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1.
Partial migration describes intrapopulation variation in the migratory behavior, i.e. some individuals from a population migrate to low-salinity river areas, while others remain in coastal areas. This paper reviews the partial migration pattern of juvenile temperate seabass Lateolabrax japonicus, which is a migration pattern not commonly seen in Japan. Seabass spawn offshore, and eggs and larvae are transported to coastal areas. Some of these juveniles then ascend rivers, while others remain in coastal areas. Juveniles efficiently use physical structures in their habitat; they use tidal currents to ascend rivers in macrotidal estuaries, while they use the salt wedge in microtidal estuaries. Once juveniles ascend the river, they can feed on the abundant prey and attain more rapid growth than those remaining in coastal areas. As estuaries are highly productive areas, they play significant roles as nurseries for juveniles of various fishes. However, compared with coastal areas, the relative area of estuaries is considerably smaller and its environmental conditions are more variable. For example, nearly 40% of adult seabass in Tango Bay were estimated to use estuarine areas as a nursery, while the other 60% use coastal areas during their juvenile stage. Using both estuaries and coastal areas through partial migration during the juvenile stage is concluded to contribute to the stabilization and yield of seabass populations. 相似文献
2.
Searching for sensitivity in the life history of Atlantic menhaden: inferences from a matrix model 总被引：1，自引：0，他引：1
We used modified Leslie matrix models to explore the life history of Atlantic menhaden ( Brevoortia tyrannus ). By examining the sensitivity of long-term population growth rates to changes in vital rates, we identified those life history components which can cause large population level responses. Our models subdivide the first year of life into five stages (eggs, early larvae, late larvae, juveniles, and 'peanuts' or subadults), and population growth rate responds most strongly to changes in juvenile and late larval stages. The relative ranking between these stages is dependent on the magnitude of mortality during the prejuvenile stages relative to juvenile mortality. An examination of low-level model parameters indicates that the population growth rate is influenced by the growth and mortality rates during the time when young-of-the-year menhaden are gaining access to and residing in the estuaries. Sensitivity to changes in many adult metrics, such as fishing mortality, were relatively low. We conclude that a better understanding of biotic and abiotic factors that influence the late larval and juvenile stages will further our understanding of population dynamics in this species. 相似文献
3.
In this study we developed and utilized a complex model approach to investigate the impact of stage‐specific transport processes on the development and spatial distribution of brown shrimp (Crangon crangon) post‐larvae and juveniles in the German Bight. First, we focused on drift processes during the pelagic larval stage by coupling an individual‐based model for egg and larval development ‘off‐line’ to a 3D hydrodynamic model utilizing the Lagrangian method. Secondly, we investigated tidal‐induced transport processes after juvenile settlement. To determine the tidal cycle, the model coupling was accomplished ‘on‐line’ by resolving the individual‐based model and hydrodynamic model with the same time step. The vertical migration of juveniles, a prerequisite for the selective tidal stream transport (STST), was modelled as a sub‐grid scale physical process (balance of forces: gravitation, buoyancy, Stoke’s friction and dynamic uplift) and considered complex particle dynamics. We applied the model to test temperature and salinity cues as possible tidal indicators utilized by juvenile brown shrimp. Our results indicated that transport processes could significantly change the timing and spatial distribution of post‐larval abundance. We also showed that the small‐scale hydrodynamic forcing acting on the bodies of juvenile brown shrimps was sufficient to account for the vertical migration required to use STST. For both investigated tidal cues STST performing juvenile brown shrimp were transported on‐shore. A faster and more continuous STST was calculated for the salinity cue, resulting in larger abundances of brown shrimp in estuarine areas. 相似文献
4.
Modeling the effects of temperature on the survival and growth of North Sea cod (Gadus morhua) through the first year of life 
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下载免费PDF全文 Temperature and body size are widely agreed to be the primary factors influencing vital rates (e.g., growth, mortality) in marine fishes. We created a biophysical individual‐based model which included the effects of body size and temperature on development, growth and mortality rates of eggs, larvae and juveniles of Atlantic cod (Gadus morhua L.) in the North Sea. Temperature‐dependent mortality rates in our model were based on the consumption rate of predators of cod early‐life stages. The model predicted 35%, 53% and 12% of the total mortality to occur during the egg, larval and juvenile stages, respectively. A comparison of modeled and observed body size suggested that the growth of survivors through their first year of life is high and close to the growth rates in ad libitum feeding laboratory experiments. Furthermore, our model indicates that experiencing warmer temperatures during early life only benefits young cod (or theoretically any organism) if a high ratio exists between the temperature coefficients for the rate of growth and the rate of mortality. During the egg stage of cod, any benefit of developing more rapidly at warmer temperatures is largely counteracted by temperature‐dependent increases in predation pressure. In contrast, juvenile (age‐0) cod experiences a higher cumulative mortality at warmer temperatures in the North Sea. Thus, our study adds a new aspect to the ‘growth–survival’ hypothesis: faster growth is not always profitable for early‐life stages particularly if it is caused by warmer temperatures. 相似文献
5.
对驼背鲈(Chromileptes altivelis)的胚胎发育及仔、稚、幼鱼的形态特征进行了详细的观察与研究,描述了从受精卵到仔、稚、幼鱼各发育期的时间和形态特征变化。结果表明,在水温25-26℃、盐度30的海水中,受精卵历时27 h 25 min完成整个胚胎发育过程,经历从卵裂、囊胚、原肠、神经胚到肌节形成、各器官的逐渐形成、变化、完善等一系列的胚胎发育和变化过程;根据其卵黄囊消长情况、鳞片的覆盖状态、体色发生的不同变化以及第二背鳍和腹鳍的消长,将胚后发育分为仔、稚、幼鱼3个阶段。在水温22-26℃、盐度29-31、DO≥5 mg/L的条件下,2-3 d仔鱼卵黄囊消失,开口摄食;生长发育至31 d,仔鱼已变态进入稚鱼期;培育至57 d,稚鱼完成变态,成为幼鱼。第二背鳍棘和腹鳍棘的生长与收缩等石斑鱼类早期发育的共性生长特征及其体表特性体色变化特征为驼背鲈胚后发育过程中最明显的特征。 相似文献
6.
In Sendai Bay, stone flounder larvae settle and spend their juvenile period in either shallow exposed inshore nursery grounds or estuarine nursery grounds. The purpose of this study is to examine the relative contributions of these two kinds of nursery grounds to the flounder population using otolith strontium:calcium ratios. Stone flounder juveniles were collected from both nursery grounds, and one- and two-year-old flounder were caught deeper in Sendai Bay. Sr and Ca content in the otoliths were measured by electron probe micro analysis. The Sr:Ca ratios in the otolith section corresponding to the early postsettlement period ranged from 3.06 to 3.85 for the exposed inshore areas with stable low temperature and high salinity conditions, and from 3.81 to 5.32 in brackish estuaries with high temperature and low salinity conditions but with large diel and tidal cyclical fluctuations. Values from an estuarine site with stable salinity ranged from 3.58 to 4.15 overlapping with both the above ranges. Rearing experiments supported our inference that the high otolith Sr:Ca ratios of juveniles inhabiting estuarine nursery grounds are attributable to higher temperature and physiological stress caused by the large diel temperature and salinity fluctuations within the estuaries. Estimation of the Sr:Ca ratio of recruited fish using the otolith section formed while in the nursery area showed that at least 20 out of 42 individuals examined originated from estuarine nursery grounds. The present study indicates that estuaries play an important role as nursery grounds for stone flounder, producing about half of the stock in spite of the small and restricted area compared with the wide expanse of the exposed inshore area. 相似文献
7.
Manh Hung Pham Jean‐Dominique Durand Minh Phong Le Bich Thao T. Vo Duc Huy Hoang Jacques Panfili 《水产资源保护:海洋与淡水生态系统》2020,30(8):1626-1637
- 1. Marine protected areas (MPAs) are set up to conserve biodiversity, but their design is not always based on strictly scientific considerations. Ideally, an MPA should protect all key habitats necessary for a marine species to complete its life cycle. The identification of these key habitats is complex, especially during the early life of marine fishes.
- 2. A widely distributed tropical and important low trophic‐level fish species, Spratelloides delicatulus (Clupeidae), was used to evaluate the significance of various coastal habitats for its larvae and juveniles in the Con Dao Archipelago MPA in Vietnam. Early stages (larvae and juveniles) were sampled monthly over one year (June 2016 to May 2017) using light traps in three main habitats (seagrass beds, coral reefs and harbour). The species was identified using morphometry and DNA barcoding. Age and growth variables were estimated using otolith daily growth increments.
- 3. A total of 3,581 fish were caught. The species was not found in captures between January and February, directly linked to the decrease in seawater temperature and was most abundant from April to June. For a subsample of 248 fish (7–38 mm standard length), ages ranged from 7 to 108 days.
- 4. Captures and back‐calculated birthdates using otolith daily increments showed that S. delicatulus spawns during the period of high seawater temperature, from March to October. The species colonizes all three habitats during the early stages (0–26 days old), with growth rate lowest on the seagrass beds. Nevertheless, the species occupies seagrass beds exclusively during the older stages.
- 5. The conservation of seagrass beds in the Con Dao archipelago is essential for protection of juvenile stages of this species but this habitat is presently not included in the MPA patches. Establishment of a continuum of protected areas linking habitats, rather than the existing patches is needed to conserve the complete life cycle of this species in the Con Dao MPA.
8.
A. K. WHITFIELD 《水产资源保护:海洋与淡水生态系统》1997,7(1):1-11
1. Habitat degradation, mainly through land use changes and excessive freshwater abstraction, has a major negative effect on southern African estuarine systems. Less important at present, but showing increasing signs towards becoming a major problem is environmental pollution, especially organic and inorganic wastes from industrial, agricultural and domestic sources. Although the major threats to estuarine-associated fishes are usually linked to environmental degradation, there is also evidence to suggest that certain fish species are declining in abundance primarily as a result of overfishing. 2. The viability of estuaries as nurseries and feeding grounds for fishes is directly related to the accessibility and productivity of these systems. Examples of the mismanagement of South African estuaries through excessive siltation, freshwater deprivation, poorly planned dredging activities, and artificial manipulation of estuary mouths, are discussed. 3. The need for conservation legislation based on a sound knowledge of the biology and ecology of threatened fish species, their communities and their habits is highlighted. Examples of possible ‘indicator’, ‘keystone’, ‘umbrella’ and ‘flagship’ species for South African estuaries are given. 4. Although estuaries on the subcontinent have long been recognized as nursery areas for a number of recreationally important marine fish species, these systems have not formed an integral component in the selection of marine reserves. The dependence of many marine teleosts on estuarine habitats necessitates the inclusion of these ecosystems in any aquatic reserve planning exercise. 5. The plight of endemic fish species is discussed, with the effects of both environmental degradation and overexploitation being highlighted. 6. It is concluded that the future health of South Africa's estuaries and their fishes depends on imaginative resource management and on the improved implementation of conservation measures in partnership with decision-makers, managers, scientists and estuarine users. © 1997 John Wiley & Sons, Ltd. 相似文献
9.
E. L. WENNER D. M. KNOTT C. A. BARANS S. WILDE J. O. BLANTON J. AMFT 《Fisheries Oceanography》2005,14(3):175-194
We examined conditions under which white shrimp (Litopenaeus setiferus) post‐larvae enter an estuarine channel receiving high freshwater discharge and one receiving negligible discharge in the Ossabaw Sound system of Georgia, USA, during 1997 and 1998. We used surface nets to collect plankton over several 14‐day periods, during which consecutive tows were made at night against the flooding current at stations in the inlet channels. During these sampling periods, additional intensive periods of around‐the‐clock surface and near‐bottom (using a bottom sled) plankton tows were made. Data on oceanographic conditions were obtained from moored instrument arrays and shipboard sampling. We identified three key factors that influenced the densities of post‐larval white shrimp in time and space within the Ossabaw inlet system. The first factor was a critical minimum temperature of coastal waters of 27–28°C. Once the threshold temperature was reached, lunar tidal stage became a key factor when the full duration of the flood tide coincided with darkness during peak ingress. This peak also coincided with an increase in water level within the system by more than 0.2 m, which induced an additional influx of water that reinforces the flood current over the ingress period. Our results suggest that the direction of subtidal currents (into or out of the system) becomes a significant factor in post‐larval ingress when influx of water coincides with the time of favorable temperature conditions and nighttime flood tides. 相似文献
10.
Taiki Fuji Akihide Kasai Keita W. Suzuki Masahiro Ueno Yoh Yamashita 《Fisheries Science》2010,76(4):643-652
Juvenile temperate seabass Lateolabrax japonicus were sampled along the Yura River estuary from April to July 2008 to determine their distribution and feeding habits during
migration within a microtidal estuary. Throughout the sampling period, juvenile seabass were distributed not only in the surf
zone, but also in the freshwater zone, and they were particularly abundant in areas with aquatic vegetation in the freshwater
zone. This distribution pattern suggests that the early life history of the temperate seabass depends more intensively on
the river (freshwater) than previously considered. Small juveniles in the freshwater zone fed on copepods and chironomid larvae
and upon reaching a standard length (SL) of approximately 20 mm did they fed on mysids. In contrast, juveniles (approx. 17–80 mm
SL) in the surf zone fed mainly on mysids. 相似文献
11.
Hershberger PK Gregg J Pacheco C Winton J Richard J Traxler G 《Journal of fish diseases》2007,30(8):445-458
Pacific herring were susceptible to waterborne challenge with viral haemorrhagic septicaemia virus (VHSV) throughout their early life history stages, with significantly greater cumulative mortalities occurring among VHSV‐exposed groups of 9‐, 44‐, 54‐ and 76‐day‐old larvae than among respective control groups. Similarly, among 89‐day–1‐year‐old and 1+year old post‐metamorphosed juveniles, cumulative mortality was significantly greater in VHSV‐challenged groups than in respective control groups. Larval exposure to VHSV conferred partial protection to the survivors after their metamorphosis to juveniles as shown by significantly less cumulative mortalities among juvenile groups that survived a VHS epidemic as larvae than among groups that were previously naïve to VHSV. Magnitude of the protection, measured as relative per cent survival, was a direct function of larval age at first exposure and was probably a reflection of gradual developmental onset of immunocompetence. These results indicate the potential for easily overlooked VHS epizootics among wild larvae in regions where the virus is endemic and emphasize the importance of early life history stages of marine fish in influencing the ecological disease processes. 相似文献
12.
ABSTRACT: To clarify the feeding habits of tidal mudflat fishes, the gut contents of 29 fish species, collected from unvegetated tidal mudflats in Tokyo Bay, central Honshu, Japan, were examined. Ontogenetic changes in food preference were recognized in 21 species, including several of commercial importance (e.g. Acanthogobius flavimanus , Konosirus punctatus , Mugil cephalus cephalus , Plecoglossus altivelis altivelis , and Sardinella zunasi ). In general, larvae and/or juveniles of these species fed mainly on small zooplankton or benthic harpacticoid copepods, later switching to other prey items with growth (e.g. gammaridean amphipods, mysids, polychaetes, detritus, bivalves, and juvenile fishes). A cluster analysis based on dietary overlaps showed that the tidal mudflat fish assemblage comprised six feeding guilds (small benthic and epiphytic crustacean, zooplankton, detritus, mollusc, polychaete, and fish feeders). Of these, small benthic and epiphytic crustacean feeders were the most abundantly represented in the number of species. 相似文献
13.
14.
Carter R. Newell H. Hidu B. J. McAlice G. Podniesinski F. Short L. Kindblom 《Journal of the World Aquaculture Society》1991,22(2):134-152
A thorough understanding of recruitment in the blue mussel is necessary if the new industry is to maximize seed procurement without impinging upon other fisheries. Larval appearance is a relatively precise event in Maine, cued to early summer water temperature of 10–12 C and, apparently, full moon spawning events. Mussel larvae are more abundant on the flood tides indicating inshore and estuarine retention, although this retention relates to the morphometry and relative energy of the system. Webb Cove, a wide embayment with maximum sample station current velocity of 0.2 m/s, showed a random ebb tide vs. flood tide larval distribution; the narrow, long Damariscotta River estuary with 0.35 m/s current velocity showed a two-fold flood tide larval enhancement and the Jordan River with 1.5 m/s current velocities showed up to a 14-fold flood tide enhancement of mussel larvae and bysally drifting juveniles. Thus certain Maine estuaries may act as larval traps, providing areas of concentrated settlement and seed abundance. Primary setting normally begins with a large initial pulse in June followed by one or more secondary pulses throughout the summer. Secondary settlement (reattachment of bysally drifting juveniles) occurs at lower levels throughout the year, especially in late July and early August. Maximum attachment of larvae and juveniles occurs during periods of maximum current velocity. Extensive eelgrass beds at the mouths of some estuaries (i.e., Jordan River) may be the sites of extensive primary and secondary setting. Great Eastern Mussel Farms, the industry component, guided by these studies, is testing the deployment of live and shell mussel cultch to develop and optimize a new seed procurement system. 相似文献
15.
Elorri Arevalo Henrique N. Cabral Bertrand Villeneuve Carl Possémé Mario Lepage 《Fish and Fisheries》2023,24(3):466-487
Early life stages of fish (eggs and larvae) are particularly vulnerable with mortality rates of up to 99% recorded for a large number of species. High mortality rates result from the limited swimming ability of larvae preventing them from escaping sub-optimal environmental conditions, predators or low prey density areas. In this context, estuaries are key nursery areas for larval and juvenile fish. Estuarine habitats offer environmental conditions favourable to the survival and growth of early stages, through abundant good-quality prey and protection from predators. A vast literature on larvae occurring in temperate estuaries exists, but an overall perspective is lacking. The occurrence of fish larvae in temperate estuaries depends on several factors. First, the choice of spawning time and location is primordial, as they have evolved to optimise the entry and the retention of larvae in the estuary as well as the conditions experienced by young stages. Secondly, larval growth and survival depend on key environmental factors (e.g. salinity, water temperature, freshwater inputs, turbidity and dissolved oxygen concentration). Knowledge of the larval dynamics in temperate estuaries is scarce for some topics and biased towards some species or geographical areas. The main goal of the present literature review is to synthesise existing knowledge regarding spawning timing and location and larval ecology for fish species occurring in coasts and estuaries, identifying the main patterns, consensus or conflicting hypotheses and highlighting major gaps. Research needs and future perspectives were outlined. 相似文献
16.
Nan Lin Yuange Chen Yan Jin Xingwei Yuan Jianzhong Ling Yazhou Jiang 《Fisheries Science》2018,84(2):357-363
The horizontal distribution of the early life stages of small yellow croaker Larimichthys polyactis in the Yangtze River estuary and its adjacent area was investigated through six ichthyoplankton surveys conducted during the period of mid-April to mid-July 2015. A total of seven eggs and 2461 larvae and juveniles of small yellow croaker were collected. Abundance of the specimens was highest in mid-May and lowest in mid-July. The composition of the different development stages of small yellow croaker varied among the six cruises, although post-flexion larvae and juveniles dominated the ichthyoplankton collection in each cruise. Specimens at different development stages showed different distribution patterns in the study area. The eggs, yolk-sac and pre-flexion larvae were mainly collected at stations with depth exceeding 30 m, while post-flexion larvae and juveniles were mainly distributed in the relatively shallow waters near to the mouth of the Yangtze River. In conclusion, the study suggested that the study area had largely lost the ecological function to support small yellow croaker spawning, although it could still serve as nursery ground for the species. 相似文献
17.
日本鳗鲡仔鱼摄食机理及其营养策略 总被引：2，自引：1，他引：2
鳗鲡属(Ａｎｇｕｉｌｌａ)鱼类共有19种和亚种,其中以欧洲鳗鲡(Ａ.ａｎｇｕｉｌｌａ)和日本鳗鲡(Ａ.ｊａｐｏｎｉｃａ)最为重要。鳗鲡属鱼类发育需经历奇特的柳叶状仔鱼(ｌｅｐｔｏｃｅｐｈａｌｕｓｌａｒｖａ)阶段,其人工育苗技术是一道世界难题。柳叶状仔鱼现象仅见于真骨鱼类最原始的一个类群海鲢总目Ｅｌｏｐｏｍｏｒｐｈａ(鳗鲡目Ａｎｇｕｉｌｌｉｆｏｒｍｅｓ,海鲢目Ｅｌｏｐｉｆｏｒｍｅｓ,背棘鱼目Ｎｏｔａｃａｎｔｈｉｆｏｒｍｅｓ)。有关柳叶状仔鱼的发育策略,已从形态学、生理学及生物化学等方面进行了不少研究,但柳叶状仔鱼… 相似文献
18.
Churchill Forward Luettich Hench Hettler Crowder & Blanton 《Fisheries Oceanography》1999,8(S2):173-189
In March 1996 two surveys of larval fish abundance and water flow were carried out within the estuarine region near Beaufort Inlet, NC. Each survey extended over two full semidiurnal tidal cycles and included measurements of larvae concentration and velocity distribution at several locations. There was a large across-channel variation in the subtidal flow passing through Beaufort Inlet, with net inflow over the eastern and central portions of the inlet and net outflow on the western side of the inlet. This pattern was consistent with moored current meter measurements of a previous study, and was reproduced by a numerical model circu-lation forced only by the M2 tide. A net ingress of larvae from the open ocean into the estuary was observ-ed during both surveys. Most larvae entered the estuary over the eastern and central portions of the inlet, where the subtidal flow was up-estuary. However, the mean circulation played a minor role in the net movement of larvae into the estuary. Rather, net up-estuary transport of larvae was principally due to variation of larval abundance with tidal flow; with abundance during flood tide usually far exceeding ebb tide abundance. This mode of transport was likely driven by a behavioural response to tidal flow in which larvae tended to descend to the bottom on falling tides and reside throughout the water column on rising tides. 相似文献
19.
Robert T. Cooney J. R. Allen M. A. Bishop D. L. Eslinger T. Kline B. L. Norcross C. P. Mcroy J. Milton J. Olsen V. Patrick A. J. Paul D. Salmon D. Scheel G. L. Thomas S. L. Vaughan T. M. Willette 《Fisheries Oceanography》2001,10(Z1):1-13
Five years of field, laboratory, and numerical modelling studies demonstrated ecosystem‐level mechanisms influencing the mortality of juvenile pink salmon and Pacific herring. Both species are prey for other fishes, seabirds, and marine mammals in Prince William Sound. We identified critical time‐space linkages between the juvenile stages of pink salmon and herring rearing in shallow‐water nursery areas and seasonally varying ocean state, the availability of appropriate zooplankton forage, and the kinds and numbers of predators. These relationships defined unique habitat dependencies for juveniles whose survivals were strongly linked to growth rates, energy reserves, and seasonal trophic sheltering from predators. We found that juvenile herring were subject to substantial starvation losses during a winter period of plankton diminishment, and that predation on juvenile pink salmon was closely linked to the availability of alternative prey for fish and bird predators. Our collaborative study further revealed that juvenile pink salmon and age‐0 herring exploit very different portions of the annual production cycle. Juvenile pink salmon targeted the cool‐water, early spring plankton bloom dominated by diatoms and large calanoid copepods, whereas young‐of‐the‐year juvenile herring were dependent on warmer conditions occurring later in the postbloom summer and fall when zooplankton was composed of smaller calanoids and a diversity of other taxa. The synopsis of our studies presented in this volume speaks to contemporary issues facing investigators of fish ecosystems, including juvenile fishes, and offers new insight into problems of bottom‐up and top‐down control. In aggregate, our results point to the importance of seeking mechanistic rather than correlative understandings of complex natural systems. 相似文献
20.
海水养殖鱼类仔、稚鱼骨骼发育与畸形发生 总被引：1，自引：1，他引：1
骨骼畸形可导致鱼类运动困难、摄食能力降低、生长缓慢、成活率低,因此,畸形鱼苗的出现将增加生产成本、影响养殖的经济效益。在海水鱼类人工育苗阶段,骨骼畸形现象普遍存在,严重制约了海水鱼类养殖产业的可持续发展。本文首先系统总结了卵形鲳鲹、黄尾鰤、尖吻鲈等经济海水鱼类颌骨、脊柱、尾骨的早期发育时序及特点,比较了仔、稚鱼骨骼畸形发生的部位、时间及发生规律。之后针对仔、稚鱼阶段影响骨骼发育的主要因素,从遗传、环境、营养等方面进行了剖析,以期为寻找降低人工养殖条件下海水鱼类仔、稚鱼的骨骼畸形提供启示。 相似文献