张氏(餐)的繁殖生物学特性

文章对赤水河河口段张氏(餐)的繁殖生物学进行了研究.结果表明:5-9月份为其繁殖期;最小性成熟个体为雌性体长77mm,体重5.3g;雄性体长108mm,体重9.4g,均为1龄;繁殖群体性比为1.07:1,由4个年龄组组成,其中2龄个体占绝对优势.性成熟系数3-7月份逐渐增大,然后持续减小,至12月降到全年最小值.卵径(0.75±0.14)mm呈单峰型,绝对繁殖力(11010±7723)粒,相对繁殖力(275.1±138.4)粒/g,每克卵巢卵粒数(3789±1389)粒.该种为单批产卵类型鱼类.绝对繁殖力随着鱼体体长、体重和年龄的增长而增大.     

塔里木河叶尔羌高原鳅繁殖生物学研究

2010年7月至2011年12月,在塔里木河阿拉尔段采集叶尔羌高原鳅Triplophysa (Hedinichthys) yar-kandensis (Day)940尾(除性别未辨个体外)用于繁殖生物学研究。种群雌雄比为0.85︰1,最小性成熟,雌性个体体长为8.2 cm,体重为7.4 g,年龄为3龄;雄性个体体长为6.5 cm,体重为3.4 g,年龄为2龄。叶尔羌高原鳅卵径分布呈单峰形,推测应属于同步产卵类型。计算了88尾Ⅳ-Ⅴ期雌鱼的怀卵量,其体长范围30-195 mm,体重范围3.59-114.04 g,绝对繁殖力为1101-56320(9944±5487)粒,相对繁殖力为824-1140(982±158);塔里木河阿拉尔段叶尔羌高原鳅种群繁殖力(Fp)为403.46万粒。     

西藏浪错兰格湖裸鲤种群繁殖生物学特征

2017年7月至2018年6月,于西藏自治区昂仁县浪错采集兰格湖裸鲤(Gymnocypris chui)307尾,开展种群繁殖生物学研究。结果显示,浪错兰格湖裸鲤在3～5月性成熟系数较高。雌性最小性成熟个体年龄为7龄,体长217mm,体重122.68g,成熟系数为3.92%;雄性最小性成熟个体年龄为6龄,体长198 mm,体重91.93 g,成熟系数为3.34%。其平均成熟卵径为2.18 mm,卵径分布为单峰型。绝对繁殖力为862～8 933粒/尾,平均绝对繁殖力为(2 885±2 765)粒,相对繁殖力为7～43粒/g,平均相对繁殖力为(15±11)粒/g。绝对繁殖力与体长和体重呈显著正相关,相对繁殖力与体长、体重的相关性不显著。繁殖群体性比(♀︰♂)为1︰0.967,符合1︰1比例。     

长江宜昌段鲢的繁殖生物学特征

2014年3月至2016年9月在长江中下游宜昌江段共收集鲢(Hypophthalmichthys molitrix)样本433尾,进行繁殖生物学研究。该江段鲢的繁殖时间为每年的5月下旬至8月上旬,以6~7月为盛产期。繁殖群体体长310~927 mm,体重600~17 090 g,由3~7龄共5个年龄组组成,3龄群体数量上占绝对优势,占繁殖群体的45.2%。雌雄性比为1.43︰1,雌雄群体间体长-体重关系存在显著性差异(0.01P0.05)。采用Logistic方程推算出初次性成熟雌性个体体长为482.3 mm,体重为2 206.7 g;初次性成熟雄性个体体长为484.0 mm,体重1 677.5 g。卵径(1.01±0.12)mm,大小分布呈单峰型,为单批产卵型鱼类。绝对繁殖力(477 662±9 631)粒,相对繁殖力为(93.38±5.92)粒/g,绝对繁殖力随着鱼体长、体重增长而增大。与其他地理种群相比较,宜昌江段鲢总体表现为卵径相对较小而繁殖力较大。     

金沙江攀枝花江段白缘(鱼央)的繁殖生物学

为丰富白缘(鱼央)Liobagrus marginatus(Günther)的基础生物学资料,于金沙江攀枝花江段收集到729尾性腺可辨的样本,分析其年龄结构、性别比、初次性成熟个体大小以及繁殖力等繁殖生物学特征。结果表明:繁殖群体由1~4龄4个年龄组组成,其中2龄个体在数量上占绝对优势(63.83%),其对种群繁殖力的贡献为62.07%。在性成熟个体中,雌性和雄性分别为64尾和77尾,雌雄比=1∶1.20;符合1∶1理论比值(χ~2=1.199,P0.05);雌、雄最小性成熟个体体长分别为66.80 mm、67.32 mm,体质量分别为5.7 g、6.7 g。攀枝花江段白缘(鱼央)的繁殖季节为3—6月,绝对繁殖力平均值为161.2粒±55.1粒。Ⅳ期卵巢中卵子发育不完全同步,卵径变幅为0.29~3.86 mm。金沙江攀枝花江段白缘性成熟快,但繁殖力低,繁殖群体主要由低龄个体组成,种群资源亟需保护。     

雅鲁藏布江中游双须叶须鱼群体繁殖力与繁殖策略研究（英文）

双须叶须鱼Ptychobarbus dipogon隶属裂腹鱼亚科,叶须鱼属,是西藏特有经济鱼类,研究通过对其繁殖力和繁殖策略的研究,旨在为双须叶须鱼的科学保护和合理开发提供理论依据。于2013年2月至3月以及2014年2月中旬至6月中旬,在雅鲁藏布江中游区段采集到1030尾双须叶须鱼,雄鱼体长主要集中在325—400 mm,雌鱼体长主要集中在375 mm以上,其中Ⅳ期、Ⅴ期的雌鱼65尾,体长为320—500 mm,体重为411.6—1328.0 g。采用SL50%的方法,雌鱼初次性成熟体长为360.90 mm,初次性成熟年龄为13.0龄;雄鱼初次性成熟体长为354.53 mm,初次性成熟年龄为13.5龄。从不同月份不同性腺发育期所占比例,不同月份的性体指数变化以及不同月份卵径分布图,可以看出双须叶须鱼属于同步产卵类型,集中在2—4月份。双须叶须鱼平均绝对繁殖力为3487粒,平均相对体长繁殖力为7.2粒/mm,平均相对体重繁殖力为4.3粒/g,绝对繁殖力与体长、体重呈正相关,与年龄无显著相关性。群体性比为1.23鲶1。综上所述,双须叶须鱼是繁殖力较低、性成熟较晚和繁殖期较短的鱼类,我们针对其繁殖特性提出了一些保护性建议。     

雅鲁藏布江中游双须叶须鱼群体繁殖力与繁殖策略研究

双须叶须鱼Ptychobarbus dipogon隶属裂腹鱼亚科, 叶须鱼属, 是西藏特有经济鱼类, 研究通过对其繁殖力和繁殖策略的研究, 旨在为双须叶须鱼的科学保护和合理开发提供理论依据。于2013年2月至3月以及2014年2月中旬至6月中旬, 在雅鲁藏布江中游区段采集到1030尾双须叶须鱼, 雄鱼体长主要集中在325—400 mm, 雌鱼体长主要集中在375 mm以上, 其中Ⅳ期、Ⅴ期的雌鱼65尾, 体长为320—500 mm, 体重为411.6—1328.0 g。采用SL50%的方法, 雌鱼初次性成熟体长为360.90 mm, 初次性成熟年龄为13.0龄; 雄鱼初次性成熟体长为354.53 mm, 初次性成熟年龄为13.5龄。从不同月份不同性腺发育期所占比例, 不同月份的性体指数变化以及不同月份卵径分布图, 可以看出双须叶须鱼属于同步产卵类型, 集中在2—4月份。双须叶须鱼平均绝对繁殖力为3487粒, 平均相对体长繁殖力为7.2粒/mm, 平均相对体重繁殖力为4.3粒/g, 绝对繁殖力与体长、体重呈正相关, 与年龄无显著相关性。群体性比为1.23 鲶1。综上所述, 双须叶须鱼是繁殖力较低、性成熟较晚和繁殖期较短的鱼类, 我们针对其繁殖特性提出了一些保护性建议。     

华南地区外来鱼类革胡子鲶的繁殖生物学

2011年8月—2015年8月在华南地区主要河流收集255尾革胡子鲶(Clarias gariepinus)样本,对其繁殖生物学特征进行研究。结果表明:革胡子鲶繁殖季节为5—8月,繁殖旺季为6—7月,卵径分布呈现明显的多峰型;成熟系数与脂肪系数和肥满度的周年变化存在相反的趋势;绝对繁殖力为2850~605720粒,均值234232±175498粒,与体长、体重和年龄呈正相关;相对繁殖力为20~445粒·g~(-1),均值165±99粒·g~(-1),随体长、体重和年龄的增加呈先增加后趋于稳定趋势;绝对繁殖力和相对繁殖力均大于常见的鲶科鱼类。繁殖群体性比为1∶1.12,符合1∶1比例;雌、雄鱼最小性成熟个体均为1龄,Ⅳ期性腺;雌鱼体长174 mm,体重119.5 g,成熟系数为8.50%;雄鱼体长205 mm,体重116.2 g,成熟系数为0.45%;繁殖群体以1和2龄鱼为主,分别占繁殖群体总数的42.28%和51.68%,以补充群体占优势;华南地区革胡子鲶野生种群具有分批产卵、相对繁殖力高、卵径小、性成熟年龄低的特征,有利于其迅速建立稳定的种群,应加强对革胡子鲶野生种群动态的监测力度,并进一步采取防控措施。     

额尔齐斯河银鲫繁殖生物学研究

2013年4—10月在额尔齐斯河中国段下游采集了546尾银鲫(Carassius auratus gibelio)样本, 依据传统生物学和组织学方法, 对额尔齐斯河银鲫的繁殖生物学特性进行了分析和研究。统计表明, 额尔齐斯河银鲫的性比(雌/雄)为10.84﹕1。根据卵母细胞和精细胞发育及比例情况, 将银鲫卵巢和精巢发育分别划分为6期。依据不同性腺发育期比例、性体指数和卵径频率分布, 推测银鲫为同步产卵鱼类, 繁殖期为5—7月, 6月为高峰期。采用Logistic回归方程获得其初次性成熟体长(SL₅₀)和年龄(A₅₀)分别为: 雌鱼161 mm和2.3龄; 雄鱼135 mm和1.9龄。绝对繁殖力为(42453±28205)粒, 相对繁殖力为(98.19±34.6)粒/g。绝对繁殖力与体长线性相关性较低, 与体重呈幂指数相关, 但与年龄及卵巢重的相关性不显著。研究进一步丰富了额尔齐斯河银鲫生物学研究资料, 为其资源养护和可持续利用提供科学依据。     

锦江翘嘴鲌的繁殖生物学特征

对2015年1月至12月采集于锦江的翘嘴鲌(Culter alburnus)进行了繁殖生物学特征的研究。锦江的翘嘴鲌繁殖期集中在6~7月,属分批产卵类型。繁殖群体年龄在3+龄至6+龄之间,体长250~537 mm,体重184.9~2 587.5 g。雌雄性比1.14︰1,体表差异表现在泄殖孔和腹部膨胀程度,雌雄群体间体长-体重关系存在显著性差异(0.01P0.05)。性成熟雌鱼绝对繁殖力25 067~54 274粒,相对繁殖力24.2~36.9粒/g,平均卵径(1.1±0.3)mm。性成熟系数在1~5月份逐渐增大,6月明显上升,7月达到最高峰,8月显著下降,9~12月逐渐趋于平缓。采用Logistic方程推算了初次性成熟个体特征,雄性体长273 mm,体重192.0 g,年龄3.4龄;雌性体长311 mm,体重249.4 g,年龄4.2龄。锦江种群繁殖期与其他地理种群相近,但绝对繁殖力和相对繁殖力明显偏小。     

湖南沅水下游?繁殖期内繁殖力和卵径的变化研究

为分析鱼类繁殖期内繁殖力和卵径变化趋势, 研究于4—10月在沅水下游逐月采集180尾?(Hemiculter leucisculus), 分析81尾雌性成熟个体的繁殖力。研究结果表明: ?的性体指数在5、6月最高, 其次在7、8和9月, 在4和10月最低。绝对繁殖力平均值为(30116±19390)粒, 以10000—30000粒为主, 相对繁殖力的平均值为(650±324)粒/g, 以400—800粒/g为主。绝对繁殖力与体长、空壳重呈幂函数关系(P<0.05)。绝对繁殖力和相对繁殖力在5和6月最大, 7、8和9月次之, 在4和10月最小。不同月份成熟卵子的卵径无显著差异, 补充卵子的卵径在5和6月最大, 暗示5和6月分批繁殖次数较多。不同繁殖时期的分批繁殖力、繁殖次数不一样, 对评估种群的繁殖潜能具有重要的指导意义。比较不同水系繁殖力发现, 湖泊种群的个体繁殖力普遍大于河流种群, 沅水种群的个体繁殖力跟湖泊种群的相似, 可能与其具有类似湖泊的缓流水或静水生境有关。研究揭示了?的基本繁殖特征, 为渔业资源管理提供了基础数据资料。     

Reproduction of Capoeta damascina (Valenciennes, 1842), a cyprinid fish,in Zayandeh‐Roud River,Iran

Reproductive characteristics of siahmahi, Capoeta damascina (Valenciennes, 1842), a native cyprinid in the Zayandeh‐Roud River, were investigated by monthly sampling from March 2007 to April 2008. Among 689 specimens captured, the overall sex ratio was 1 : 1.57 (males : females). Males matured at age 2⁺. Females matured between ages 4 and 6, with 100% maturity at age 7⁺. Based on the gonadosomatic index (GSI), the reproductive period peaked between May and June. Histological and macroscopic characteristics of the gonad indicated the species to be group‐synchronous. Absolute fecundity varied greatly with female size, ranging 2520 to 72 650 (mean 24 800 ± 17 800) eggs for females 25.5–54.2 cm TL and weighing 320–2340 g. Fecundity increased with fish age, averages being 9446 ± 8028 for 4⁺ old females and 54 503 ± 13 803 eggs in mature 8⁺ year old females.     

Reproductive biology ofAwaous guamensis, an amphidromous Hawaiian goby

Synopsis Spawning season, size at first reproduction, oocyte maturation, and fecundity ofAwaous guamensis, an amphidromous Hawaiian goby, were studied from June 1989 through May 1991 in the Wainiha River, Kau'ai, Hawai'i. Female fish larger than 73 mm standard length (SL) had mature gonads from August through December in 1989 and 1990. Gonadosomatic index (GSI) values for mature females ranged from 0.2 to 14.5 during the spawning season. Male fish larger than 64 mm SL had elevated GSI values from June 1989 through December 1989 and from August 1990 through December 1990. Mature sperm were found in two male fish collected in January and February. GSI values for mature males ranged from less than 0.01 to 4.0 in the spawning season. Size-frequency distributions of measurements of vitellogenic oocyte diameters and microscopic observations of oocytes indicated this species has group-synchronous oocyte development. Ovarian maturation stages examined over a 29-month period suggest that members of the stock spawned at different times within the spawning season, although mass spawning events have been documented for this species. Estimates of clutch sizes from nests measured in situ were comparable to estimates of potential fecundity from in vitro examination of ovaries, and indicated that female fish deposited an entire clutch during a spawning event. No evidence for multiple spawning by an individual fish in a single season was found. However, microscopic observations of brown bodies in some ovaries suggested that individual fish probably spawn more than once in a lifetime.     

Observations on the age, growth, reproduction and food of the roach Rutilus rutilus (L.) in two rivers in southern England

Scales and opercular bones from 632 roach from the River Stour were used for age and back-calculated growth determinations. The scales had clearer inner annuli but operculars clearer outer annuli in fish more than nine years old. The annuli were laid in late May or early June at the beginning of the growth period. Growth was minimal between November and April. Roach from both rivers grow faster than those in most other European waters. Female roach grow faster than males; River Frome roach faster than those from the Stour. Spawning occurred in May and elaboration of gonads between September and May. Immature roach have an annual cycle in condition with a maximum in June and a minimum in early Spring. The condition of mature females is affected by the gonad cycle. The fecundity of Stour roach is represented by the formula: log egg number=4.43 log length (mm)—1.69. Approximately half of the Stour males attained sexual maturity at age III and most of the rest by age IV. Half of the females were mature at age IV and the remainder by age V. Both brood success and growth rate varied from year to year but independently of one another. Most Stour roach ate aquatic insect larvae and molluscs but algae were more frequent in the diet of larger fish.     

Reproductive cycle and reproductive output of the sea urchin Loxechinus albus (Echinodermata: Echinoidea) from Beagle Channel, Tierra del Fuego, Argentina

Reproductive cycle, frequency and duration of spawning, energetic content of gonads, and reproductive output of the common green sea urchin Loxechinus albus were analyzed in the Beagle Channel (Tierra del Fuego) between May 2004 and May 2005. Gonad indices (GI, percentages of gonad mass in total body mass) were significantly higher in March, April, July, and August than in November and May, thus showing a negative correlation with the photoperiod. Highest GI values of mature individuals were observed in August, and spawning occurred from September to December. In females, the mass-specific energy content of gonads (ECG) was highest in spawned gonads and lowest in mature ones, while in males ECG values were higher in immature stage and lower in premature and mature stages. High ECG values can be explained by the abundance of nutritive phagocytes. Both ECG and total gonad energy content (TECG) were higher in females than in males. Mean reproductive output was 7.28% for females and 6.15% for males (expressed as the difference between mean GI of mature and spawned gonads) and 25.02 kJ for females and 19.26 kJ for males (expressed as the difference between mean TECG of mature and spawned gonads).     

Reproduction of the Arctic copepodCalanus hyperboreus in the Greenland Sea-field and laboratory observations

The seasonal vertical migration of adultCalanus hyperboreus Krøyer and their female reproductive biology have been studied in the central Greenland Sea, based on 7-month coverage during one annual cycle. Females dwelled in surface waters only between April and July. Gonad maturation began after the summer descent into deeper waters between September and October in the absence of food. Breeding was assessed from gonad development and egg production experiments. It started around the beginning of November and was mostly completed by March/April, before the spring ascent. The overwintering depth of females ranged from close to the surface to 3000 m, and mature females had a preference for shallower depths. Males were mostly found during the breeding period, where they inhabited the 500- to 1000-m layer. Female dry weight was highest in August and November and lowest in February. Field observations were supplemented by observations on gonad development and egg production of females, which were collected in June and August and kept in the laboratory for up to 6 months. Clutch size, spawning interval and fecundity were determined at 0°C. Females collected in June were mature earlier. Due to their low dry weight, they developed only small gonads and very few of them spawned. Females from August were much fatter and produced up to 1000 eggs in several clutches deposited at regular intervals.     

Gonadal maturation,fecundity, spawning,and timing of reproduction in the mud snail,Cerithidea cingulata,a pest in milkfish ponds in the Philippines

Summary

Gonadal maturation, spawning, fecundity and timing of reproduction of the snail Cerithidea cingulata in a brackish water pond in Molo, Iloilo, Philippines, are described. Snails 4–41 mm in shell length were sampled monthly from May 1997 to May 1998; 25% were <25 mm, 67% were 20–30 mm, and 8% were >30 mm. The sexes are separate and could first be distinguished at 15 mm. Males are aphallic, have narrower shells than females of the same length, and have bright yellow-orange testes overlying the digestive gland deep inside the shell. Females have more robust shells, an ovipositor at the right side of the foot, and yellow-green ovaries overlying the digestive gland. The sex ratio was one male to two females in the pond population studied. Gonadal maturation was monitored by means of gonadosomatic index (GSI, gonad weight as a percent of visceral weight); maturation stages were based on the gonad appearance (immature, developing, mature) and histology (immature, developing, mature, redeveloping). GSI increased with snail size, and reached 16% in a 33-mm female. The smallest mature males and females were 18–19 mm, and most snails >20 mm were mature, spawning, or redeveloping. Histological sections showed all stages of gametogenesis in mature male snails. The oocyte size-frequency distributions in mature females showed mostly mature oocytes and secondary oocytes, but also oogonia and primary oocytes. GSI and the frequency of snails at different maturation stages varied over the year. Both GSI and the frequency of mature snails were highest during the summer months, April to August. Nevertheless, mature snails occurred throughout the whole year, as did mating and egg-laying. Fecundity (= number of oocytes >70 pμ) increased with size in mature females 2041 mm; an average 25-mm female produced about 1,500 oocytes and larger females produced a maximum of about 2,500 oocytes. Eggs strings laid on the pond bottom were 45–75 mm long; an average 64-mm string contained 2,000 eggs 210+20 pm in diameter. The density of eggs strings was highest (80–120/m²) during March-September. Eggs hatched after 6–7 d into planktonic veligers, which in turn settle on the pond bottom 11–12 d later as juveniles. Juveniles 2–6-mm long were most abundant in the pond during August-October.     

Reproductive cycle of Triplophysa stenura (Herzenstein, 1888) (Balitoridae: Nemacheilinae) from the Yarlung Tsangpo River in the Tibetan Plateau,China

The reproductive biology of Triplophysa stenura, an indigenous cyprinid species from the Qushui County in the middle of the Yarlung Tsangpo River in the Tibetan Plateau, China, was investigated by bimonthly sampling from May 2014 to April 2015 using electrofishing. The gonadosomatic index (GSI) of T. stenura differed significantly between males and females over the seasonal trend, indicating that spawning extends from March (shortly after the ice melts) to May, as observed for indigenous species in response to environmental conditions on the cold plateau. Average oocyte diameter was 0.66 ± 0.13 mm, whereby the oocyte diameter distribution exhibited a clear seasonal pattern as the temporal pattern of GSI. Absolute fecundity of T. stenura was 3999 eggs/individual, which increased significantly with the increase in fish size and gonad weight, demonstrating the relationship of an exponential equation between them.     

Reproduction characteristics of a stunted population of rudd, <Emphasis Type="Italic">Scardinius erythrophthalmus</Emphasis> (Linnaeus, 1758) living in the Anzali Lagoon (the southwest Caspian Sea,Iran)

A total of 486 specimens of Scardinius erythrophthalmus caught in the Anzali lagoon, a large lagoon located in the southwest Caspian Sea (Iran), between March and June 2007 were examined. Age determination showed that the maximum ages observed were 4+ in males and 5+ in females. Isometric growth was identified from length-weight relationship in males, females and pooled data. There was no significant difference from parity in the overall sex ratio of 252 males to 234 females. The fish spawn from mid April to late May, with peak spawning in mid May with the highest average GSI value of 7.12 and 13.52 for males and females respectively. The absolute fecundity ranged between 1482–59620 eggs with the mean of 9287.87 eggs while relative fecundity ranged from 127.8 to 1737.6 eggs/g with the average of 709 eggs/g of body weight. Egg diameter ranged from 0.43 to 1.23 mm with a mean of 0.73 mm. The characteristics of rudd in the stunted population from the Anzali lagoon differ markedly from those of other localities of its range.