共查询到20条相似文献，搜索用时 15 毫秒
1.
Studies on development of eight species of flat fishes (Psettodes erumei, Brachypleura novae-zeelandiae, Pseudorhombus arsius, Bothus myriaster, Synaptura albomaculata, S. commersoniana, Cynoglossus arel and C. monopus) were carried out with plankton collections and with laboratory reared larvae. The development stages of Cynoglossus arel and C. monopus from egg to metamorphosis are described. 相似文献
2.
莱州湾口虾蛄的生物学特征与时空分布 总被引：8，自引：5，他引：3
根据2011年5月-2012年4月期间进行的9个航次(月份)的底拖网采样,研究了莱州湾水域口虾蛄的生物学特征、资源密度的时空分布以及环境因子的影响,以期为口虾蛄资源的利用和保护提供理论依据。结果显示,口虾蛄资源密度(生物量和个体数)月间变化为8月 >7月 >9月 >10月 >5月 >11月 >6月 >4月 >3月。口虾蛄体长范围为41~171 mm,平均体长5月最低(102 mm),7月最高(118 mm);体重范围为0.30~68.00 g,平均体重5月最低(13.64g),11月最高(17.67g)。雌、雄个体肥满度均以10月最高,分别为1.49和1.56,肥满度的月间变化趋势为5-7月下降,8-10月上升,11月以后再次下降。肥满度的性别差异不显著(P >0.05)。除5月雌体数量高于雄体外,其他月份雌、雄比均小于1。口虾蛄于5-7月(产卵期)主要分布在黄河口、龙口近岸等浅水区,8月开始向深水区迁移,9月至翌年3月主要分布在深水区,4月开始返回近岸水域。Pearson相关分析表明,口虾蛄个体数密度与海表温度相关性最高,其次是盐度、水深、浮游动物及其他渔获生物量,与底层溶解氧、浮游植物的相关性最低;口虾蛄平均个体重量在8-9月与水深分别呈极显著相关(P <0.001)和显著相关(P <0.005)关系,与其他渔获生物量在2011年7-8月及2012年4月呈显著相关(P <0.005),与其它环境因子的相关性在各月份均不显著(P >0.05)。 相似文献
3.
Adult mirror carp (Cyprinus carpio), put into a small artificial pond (area 30 m2; volume about 6.5 m3) in the Al-Fateh University campus, in Tripoli, Libya, in autumn 1977, consumed all molluscs and higher plants and were feeding on Cyanophyta (Coelosphaerium and Lyngbia) prior to spawning in May 1978. The young grew to 136 mm fork length and yielded 2.2 kg (live weight) in 14 months (62.8 g/m2 per year) without food or fertilisers being added. They stayed under cover for five winter months and at this time growth was not affected much. Quantitative or semi-quantitative data are given for water depths, salinity balance, maximum and minimum water and other temperatures, solar radiation, and for biomass of producer and consumer species, together with observations on algal species, carp and goldfish (Carassius auratus). 相似文献
4.
This is the second of a series of investigations into the biology of young grey mullet, Mugil cephalus L., and the feasibility of its culture in the coastal, estuarine waters of Sri Lanka. The food and feeding habits of mullet, 20–55 mm in length, from the coastal Negombo Lagoon (7° 10′ N; 79° 50′ E) were studied from November 1974 to October 1975.The feeding intensity, estimated as the number of food organisms found in stomachs per feeding individual, followed a seasonal pattern with the intensity increasing from April onward and reaching a peak during June–August. Over 80% of the individuals were found to feed throughout the year. The diet consisted of 18 genera of diatoms, eight genera of green algae, some desmids, six genera of blue-green algae and eight other food groups. No sand or detritus was found to occur in fish smaller than 25 mm in length, and the percentage occurrence of detritus and/or sand particles increased with increase in body length. Quantitatively and qualitatively, diatoms were the most predominant food items, accounting for more than 50% of the total diet. Although only one genus of Xanthophyceae was found to occur in the diet, its contribution was significant.M. cephalus was found to show diurnal periodicity in feeding activity; peaks of activity occurred at dawn and around midday and were unrelated to the state of the tide.The significance of the nature of the diet and the occurrence of two peaks of feeding activity within a 24-h period is evaluated in the light of present knowledge of the food and feeding behaviour of M. cephalus at various stages of growth, and the possibilities of polyculture with other herbivorous species is discussed briefly. 相似文献
5.
Ted R. Sommer 《Aquaculture (Amsterdam, Netherlands)》1984,41(4):373-384
The population dynamics of the crayfish Procambarus clarkii was studied in California ricefields to investigate the effects of range extension and to examine its potential for harvest. The species was shown to undergo distinct cycles of activity related to depth, temperature and reproduction. Juveniles were observed to have two peaks in activity during late summer and winter, while adults only had a single peak. Ovarian maturity was found during summer and maximum hatching occurred in late summer and winter. Males matured at 35.8 mm carapace length (CL) on the average, while females matured at 36.5 mm CL. A direct correlation between female egg production and body size was noted. P. clarkii in California were shown to be cued into similar cycles as Louisiana crayfish, even though the timing and extent of the hydrological cycle was considerably different. Breeding activity paralleled the Louisiana crayfish, while winter-spring juvenile growth rates (16.32 mm in 120 days) and biomass (208 kg/ha) were much lower. Crayfish emigration during ricefield draining was found to be substantial (31% of population) and may provide an excellent opportunity for harvest. 相似文献
6.
Chunchi Liu Xin Gao Huanshan Wang Huanzhang Liu Wenxuan Cao Patrick D. Danley 《Fisheries Science》2013,79(5):799-806
Knowledge on the reproductive biology of fishes is critical for understanding a species’ life history and devising appropriate management strategies. Anthropogenic forces, such as damming and overfishing, threaten fishes endemic to the upper Yangtze River. We conducted a study on the reproductive biology of an endemic species, Ancherythroculter nigrocauda in order to provide information on the life history of this species and to assist in its conservation. From July 2011 to June 2012, a total of 417 fishes were captured via monthly sampling by fishermen in the Longxi River, a tributary in the upper Yangtze River. Although the female-male ratio was 1:1.03, females were predominantly larger in body size. Gonad somatic indices and oocyte diameter distribution showed that the spawning period of A. nigrocauda in the Longxi River ranged from April to August, with the peak in April. Body length at 50 % sexual maturity of A. nigrocauda was estimated to be 125 and 106 mm for females and males, respectively. Absolute fecundity of A. nigrocauda varied between 11,300 and 504,630 eggs, with the mean of 162,377 eggs. In conclusion, A. nigrocauda mature early, spawn once, and are highly fecund, all of which are consistent with an r-selected life history. It is recommended that a moratorium on fishing this species be enacted and the culture of this species be continued. 相似文献
7.
The seasonal gonadal changes in the edible clam, Paphia laterisulca, from the Kalbadevi Estuary at Ratnagiri were studied for the period from May 1972 to April 1973 with the help of fresh gonad smears and histological study. The observations of gonad smears revealed the probable commencement of spawning between September and April from the occurrence of spent gonads. Male and female clams were present in almost equal numbers throughout the year.Histological details revealed that the clam P. laterisulca has a prolonged spawning period extending from mid-September to the end of March with two peaks, the first in October–November and the second in February–March. Lysis of the ripe gametes in both sexes for 2.5 months preceding spawning was observed. The second spawning peak was followed by regression in the gonads.Active gametogenesis was observed in May and June (33.5°C and 30.0°C), and again in December and January (21.5°C and 26.0°C) in clams that had spawned during the first spawning peak.The spawning stimulus in Paphia laterisulca appeared to be the sudden increase in salinity (from 4.1 to 22.5‰) in September in the Kalbadevi Estuary. 相似文献
8.
T.K. Mok 《Aquaculture (Amsterdam, Netherlands)》1985,44(1):41-49
The white seabream, Mylio berda, was induced to spawn spontaneously by hormone injections of synahorin or human chorionic gonadotropin for over 3 months between December and April in Hong Kong. Fertilized eggs were also obtained during the peak spawning period between February and March through natural spawning or artificial insemination. The hatched larvae were reared in 500-1 circular tanks and fed initially on rotifers, Brachionus sp., followed by brine shrimp nauplii or copepod nauplii and finally weaned onto fish meat. Larval rearing trials for growth and survival to 60 days produced larvae of average length, 26.2 mm, at survival rates ranging from 1.32 to 11.62%. 相似文献
9.
10.
Commercially farmed Atlantic halibut (Hippoglossus hippoglossus) were reared at the Aga Marin's facility located on Dønna (Norway) under ambient environmental conditions in duplicate 15 × 15 × 8 m netpens (May 2004 to May 2005). Twenty fish were sampled five times over a twelve month production period during which time the average body weight increased from 1.26 to 2.08 kg (n = 100 fish). Body mass, fork length (LF), and the number and size distributions of fast muscle fibres were determined in male and female fish. All males matured during the autumn whereas no maturation was observed in females. From the point of maturation females had superior growth performance to males and body mass and the total cross-sectional area of muscle were 1.4-fold (P < 0.05) and 1.3-fold higher (P < 0.01) respectively by May 2005. The total number of fast muscle fibres per trunk cross-section at 0.55 LF was 24.5% higher in females (7.58 × 105) than males (5.80 × 105) prior to sexual maturation. In females, muscle fibre recruitment slowed with short days and low water temperatures (< 6.5 °C), but had increased to 1.01 × 106 by May 2005 (P < 0.001). In contrast, there was no growth and no increase in muscle fibre number in males following the onset of maturation. The distribution of muscle fibre diameters prior to maturation in males was also significantly different between male and female fish matched for LF. The results illustrate a sexual dimorphism of muscle fibre recruitment patterns in Atlantic halibut and highlight the adverse affects of sexual maturation in males on muscle growth. 相似文献
11.
Epinephelus tauvina (Forskål) has spawned naturally in captivity. The larvae were reared to metamorphosis using rotifers, Artemia nauplii, copepods and minced shrimp meat. The developmental stages from hatching through to metamorphosis are described. Larvae grew from 2.25 mm total length at hatching, to 31.40 mm by day 50. Two mortality peaks were observed: the first between days 4 and 5, and the second between days 24 and 35. The first peak corresponded to first feeding and the unsuitability of rotifers, and the second to the change from feeding Artemia nauplii to copepods, which were not available in sufficient quantities. 相似文献
12.
T.M. Aronovich S.I. Doroshev L.V. Spectorova V.M. Makhotin 《Aquaculture (Amsterdam, Netherlands)》1975,6(3):233-242
The embryonic and larval development of three White Sea cold-water fish species, rate of yolk sac absorption, age at first feeding and their survival and growth when fed different food organisms, were studied.Eggs were obtained from spawners in the Bay of Kandalaksha, White Sea, and incubated in troughs and aquaria at a mean temperature of 1.5 °C, slightly above that of the sea. The incubation period for polar cod eggs lasted 35 days, for arctic flounder, 42 days and for navaga eggs, 48 days. Emergent larvae were 5.5–6.0 mm long and began feeding at 2–4 °C, 5–6 days (navaga) and 12–14 days (polar cod) after hatching, when their yolk sac was still fairly large.They were fed day-old Artemia nauplii and zooplankton taken from the sea and consisting of Calanus and Pseudocalanus nauplii 400–600 μ in length.The period of establishing first feeding is the most critical for larvae. 相似文献
13.
Abdul Q. Siddiqui Anil Chatterjee Asif A. Khan 《Aquaculture (Amsterdam, Netherlands)》1976,7(2):181-191
Spawning in Labeo bata occurs during July and August. Each individual spawns only once, with the onset of spawning directly dependent on the monsson season. Its success depends upon the access of gravid fish to a suitable spawning ground. The average fecundity is 192 785. 相似文献
14.
黄河口及其邻近水域矛尾虾虎鱼渔业生物学特征 总被引：5，自引：3，他引：2
为了查明黄河口及其邻近水域矛尾虾虎鱼(Chaeturichthys stigmatias)的生物学特征,为其渔业资源评估和管理提供基本参数,本研究根据2013年6月至2014年5月在黄河口及邻近水域进行底拖网调查所得的矛尾虾虎鱼资源生物学数据,对其群体组成、体长-体重关系和性成熟等渔业生物学特性进行了初步分析。结果表明,该海域矛尾虾虎鱼体长分布范围为25~154 mm,平均体长为(87.77±24.18)mm,优势体长为60~120 mm,占总渔获尾数的76.71%。体重范围为0.08~37.83 g,平均体重为(9.1±6.905)g,优势体重为0~10 g,占63.03%。全年矛尾虾虎鱼体长(SL)-体重(W)关系式为W=4.7×10~(-6)SL~(3.183)(R~2=0.962,n=1842)。矛尾虾虎鱼性腺成熟度和性成熟系数均呈现出明显的月变化,其主要繁殖期为4―5月,产卵持续至6月上旬;体长与性腺成熟度之间的关系无显著雌雄差异,瞬时性成熟速率K=0.039,50%性成熟体长L_(50)=117.92 mm。 相似文献
15.
西南大西洋阿根廷滑柔鱼夏季产卵种群繁殖生物学的初步研究 总被引：4，自引：1，他引：3
根据我国鱿钓船于2012年12月—2013年3月渔汛期间,在西南大西洋公海海域作业时随机采集的阿根廷滑柔鱼夏季产卵种群样本(雌性148尾,雄性99尾),初步研究了其种群繁殖生物学。结果表明,渔汛期间阿根廷滑柔鱼夏季产卵种群雌性胴长172~252 mm,雄性胴长164~248 mm。随着月份推移,雌性占比逐月递减,从12月份的84.21%递减至次年3月份的27.03%;雄性个体占比则逐月递增,从12月份的15.79%递增至次年3月份的72.97%。雌性样本超过30%的个体性腺发育成熟并且部分处于繁殖期,雄性个体超过60%的个体性腺发育成熟并且部分处于繁殖期。雌雄个体的胴长和体质量均在性腺功能发育成熟时达到最大值,但是雌性胴长大于雄性,体质量却小于雄性。性腺指数、缠卵腺指数和精荚复合体指数随着个体生长逐渐增长。雌性个体性腺指数为0.001 2~0.31,平均值0.074;缠卵腺指数为0.003 1~0.55,平均值0.29;两者随着个体生长逐渐增长,在性腺功能成熟时达到最大值。雄性个体性腺指数为0.007 5~0.084,平均值0.038;精荚复合体指数为0.000 79~0.035,平均值0.012;两指数在繁殖期时达到最大值。 相似文献
16.
Abstract: The ridgeback shrimp Solenocera choprai has emerged as one of the important commercial species in 60–100 m depth zone off Karnataka coast, India, since 1993. Studies were conducted on S. choprai to understand its reproductive biology which can help in formulating policies for management of the species. The diagnostic features of reproductive morphology of the species were studied and illustrated in detail. Based on the coloration and size of the ovary and ova diameter variations, five stages of maturity in female S. choprai were identified. The mature ova are fully yolked with diameters between 0.24 and 0.35 mm. Size at maturity (50%) has been estimated at 54.5 and 66.5 mm total length (TL) in males and females, respectively. The gonadosomatic index (GSI) showed an increasing trend according to the advancement of maturity of the ovary, and monthly mean GSI showed a positive correlation with monthly percentage of spawners. Solenocera choprai was found to be a continuous breeder with two peaks: a major peak in November and another extended peak during January–February. The estimated numbers of ova in the mature ovary were 38 532 and 133 689 in shrimps measuring 80 and 110 mm TL, respectively. A sigmoidal increase in the female-to-male sex ratio with increase in size was noticed in the species. A χ 2 -test showed that the annual distribution of females and males is not significantly different from a 1:1 ratio at the 1% level. 相似文献
17.
Preliminary studies on rearing of the gilthead seabream, Sparus aurata (L.), in brackish water ponds
The first attempt to rear the gilthead seabream, Sparus aurata, in brackish water ponds in Egypt was conducted from April 1976 to February 1977. Experimental ponds were stocked with Sparus aurata fry of about 32 mm and 1.5 g average length and weight respectively at a rate of 3000 fry per one feddan of pond water (i.e. 0.42 ha). The growth rate was recorded monthly. An average length and weight of 190 mm and 78 g respectively was attained after 8 months without supplementary feeding or fertilization of pond water. mathematical equations expressing length-weight relationship and condition factor were derived for both wild and reared fish. The higher values of condition factor obtained for the reared fish in comparison to the wild fish signify their improved condition and hence their suitability for farming in Egypt. 相似文献
18.
This study documents the rearing and life history stages of the rare blue Mauritius angelfish, Centropyge debelius, from spawning of eggs through sexual maturity. A C. debelius pair was maintained at our facility for 22 mo. The pair was conditioned to spawn for a 4‐mo period in the fall of 2005 and a 4‐mo period in the summer of 2006 using water temperature and photoperiod manipulation. Continuous spawning was achieved at water temperatures between 22 and 24 C and a photoperiod of long day (LD) 13.5:10.5. Over a 124‐d period, the female produced 97 spawns, 59% of which resulted in fertile eggs. The average fecundity per spawn was 237 eggs (range 13–813 eggs). Fertility of all preserved spawns averaged 19.0 ± 19.8%. Larval rearing attempts using wild caught zooplankton and Artemia nauplii resulted in a total of 10 C. debelius juveniles raised through metamorphosis with an average larval survival up through metamorphosis of 0.36%. Three resulting juveniles were raised through sexual maturity. Sexual dichromatism was first observed about 180 d posthatch. A statistical model: Y = (X× 0.32437) ? (X2× 0.00043) ? 2.004, where Y = total length (mm) and X = number of days in culture, explained 97.6% of the variation in growth (P < 0.001, R2 = 0.976). The development of eggs and larvae was observed to be similar to that of other Centropyge species that have been cultured. Results of this study indicate that the artificial propagation of C. debelius is technically feasible and forms the basis for this report. 相似文献
19.
Damian Moran Cea K. Smith Carolyn W. Poortenaar 《Aquaculture (Amsterdam, Netherlands)》2007,262(1):95-104
The spawning behaviour of wild caught brood stock as well as early egg and larval development were studied in yellowtail kingfish (Seriola lalandi). Spawning occurred naturally in the austral spring/summer (November-February) when the seawater temperature was above 17 °C. Courtship behaviour involved one male and female, and consisted of a high-speed pursuit punctuated by stalling, nipping and touching. This lasted for approximately 0.5-1.5 h until, immediately prior to spawning, the male would nip at the female gonoduct, presumably to induce spawning. At this stage, in 50% of spawns, a second male would become involved. The release of gametes involved frenzied circling behaviour near the bottom of the tank and lasted approximately 22 s. Spawning occurred in the early daylight hours at the start of the spawning season, but shifted to around dusk in the latter part. Spawned eggs were positively buoyant, had a high fertilisation rate (> 99%), ranged 1.33-1.50 mm in diameter with a single oil droplet 0.30-0.33 mm diameter, and developed in a similar manner to that described in congenerics. Egg viability within the floating fraction was visually determined to be 74% ± 17% over the entire reproductive season. Indistinct cell margins and asymmetrical cleavage were the most common blastomere deformities observed. Egg and oil droplet volume were found to decrease by 15-20% over the spawning season, though no relationship was found between visually assessed egg viability and date. Egg incubation trials between 16 and 24 °C indicated that temperature accelerated the time to hatch by a Q10 of 5.0. While larvae were found to hatch at a smaller length with a larger yolk sac and oil droplet at warmer incubation temperatures, there was little difference in the maximum larval length reached at the onset of first feeding among the rearing temperatures used. It is proposed that the reason for this was that higher incubation temperatures accelerated the hatching process faster than the rate of tissue deposition. The findings from this study are discussed in terms of the biological significance and implications for the larviculture of this species. 相似文献
20.
Nicole J. de Voogd 《Aquaculture (Amsterdam, Netherlands)》2007,262(1):54-64
In the present study, the Indonesian reef-dwelling sponge Callyspongia (Euplacella) biru de Voogd [de Voogd, N.J., 2004. Callyspongia (Euplacella) biru spec. nov. (Porifera: Demospongiae: Haplosclerida) from Indonesia. Zool. Meded. 78, 477-483.] (Demospongiae, Callyspongiidae) was cultured for a period of 6 months at three sites in the Spermonde Archipelago, Indonesia. A total of 250 sponge cuttings of two size classes (30 and 40 mm in length) were threaded on either polyethylene or very fine nylon rope and attached to horizontal mooring systems. All sponge cuttings were photographed at regular time intervals. Survival rates were high (82%-100%) among all treatments used. Growth rates differed significantly among treatments, but did not differ significantly per location, farming method, explant size and explant position obtained from the parent sponge. The concentration of the bioactive compound amphitoxin in the cultured explants was not significantly lower than in the natural population, but the concentration did vary significantly between explants used in the different treatments, and also between the different fragments of the natural population. The high growth potential and high survival rate suggest that this sponge species is a promising candidate for further mariculture development. 相似文献