长江口潮下带大型底栖动物群落特征

2013年至2014年,对长江口及其邻近水域进行了8个航次104个站点的潮下带大型底栖动物调查,通过Shannon-Wiener多样性指数(H)、Pielou种类均匀度(E)、种类丰度(D)和优势度指数(Y)等指标参数分析了大型底栖动物的物种多样性,应用等级聚类和非度量多维标度排序分析了底栖动物群落结构。结果显示,2013年共采获大型底栖动物49种,2014年40种,每年不同季节种类更替明显。2013年大型底栖动物丰度和生物量最高分别出现在春季和秋季,2014年分别为冬季和夏季,不同年份不同季节的生物量和丰度明显不同。不同年份的特征种均以甲壳动物类群为主,鱼类优势种增多。2013年秋季和2014年春季的大型底栖动物相对于同年度其他季节有更高的多样性,年度变化上多样性指数整体增高。群落结构分析表明,2013年夏秋冬聚为1组,春季为1组;2014年春夏秋聚为1组,冬季为1组。ABC曲线结果显示,潮下带大型底栖动物群落在2013年四季受到中度干扰,2014年春夏秋受干扰不明显,冬季受到中等程度以上的干扰。本研究结果为长江口生态环境保护及修复提供了理论依据。     

长江口九段沙潮间带大型底栖动物季节分布特征的初步研究

2005年4月（春季）、7月（夏季）、10月（秋季）和2006年1月（冬季）。对长江口九段沙潮间带大型底栖动物进行了定性和定量调查。共采集到大型底栖动物73种，平均丰度442．94ind·m^-2，生物量40．78g·m^-2．与历史资料比对，大型底栖动物的种数显著增加，新记录31种，曾经有过报道但未采集到标本的有3种；大型底栖动物的丰度变化不大，生物量有明显增加，多样性指数增大。大型底栖动物的丰度、生物量、多样性指数和相对重要性指数随季节的不同而有所变化，其中丰度和生物量以秋季最高，夏季次之，春季和冬季较低；多样性指数冬季最高，夏季次之，春季和秋季较低。优势种为谭氏泥蟹、梨形环棱螺、绯拟沼螺、琵琶拟沼螺、河蚬、焦河篮蛤、中国绿螂和丝异蚓虫；相对重要性指数值较高的有无齿相手蟹、天津厚蟹、谭氏泥蟹、中华拟蟹守螺、堇拟沼螺、绯拟沼螺、琵琶拟沼螺、梨形环棱螺、中国绿螂、焦河篮蛤、河蚬和丝异蚓虫。大型底栖动物的分布主要受水温、水文和工程的影响，此外，工程建设和互花米草扩散对其也造成了一定的影响。     

长江口九段沙潮间带大型底栖动物季节分布特征的初步研究

2005年4月(春季)、7月(夏季)、10月(秋季)和2006年1月(冬季).对长江口九段沙潮间带大型底栖动物进行了定性和定量调查.共采集到大型底栖动物73种,平均丰度442.94 ind·m-2,生物量40.78 g·m-2.与历史资料比对,大型底栖动物的种数显著增加,新记录31种,曾经有过报道但未采集到标本的有3种;大型底栖动物的丰度变化不大,生物量有明显增加,多样性指数增大.大型底栖动物的丰度、生物量、多样性指数和相对重要性指数随季节的不同而有所变化,其中丰度和生物量以秋季最高,夏季次之,春季和冬季较低;多样性指数冬季最高,夏季次之,春季和秋季较低.优势种为谭氏泥蟹、梨形环棱螺、绯拟沼螺、琵琶拟沼螺、河蚬、焦河篮蛤、中国绿螂和丝异蚓虫;相对重要性指数值较高的有无齿相手蟹、天津厚蟹、谭氏泥蟹、中华拟蟹守螺、堇拟沼螺、绯拟沼螺、琵琶拟沼螺、梨形环棱螺、中国绿螂、焦河篮蛤、河蚬和丝异蚓虫.大型底栖动物的分布主要受水温、水文和工程的影响,此外,工程建设和互花米草扩散对其也造成了一定的影响.     

洋山深水港海域大型底栖动物初步研究

2003~2005年每年2月、5月和8月按《海洋监测规范》中大型底栖动物调查方法,分别对洋山深水港一期工程施工海域(30°30′~30°54′N、121°45′~122°30′E)20个取样点进行了大型底栖动物调查。根据调查结果,分析与讨论该海域底栖动物的种类组成、生物量、栖息密度和群落多样性的分布与变化。监测结果显示:一期工程施工期,底栖动物的种类数逐年减少,2003~2005年种类数分别为21种、17种和16种;底栖动物栖息密度逐年下降,2003年(31.10 ind/m2)>2004年(12.50 ind/m2)>2005年(11.00 ind/m2);底栖动物平均总生物量总体表现为逐年降低,2003年(4.26 g/m2)>2005年(2.18 g/m2)>2004年(0.62 g/m2),2004年生物量下降尤为显著,2005年生物量略有回升;生物多样性指数也逐年降低,2003~2005年分别为0.81、0.36和0.16。三年监测结果表明,洋山深水港一期工程海域施工期底栖动物种类数、总生物量、栖息密度以及多样性指数总体呈逐年下降趋势,群落结构趋于简单化,说明工程海域施工期对大型底栖动物产生了一定程度的影响。     

西藏雅鲁藏布江大峡谷墨脱江段大型底栖动物群落结构及多样性的时空分布特征

为摸清西藏雅鲁藏布江大峡谷墨脱江段在 2017 年遭遇大型泥石流滑坡等自然灾害后大型底栖动物分布现状及多样性的时空分布特征, 分别于 2022 年 10—11 月(秋季)和 2023 年 4—5 月(春季)对墨脱江段及其附属支流大型底栖动物的种类组成进行了调查, 并对其群落结构及多样性的时空分布特征进行了分析。结果表明, 春、秋两季共采集大型底栖动物 52 个种类, 隶属于 3 门 3 纲 10 目 30 科, 其中水生昆虫占绝对优势(50 种)。春季大型底栖动物优势种为四节蜉属一种(Baetis sp.1)、鳞石蛾属一种(Lepidostoma sp.); 秋季优势种为四节蜉属一种(Baetis sp.1)、缺距纹石蛾属一种(Potamyia sp.), 且大型底栖动物群落组成在春季和秋季间存在一定的差异(P＜0.001)。流域内秋季大型底栖动物的总平均丰度为 6.67 ind/m² , 总平均生物量 0.04 g/m² ; 春季大型底栖动物的总平均丰度高于秋季, 为 8.71 ind/m² , 总平均生物量 0.04 g/m² 。此外, 大型底栖动物生物多样性在不同季节的干、支流均呈现出一定的差异(P＜0.01)。对比已发表数据(2015—2016 年)并结合现阶段水体环境因子现状, 大型底栖动物优势种已发生明显变化, 且物种总丰度及生物量严重下降, 说明灾害后水生生物栖息环境已受到干扰, 大型底栖动物现存量较少, 结果可为高原地区生物多样性保护提供参考依据。     

罗源湾底栖动物群落结构变化对海域退养行为的响应

在罗源湾全面网箱退养前后(2010—2017年)共进行了6个航次的夏季大型底栖动物调查,共鉴定大型底栖动物156种,其中多毛类71种,甲壳动物37种,软体动物20种,棘皮动物10种,其它类动物18种。生物群落结构的年际变化与全面退养行为呈明显的相关性。退养前(2010—2013年)种类数年际变化呈现显著下降的趋势,实施海域退养整治后(2016—2017年)年种数明显回升;年度总丰度和总生物量呈现以退养前后为返转的显著年际上升再回落的趋势,优势类群多毛类的年际变化趋势与此相同,而主要类群软体动物的变化趋势与此相反;总体上三项多样性指数都呈现以退养前后为拐点的逐渐降低再回升趋稳的大致变动过程,多样性变动与退养整治前后环境的转变明显关联。ABC曲线应用分析表明退养前底栖动物群落受到中度的污染扰动,退养后群落未受污染扰动;罗源湾底栖动物群落结构变化对海域退养行为的响应明显。     

2010─2019年莱州湾夏季蟹类群落年际变化及其影响因子

根据 2010─2019年夏季底拖网调查资料, 对莱州湾蟹类群落结构特征年际变化及其影响因子进行相关研究, 包括群落的种类组成、优势种、物种多样性和群落聚类分析等, 运用冗余分析分析影响蟹类群落年际变化的环境因子。结果表明: 2010─2019 年夏季共捕获蟹类 16 种, 蟹类种数年间波动较大, 减少趋势明显, 2011 年种类数最多, 为 14 种, 2017 年最少, 为 7 种, 优势种每年 2~4 种。生物量和尾数呈先减少后增加的变化趋势, 多样性指数在 2014─ 2015 年明显下降。10 年间蟹类群落共分为 4 组, 组 A 为 2010 年, 组 B 为 2011 年、2014 年和 2015 年, 组 C 为 2012 年、 2013 年、2018 年和 2019 年, 组 D 为 2016 年和 2017 年。PERMANOVA 分析结果显示, 各组间差异显著(P＜0.01)。 SIMPER 分析表明, 各组特征种为日本蟳(Charybdis japonica)、三疣梭子蟹(Portunus trituberculatus)和隆线强蟹 (Eucrate crenata)等, 分歧种主要为日本关公蟹(Dorippe japonica)、日本蟳、绒毛近方蟹(Hemigrapsus penicillatus) 和隆线强蟹等。冗余分析表明, 对蟹类群落年际变化影响较大的因子是底层叶绿素、底栖生物生物量和厄尔尼诺指数。本研究通过对蟹类群落年间动态变化的调查, 旨在为三疣梭子蟹增殖放流工作提供科学依据。     

江苏中南部潮间带大型底栖动物时空分布特征

2013年5月(春季)、8月(夏季)、11月(秋季),对江苏中南部潮间带大型底栖动物进行了定性和定量调查。共采集到大型底栖动物68种,定量63种,定性19种,多毛类、软体动物以及甲壳动物是组成大型底栖动物的主要类群。优势种为文蛤(Meretrix meretrix)、泥螺(Bullacta exarata)、四角蛤蜊(Mactra veneriformis)、托氏虫昌螺(Umbonium thomasi)、加州齿吻沙蚕(Nephtys californiensis)、双齿围沙蚕(Nereis aibuhitensis)以及宽身大眼蟹(Macrophthalumus dilatatus)等。年平均总生物密度65.15 ind·m-2,平均总生物量94.21g·m-2。和历史资料比较后发现,自20世纪80年代至今,江苏中南部潮间带大型底栖动物生物量有增无减。大型底栖动物的生物密度、生物量、多样性和相对重要性指数随季节的不同而有所变化,其中生物密度、生物量以及多样性指数均以春季最高。江苏中南部潮间带大型底栖动物群落生物量优势度曲线位于丰度曲线上方,群落结构稳定性较高,未出现明显扰动。     

山东南部沿海夏季大型底栖动物群落结构特征

2006年8月在山东南部沿岸海域32个站位进行了大型底栖动物研究,共发现大型底栖动物182种,其中,多毛类92种,甲壳类42种,软体动物29种,棘皮动物9种,其他类群10种。研究海域大型底栖动物总平均丰度为2001 ind./m~2,总平均生物量为15.92 g/m~2。根据IRI指数,优势种前4种分别是寡鳃齿吻沙蚕(Nephtys oligobranchia)、中蚓虫(Mediomastus sp.)、独指虫(Aricidea fragilis)和巴氏钩毛虫(Sigambra bassi)。Shannon-Wiener多样性指数(H￠)为2.20~4.59,平均值为3.92;Margalef丰富度指数(d)为0.99~5.39,平均值为3.98;Pielou均匀度指数(J)为0.61~0.89,平均值为0.80。根据CLUSTER分析结果,在36%的相似性水平上可将研究站位划分为2个群落。多样性分析表明,研究海域底栖生态环境总体为清洁。Pearson相关性分析显示,大型底栖动物丰度和水深呈显著负相关(r=-0.38,P0.05)。BIOENV分析表明,与群落结构关系最密切的环境因子组合是粉砂+水深+有机碳(r=0.46)。     

渔山列岛潮间带大型底栖动物群落结构

于2009年3月的大潮期间对渔山列岛潮间带布设5个断面,进行大型底栖动物调查。结果表明,该海域潮间带采集到大型底栖动物90种,其中腔肠动物3种,多毛类11种,软体动物45种,甲壳类19种,棘皮动物6种,其它6种。潮间带大型底栖动物总平均生物量5307.06g/m2,总平均丰度为2323.20ind/m2。在各类群底栖动物中,软体动物的平均生物量及丰度居首位。渔山列岛潮间带大型底栖动物的Shannon-Wiener多样性指数(H’)、Simpson多样性指数(D)、Mangalef丰富度指数(d)和Pielou均匀度指数(J)分别为1.421～2.417、0.497～0.624、1.396～3.223和0.484～0.648,平均值为2.052、0.577、2.477和0.590。大型底栖动物ABC曲线分析表明,底栖动物群落无干扰或轻度干扰。     

Protein and amino acid composition from the mantle of juvenile O ctopus vulgaris exposed to prolonged starvation

Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg^?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg^?1 protein) than essential amino acids (425.82 ± 9.15 g kg^?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.     

美人鱼发光杆菌对凡纳滨对虾非特异性 免疫功能及抗病力的影响

在基础饲料中分别添加0.1%和1%美人鱼发光杆菌灭活菌、0.1%美人鱼发光杆菌活菌配制成3种免疫实验饲料,以基础饲料为空白对照组饲料,每组设3个平行样。对个体质量为(4.83±0.36)g的凡纳滨对虾进行为期20 d的饲养实验,分别在0、5、10、15和20d进行取样,以血清中的酚氧化酶(PO)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、超氧化物歧化酶(SOD)和溶菌酶(UL)活性为免疫指标,探讨了美人鱼发光杆菌作为免疫制剂对凡纳滨对虾非特异性免疫效应的影响;在投喂免疫饲料后的第22天,按0.004 2 kg/kg体重的剂量,直接投喂对虾白斑综合征病毒(WSSV)病料,并记录累积死亡率。结果表明,美人鱼发光杆菌免疫实验组对凡纳滨对虾血清中PO、ACP、AKP、UL和SOD活性影响明显高于对照组,并且在饲料中添加美人鱼发光杆菌后,明显提高了对虾抵御WSSV感染的能力。其中0.1%美人鱼发光杆菌活菌实验组的抗病毒感染能力最强,WSSV感染14d内累计死亡率为63.3%±5.8%;而对照组为96.7%±3.3%。研究表明,美人鱼发光杆菌添加在对虾饲料中能提高凡纳滨对虾非特异性免疫水平,增强抵抗疾病的能力,将其作为对虾免疫增强剂具有良好的应用前景。     

Effects of Spirulina platensis as a feed additive on growth and coloration of blue dolphin cichlids (Cyrtocara moorii Boulunger, 1902)

This study was carried out to investigate the effects of replacing fish meal with dietary Spirulina as a feed supplement on the growth performance and coloration of blue dolphin cichlids (Cyrtocara moorii). Five isonitrogenous (47% crude protein) and isocaloric (17.36 kJ/g digestible energy) diets were for formulated to replace FM with 0, 5, 10, 15 and 20% Spirulina (designated as Control, SP5, SP10, SP15 and SP20 respectively) and fed to the fish (initial body weight, 3.15 ± 0.01 g). Fish were randomly distributed into fifteen 120 L aquariums (26.5 ± 1.00°C), 15 fish per aquarium. The diets were tested in triplicate for 12 weeks. Experimental groups were fed twice daily (09:00 and 17:00) by hand to satiation. At the end of the feeding trial, significantly (p < 0.05) higher weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER) and lower feed conversion ratio (FCR) were observed in fish fed the SP10 diet when compared to the SP20 diet. There was no significant difference in these parameters between the other groups. The skin coloration of blue dolphin cichlid fed a diet containing Spirulina meal was enhanced. The best coloration was observed in the SP15 group. These impressions were objectively validated by chemical determinations of carotenoids extracted from fish skins and passed statistical tests of significance. The study findings show that Spirulina meal does not diminish growth rates except at very high levels.     

Sea bream culture in Egypt; status, constraints and potential

Marine fish farming in Egypt began in 1976 with the culture of gilthead sea bream, (Sparus aurata) as this fish was notably adaptable to brackish and marine pond conditions. Today, marine fish and shrimp farms amount to about 19,000 ha, out of which 42% is already in production while the rest, i.e., 58% is still under construction. In 1997, cultured gilthead sea bream production of 2,250 tons made up 3% of the 75,000 tons total aquaculture catch. In polyculture, usually with the grey mullet and sea bass, gilthead sea bream contributed 440 kg ha^–1 to the total yield of 1,700 kg ha^–1 (26%) over a period of 16 months. For the same period, the yield of monoculture ponds averaged 100 kg ha^–1, while in marine cages, yields ranged from 4–10 kg m³. In 1996–1997, fry of 0.25–1 g and fingerlings 1–10 g with a total of 3 million, were collected from the wild and 1 million fry were produced in the three marine hatcheries out of the four existing ones. The development of sea bream culture in Egypt is now severely inhibited by the shortage of seeds and adequate feeds. Exports of both sea bream and sea bass, during 1994–1996 averaged 1,300 tons per year.     

Dietary thiamin and pyridoxine requirements of fingerling Indian major carp,Cirrhinus mrigala (Hamilton)

Two experiments were conducted to quantify the dietary thiamin (experiment I) and pyridoxine (experiment II) requirements of fingerling Cirrhinus mrigala for 16 weeks. In experiment I, dietary thiamin requirement was determined by feeding seven casein–gelatin‐based diets (400 g kg^?1 CP; 18.69 kJ g^?1 GE) with graded levels of thiamin (0, 0.5, 1, 2, 4, 8 and 16 mg kg^?1 diet) to triplicate groups of fish (6.15 ± 0.37 cm; 1.89 ± 0.12 g). Fish fed diet with 2 mg kg^?1 thiamin had highest specific growth rate (SGR), protein retention (PR), RNA/DNA ratio, haemoglobin (Hb), haematocrit (Hct), RBCs and best feed conversion ratio (FCR). However, highest liver thiamin concentration was recorded in fish fed 4 mg thiamin kg^?1 diet. Broken‐line analysis of SGR, PR and liver thiamin concentrations exhibited the thiamin requirement in the range of 1.79–3.34 mg kg^?1 diet (0.096–0.179 μg thiamin kJ^?1 gross energy). In experiment II, six casein–gelatin‐based diets (400 g kg^?1 CP; 18.69 kJ g^?1 GE) containing graded levels of pyridoxine (0, 2, 4, 6, 8 and 10 mg kg^?1 diet) were fed to triplicate groups of fish (6.35 ± 0.37 cm; 1.97 ± 0.12 g). Fish fed diet containing 6 mg kg^?1 pyridoxine showed best SGR, FCR, PR, RNA/DNA ratio, Hb, Hct and RBCs, whereas maximum liver pyridoxine concentration was recorded in fish fed 8 mg kg^?1 dietary pyridoxine. Broken‐line analysis of SGR, PR and liver pyridoxine concentrations reflected the pyridoxine requirement from 5.63 to 8.61 mg kg^?1 diet. Data generated during this study would be useful in formulating thiamin‐ and pyridoxine‐balanced feeds for the intensive culture of this fish.     

A Minchinia mercenariae‐like parasite infects cockles Cerastoderma edule in Galicia (NW Spain)

The cockle Cerastoderma edule fishery has traditionally been the most important shellfish species in terms of biomass in Galicia (NW Spain). In the course of a survey of the histopathological conditions affecting this species in the Ria of Arousa, a haplosporidan parasite that had not been observed in Galicia was detected in one of the most productive cockle beds of Galicia. Uni‐ and binucleate cells and multinucleate plasmodia were observed in the connective tissue mainly in the digestive area, gills and gonad. The parasite showed low prevalence, and it was not associated with abnormal cockle mortality. Molecular identification showed that this parasite was closely related to the haplosporidan Minchinia mercenariae that had been reported infecting hard clams Mercenaria mercenaria from the Atlantic coast of the United States. The molecular characterization of its SSU rDNA region allowed obtaining a fragment of 1,796 bp showing 98% homology with M. mercenariae parasite. Phylogenetic analysis supported this identification as this parasite was clustered in the same clade as M. mercenariae from the United States and other M. mercenariae‐like sequences from the UK, with bootstrap value of 99%. The occurrence of M. mercenariae‐like parasites infecting molluscs outside the United States is confirmed.     

Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China

Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.     

A novel approach to denitrification processes in a zero-discharge recirculating system for small-scale urban aquaculture

This paper presents an innovative process to solve the nitrate build-up problem in recirculating aquaculture systems (RAS). The novel aspects of the process lie in a denitrification bioreactor system that uses solid cotton wool as the primary carbon source and a unique degassing chamber. In the latter, the water is physically stripped of dissolved gaseous O₂ (by means of a Venturi vacuum tube), and the subsequent denitrification becomes more efficient due to elimination of the problems of oxygen inhibition of denitrification and aerobic consumption of cotton wool. The cotton wool medium also serves as a physical barrier that traps organic particles, which, in turn, act as an additional carbon source for denitrification. Operation in the proposed system gives an extremely low C/N ratio of 0.82 g of cotton wool/g of nitrate N, which contributes to a significant reduction of biofilter volume. The additional advantage of using solid cotton wool as the carbon source is that it does not release organic residuals into the liquid to be recycled. Operation of the system over a long period consistently produced effluents with low nitrate levels (below 10 mg N/l), and there was only a very small need to replace system water. The overall treatment scheme, also incorporating an aerobic nitrification biofilter and a granular filtration device, produced water of excellent quality, i.e., with near-zero levels of nitrite and ammonia, a sufficiently high pH for aquaculture, and low turbidity. The proposed system thus provides a solution for sustainable small-scale, urban aquaculture operation with a very high recovery of water (over 99%) and minimal waste disposal.     

Fertilization by refrigerator stored sperm of the Indian major carp, Labeo calbasu (Hamilton, 1822)

This study reports on the spermatological properties, and on the development of a protocol for refrigerator storage (4°C) of Labeo calbasu (Hamilton, 1822) sperm for artificial breeding. Volume, motility, concentration and pH of the freshly collected sperm were 2.21 ± 0.53 (μL g^?1 of fish weight) (mean ± SD), 95 ± 1 (%), 1.93 ± 0.44 × 10⁹ (cells mL^?1) and 7.56 ± 0.17 respectively. Sperm activation was evaluated at different osmolalities of NaCl solution, and motility ceased completely when osmolality of the extender was ≥287 mOsmol kg^?1. Sperm retained motility for 24, 72 and 108 h, after refrigerator storage when sperm were undiluted, suspended in Alsever's solution and suspended in Alsever's solution containing 5% methanol respectively. Fertilization rate of fresh eggs with sperm stored at 4°C in Alsever's solution and Alsever's solution containing 5% methanol was 77% and 60% with a hatching rate of 60% and 43% respectively. The fertilization and hatching success of the stored sperm suggests potential to use refrigeration for transporting genetic material to hatcheries for artificial breeding of L. calbasu in Bangladesh.