金乌贼性腺发育的特征及初次性成熟胴长估算

作为我国重要的头足类资源,金乌贼（Sepia esculenta Hoyle, 1885）具有较高的经济价值和营养价值。为探究金乌贼性腺发育、胴长体质量关系、初次性成熟胴长（ML50）,本文根据2017-2022年拖网渔船在东海北部外海（123.0°E-127.5°E,27.5°N-31.5°N）采集的金乌贼调查数据,分别通过统计学分析探究胴长和体质量组成及性腺发育,采用基于性腺成熟度的逻辑斯蒂方程和多项式胴长体质量方程估算初次性成熟胴长。结果显示,金乌贼雌雄个体优势胴长组分别为80-120 mm、80-140 mm;优势体质量组分别为40-280 g、40-200 g。金乌贼为负异速生长（b<3）;不同阶段的雌性a、b值不同,雄性a、b值相近。调查期间（9月至翌年3月）,性腺随时间发育;160 mm以上的胴长组中未有Ⅰ期个体被发现。应用逻辑斯蒂方程和多项式胴长体质量模型估算ML50结果分别为：雌性124.30mm、127.98mm、雄性129.18mm、142.44mm。基于多项式胴长体质量方程估算的ML50拟合效果更好。研究表明,金乌贼存在明显的季节性生殖特征,繁殖期为1-3月;雌性在性成熟期间能量更多的从身体生长转变为性腺发育;建议东海外海金乌贼雌、雄个体最小开捕胴长应当分别大于127.98mm、142.44mm。     

乌贼墨多糖对环磷酰胺介导小鼠睾丸氧化应激损伤的干预效应

[目的]探讨乌贼墨多糖对环磷酰胺致小鼠睾丸氧化应激损伤的保护作用.[方法]随机将70只成年雄性昆明小鼠分成7组：正常组、模型组、治疗组1、治疗组2、治疗组3、治疗组4和治疗组5,通过对小鼠腹腔注射环磷酰胺进行造模,灌胃乌贼墨多糖作为化疗保护剂,检测小鼠的体重、睾丸和附睾重量、睾丸指数和附睾指数、精子畸形率、睾丸中抗氧化指标,同时观察睾丸组织结构.[结果]乌贼墨多糖能提高小鼠体重和睾丸重量,降低精子畸形率,提高睾丸组织中抗氧化酶SOD和CAT活性,降低MDA含量,修复睾丸病理学损伤.乌贼墨多糖明显缓解环磷酰胺对睾丸的氧化损伤,其最佳灌胃剂量为80 mg/kg.[结论]乌贼墨多糖有可能作为临床上的化疗辅助药物.     

金乌贼雄性规格和社群数量对求偶与交配行为的影响

为探讨不同规格雄性金乌贼(Sepia esculenta)在求偶交配过程中的竞争及优势等级,采用实验生态学方法,在室内可控条件下分别设置1L1S组、1L2S组和1L4S组(L和S分别表示大规格雄性和小规格雄性,数字表示实验中雄性金乌贼数量),连续摄像观察和记录金乌贼的繁殖行为。结果显示:(1)繁殖过程中金乌贼具有明显的领域行为和护卫伴游行为。(2)随着群体中小规格雄性比例的增加,处于优势地位的大规格雄性个体的优势等级发生变化,主要表现为大规格雄性护卫伴游时间、成功交配次数逐渐减少,而小规格雄性护卫伴游时间、成功交配次数逐渐增多。(3)当群体中小规格雄性较少时,大规格雄性常常主动攻击小规格雄性,而当小规格雄性数量远大于大规格雄性时,小规格雄性主动向其他雄性发起攻击,以争取护卫权和交配权。研究表明,雄性金乌贼的规格和数量对于求偶竞争以及交配行为具有显著影响。随着繁殖群体中小规格雄性增多,大规格雄性成功交配次数逐渐降低。1L4S组成功交配次数稍高于1L2S组,显著高于1L1S组(P0.05)。人工苗种繁育过程中选择合适规格的雄性亲体和合理的雌雄比例,对提高金乌贼繁殖效率具有重要意义。     

乌贼墨多肽体外抗氧化活性研究

[目的]研究乌贼墨多肽体外抗氧化活性。[方法]采用分光光度法测定多肽对2,2’-连氮基-双-（3-乙基苯并二氢噻唑林-6-磺酸）二铵盐（ABTS）、1,1-二苯基-2-三硝基苯肼（DPPH）、羟自由基（·OH）的清除能力和还原能力,利用琼脂糖凝胶电泳检测多肽对羟自由基诱导的DNA损伤的保护作甩。[结果]乌贼墨多肽具有明显清除ABTS自由基（半数有效浓度EC。为3．45mg／ml）、·DPPH自由基（EG。为4．34mg／m1）和羟自由基（E‰为3．30mg／ml）的能力;当乌贼墨多肽的浓度达到5．00mg／ml时,还原力达到0．387。[结论]乌贼墨多肽具有较好的抗氧化活性。     

Growth performance and nutritional composition of Sepia pharaonis under artificial culturing conditions

This study investigated the growth performance and nutritional composition of scale artificially cultured cuttlefish Sepia pharaonis. Juveniles were cultured in an open‐culturing cement pool system for 120 days. The body weight increased from 10.21 ± 1.44 g to 570.71 ± 126.32 g from 50 days old to 170 days old, and the average growth rate was 4.67%. The proximate, amino acid and fatty acid compositions of S. pharaonis muscles were analysed every 40 days to compare the quality. The cultured S. pharaonis were rich in essential amino acids (EAAs), functional amino acids (FAAs), docosahexaenoic acid (DHA) and polyunsaturated fatty acids (PUFAs), which accounted for 32%, 46%, 28% and 54% (dry weight) respectively. Total amino acids (TAAs) and EAAs exhibited a clear distinction between ages, and significant differences were observed among the levels of individual amino acids, including Pro, Ala, Asp and Lys, which were significantly higher at 130–170 days old than at 50 days old (p < 0.05). Although the total saturated fatty acids, monounsaturated fatty acids and PUFAs were statistically similar between ages, C17:0, C22:6 n‐3 and PUFAs were higher at 130–170 days old than at 50 days old (p < 0.05). The results indicate that large‐scale artificial culture of S. pharaonis can be achieved under the conditions of a cement pool. This study also provides new information regarding the growth performance and nutritional composition of cultured S. pharaonis, which will contribute to the development of aquaculture practices for this species.     

Effect of Artificial Diets on Growth,Survival and Condition of Adult Cuttlefish, <Emphasis Type="Italic">Sepia officinalis</Emphasis> Linnaeus, 1758

The effects of artificial diets on growth and body condition of adult cuttlefish, Sepia officinalis were tested in two experiments. Supplemented prepared diets (fish myofibrillar protein concentrate) were fed during a 30-day and a 21-day experiments. Growth, feeding rate and food conversion of group-reared cuttlefish were analyzed. The first of these experiments tested four artificial diets, made with increasing levels of lysine, on adult cuttlefish. According to the chemical analysis, diets 1–3 had limiting concentrations of lysine and other essential amino acids (compared to mantle composition of the cuttlefish), while diet 4 was the only one where almost all essential amino acids were present in concentrations similar or higher than the ones present in cuttlefish mantle. A second experiment was conducted by isolating 16 adult cuttlefish individually, and feeding them the same four artificial diets, in order to obtain individual data. During Experiment 1, only the diet with the best chemical score (diet 4) produced growth (p < 0.05), with a mean instantaneous growth rate (MIGR) of 0.30% wet body weight (BW) d⁻¹. Similarly, individually reared cuttlefish fed diet 4 produced the highest IGR’s (0.26, 0.38 and 0.48% BW d⁻¹) and grew larger (p < 0.01). Comparison of cuttlefish fed the artificial diets vs. thawed shrimp and unfed cuttlefish indicated that cuttlefish fed the artificial diets were in an intermediate state. Growth rates obtained with the artificial diets (<0.4% BW d⁻¹) were considerably lower compared to natural prey, live or frozen, reported by other authors.     

First multi-generation culture of the tropical cuttlefish Sepia pharaonis Ehrenberg, 1831

Sepiapharaonis, the pharaoh cuttlefish was cultured through multiplegenerations in the laboratory (5 consecutive generations) using closed,recirculating water filtration systems. The eggs of the original parentalgeneration (G_P) were spawned by a wild caught Gulf of Thailandfemale in alocal fisheries laboratory, then packed and shipped air cargo to Texas wherehatching occurred. The culture temperature ranged 25°–28°C, except for one generation that was chilled intentionallyto21 °C and then warmed to 25 °C after 9.6months. Spawning occurred as early as day 161. Spawning output was high in allgenerations except the group that was cultured at 21 °C. Eggfertility was low in captivity (< 20%), but hatchling survival was high(>70%). The average egg incubation time was 13.6 d at 25–28°C. The largest spawn resulted in 600 viable hatchlings andthesmallest resulted in 11 hatchlings. The cuttlefish ate a wide variety ofestuarine crustaceans and fishes as well as frozen shrimp. There were noapparent disease problems since survival from hatching to maturity was over70%.The average life span for cuttlefish cultured at 25–28°Cwas 8.9 months and 12.3 months at 21 °C. Size at hatching wasmeasured for fourth generation (G₄) hatchlings; the mean weight athatching was 0.103 g and the mean mantle length was 6.4mm. The largest cuttlefish cultured was a male 300 mmML and 3,045 g; the oldest cuttlefish lived 340 d.This cuttlefish species presents an excellent choice for commercial mariculturebecause of its rapid growth, short life span, tolerance to crowding andhandling, resistance to disease and feeding habits.     

金乌贼同工酶分析

采用水平淀粉凝胶电泳技术对金乌贼（Sepia esculenta）同工酶的组织特异性及其山东日照近海群体的遗传结构进行研究。对金乌贼眼、鳃、肌肉、口球、肝脏、鳃心6种组织的19种同工酶进行分析，检测出PGDH、GPI、MPI、IDHP、SOD、ME、AAT、DIA、MDH、LDH、G3PDH、PGM共12种同工酶在几种组织中有较稳定而清晰的表达。结果表明，金乌贼同工酶的表达有明显的组织特异性。选择金乌贼3种组织（眼、口球、鳃心）进行同工酶分析，共记录了18个基因座位，其中3个基因座位LDH-2^＊、G3PDH-1^＊、PGM^＊呈多态，其多态座位比例为0．1667（P0．99）和0．0556（P0.95），平均观测杂合度和预期杂合度分别为0．0159和0．0143，平均有效等位基因数为1．0201，表明日照近海金乌贼群体的遗传多样性较低。