morphology parameters,weight parameters,and abdomen meat percentage of P.clarkii,the diet is the main nutrient source for the abdominal muscle growth of P.clarkii in this study,but even when the diet is sufficient,P.clarkii still feeds heavily on aquatic plants.Traditional methods of stable nitrogen isotope trophic level study may not suitable for aquaculture ecosystems which are strongly influenced by diets.The results of this study can provide basic data for the genetic selection of P.clarkii and the ecological research on the integrated breeding model of rice-crayfish.
作者
周晖
汤保贵
龚汉夫
雷元刚
杜书敏
于鸽
吕刚
钟培贵
ZHOU Hui;TANG Baogui;GONG Hanfu;LEI Yuangang;DU Shumin;YU Ge;LYU Gang;ZHONG Peigui(Fisheries College,Guangdong Ocean University,Zhanjiang 524088,China;Yurentang Biotechnology(Zhanjiang)Co.,Ltd.,Zhanjiang 524099,China;Guangdong Evergreen Breeding Technology Service Co.,Ltd.,Zhanjiang 524094,China;Haiste(Zhanjiang)Aquatic Technology Co.,Ltd.,Zhanjiang 524099,China)
出处
《动物营养学报》
CAS
CSCD
北大核心
2023年第4期2455-2464,共10页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
国家海洋局“十三五”海洋经济创新发展示范市项目(XM-202012-03B2)。
关键词
克氏原螯虾
形态学参数
质量参数
出肉率
碳、氮稳定同位素
Procambarus clarkii
morphological parameters
weight parameters
abdomen meat percentage
stable carbon and nitrogen isotopes
