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1.
Satoshi Katayama 《Fisheries Science》2001,67(3):401-407
SUMMARY: The objective of this study was to reveal the spawning grounds and reproductive characteristics of anadromous and resident pond smelt, Hypomesus nipponensis , coexisting in Lake Ogawara. Life history styles of females shedding in spawning grounds in the lake and its inflowing rivers were differentiated by otolith increment analysis. Size, dry weight, and water content of mature oocytes and fecundity of fish were compared between resident and anadromous fish. Both anadromous and resident fish spawned in the lake. In contrast, no resident fish were found in any of the inflowing rivers, where only anadromous fish spawned. Regression of fecundity against standard length was discontinuous with an inflection point at 63.8 mm, which is the body size that differentiates large anadromous spawning groups from small resident spawning groups. Mean oocyte diameters were not significantly different between resident and anadromous fish. The eggs of resident fish had significantly more water content and a significantly lower dry weight than those of anadromous fish. These differences might influence the growth and developmental processes of progeny. 相似文献
2.
《水生生物资源》1999,12(1):11-22
Duplicate groups of first-feeding (4-5-d-old) Tilapia zillii (Gervais) were maintained on two feeding regimes (high and low ration size) for a total period of 550 d (~ 17 months) in environmentally-controlled aquaria. Differences in mean individual fish weight were evident between fish fed the different ration sizes after just 3 months, though these differences were not statistically significant until day 180. Thereafter, fish maintained upon the higher ration were significantly larger than fish fed a reduced ration. Mortality in high ration fish over the course of the experiment was ~60 % compared to ~88 % in low ration fish. Mortality in both treatment groups was most pronounced during the first three months (particularly during the first 30 d) but was much reduced there-after. Spawning trials undertaken from day 450 onwards indicated that there was no significant difference between the two ration groups in terms of spawning periodicity over a discrete time period of 60 d. Mean total fecundity was significantly higher in fish on high rations though mean egg diameter and gonadosomatic index remained unchanged. Adjustment of spawning data to a common maternal fish size using one-factor ANCOVA failed to detect significant differences between the two ration levels in terms of either mean total fecundity or mean egg diameter. Stereological analysis of plastic-embedded ovarian tissue revealed that the ovaries of low ration fish possessed significantly more stage 2 and 3 (early and late perinucleolar) oocytes and significantly less stage 6/7 (late-vitellogenic/maturing) oocytes than the ovaries of fish fed the higher ration. No significant differences were detected between the two rations in terms of ovarian atresia. It is suggested that under prolonged food restriction, female T. zillii sacrifice somatic growth such that reproductive investment can be maintained. 相似文献
3.
Experimental evaluation of rainbow trout Oncorhynchus mykiss predation on longnose dace Rhinichthys cataractae 
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下载免费PDF全文 Laboratory and in‐stream enclosure experiments were used to determine whether rainbow trout Oncorhynchus mykiss influence survival of longnose dace Rhinichthys cataractae. In the laboratory, adult rainbow trout preyed on longnose dace in 42% of trials and juvenile rainbow trout did not prey on longnose dace during the first 6 h after rainbow trout introduction. Survival of longnose dace did not differ in the presence of adult rainbow trout previously exposed to active prey and those not previously exposed to active prey ( = 0.28, P = 0.60). In field enclosures, the number of longnose dace decreased at a faster rate in the presence of rainbow trout relative to controls within the first 72 h, but did not differ between moderate and high densities of rainbow trout (F2,258.9 = 3.73, P = 0.03). Additionally, longnose dace were found in 7% of rainbow trout stomachs after 72 h in enclosures. Rainbow trout acclimated to the stream for longer periods had a greater initial influence on the number of longnose dace remaining in enclosures relative to those acclimated for shorter periods regardless of rainbow trout density treatment (F4,148.5 = 2.50, P = 0.04). More research is needed to determine how predation rates will change in natural environments, under differing amounts of habitat and food resources and in the context of whole assemblages. However, if rainbow trout are introduced into the habitat of longnose dace, some predation on longnose dace is expected, even when rainbow trout have no previous experience with active prey. 相似文献
4.
The reproductive biology of 315 cobia, Rachycentron canadum, from northeastern Australia was studied for an 18-month period. Cobia ranged from 181 to 1,470 mm FL (0.06–55 kg). Length–frequency distributions of males and females did not differ significantly. The sex ratio of females to males was 2.18:1. Histological data showed that cobia developed hydrated oocytes during a protracted spawning season between September and June. Gonadosomatic index peaked from October to December, coinciding with the monsoon or “wet” season. Estimated length at first maturity for female cobia was 671 mm FL. Length at 50% maturity (L 50) for females was estimated at 784 mm FL (1–2 years of age). Batch fecundity ranged from 577,468 to 7,372,283 eggs with a mean of 2,877,669 (± SD 1,603,760) eggs. Relative batch fecundity was 249 eggs per g, and no relationship between relative fecundity and fork length was found. There was a significant positive relationship between the total number of eggs produced and fork length. Spawning frequency, estimated by the post-ovulatory follicle method, was 7.6 days. Based on the detection of hydrated oocytes in fish caught at night, cobia most likely spawn at night. Cobia also feed throughout the spawning period. This is the first report on the reproductive biology of cobia in Australian waters, and provides valuable data for future population assessments of cobia throughout the Indo-Pacific. 相似文献
5.
Han Kyu Lim Minh Hoang Le Cheul Min An Sung Yeon Kim Mi Seon Park Young Jin Chang 《Fisheries Science》2010,76(6):971-980
The reproductive cycle and batch fecundity of yellow croaker Larimichthys polyactis were examined in 981 specimens (286 males, 695 females) caught from waters around Mokpo, Busan, and Jeju-do (Korea) between
February 2008 and January 2009. Males and females with ripe-stage gonads were collected between April and June, at which time
the mean gonadosomatic indices were also high, indicating that the spawning season of yellow croaker around the waters off
southern Korea occurs from April to June. Degenerating postovulatory follicles as well as oocytes in the migratory-nucleus
stage or hydrated stage were found in ripe-stage gonads, suggesting that this species can spawn repeatedly in a season. Batch
fecundity in 45 females with migratory-nucleus or hydrated oocytes ranged from 19,396 to 106,311 eggs in fish varying from
20.0 to 26.7 cm in total length and was found to be positively related to total length and body weight. Our findings should
assist in implementing a proper stock assessment of yellow croaker around the waters off Korea. 相似文献
6.
ABSTRACT: The dolphin fish, Corphaena hippurus Linnaeus, is one of the most important migratory fishes on the east coast of Taiwan. Present results are based on an investigation of 1439 specimens caught using long-line and driftnet, and set net collected monthly between September 1996 and September 1997. The sex ratio of female to male and female combined was 65%, demonstrating a female predominance. Oocytes became mature and transparent when they attained 1.0 mm in diameter. The total number of oocytes per ovary was estimated to range from 2.78 × 105 to 23.48 × 10>5 , but batch fecundity was noticeably lower than the total number of ovarian eggs, ranging 5.3–32.7% (average 30.1%), and the relative fecundity ranging 10–344/g bodyweight (mean 111/g bodyweight). Minimum body size at sexual maturity was estimated to be 51 cm for both sexes. Dolphin fish spawned throughout the year with reproductive activity peaking in February to March. It is suggested that the dolphin fish has an extended spawning season, during which it lays eggs almost continuously. 相似文献
7.
珠星雅罗鱼Leuciscus haronensis（Gunther）为鲤科鱼类中少有的溯河洄游类型。本研究采集了880尾2009年度绥芬河溯河洄游生殖群体样本,分析了溯河期、产卵期以及个体的体长、体重组成、年龄与生长、生殖能力、成熟系数、肥满度等主要生态学特征及种群数量。绥芬河珠星雅罗鱼生殖群体分三批溯河繁殖,即3月中旬至4月上旬;4月中旬至4月末;5月初至5月中旬。每批次体色、性比、成熟系数、肥满度等均有所差异。其中第二批次洄游群体为主要的产卵群体。根据绥芬河珠星雅罗鱼的生态学特征提出了该鱼的增殖保护措施。 相似文献
8.
Reproductive biology of female Pacific bluefin tuna Thunnus orientalis from south-western North Pacific Ocean 总被引：1，自引：1，他引：1
Pacific bluefin is a highly valuable pelagic species that inhabits a broad range in the North Pacific Ocean. The reproductive
biology, especially for the spawning aggregation in the south-western North Pacific Ocean, is not well understood. Thus, a
total of 119 paired ovary specimens were collected from the Taiwanese longline fleet during the 1999 fishing season (late
April through June) to gain a better understanding of important reproductivity-related stock parameters associated with this
species. The following conclusions were made: (i) condition factor decreased from late May to early June; (ii) the sex ratio
might be 1∶1 for spawners; (iii) the gonadosomatic index stayed at a relatively high level and markedly increased from late
May to early June; (iv) histological examination of oocytes indicated that all specimens were sexually mature; (v) spawning
activity appeared to start in May and peak in late May to early June; (vi) batch fecundity incre ased with fork length; and
(vii) preliminary estimates of spawning frequency between batches ranged 2–4.5 days based on analysis of postovulatory follicles. 相似文献
9.
10.
Abstract. Sanguinicola fontinalis sp. nov., from the branchial, renal and cardiac blood vessels of brook trout. Salvelinus fontinalis (Mitchill), and longnose dace, Rhinichthys cataractae (Valenciennes), is described. The new species most closely resembles, hut differs from, Sanguinicola davisi of steelhead and rainbow trout, Salmo gairdneri Richardson. The adult differs from all known North American species in having 29–33 lateral tufts of blunt spines. The snail host is Leptoxis (Mudalia) carinata (Bruquière, 1792). Lodged and migrating miracidia caused considerable gill damage in the brook trout, resulting in high mortality when the fish were moved. To remove the hazard, the most severely affected brook trout were destroyed and the ponds drained and disinfected. Adult worms from Pennsylvania brook trout and West Virginia longnose dace were studied, as well as infected snails. 相似文献
11.
Annual reproductive cycle, age and body size at maturity, and potential and relative fecundity were examined in female willowy
flounder in the North Pacific off Japan. Vitellogenesis became active from September, followed by the beginning of spawning
in December. The spawning season continued until May with its peak in January. Estimated maturation rate was 50% at a standard
length of 16 cm, 30% in 2-year-olds, and almost 100% in ≥3-year-old fish. Potential fecundity increased with age, while relative
fecundity decreased in older fish. The results clarify some aspects of the detailed reproductive biology of female willowy
flounder and emphasize the importance of age-composition data in estimating reproductive potential within a population. 相似文献
12.
《Aquaculture (Amsterdam, Netherlands)》1996,140(3):281-291
A histological study was made of the reproductive cycle of captive sharpsnout seabream Diplodus puntazzo during the 3rd year of life. All specimens contained both ovarian and testicular tissue. Ovarian tissue prevailed in 64 out of 120 fish sampled throughout one year. The ovary underwent a long resting phase from October to August, during which time it contained oogonia, primary growth phase (PGP) and occasional yolk vesicle stage oocytes. Intense ovarian development took place in September leading to the formation of advanced vitellogenic oocytes. Final maturation and spawning were not achieved in any of the fish. The testicular area in the predominantly female gonads contained only spermatogonia and was found to be histologically normal in 76% of individuals, but severely regressed in the remaining fish. The testicular portion was found to be dominant in 56 out of 120 fish sampled throughout one year. These underwent a resting phase from November to July, a maturing/pre-spawning phase in August, and a spawning phase with spontaneous sperm release in September to October, as in the natural environment. The ovarian portion in the functional male gonads contained only oogonia and oocytes which did not develop beyond the perinucleolus stage at any point during the reproductive cycle. Apart from the pre-spawning/spawning phase, during which the gonadosomatic index (GSI) was comparable in the two groups, the GSI values were approximately ten-fold higher in those fish in which the ovary predominated than in those in which the testis predominated. 相似文献
13.
Tetsuro Shiraishi Suvarna D. Ketkar Yoshiki Katoh Mitsuo Nyuji Akihiko Yamaguchi Michiya Matsuyama 《Fisheries Science》2009,75(3):649-655
Female Japanese chub mackerel Scomber japonicus of the Tsushima Current subpopulation were collected during the spawning season from March to May 2001. A total of 137 adult
females were caught between midnight and daybreak. A considerable number of fish displayed new postovulatory follicles (POF),
whereas there was no evidence of germinal vesicle breakdown or hydrated oocytes in any of the fish collected. This suggests
a daily spawning synchronicity toward midnight. To estimate the spawning frequency (S), the female reproductive state was classified into four criteria based on the degenerative stage of the POFs and the developmental
stage of the oocytes. To stage the POFs according to age and determine the stage duration, ovaries from S. japonicus were induced to spawn in the laboratory and were sampled 0–72 h after ovulation at appropriate intervals. The average S, which is evaluated from four different indices, was 16.9%, corresponding to the average female chub mackerel spawned every
5.9 days (8.5 times) during the 50 days. 相似文献
14.
采用组织学方法系统研究了人工养殖条件下半滑舌鳎亲鱼卵巢的组织发育周年变化特征.结果表明,卵母细胞发育可分为6个时相,卵巢发育分为6期.卵巢不同发育时期都由不同类型的卵母细胞组成,半滑舌鳎为非同步分批多次产卵类型.周年发育过程中,6月龄前的鱼卵巢发育处于第Ⅰ期;9～12月龄卵巢可发育至第Ⅱ期;12月龄半滑舌鳎性腺可发育达到Ⅲ期,并一直保持至24月龄.3龄雌鱼达到性成熟,卵巢可发育至第Ⅳ期;随着水温和光周期的调控,卵巢发育进入成熟期(Ⅴ期),发生水合现象是卵母细胞成熟并准备排卵的信号;产卵结束后卵巢退化至第Ⅵ期,排出的卵母细胞退化吸收,以Ⅲ期卵巢越冬后,卵巢退化至Ⅱ期并持续至下一个繁殖周期.人工养殖条件下,卵巢内存在卵母细胞闭锁现象.性腺周年发育过程中,性腺指数(GSI)在性腺达到成熟期时达到峰值,产卵结束后性腺快速退化,GSI值各月份差异显著(P<0.05),亲鱼性腺重量在卵巢发育成熟过程中一直处于生长状态.亲鱼肝脏指数(HSI)在产卵前7～8月份(性腺达到成熟期前30 d左右)达到最大,表明7～8月份是性腺进行卵子发育、卵黄能量储备的重要时期,亲鱼在产卵前通过积极摄食储备体内能量,肝脏在卵母细胞卵黄积累方面具有重要的生理作用.肥满度(CF)值在繁殖盛期10～11月份达到最大,表现出与GSI类似的变化趋势. 相似文献
15.
ABSTRACT: Final oocyte maturation and ovulation of captive chub mackerel Scomber japonicus with fully yolk-accumulated oocytes were induced by a single injection of human chorionic gonadotropin. Reproductive parameters, including spawning frequency and batch fecundity, which are required to estimate spawning biomass in pelagic fish by the daily egg production method, were analyzed. Germinal vesicle migration (GVM) occurred at 18–24 h post-injection, and the hydration and ovulation of oocytes were completed at 30 and 36 h post-injection, respectively. The results of the maturation process suggest that fish with GVM-stage ovaries captured in the daytime from the field are capable of spawning on the night following their capture. The oocytes used in the oocyte size-frequency distribution method for batch fecundity estimates should be at late GVM and more advanced stages. The results of sequential artificial insemination showed that the quality of ovulated eggs held in the ovarian lumen rapidly deteriorated as time progressed after ovulation. This indicates that the fertilization window for the ovulated eggs of chub mackerel lasts only a few hours, and spawning behavior should be performed within a few hours after ovulation in the wild population. 相似文献
16.
Annual and lunar-synchronized ovarian activity in two rabbitfish species in the Chuuk lagoon, Micronesia 总被引：1，自引：0，他引：1
ABSTRACT: This study examined the annual and the lunar cycles of ovarian activity in the forktail rabbitfish Siganus argenteus (Quoy & Gaimard, 1825) and the spiny rabbitfish Siganus spinus (Linnaeus, 1758), which were collected from the Chuuk lagoon, Federated States of Micronesia. Gonadosomatic index (GSI) increased in May and June for S. argenteus . For S. spinus , GSI increased in March, and from July to September. During these periods, the ovaries of these species contained oocytes at the tertiary yolk stage or the maturation stage, suggesting that these months are the reproductive season of the two species. During the reproductive season, weekly collection of the fish according to the lunar phase revealed that high GSI occurred around the last quarter moon for S. argenteus and the new moon for S. spinus . In the ovaries, oocytes developed synchronously, and postovulatory follicles, an indicator of spawning, were observed after the respective moon phase, suggesting that these species are restricted lunar-synchronized spawners. Comparisons of the reproductive activity of the two rabbitfishes in the Chuuk lagoon with that in Okinawa waters revealed that there is a geographic difference in the reproductive activity between habitats. However, the lunar phase for exertion of synchronous gonadal maturation and spawning is common in both regions. 相似文献
17.
David Nguenga Guy G Teugels Marc Legendre & Frans Ollevier 《Aquaculture Research》2004,35(14):1349-1357
A comparison was made between the oocyte diameter, pseudo‐absolute fecundity (PAF) and egg quality of two strains of the catfish, Heterobranchus longifilis, maintained in outdoor ponds under a tropical highland climate in Cameroon. The results indicated that circannual endogenous rhythms for ovarian recrudescence and regression are absent in H. longifilis, irrespective of breeding history, age and strain. There appeared to be a possible slight adverse effect of climate (dry season) on reproductive performance of both strains. Oocyte diameter and PAF increased with increasing fish weight when data from both strains were combined, indicating that the two strains may exhibit the same reproductive performance. Viable eggs were obtained all year round after hormonal induction. It is concluded that for propagation of H. longifilis in tropical African countries, broodfish could be maintained in outdoor earthen fish ponds with proper feeding. 相似文献
18.
Abstract— Temporal and spatial variability of fish communities were examined within a 91-km2 catchment in central New York over four years. Riffle-dwelling species, slimy sculpin Cottus cognatus , longnose dace Rhinichthys cataractae , and young-of-the-year brown trout Salmo trutta , were more strongly affected by flood and drought than pool-adapted species, adult brown trout, blacknose dace Rhinichthys atratulus , white sucker Catostomus commersoni , and creek chub Semotilus atromaculatus . Canonical correspondence analysis using seven abiotic variables (mean width, residual pool depth, water surface slope, mean Froude number, variance in Froude number, maximum monthly discharge and minimum monthly discharge) separated fish communities among sites and years. The first axis represented a headwater-to-valley gradient; the second axis reflected habitat complexity, based on both geomorphic and hydraulic features. Temporal differences in fish densities were related to hydrological factors. Fish communities throughout the catchment showed similar responses to flood and drought. 相似文献
19.
探究中华花鳅(Cobitis sinensis)的繁殖生物学特性,可为其人工增养殖和资源保护利用提供科学依据。2017年11月至2018年5月,在贵州境内舞阳河施秉段采集中华花鳅样本381尾,以鳞片作为年龄鉴定材料,将样本解剖后进行性别鉴定和性腺分期。结果表明,舞阳河中华花鳅体长(L)为58.9~100.2 mm,体重(W)为2.0~13.7 g,年龄在1~4龄。381尾样本中,性别不可辨样本有23尾,雄248尾,雌110尾,性腺发育至IV期最多。经肉眼观察发现,中华花鳅的精巢和卵巢均可分为6期,有70尾雌鱼性腺发育达到IV期,其绝对繁殖力(F)为542~2 865粒,体长相对繁殖力(FL)为6.6~28.6粒/mm,体重相对繁殖力(FW)为99.8~490.7粒/g;绝对繁殖力(F)、体长相对繁殖力(FL)均与体长(L)、体重(W)、净体重(W0)、性腺重(W1)、成熟系数(GSI)之间具有极显著相关性(P<0.01),体重相对繁殖力(FW)与性腺重(W1)、成熟系数(GSI)之间具有极显著相关性(P<0.01)。实地调查发现,中华花鳅的产卵场主要在砂质底质、水质清新、水流较缓、水草丰富的浅水区,繁殖期为5-8月,繁殖高峰期为5月中旬至6月上旬。研究显示,中华花鳅的繁殖力较低,繁殖高峰期时间较短,低龄化严重,亟需对其进行资源保护和系统研究。 相似文献
20.
Peter E. Jones Alistair Senior Richard M. Allibone Gerard P. Closs 《Ecology of Freshwater Fish》2016,25(2):174-189
Life‐history theory predicts that the optimal strategy in the trade‐off between egg size and number varies in relation to resource availability and environmental disturbance. We assessed interspecific differences in egg size, fecundity and other life‐history traits in a species complex of stream‐resident galaxiid fish, which are distributed across a range of contrasting habitat types on the South Island, New Zealand. Oocyte size, fecundity and reproductive effort were measured from gravid females collected immediately before spawning. Proxy measures of stream productivity, flow variability and predation pressure were extracted from modelled data sets. A suite of different egg sizes were identified across species within the Galaxias vulgaris complex, with mean oocyte volume differing by up to 133% between species. The species with the smallest eggs showed mean size‐relative fecundities 246% higher than the species with the largest eggs. A significant negative relationship was found between species’ mean egg size and size‐relative fecundity, suggesting a trade‐off between these traits. Species with larger eggs had larger maternal body size, lower reproductive effort and delayed maturity compared to ‘small‐egg’ species. Consistent with the predictions of life‐history theory, species with larger eggs, lower size‐relative fecundity, lower reproductive effort and delayed maturity were associated with low productivity, stable streams, whereas species exhibiting the opposite set of traits occurred in relatively productive but disturbed systems. 相似文献