Geographic and bathymetric trends in abundance, biomass and body size of four grenadier fishes along the Iberian coast in the western Mediterranean     

Joan Moranta  Enric Massutí  John D.M. Gordon 《Progress in Oceanography》2007,72(1):63-83

The present study is a mesoscale analysis of latitude and depth related trends in abundance, biomass and body size of the four grenadier species Caelorinchus caelorhincus, Hymenocephalus italicus, Nezumia aequalis and Trachyrinchus scabrus inhabiting the deep western Mediterranean. We have analysed data from seven annual bottom trawl surveys, carried out down to 800 m depth along the Iberian Mediterranean coast covering a distance of approximately 1200 km. The objectives were to establish general patterns in the mesoscale distribution of abundance, biomass and body size of deep-water grenadier fishes and also analyse the consistency of the bathymetric distribution of these parameters along a large latitudinal gradient. Five complementary series of analyses have been completed. The first focussed on describing the general patterns of abundance and size by correspondence canonical analysis, CCA, in the area. The second and third series focussed on the existence of temporal, geographical and bathymetric trends of abundance, weight and mean size by analysis of covariance, ANCOVA and multiple regression analysis. The fourth series compared the frequency distributions of body length. Finally, the last series focussed on the patterns of abundance versus size. The total number of individuals of all four grenadier species captured in 260 bottom trawls amounted to 27,435 and their weight was 1404 kg. No general trends for the four species have been observed between years. All four species showed a general pattern of increasing size with depth, which, except in the case of C. caelorhincus, was consistent along a large latitudinal gradient. Nezumia aequalis was unique in showing the same noticeable trend of increasing abundance with depth along the entire latitudinal range, but with clear differences in the intercepts. The abundance of N. aequalis and C. caelorhincus decreased significantly northwards. Hymenocephalus italicus was the least abundant species and had a homogeneous distribution without any specific trend along the entire latitudinal range analysed. The distribution of T. scabrus in the Mediterranean seemed to be more localised. Higher abundances were found to the north and south of the latitudinal gradient with lower values between. The grenadiers studied also showed a general trend of decreasing mean size northwards, except in the case of the smallest species, H. italicus. The relation between abundance and body size differed between sectors for the whole grenadier population and species-specific variations were also observed. The relationship between individual body mass and population density fit well to a second-order polynomial function rather than to a linear regression, showing a significant trend for density to increase with increasing size until some mid-point, then to decline with increasing size thereafter. The observed latitudinal gradient in the distribution patterns of grenadiers along the upper slope of the western Mediterranean can be discussed in relation to direct and indirect factors of biogeographic, environmental and anthropogenic origin.  相似文献   

Using fish-processing time to carry out acoustic surveys from commercial vessels     

O'Driscoll  Richard L.; Macaulay  Gavin J. 《ICES Journal of Marine Science》2005,62(2):295-305

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应用水声方法考察底栖鱼类和DSL(深海散射层)的垂直移动     

陈次颖  章淑珍 《海洋科学》1994,18(3):53-56

利用彩色显示回声探测仪在南海北部水域中测到的图象进行调查底栖鱼类和ＤＳＬ的垂直移动；仪器的量程扩功能用于考察底栖鱼类的贴海底，超浮，聚薄层和扩散等情景；ＤＳＬ在黄错时期的聚层起浮，午液出现集群最密，黎时下降，解体；示出ＤＳＬ聚层的厚度及垂直移动的速度。  相似文献   

Summer and winter plankton fish assemblages around offshore oil and gas platforms in south-eastern Australia     

Francisco J. Neira 《Estuarine, Coastal and Shelf Science》2005,63(4):72

Opportunistic plankton surveys were conducted within a 5-nmi radius of nine offshore oil and gas platforms in Bass Strait, south-eastern Australia, in February 1998 and 1999 (summer) and August 1998 (winter). The 108 day-night samples collected alongside (vertical tows) and nearby (surface and oblique tows) platforms yielded 1526 larval and early juvenile fishes representing 55 taxa from 45 families. Epipelagic/mesopelagic taxa dominated the catches, whereas hard/soft habitat-associated taxa were uncommon. Carangidae (36.2%) and Myctophidae (31.5%) dominated in summer and winter, respectively. The most abundant taxon was Trachurus declivis (Carangidae, 35.1%), followed by Bovichtus angustifrons (Bovichtidae, 8.7%), Scomberesox saurus (Scomberesocidae, 3.7%), Centroberyx affinis (Berycidae, 3.0%) and Arripis trutta (Arripidae, 1.7%). Fish concentrations (nos. per 100 m³) alongside platforms did not differ significantly between day and night across all surveys. Likewise, concentrations nearby platforms in February 1999, including those of T. declivis, did not vary significantly by tow type (surface vs. oblique) or day vs. night. The far greater diversity and abundance recorded in February 1999 are likely the result of upwelling conditions over the eastern Bass Strait shelf during the sampling period, and which were not detected in February 1998. In the absence of data on adult fishes associated with the Bass Strait platforms, and given the limited availability of reefs directly around the area, it could be argued that some of the taxa caught may originate from spawning around neighboring natural reefs, particularly those off the Gippsland coastline and the south-east corner of mainland Australia. However, the prime position of the platforms almost right in the center of a productivity “hotspot” would have a confounding effect on the potential source(s) of larval fishes in that region of south-eastern Australia. The role of platforms as potential de-facto reefs for juvenile fishes in Bass Strait, as well as spawning areas, is discussed based on the findings of this study, the first on early stages of fishes around oil and gas platforms in Australia.  相似文献   

Relationships between sea surface temperature, salinity, and pelagic fish distribution off northern Chile   总被引：2，自引：0，他引：2  

Castillo  J.; Barbieri  M. A.; Gonzalez  A. 《ICES Journal of Marine Science》1996,53(2):139-146

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几种鲈形目鱼类口腔齿的比较研究     

余云军  武云飞 《中国海洋大学学报(自然科学版)》2004,34(1):29-36

对中国海洋大学鱼类标本室保存的部分鲈形目鱼类——鲷科 Sparidae,大眼鲷科 Priacan-thidae,科 Serranidae的几种鱼类的口腔齿进行了研究。结果显示 :科与大眼鲷科的前颌骨、齿骨、犁骨、腭骨、咽骨上都着生有形态较单一的口腔齿 ,但较小 ,不是很坚固 ;而鲷科的几种鱼类口腔齿都着生在前颌骨、齿骨、咽骨上 ,且较强硬 ,形态较多样 ,特别发达。本研究为 3种鱼类的进化关系提供了某些佐证。  相似文献   

Diving behaviour of freshwater finless porpoises (Neophocaena phocaenoides) in an oxbow of the Yangtze River, China   总被引：1，自引：0，他引：1  

Akamatsu  Tomonari; Wang  Ding; Wang  Kexiong; Wei  Zhuo; Zhao  Qingzhong; Naito  Yasuhiko 《ICES Journal of Marine Science》2002,59(2):438-443

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Prey consumption of Australasian gannets (Morus serrator) breeding in Port Phillip Bay, southeast Australia, and potential overlap with commercial fisheries     

Bunce  Ashley 《ICES Journal of Marine Science》2001,58(4):904-915

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真鲷仔,稚,幼鱼期消化酶活性的变化   总被引：17，自引：4，他引：17  

陈品健  王重刚 《台湾海峡》1997,16(3):245-248

本文研究了真鲷仔，稚，幼鱼不同发育期三种消化酶活性的变化，结果表明，蛋白酶活性两个极低点分别出现在受精后５日龄和２５日龄，２５－４４日龄蛋白酶活性上升明显，之后活性上升稍缓；淀粉酶从受精后到５日龄活性急剧下降，５－４４日龄变化很小，４５日龄后活性略有提高；脂肪酶活性从受精后至５日有所提高，４０日龄活性到最低点，之后上升较快。  相似文献   

东海区底拖网渔业主要经济鱼类渔业生物学的初步研究   总被引：23，自引：0，他引：23  

林龙山  郑元甲  程家骅  刘勇  凌建忠 《海洋科学》2006,30(2):21-25

根据1997~2000年东海区底拖网渔业资源调查资料,分析了18种主要经济鱼类的渔业生物学特征,运用体长频率法估算了von Bertalanffy生长参数、总死亡系数、自然死亡系数、捕捞死亡系数和开发率。结果表明,大部分鱼类已出现个体小型化,15种鱼类的开发率过高,处于超额开发状态,其中,4种为重度超额开发,开发率大于0.8,7种为中度超额开发,开发率介于0.7~0.8之间,4种为轻度超额开发,开发率为0.5~0.7。建议加强保护和管理,以利于鱼类资源的可持续利用。  相似文献