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。     

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

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。     

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.     

岷江眉山段四川华鳊的繁殖生物学资料

于2013年3月至2014年1月对岷江眉山段四川华鳊(Sinibrama taeniatus)的繁殖生物学进行了研究。四川华鳊的繁殖时间主要集中在4~5月份,最小性成熟雌性个体体长70 mm,体重7.1 g;最小性成熟雄性体长为65 mm,体重为4.5 g。四川华鳊种群性比(雌︰雄)为1.00︰1.57,主要由4个年龄组组成,其中1龄个体数量占绝对优势。性成熟系数4~5月份最大,同期丰满度最小。卵径(1.05±0.17)mm,大小分布呈单峰型,为单批产卵型鱼类。绝对繁殖力(2 734±258)粒,相对繁殖力为(236±20)粒/g,绝对繁殖力随着鱼体长、体重增长而增大。分析显示,选择适合的渔具、渔法对保护岷江眉山段四川华鳊自然种群资源十分重要。     

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。     

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。     

雅鲁藏布江黑斑原鮡繁殖生物学研究

对2004-2006年采集于雅鲁藏布江拉萨河的190尾黑斑原鮡进行了繁殖生物学研究。雄性最小性成熟(精巢Ⅳ期)个体体长141.7mm,体重45.2g,性体指数1.09%,雌性最小性成熟(卵巢Ⅳ期)个体体长146.8mm,体重66.7g性体指数11.52%,相应年龄均为5龄。初次性成熟年龄(L50):♂,170.1mm相应年龄为7龄;♀,150.2mm,相应年龄5龄。通过组织切片法和GSI的周年变化分析,繁殖时间集中在5-6月,每年繁殖一次,繁殖之后的6-8月卵巢从Ⅵ期回复到Ⅲ期,9月卵巢发育到Ⅳ期越冬。卵径频率分布显示,卵巢发育类型为分批同步型,卵巢中至少存在2批卵径,每年成熟一批卵并同时产出,产卵类型为完全同步产卵。卵黏性,成熟卵卵径在2.04-3.37mm之间,平均(2.83±0.16)mm。对19尾产卵前夕(体长为151.0-210.0mm)的标本进行统计,其绝对繁殖力范围在525-2058粒之间,平均为(1244±346)粒,相对繁殖力为(14.7±5.8)粒/g。绝对繁殖力与体长呈直线正相关,表达式为F=13.624L-1187。       

金沙江中下游圆口铜鱼的繁殖生物学

根据2013—2014在皎平渡圆口铜鱼产卵场的定点亲鱼收集(n=206)和2006—2014年在金沙江中下游金安桥至巧家干流江段的流动亲鱼采集(n=70), 对圆口铜鱼的繁殖生物学进行了初步研究。定点亲鱼收集的结果显示: 圆口铜鱼雌性最小性成熟个体全长330 mm, 体质量441.0 g, 年龄4龄; 雄性最小性成熟个体全长352 mm, 体质量396.6 g, 年龄3龄; 50%个体达到性成熟的年龄和全长分别为雌性4.32龄 406 mm, 雄性4.44龄 412 mm; 繁殖群体雌雄性比为1.37﹕1, 繁殖群体中雌性年龄为4—7龄, 雄性年龄为3—7龄; 雌雄个体的性成熟系数平均值均以6龄个体最高, 分别为10.55%和3.45%; 平均卵径为0.16 cm, 卵径分布呈双峰型。定点和流动亲鱼收集的雌性性成熟个体的结果表明: 圆口铜鱼绝对繁殖力变动范围为4055—137900粒/尾, 平均值为22817粒/尾; 相对繁殖力变动范围为5—73粒/g, 平均值为20粒/g, 75.68%个体的绝对繁殖力在10000—30000粒/尾之间, 70.27%个体的相对繁殖力在15—20粒/g之间; 绝对繁殖力和相对繁殖力均随着体长和体质量的增加而增加, 其中全长、体质量与绝对繁殖力呈指数分布函数正相关, 而与相对繁殖力呈二次项函数正相关。研究结果可为长江流域圆口铜鱼资源的保护提供重要的基础数据支撑。     

Reproduction in an invasive exotic catfish Pterygoplichthys disjunctivus in Volusia Blue Spring,Florida, U.S.A.

Morphology and reproductive strategies of a population of invasive loricariid catfish, Pterygoplichthys disjunctivus, in Volusia Blue Spring, Florida, were examined using morphological characters, gonado‐somatic indices and batch fecundity. This species has cystovarian ovaries, a left ovary that is significantly larger than the right ovary, and is highly fecund. Ovaries contained multiple oocyte size classes and completely spent females were not found, both of which indicate that this species is a multiple spawner. Reproductive patterns changed significantly between the first (2005) and the last (2007) years of this study; female fish became capable of spawning at a smaller size, a greater proportion of the captured population were capable of spawning each year and female batch fecundity increased, as did male and female gonado‐somatic indices. Plasticity of P. disjunctivus reproductive patterns is discussed in relation to resource availability and environmental stability.     

从线粒体细胞色素b探讨长臀鲃属三个种分类与进化的关系

本研究测定了长臀属(MystacoleucusG櫣ｎｔｈｅｒ）中的３个种 :月斑长臀(M.chilopterusFowler)、长臀[M.marginatus(CuvieretValenciennes)]和细尾长臀(M.lepturusHuang)共22个个体的线粒体细胞色素b部分基因片段 ,其序列为408bp,并选用亚科(Acheilognathinae)中华(RhodeussinensisG櫣ｎｔｈｅｒ）及亚科（Ｂａｒｂｉｎａｅ）中的云南倒刺(Spinibarbus.denticulatusyunnanensisTsu)作为外群。结果表明 :细尾长臀与月斑长臀、长臀间存在遗传分化 ,分化程度与鲤科其它鱼类相似 ;而月斑长臀和长臀却无法分开。结果提示 ,月斑长臀和长臀很可能为同一个种。此外 ,长臀属与云南倒刺的亲缘关系较近 ,表明有争议的长臀属归入亚科是合理的。     

Reproductive life history of the introduced peacock grouper Cephalopholis argus in Hawaii

This research investigated the reproductive biology (sex ratio, hermaphroditic pattern, size and age at maturity) of Cephalopholis argus, known locally in Hawaii by its Tahitian name roi. The results suggest that C. argus exhibits monandric protogyny (female gonad differentiation with female to male sex change) with females reaching sexual maturity at 1.2 years (95% c.i .: 0.6, 1.6) and 20.0 cm total length (L_T; 95% c.i .: 19.6, 21.2). The female to male sex ratio was 3.9:1. The average age and L_T at sex change was 11.5 years (95% c.i .: 11.1, 12.9) and 39.9 cm (95% c.i .: 39.5, 41.2), respectively. Current information on spawning seasonality of this species is incomplete, but based on the occurrence of spawning capable and actively spawning females, spawning probably takes place from May to October. Evidence of lunar spawning periodicity was found, with an increased proportion of spawning capable and actively spawning females, and an increased female gonado‐somatic index during first quarter and full‐moon phases. This information fills a valuable information gap in Hawaii and across the species' native range.     

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。     

Life-history strategies of Acrossocheilus fasciatus (Barbinae, Cyprinidae) in the Huishui Stream of the Qingyi watershed, China

Life-history traits of Acrossocheilus fasciatus were examined using 384 specimens collected monthly during May 2009 and April 2010 in the Huishui Stream of the Qingyi watershed, China. Using scales for age determination, female and male fish comprised five and four age groups, respectively. The monthly changes in marginal increment ratio suggested that annuli on scales were formed during March through May. Total lengths back-calculated significantly increased with age for both sexes and varied significantly between the two sexes at each age. The fact that females had larger body size and grew faster than males indicated the sexual size dimorphism for this species. Both sexes got their 50% maturity at age 3, when females and males were 105.3 and 112.1?mm total length, respectively. Based on the monthly changes in the gonado-somatic index and egg-development process, fish spawned from April through August. Absolute fecundity ranged from 295 to 3,573 eggs per fish and increased significantly with age. But relative fecundity, ranging from 11.77 to 69.96?eggs/g, was not significantly different among age groups. Compared with the life-history traits of an upstream population in the Puxi Stream (a headwater stream within this study watershed), the downstream population of A. fasciatus in the Huishui Stream (a 4th-order stream) exhibits larger body size, faster somatic growth, later sexual maturity, and lower reproductive investment. These variations in life-history strategies between the two populations could perhaps be explained by the spatial heterogeneity in habitat environment along the upstream–downstream gradient in this watershed.     

Reproductive regulation in the female Japanese minnow, Pseudorasbora parva (Cyprinidae)

The Japanese minnow, Pseudorasbora parva, is a multiple spawner that lays eggs repeatedly during the spawning season. In laboratory aquaria, 19 of 63 females did not spawn, whereas 44 other females laid 167 to 6285 eggs in 1 to 14 mating sequences. Neither fish density nor sex ratio (number of males per female) affected fecundity, but the increase in fish density significantly decreased the growth rate of females. The increase in male length significantly increased fecundity in aquaria which contained only a single male, whereas it decreased female growth rate. These relationships were not evident in aquaria housing three or ten males. Since larger males were more dominant and had larger testes than smaller males, the correlation between fecundity and male size strongly suggests that individual females regulated fecundity to increase their reproductive success.     

SEXUAL SIZE DIMORPHISM AND SELECTION IN THE WILD IN THE WATERSTRIDER AQUARIUS REMIGIS: LIFETIME FECUNDITY SELECTION ON FEMALE TOTAL LENGTH AND ITS COMPONENTS

Darwin's fecundity advantage model is often cited as the cause of female biased size dimorphism, however, the empirical studies of lifetime selection on male and female body size that would be required to demonstrate this are few. As a component of a study relating sexual size dimorphism to lifetime selection in natural populations of the female size-biased waterstrider Aquarius remigis (Hemiptera: Gerridae), we estimated coefficients for daily fecundity selection, longevity selection, and lifetime fecundity selection acting on female body size and components of body size for two consecutive generations. Daily fecundity was estimated using females confined in field enclosures and reproductive survival was estimated by twice-weekly recaptures. We found that daily fecundity selection favored females with longer total length through direct selection acting on abdomen length. Longevity selection favored females with smaller total length. When daily fecundity and reproductive longevity were combined to estimate lifetime fecundity we found significant balancing selection acting on total length in both years. The relationship between daily fecundity and reproductive longevity also reveals a significant cost of reproduction in one of two years. We relate these selection estimates to previous estimates of sexual selection on male body size and consider the relationship between contemporary selection and sexual size dimorphism.     

Reproductive biology of little tunny,Euthynnus alletteratus (Rafinesque), from the north‐eastern Mediterranean Sea

The study aimed at identifying spawning season and potential year classes reaching maturity in the north‐eastern Mediterranean, an area where little information on tuna spawning is available. Gonads (60 ovaries and 36 testis) were obtained from little tunny, Euthynnus alletteratus. The fish were caught between November 2002 and May 2005 in the north‐eastern Mediterranean Sea. The ovaries were histologically examined to determine the reproductive conditions and developmental stages of oocytes. Seven females sampled in May, July, and August were sexually mature (stage III or IV). The gonado‐somatic index (GSI) indicated that spawning generally occurred between May and September. The most intensive spawning period was observed between July and August. The sex ratio was calculated as 1 : 1.7 M/F (total n = 96). The length and weight relationship was calculated with W = 0.038 L^2.77, ages from year I to IV being included in the analysis.     

The reproductive cycle of female Ballan wrasse Labrus bergylta in high latitude,temperate waters

This 2 year study examined the reproductive cycle of wild female Ballan wrasse Labrus bergylta in western Norway as a precursor to captive breeding trials. Light microscopy of ovarian histology was used to stage gonad maturity and enzyme‐linked immuno‐absorbent assay (ELISA) to measure plasma concentrations of the sex steroids testosterone (T) and 17β‐oestradiol (E₂). Ovarian recrudescence began in late autumn to early winter with the growth of previtellogenic oocytes and the formation of cortical alveoli. Vitellogenic oocytes developed from January to June and ovaries containing postovulatory follicles (POF) were present between May and June. These POF occurred simultaneously among other late maturity stage oocytes. Plasma steroid concentration and organo‐somatic indices increased over winter and spring. Maximal (mean ±s.e .) values of plasma T (0·95 ± 0·26 ng ml^?1), E₂ (1·75 ± 0·43 ng ml^?1) and gonado‐somatic index (I_G; 10·71 ± 0·81) occurred in April and May and decreased greatly in July when only postspawned fish with atretic ovaries occurred. Evidence indicates that L. bergylta are group‐synchronous multiple spawners with spawning occurring in spring and peaking in May. A short resting period may occur between late summer and autumn when previtellogenic oocytes predominate and steroid levels are minimal.