Limited flexibility in resource use in a coral reef grazer foraging on seasonally changing algal communities |
| |
Authors: | Y Afeworki J H Bruggemann and J J Videler |
| |
Institution: | (1) Department of Ocean Ecosystems, University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands;(2) Department of Applied Marine Science, College of Marine Science and Technology, P.O. Box 170, Massawa, Eritrea;(3) Laboratoire ECOMAR, Facult? des Sciences et Technologies, Universit? de La R?union, 15 Avenue Ren? Cassin, BP 7151, 97715 Saint-Denis, R?union, France |
| |
Abstract: | Feeding ecology of three life phases of the parrotfish Scarus ferrugineus was studied on a southern Red Sea fringing reef by comparing availability and consumption of benthic algae during the monsoon
hot and cool seasons. Dominant biota covering dead carbonate substrates were in decreasing order of importance: turfs on endoliths,
turfs on crustose corallines, and crustose corallines. On the reef crest and shallow fore reef, composition of the biota changed
seasonally. Cover of turfs on endoliths and turfs on crustose corallines was higher during the hot season, while crustose
corallines and macroalgae (only on reef crest) increased during the cool season. Biota in the deep fore reef did not show
seasonal variation. All life phases used similar resources and showed selective feeding in all zones. Turfs on endoliths,
followed by turfs on crustose corallines, was the primary feeding substrate. These two sources represented over 92% of bites
during both seasons. Crustose corallines, macroalgae, and living corals were negligible components being strongly avoided
at all zones and seasons. Resource use varied seasonally on the reef crest and shallow fore reef, while it remained unchanged
on the deep fore reef. Turfs on endoliths were consistently preferred in both seasons but their contribution increased from
45% in the cool to 70% of bites in the hot season. Electivity for turfs on crustose corallines shifted from random feeding
in the hot (27% of bites) to selection in the cool season (47% of bites). Feeding pattern changed diurnally with more bites
taken from crustose corallines and turfs on crustose corallines during morning. During the rest of the day, bites from turfs
on endoliths predominate. S. ferrugineus shows limited capacity to exploit seasonal increases in the biomass of foliose and canopy forming macroalgae, despite indications
of energetic limitation during the cool season. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|