软刺裸裂尻鱼耳石日轮及年轮沉积规律研究

研究利用软刺裸裂尻鱼(Schizopygopsis malacanthus)确证了耳石生长轮沉积规律,并在此基础上,探究了其生长轮与年轮关系,推算了第一年轮形成时间。研究结果表明:仔鱼微耳石第一轮纹在出膜后第二天形成,在实验条件下,轮纹沉积具有日周期性,生长轮为日轮;成鱼轮纹沉积具有年周期性,生长轮每年增加1轮。基于耳石日轮技术推算养殖和野生软刺裸裂尻鱼第一年轮形成时间分别为2021年1月28日至3月13日(n=40)和2017年3月8日至5月10日(n=75)。养殖和野生样本耳石轮纹数年际间的分析结果发现,软刺裸裂尻鱼耳石轮纹数和耳石年生长宽度随着年龄增加逐渐降低,耳石年生长面积随着年龄增加逐渐增加。这些结果揭示了软刺裸裂尻鱼耳石轮纹沉积规律,有助于增加年龄鉴定的准确性,进而为种群动态研究和渔业管理政策制定等提供参考。     

齐口裂腹鱼耳石早期生长发育与日轮特征研究

文章研究了在实验室条件下齐口裂腹鱼仔稚鱼耳石早期形态发育与生长特点、第一轮纹出现时间和轮纹沉积规律。结果表明: 在13.5-17.2℃孵化条件下,微耳石和矢耳石在出膜前形成,而星耳石于出膜后第12天出现。在仔稚鱼生长过程中,微耳石由近圆形发育成贻贝形,矢耳石经历近圆形、锲形后发育为箭矢状,星耳石形状由近圆形发育为星芒状。微耳石的前区、背区和腹区及矢耳石的背区和腹区生长呈幂函数关系,而微耳石的后区、矢耳石前区和后区生长以及两对耳石的前后区半径之和与全长均呈线性相关。在(18.50.5)℃和(15.61.1)℃条件下,50%矢耳石样本第一轮纹均在出膜后第 2 天形成(分别为出膜后18h和19h),以后每天形成一轮。微耳石和矢耳石轮纹数均与日龄呈线性相关,方程斜率均与1差异不显著(P0.05),表明两对耳石的轮纹沉积均为日周期性。这些结果为研究齐口裂腹鱼野生种群繁殖期和早期生活史特征等生态学问题提供了重要依据。     

骨唇黄河鱼耳石早期形态发育和轮纹特征研究

研究了骨唇黄河鱼仔稚鱼耳石在实验室养殖条件下的发育过程和生长特点,确证了轮纹沉积规律。结果表明,在14.0-17.8℃孵化条件下,微耳石和矢耳石在受精后96h 30min出现,星耳石在出膜后第16天出现。仔稚鱼生长过程中矢耳石形状变化较大,由出膜时的圆形发育到稳定时的箭矢状。微耳石由近圆形发育成贻贝形,其中心核位置随发育明显偏移。星耳石形状不规则,从出现时的心形发育成为星芒状。微耳石和矢耳石在前后轴方向上后区的生长快于前区（P0.05）;在背腹轴方向上,微耳石腹区的生长快于背区（P0.05）,矢耳石背区的生长快于腹区（P0.05）,两对耳石的前后区半径之和与全长均呈线性相关。微耳石和矢耳石的第1个轮纹均在出膜后第2天形成,新增的轮纹数（微耳石IL,矢耳石IS）与出膜后的天数（D）表现出显著的线性相关,方程分别为: IL=0.9911D-1.0008（R2=0.9971,n=220,P0.001）和IS=0.9925D-0.10873（R2=0.9919,n=161,P0.001）,方程的斜率与1均无显著差异（P0.05）,表明两对耳石轮纹沉积均呈日周期性,生长轮为日轮。研究结果丰富了骨唇黄河鱼的发育生物学资料,可为研究其自然种群早期生活史提供参考。       

鸭绿江香鱼耳石日轮与生长的研究

１９９２年对鸭绿江香鱼耳石日轮与生长进行了研究。人工受精卵胚胎发育后期和前仔鱼期连续剖察表明，受精后约９６小时胚体听囊内出现一对矢耳石，孵出后第２天耳石上出现第一个日轮，之后每天形成一轮。在光镜和扫描电镜下测定了幼、成鱼矢耳石的形态、直径、日轮数及其间距变化。耳石短径（ｖ， μｍ）与鱼体长（ｘ， ｍｍ）呈线性关系， ７５尾幼、成鱼的关系式为ｙ＝３．２８ｘ＋２４８．３０。以耳石日轮数推算其产卵孵化期与实地调查结果一致。耳石日轮数（Ｄ）可用孵化后日数（Ｎ）减１表示。日轮间距有规律性变化，与鱼体生长发育和生态条件密切有关。依据日龄和相关体长体重资料进行了香鱼生长特性研究，用生长方程描绘的生长速度曲线和生长拐点（位于２８３日龄）等均较客观地反映了其生长特点。     

错鄂裸鲤年轮与生长特征的探讨

在描述鳞片、背鳍条和矢耳石三种材料轮纹特征的基础上,比较了这些年龄鉴定材料在判读错鄂裸鲤年龄和反映生长特征上的异同。在个体早期生长阶段,耳石轮纹阻断、8龄以上个体鳞片上年轮环纹的缺失和背鳍条出现轮纹的重叠是影响错鄂裸鲤年龄准确判读的主要因素。采用耳石和鳞片的体长退算数据,Von Bertalanffy方程较好地描述了错鄂裸鲤的生长。由于背鳍条的生长在个体的生长过程中始终呈现为负的异速生长,因此耳石、鳞片在解释个体生长时优于鳍条。     

湘江鳡仔稚鱼个体和耳石生长发育研究

2008 年6 月至7 月间于鳡(Elopichthys bambusa Richardson)的主要繁殖季节在湘江采集鳡仔稚鱼共370尾, 耳石分析表明这些仔稚鱼日龄在4-25d 间, 推算孵化日期为5 月27 日至6 月22 日。仔鱼前弯曲期向弯曲期转化时间为第6 日龄, 弯曲期向后弯曲期转化为第10 日龄, 后弯曲期向稚鱼期转化为15.5 日龄。体长生长和耳石生长均在进入后弯曲期后(12-13 日龄)出现1 个节点: 节点后体长生长速度是节点前的5 倍,节点后耳石生长速度是节点前的2 倍。早期生活史不同阶段鳡微耳石形态显著改变: 前弯曲期耳石为圆形;弯曲期耳石前后轴的生长速度明显超过背腹轴生长, 耳石也变为椭圆形; 后弯曲期耳石进一步延长, 耳石后端形成略尖的突起, 耳石呈梨形; 进入稚鱼期后, 耳石后突起变得较为平滑, 耳石形状呈贝形。耳石半径和体长的关系在后弯曲期阶段出现节点, 节点前后呈不同的直线关系。       

鳗鲡幼鱼耳石日轮的研究

本文报道采自辽东半岛沿岸鳗鲡(Anguilla japonica)的白仔鳗和经人工培育的当年幼鳗耳石日轮生长的观察结果。白仔鳗和幼鳗耳石平均直径均与体全长成直线相关。12尾白仔鳗耳石的平均日轮数146.3,据此推测其产卵期为11—12月。观察证实从咸淡水转人到淡水生活的幼鳗耳石的环纹有过渡带存在。     

温度对尖裸鲤胚胎发育及其仔稚鱼生长性状的影响

采用实验生态学方法研究温度对尖裸鲤（Oxygymnocypris stewartii）胚胎发育及仔稚鱼生长性状的影响，旨在掌握温度对其早期发育的影响。结果表明，随着温度的升高，胚胎的孵化时间缩短，发育速度加快。在平均水温5 ℃、8 ℃、11 ℃、14 ℃和17 ℃下，尖裸鲤的胚胎孵化时间分别为530.78 h、366.12 h、214.22 h、220.63 h、153.95 h，温度和孵化时间呈幂函数关系，有效积温在水温为11 ℃时最低，为2 356.4 h ·℃。尖裸鲤胚胎不同发育时期在不同温度下的累计时间均呈现指数函数关系。随着温度的升高，孵化率呈现先降低后升高的趋势，水温范围在11 ~ 17 ℃时，温度系数Q10值和Q13值最接近2。尖裸鲤初孵仔鱼全长与温度间呈现三次多项式函数，全长与温度之间不存在显著性关系；而初孵仔鱼卵黄囊体积与温度间呈现显著性的二次多项式函数。综合各项指标表明，尖裸鲤胚胎的适宜孵化水温为11 ~ 17 ℃，仔稚鱼的适宜生长水温为14 ~ 17 ℃。     

唐鱼仔鱼耳石的形态发育及日轮

观察了实验室人工繁殖饲养的唐鱼(Tanichthys albonubes)仔鱼耳石形态发育,研究了其生长轮的沉积规律。唐鱼仔鱼耳石长径与鱼体全长(TL)均呈线性相关,其关系式为:微耳石Dl=0.019 6TL-0.031 0(r=0.961 6,P<0.001,n=218),矢耳石Ds=0.027 6TL-0.043 7(r=0.924 0,P<0.001,n=219),星耳石Da=0.016 6TL-0.004 1(r=0.369 6,P<0.001,n=44)。仔鱼耳石上第一个轮纹在孵出后第2 d形成,生长轮数目与仔鱼日龄(D)呈线性相关,其斜率与1无显著差异,因此生长轮为日轮,其关系式为:微耳石LI=1.006D-1.700 1(r=0.994 2,P<0.001,n=205),矢耳石SI=0.953 8D-0.911 6(r=0.993 5,P<0.001,n=161)。生长过程中矢耳石形状变化较大,星耳石出现时间较晚,而微耳石形状稳定,日轮可读性较好,故更适合作为日轮研究的材料。     

鸭绿江香鱼耳石日轮与生产的研究

１９９２年对鸭绿江香鱼耳石日轮与生长进行了研究。人工受精孵胚胎发育后期和前仔鱼期连续剖察表明,受精后约９６小时胚体听囊内出现一对矢耳石,孵出后第２天耳石上出现第一个日轮,之后每天形成一轮。在当镜和扫描电镜下测定了幼、成鱼矢耳石的形态、直径、日轮数及其间距变化。耳石矩径与鱼体长呈线性关系,７５尾幼、成鱼的关系式为ｙ＝３＼２８ｘ＋２４８．３０     

Otolith shape analysis and daily increment validation during ontogeny of larval and juvenile European chub Squalius cephalus

This assesses features of otoliths from laboratory-reared embryos, larvae and juvenile European chub Squalius cephalus from hatching to 180 days post-hatching (dph). We observed the development of the three pairs of otoliths (lapilli, sagittae and asterisci) and more precisely shape changes, as well as timing and deposition rate of increments of the lapilli. The lapilli and the sagittae were present at hatching, whereas the asterisci formed between 20 and 30 dph. The lapillus and sagitta shapes were round until 20 dph. From 60 dph the anterior and the posterior rostra of the sagittae were well developed, but very thin, making this otolith too fragile to manipulate for further studies of shape and validation of otolith increment deposition rate. The lapilli provided reliable age estimates for free embryos, larvae and juveniles up to 120 dph. However, caution should be taken when ageing fish older than 150 dph as an underestimation was noticeable. The regression of the number of otolith increments on age showed a slope and an intercept not significantly different from 1 and 0, respectively, which indicated that otolith growth increments were deposited on a daily basis, with the first microincrement occurring at hatching. Increment counts were consistent between three interpreters, indicating a consistent and reliable age estimate. This study validates that the otolith increment deposition rate can be used to assess hatching dates and daily growth of wild S. cephalus under 150 dph and in environments similar to the conditions used in this study.     

Otolith features and growth of Malawian characid Hemigrammopetersius barnardi from the southwestern coast of Lake Malawi

Macro- and microstructures of the sagitta, asteriscus, and lapillus of juveniles of Malawian characid Hemigrammopetersius barnardi were observed. The sagittae were arrowhead shaped and showed development of rostra. Increments in the sagitta were observable until the bases of the rostra but were invisible in the rostra. The asteriscus had an irregular shape with an ambiguous core and notches at the margin. The ambiguous core of the asteriscus led to difficulty in discerning the first increment. The lapilli were round and fan shaped. Increments in the lapilli were distinct from the core to the margin. The daily increment deposition was validated by alizarin complexone treatment, and the increments increased at the rate of 1 day⁻¹ after hatching. These features suggested that in this species the lapillus is most appropriate for daily increment analysis. The hatching months were estimated based on the lapillus increment counts, and the results showed that this species continuously hatched in the rainy season for 6 months from November to April. The growth trajectory indicated that H. barnardi attains a total length of 50 mm within 4 months of hatching.     

Validation of daily increment formation in otoliths for Gymnocypris selincuoensis in the Tibetan Plateau,China

Daily increment validation in fish otolith is fundamental to studies on fish otolith microstructure, age determination and life history traits, and thus is critical for species conservation and fishery management. However, it has never been done for Schizothoracine fish, which is the dominant component of fish fauna in the Tibetan Plateau. This study validated the daily increment formation of Gymnocypris selincuoensis, as a representative of Schizothoracine fish, by monitoring the growth of hatchery‐reared larvae group and wild‐caught post‐yolk‐sac larvae group under controlled experiments. The results from monitoring the hatchery‐reared larvae group showed that sagittae and lapilli were found in yolk‐sac larvae, and formed 5–7 days before hatching, but asterisci were not found until 11 days post‐hatching. The first increment in sagittae and lapilli was formed in the first day after hatching. The daily periodicity of increment formation was examined and confirmed in sagittae and lapilli of both larvae groups. However, sagittae were better for age determination than lapilli for larvae at earlier days. For larval G. selincuoensis older than 50 days, lapilli were the only otolith pair suitable for larvae daily age determination. This study validated the daily increment formation in Schizothoracine fish for the first time has primary implications to other fishes from this subfamily.     

三峡库区木洞江段翘嘴鲌早期生长特征研究

2013 年 910 月在三峡库区木洞江段采集翘嘴鲌(Culter alburnus)幼鱼, 摘取微耳石进行耳石微结构分析, 推算了翘嘴鲌幼鱼的日龄及孵化日期, 探讨其早期生活史阶段的生长特征。结果显示, 采集 97 尾翘嘴鲌幼鱼, 体长范围为 4098 mm。翘嘴鲌幼鱼的微耳石形状为不规则扁椭球形, 耳石横截面磨片上具有一个核和一个原基。耳石原基的直径为11.627.8 m, 平均值为(18.63.8) m。耳石核中心到第一个生长轮的距离为(13.04.7) m。翘嘴鲌幼鱼的日龄为 44104d, 推算其孵化日期为 2013 年 6 月 9 日至 8 月 17 日, 高峰期为2013 年7 月9 日至7 月22 日。耳石半径与体长、日龄与体长之间均呈显著的线性关系(P0.05)。耳石日轮宽度随着日龄的增加不断变化显示, 三峡库区翘嘴鲌早期生活史阶段的生长速率不断变化, 日平均生长率为0.774 mm/d。       

Intrastream variation in growth rates and time of first otolith increment formation for young of the year Etheostoma simoterum (Cope) (Perciformes: Percidae)

Growth rates and otolith-estimated hatching dates of young of the year Etheostoma simoterum were studied at four localities along an elevational gradient in the Little River, Tennessee, U.S.A. during the summer of 1983. Changes in otolith increment width and mean daily air temperature corresponded well with each other, suggesting that increments were laid down daily. Growth rate increased nearly threefold from the highest elevation site to the lowest. Median otolith-estimated hatching dates differed by about 2 weeks between sites, and the pattern was not directly related to elevation. These data indicate that within-stream, life-history variation of a broadly distributed species should be taken into consideration when studying factors regulating stream fish populations along elevational gradients.     

Daily growth increments in otoliths of wild-caught honmoroko Gnathopogon caerulescens

Otolith growth increments in wild-caught alizarin complex one (ALC)-marked honmoroko Gnathopogon caerulescens were examined to verify the veracity of the age determination method in cyprinids. ALC-marked G. caerulescens recaptured from their natural environment had lapilli increment counts outside the ALC ring mark that had formed on a daily basis during the juvenile stage. This apparently being the first direct evidence of daily periodicity of otolith increment formation in wild-caught cyprinids.     

Validation of daily otolith increments in larval and juvenile Chinese sucker, <Emphasis Type="Italic">Myxocyprinus asiaticus</Emphasis>

Otolith development was observed and the formation of daily growth increments in otoliths of Chinese sucker, Myxocyprinus asiaticus, was validated by monitoring known-age larvae and juveniles in the laboratory from 2003 to 2005. Otolith shape changed with larval and juvenile development, and there was an exponential relationship until a body length of 16 mm or so, and a linear relationship after a body length of 16 mm between otolith size and fish size. The first increment was identified in larvae 1 day after hatching. The regressed equations between daily age (D) and increment number in otoliths (N) were N = −0.64 + 0.96D in lapillus, and N = −0.31 + 0.98D in sagitta. The slopes were not significantly different than 1.0. This demonstrated that otolith increments in this species were formed daily and can be used for daily age determination.