| Autor: |
BRAMWELL, NIKKI A., HAMMIL, EDWARD, BOOT, DAVID J. |
| Předmět: |
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| Zdroj: |
Journal of Arts Science & Technology; Sep2023, Vol. 15 Issue 1, p65-94, 30p |
| Abstrakt: |
An organism’s habitat preference may shift to one of greater structural complexity to maximize protection from predatory attack. In south-eastern Australian coastal seascape, seagrass beds, sandy substratum and/or rocky algal reef border each other forming a matrix of varying habitat configurations with varying protection potential. We investigated the change in habitat selection in four Australian seagrass fish species, Stigmatopora argus, Acanthaluteres spilomelanurus, Pelates sexlineatus and Atherinosoma microstomata with the inclusion of predatory threat using tank experiments. The 250L, 90 cm internal diameter experimental tank contained three habitats – seagrass, sand and rock arranged in an unbroken circular path creating three distinct edge combinations and resulting in six sections of varying levels of complexity and heterogeneity. A transparent inner wall separated the habitat matrix from the central test chamber, which contained and demarcated “zone of decision”. Each test fish (n=123) was placed in the tank centre for 2–3 minutes in an isolation tube to acclimatize before being released to make its selection. This was repeated for each test fish first without predatory threat then with threat. S. argus spent significantly more time in the rock section (paired t-test: p= 0.038) and less time in the seagrass-sand section (paired t-test: p=0.05) when under threat. A. spilomelanurus spent significantly less time in homogeneous seagrass when threatened (paired t-test: p = 0.016) and displayed a non-significant increased selection of sections containing rock when threatened. Shifts to the complex rocky substratum preference with predatory threat was demonstrated along with the importance of a suite of different habitats for a species’ survival. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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