两种无鳞高原鳅年龄鉴定方法探讨

分析了采自新疆克孜河174尾长身高原鳅(Triplophysa teunis)和258尾叶尔羌高原鳅(T.yarkandensis)的矢耳石及部分个体的背鳍条(n=11和12)、主鳃盖骨(n=20和25)和脊椎骨(n=38和45)的轮纹标志,探讨了用其鉴定年龄的可行性。结果显示,背鳍条磨片和主鳃盖骨均无明显可辨的年轮标志。小个体长身高原鳅的脊椎骨磨片年轮比较模糊,总的判别能力及鉴定吻合率分别为52.63%和70.00%。叶尔羌高原鳅脊椎骨磨片的年龄判别能力为93.33%,但5龄以下个体存在轮纹的断裂、分支和聚合现象,鉴定吻合率为78.57%。所有矢耳石磨片均有日生长增长、生长阻断和年轮等生长标记,年轮由宽而不透明的暗带和窄而透明的亮带组成。174尾长身高原鳅中有171尾矢耳石磨片能观察到年轮特征,判别能力及鉴定吻合率高达98.28%和94.74%。258尾叶尔羌高原鳅有244尾矢耳石磨片能观察到年轮特征,判别能力及鉴定吻合率也高达94.57%和93.44%。两位鉴定者对同一尾鱼的脊椎骨磨片和矢耳石磨片进行年龄计数,长身高原鳅的总吻合率分别为75.00%和80.00%,叶尔羌高原鳅的总吻合率分别为73.81%和83.33%,两鉴定者间无显著性差异(P0.05)。研究表明,矢耳石是两种无鳞高原鳅类最好的年龄鉴定材料,脊椎骨可作为高龄个体的辅助鉴定材料。     

黄山九龙峰尖头鱥的年龄鉴定

鱼类的年龄鉴定及其最佳骨质材料的选择,是鱼类年龄研究的必要前提,也是鱼类基础生物学和生态学研究的基础。利用2012年4月于黄山九龙峰采集的132尾尖头鱥标本,研究了其鳞片、鳃盖骨、脊椎骨和耳石等骨质材料的年轮特征,并以根据全长分布频率确定的"真实年龄"为参照,比较了鳃盖骨、脊椎骨和微耳石在年龄判读中的精确度和准确度。尖头鱥体侧部和尾柄部的鳞片均无任何年轮标志,星耳石磨片上暗带和明带排列无明显规律,但鳃盖骨、脊椎骨和微耳石上存在明显年轮。鳃盖骨、脊椎骨和微耳石3种骨质材料的年龄判读精确度或准确度差异视不同年龄组有所不同。总体上,脊椎骨年龄判读的精确度最高,鳃盖骨次之,微耳石最低;但年龄判读的准确度正好相反,即微耳石最高、脊椎骨最低。因此,微耳石是尖头鱥年龄鉴定的最佳骨质材料,而其较低的年龄鉴定精确度及其对准确度的潜在影响可通过提高磨片质量和优化判读方法来改善。     

厚颌鲂年龄材料的比较

对长江上游特有鱼类厚颌鲂的鳞片和骨组织中的耳石、鳃盖骨、匙骨、基枕骨五种材料的形态结构及年轮特征进行了研究,对用不同材料鉴定年龄的优缺点和鉴定结果进行了比较,认为鳞片、耳石和基枕骨是鉴定厚颌鲂年龄的较理想材料,用鳞片和基枕骨鉴定年龄结果的相符率为95．5％;鳞径和骨径均与体长呈线性关系,并以鳞片和基枕骨为材料进行了生长退算,以骨径进行生长退算更接近于实测值,能更好地反映实际情况。     

西藏双须叶须鱼八种年龄鉴定材料的比较研究

用微耳石、星耳石、脊椎骨、鳃盖骨、臀鳞、胸鳞、侧线鳞和背鳞等8种年龄鉴定材料识别和鉴定西藏双须叶须鱼的年龄特征并进行比较分析, 以确定适宜的年龄鉴定材料。结果显示: 臀鳞形态特化严重, 胸鳞、侧线鳞、背鳞的年轮特征不明显, 与微耳石比较的平均百分比误差(IAPE)分别为41.63%、51.26%、50.50%和51.26%, 其他4种年龄材料与微耳石比较的IAPE相差不大, 依次为: 星耳石(12.28%)、脊椎骨(15.67%)、鳃盖骨(17.81%); 低于23龄时, 微耳石鉴定的平均年龄与耳石和脊椎骨鉴定的平均年龄较为接近(P>0.05), 分别为14.39龄、13.13龄和13.20龄, 显著高于鳃盖骨和4种鳞片(P<0.05); 高于23龄时, 7种年龄鉴定材料都显著低于微耳石所鉴定的平均年龄(P<0.05)。用微耳石鉴定所得的最大年龄为49龄, 星耳石鉴定所得的最大年龄为35龄, 脊椎骨鉴定所得最大年龄为34龄, 鳃盖骨为34龄, 臀鳞为22龄, 胸鳞为19龄, 侧线鳞为16龄, 背鳞为17龄。微耳石年龄鉴定的年龄读数与体长呈极显著的对数函数关系(P<0.01)。综合分析认为, 微耳石最适宜作为双须叶须鱼的年龄鉴定材料。     

软刺裸裂尻鱼的年龄鉴定

检测并比较了软刺裸裂尻鱼（Schizopygopsis malacanthus）鳞片、耳石、脊椎骨和背鳍条的年轮特征。结果表明,这4种材料上均具有年轮特征,以耳石最明显,且易于识别,为最好的年龄鉴定材料;鳞片上的年轮也较明显,但高龄鱼外围的年轮常挤在一起,使鉴定结果偏低;背鳍条上的环纹清晰,但边缘出现轮纹的重叠,影响年龄准确判读;脊椎骨上通常只能观察到比较有限的环纹,不适合用作年龄鉴定。     

中华鲱鲇年龄鉴定及生长特征

对2009-2010年采自澜沧江下游的188尾中华鲱鲇(Clupisoma sinensis)进行了年龄与生长的研究.采用耳石、脊椎骨、鳃盖骨、胸鳍棘4种材料对全部样本进行年龄鉴定,耳石年龄鉴定最为准确,4-5月是年轮形成高峰期.渔获种群由1-6龄共6个龄组组成,以1-4龄个体为主.体长与耳石半径呈线性函数关系.体长与...     

青海湖裸鲤不同年龄鉴定材料的年轮特征

通过各种年龄鉴定材料比较研究了青海湖裸鲤的年轮特征。微耳石和星耳石可用于鉴定年龄,而矢耳石易碎,不适合鉴定年龄。4种年龄鉴定材料对青海湖裸鲤年龄的判别能力为:背鳍条>微耳石>臀鳞>脊椎骨。对8龄以下个体,用背鳍条磨片鉴定年龄效果较佳;对8龄以上个体,臀鳞、背鳍条磨片和脊椎骨上的年轮计数明显低于微耳石磨片,微耳石磨片是高龄青海湖裸鲤较为可靠的年龄鉴定材料。       

洞庭青鲫形态性状遗传分析

为查明洞庭青鲫(Carassius auratusTungting)原种亲本种质的纯度,进行亲本、子一代之间形态学性状遗传传递规律的分析,测定了从北民湖引入的洞庭青鲫原种亲本27尾和子一代32尾,对其7项可比性状和可数性状进行统计分析,计算出各性状的均值、标准差、变异系数。对亲子之间各性状的综合差异性进行卡方检测。结果表明:亲子之间各性状的均值比较接近但子代比亲本平均多一片侧线鳞;各性状的变异系数,亲本和子代接近,且子代多数性状的变异系数小于亲本;卡方值为0.0172,说明亲子之间各性状的综合评定无显著差异。洞庭青鲫亲子间各性状统计分析说明,子一代不仅没有性状分离现象,而且基因有进一步纯化的趋势。由此推论:北民湖洞庭青鲫原种种群的纯度较高。     

鲫耳石重量与年龄的关系及其在年龄鉴定中的作用

耳石重量在年龄组间重叠较少,大小相近的个体,年龄大的,即生长慢的耳石重量比年龄小的,即生长快的大,不同龄组之间耳石重量有显著差异（P＜0．05）,按年龄组在耳石重量与相应的体长作图,可初步判断观测年龄的可靠性,分析耳石重量频率分布能分离出体长相近,年龄不同的个体,其结构与耳石年轮观测的基本一致,耳石重量与年龄呈显著线性正相关（P＜0．05）,用耳石重量与年龄关系估算的年龄从耳石上直接读取的年龄无显著差异（P＞0．05）,文中对耳石重量直接用于确定鱼类年龄的可能性作了分析和探讨。     

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。     

Assessment of growth zones on whole and thin-sectioned otoliths in <Emphasis Type="Italic">Sperata aor</Emphasis> (Bagridae) inhabiting the River Ganga,India

The present study was undertaken with the objective to assess the clarity of growth zones on whole and thin-sectioned otoliths in Sperata aor. A total of 125 sagittal otoliths of S. aor were collected monthly from the river Ganga during the period, April to December 2013 at Narora, Uttar Pradesh, India. Thin sections (approximately 0.5 mm) of one of the sagittal otoliths of each fish were cut using IsoMet® Low Speed Saw. Both whole otoliths and thin-sectioned otoliths were then examined under stereozoom microscope. Parameters of agreement on growth zones were calculated by comparing the number of growth zones obtained independentlyby the two readers (R1 and R2) from the two methods (whole otolith and thin-sectioned otolith method). Thin-sectioned otolith method exhibited higher agreement than whole otolith method based on linear regression analysis and growth zones bias plot. Between readers, higher agreement was noted for reader 1 than reader 2, plausibly due to his relatively more experience in examining the growth zones on the otoliths. However, both readers reported independently that the growth zones were clearer on thin sections than on whole otoliths especially those from older individuals. Thus, it may be concluded that the thin-sectioned otolith method should be utilized for assessment of growth zones in S. aor populations from the river Ganga.     

Validating and corroborating the deposition of two annual growth zones in asteriscus otoliths of common carp Cyprinus carpio from South Africa's largest impoundment

A total of 816 common carp Cyprinus carpio asteriscus otolith pairs were collected from Lake Gariep, South Africa. Otoliths were interpreted whole, submerged in methyl salicylate and viewed under transmitted light. The precision of growth zone counts of the primary reader was estimated at 5·54 and 7·03% using the average per cent error method and the coefficient of variation, respectively. Age-bias plots indicated no systematic bias between the primary reader and the three secondary readers for up to nine growth zones (95% of the sample). Growth zone deposition rate was validated using a mark-recapture experiment of chemically tagged C. carpio (n = 21) conducted in a large earthen pond under ambient conditions in the vicinity of Lake Gariep. The validation results were corroborated for the wild population by edge analysis and a length-based age-structured model. All three methods suggest that growth zone formation occurred biannually, exemplifying the importance of age validation as a prerequisite for understanding the life history of C. carpio.     

六种鲤科鱼类耳石形态以及在种类和群体识别中的应用

描述了6种鲤科鱼类的耳石形态特征,并利用耳石形态的测量性状,对其种类特征进行了判别分析。其中,对张氏(卜夕又鱼)、长鳍吻鮈、圆口铜鱼、宜昌鳅（鱼它）和鲫的判别正确率为100％,异鳔鳅（鱼它）的判别正确率为90.91％,6种鱼类的平均判别正确率达到了99.1％,说明了鱼类的耳石形态特征可以用于鉴别种类。三个区域鲫群体的平均判别正确率为68.9％,显示三个区域鲫群体的耳石形态存在一定的差别。     

Contrasting population characteristics of yellow bass (Morone mississippiensis) in two southern Illinois reservoirs

Two southern Illinois reservoirs were investigated with contrasting size structures of yellow bass (Morone mississippiensis) to compare growth, mortality and recruitment patterns. Yellow bass were collected from Crab Orchard and Little Grassy lakes during April–May 2009 using AC electrofishing. Total length and weight were recorded and sagittal otoliths sectioned and aged by two readers. Increments between otolith annuli were measured and the Weisberg linear growth model was used to assess age and environmental (growth year) effects on individual growth for fish from the two lakes. Von Bertalanffy growth models indicated faster growth and a greater maximum total length for yellow bass in Little Grassy Lake. However, growth of fish in Little Grassy Lake nearly ceased after age 4. The Weisberg model indicated differences in individual growth rate between the two lakes that were consistent across years (age effects were significant, but growth year effects and the age‐growth year interaction were not). Inter‐lake differences in fish growth were present up to age 3. Recruitment was relatively stable in Crab Orchard, with year classes up to age 7 observed. Recruitment was more erratic in Little Grassy, with age 5 being the dominant year class and fish up to age 11 present. Differences in growth and recruitment patterns for yellow bass in the two lakes may be attributed to substantial inter‐lake differences in turbidity, morphoedaphic index, or yellow bass density. Maximum age of yellow bass (age 11) was higher than previously reported for this species, likely due to the use of otoliths to age fish rather than scales. This study provides baseline information on age and growth, mortality, recruitment, and size structure of yellow bass that can be compared to data in future studies to elucidate factors influencing population dynamics of this species.     

Validation of the periodicity of increment formation in the otoliths of a cichlid fish from Lake Tanganyika, East Africa

Tetracycline was used as a chemical tag in a mark‐recapture study to examine the pattern of increment formation in the otoliths of Tropheus moorii , a rock‐dwelling cichlid from Lake Tanganyika. A total of 256 fish were captured by divers and injected with tetracycline. Of these, nine were recaptured after either 1 or 2 years at liberty and eight retained tags within their otoliths. Comparison of the number of growth increments formed after the tag and the time at liberty demonstrated that increments were deposited on an annual basis in the otoliths of this species. Furthermore, there was a strong relationship between otolith mass and age suggesting that otoliths grew at a predictable rate throughout the life of the fish. Validation of an annual pattern of increment deposition allowed age and growth information to be derived from otoliths. This showed that T. moorii grew rapidly to attain adult size by 3 years of age. Males grew faster than females and also attained a larger size than females (8·74 v . 7·91 cm L _S respectively). The longevity of some of these small freshwater fish was surprising; the oldest individual had an age of 10 years, while the average age of adults was 4 years.     

A comparison of different structures and methods for estimating age of northern-form Dolly Varden <Emphasis Type="Italic">Salvelinus malma malma</Emphasis> from the Canadian Arctic

Assessment of anadromous northern-form Dolly Varden Salvelinus malma malma in the Western Canadian Arctic requires reliable methods for estimating ages. Additionally, conservation efforts warrant determining whether fin rays provide a non-lethal alternative to otoliths. Precision and bias of whole and sectioned otoliths, and sectioned pectoral and pelvic fin rays were examined. Two age readers with different levels of experience ageing this species read each structure three times. Coefficient of variation (CV) was calculated to measure precision, and age bias plots were created for each method of preparation/structure within and between readers. The experienced reader demonstrated the highest precision with sectioned otoliths (CV = 1.6 %) followed by whole otoliths (CV = 4.2 %) while pectoral and pelvic fins were the lowest, CV = 7.7 % and 7.5 %, respectively. The age bias plot showed little difference between whole and sectioned otoliths, although greater imprecision/bias was evident for whole otoliths at age ≥9. Compared to otoliths, fin rays produced younger age estimates starting at 5 years; however, pelvic fins were more biased towards younger estimates than pectoral fins. The less experienced reader had greater inconsistencies, tending to overage younger and underage older samples for all methods compared to the more experienced reader, underscoring the importance of experience when estimating age for this species. We conclude that both types of fin rays are a poor non-lethal alternative to otoliths for fish ≥5 years and recommend an experienced ager could use whole otoliths up to age 8 and sectioned otoliths for fish ≥9 years (>500 mm fork length).     

Validation of scales and otoliths for estimating age of redband trout in high desert streams of Idaho

Studies validating aging structures for rainbow trout are sparse and none have been conducted for redband trout, a common western U.S. sub-species. Oxytetracycline mark-recapture methods (MR), marginal incremental analysis (MIA), and comparisons across multiple populations were used to evaluate the utility of two structures for aging redband trout in high desert streams. We assessed periodicity of annulus formation on scale and otolith samples from all age classes of trout residing in two streams, identified the location of the first annulus on otoliths, and compared age estimates and between-reader coefficient of variation on nine additional streams. The use of MIA successfully validated opaque zone periodicity for fish transitioning from age-0 to age-1, and from age 1 to age 2 in two streams. For fish at liberty 13 and 28 months in the same two streams, MR-derived age estimates from whole and sectioned otoliths were 94–100% accurate for fish from 2–9 years old. Scales were only 77% and 38% accurate for fish at liberty 13 and 28 months, respectively. Between-reader coefficient of variation (CV) for scales was high (11.5%), while CV for sectioned otoliths using whole otoliths as corroboratory structures averaged 2.3%. Scales were thus, an unacceptable aging structure for desert redband trout. Given the confusion in the literature, we suggest that more rigorous research should be conducted to define and explain otolith zone formation.     

洞庭湖中是否存在溯河洄游型刀鲚

利用电子探针微区分析(EPMA)技术, 分析了2018年8月采自湖南省岳阳市洞庭湖畔水产市场2尾刀鲚(Coilia nasus)干制个体的矢耳石中锶和钙微化学特征。定量线分析结果显示, 2尾样本的耳石锶钙比值(Sr/Ca×1000)波动显著, 从耳石核心到边缘可分别出现对应淡水生境的锶钙比值<3的低值区, 对应于半咸水生境的3—7高值区和再次为对应于淡水生境<3的低值区。面分布分析结果更直观显示两尾刀鲚个体的耳石从核心到边缘对应于不同盐度生境的锶含量变化图谱, 即从耳石核心到边缘可分别出现对应于淡水生境的蓝色区域, 对应长江口外半咸水生境的黄绿色区域和再次对应于淡水生境的蓝色区域。这种淡水-半咸水-淡水的生境转换显示出了上述个体的典型溯河洄游生活史“履历”。研究显示目前距长江河口约1400 km的洞庭湖中仍可能存在溯河洄游型刀鲚个体。     

Otolith age determination for adult tilapia, Oreochromis niloticus L. from Lake Awassa (Ethiopian Rift Valley) by interpreting biannuli and differentiating biannual recruitment

Age of mature Oreochromis niloticus in Lake Awassa, Ethiopia, was estimated by analysing optical macrozones (translucent and opaque) in sagittal otoliths from fish sampled over a 12-month period. Seasonal record on the type of macrozone at the edge of otoliths suggested that two translucent macrozones associated with biannuli were formed each year; one during January and February and another during June and July. Formation of translucent macrozones coincided with minimum water temperature, spawning associated loss in condition and presumably with reduction in the quantity and quality of the food consumed by the fish. Relative marginal increment analysis showed that biannulus formation may be completed in March and in August each year. A concurrent study has confirmed a biannual recruitment in O. niloticus in Lake Awassa, from which mid-February and mid-August were taken as median hatch-dates. A procedure to assign otolith age is described which considers median hatch-dates and uses the number of biannuli in otoliths without discriminating between fish from the two recruitment cohorts. We also show a procedure to discriminate between the two cohorts by using the number of biannuli, conditions on the edge of the otolith and time of capture to assign age for the two recruitment cohorts separately.     

L'otolithe: la ≪ boîte noire ≫ des Téléostéens

Calcified structures such as otoliths have been used successfully for estimating the age of teleost fishes for many years. Otoliths record age as well as annual and/or seasonal events in the lives of fish and they are an important source of life history information. Otoliths have been found to contain characteristics that are stock specific. Elemental composition might be useful for identifying non-mixing groups of fish that may be regarded as separate stocks for fisheries management. Examination of otolith microstructure has been used to study early life history. Papers describe the use of otolith microstructure combined with chemical analysis to assess the relative significance of environmental variables: feeding frequency, photoperiod and temperature, migration from freshwater to marine water, pollution, etc. Otoliths are the first calcified structures that appear during the early development of fish and they provide a more adequate record of the growth history than scales. Otoliths represent the black box of teleost fish.