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Abstract– The southern cavefish ( Typhlichthys subterraneus Girard) is a small troglobitic fish found in a few disjunct populations in the central United States. Protecting and managing these populations requires a knowledge of southern cavefish microhabitat requirements, including their preference for substrate. We conducted tests of their preferences for cobble, gravel, pea gravel, and sand substrates in two-way and multiple choice experiments for extended periods using time-lapse video photography. Cobble proved to be the substrate these fish preferred to occur within. In nature, this preference may provide cavefish increased foraging opportunities and/or refuge from high flows associated with flooding. Our results indicate the need to (1) maintain coarse substrate as an integral part of cavefish habitats, and (2) direct cavefish censusing attempts towards such key areas.  相似文献
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Abstract –  The population ecology of Ancistrus cryptophthalmus (Reis 1987) was studied by mark–recapture technique in caves from the São Domingos karst area, State of Goiás, northeastern Brazil. Total population sizes estimated for Angélica and Passa Três Caves were 20,000 and 1000 individuals, respectively. Densities around 1.0 individuals per m2 in Angélica, Bezerra and São Vicente I Streams, and 0.6 individuals per m2 in the smaller Passa Três Stream may be considered high for cavefish standards, as well as for epigean loricariids. As expected for benthic grazers, cave catfish are highly sedentary. The distribution of size classes did not differ among caves and within the same cave throughout the studied dry seasons; on the contrary, the condition factor decreased throughout this period probably because of the progressive depletion of organic matter available as food. Low proportions of mature individuals, low growth rates (average = 0.5 mm month−1) with cases of negative growth and high longevities (8–10 years) point to a precocial lifestyle, typical of troglobitic species.  相似文献
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研究金线鲃(Sinocyclocheilus)的游动特征——趋触性(贴近边界前行),为人工养殖、繁育和物种保护提供理论支持。试验用金线鲃均为成鱼,8种51尾,其中盲眼种2种、小眼种和正常眼种各3种。试验在安静、黑暗的环境进行,刺激条件分别为无干扰、静止障碍物和振动吸引,使用软件追踪分析试验鱼位置(距离和方向)、时间以及相对于试验缸壁的游动速度,运用线性模型分析金线鲃趋触行为差异的关键因素。结果表明:趋触前行时间占比盲眼种为73.06%、小眼种为72.65%、正常眼种为54.62%;趋触距离盲眼种(197±18)SBL、小眼种(158±14)SBL、正常眼种(139±15) SBL;趋触游动速度盲眼种(0.53±0.19)cm/(s·SBL)、正常眼种(0.37±0.18)cm/(s·SBL)、小眼种(0.46±0.22)cm/(s·SBL)。金线鲃趋触前行的行为与游泳特性如游泳速度和时间高度相关,趋触行为可能作为一种自我保护作用和觅食策略,甚至作为一种防御策略。实践中可以依据金线鲃眼部形态和行为上的趋触性偏好分类培育饲养,同时增加缓沉型鱼食以及增添静止设施。  相似文献
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