摘要:

We tested the effect of predation by rainbow troutOncorhynchus mykisson the behavior and spatial distribution of Little Colorado spinedaceLepidomeda vittata, a native cyprinid that occurs in disjunct populations in northern Arizona. Field experiments demonstrated high predation on Little Colorado spinedace even in the presence of natural refuges and abundant macroinvertebrate prey. Little Colorado spinedace showed almost no predator avoidance in the presence of rainbow trout, which implies limited interaction with large nonnative predators through evolutionary time. Results suggest that rainbow trout may have a significant influence on the habitat use, behavior, and geographic distribution of Little Colorado spinedace, and may be responsible, in part, for the disjunct geographic distribution of this threatened native fish species.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1993)122<0139:NEORTP>2.3.CO;2

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The cucumber odor emitted by the European smeltOsmerus eperlanusand Canadian surf smeltHypomesus pretiosus(both Osmeridae) and by the New Zealand common smeltRetropinna retropinnaand Stokells smeltStokellia anisodon(Retropinnidae) is shown to be caused by trans-2 -cis-6-nonadienal, as has previously been shown for the Australian graylingPrototroctes maraena(Prototroctidae). These fish are all members of the Osmeroidei. However some other groups (Argentinidae, Chlorophthalmidae, Pomatomidae) are also reported to emit the odor and it is not presently possible to determine whether the odor is a commonly derived homologous character within the Osmeroidei and is convergently present also in other families, or whether it is a primitive character in the Osmeroidei and other related groups. The function of the chemical, which occurs in the skin, is unknown, and clarification depends on understanding metabolic pathways involved.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1993)122<0144:TCNTCO>2.3.CO;2

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In a series of laboratory experiments, I examined the attraction of bluegillsLepomis macrochirusto cover as a function of light intensity and orientation of underwater structures. Changing the density from one fish to five fish per aquarium did not change the results. Fish always preferred the lowest light intensity available. In very low light, they chose areas with structure more frequently than open water. Their choice of horizontally or vertically oriented structure was influenced by the size of the interstitial spacing between the structural components. Horizontally oriented structures were used less when the interstices were smaller than the body depth of the fish, and they were used less than vertically oriented structures. When artificial habitats are added to water bodies, the orientation and the interstitial spacing of the structure may influence the size of fish attracted.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1993)122<0148:CCBBOO>2.3.CO;2

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/1548-8659-122.1.155

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor