Skip to main content
padlock icon - secure page this page is secure

Open Access Nocturnal migration reduces exposure to micropredation in a coral reef fish

Download Article:
 Download
(PDF 392.7 kb)
 
Tropical Atlantic reef fishes in the family Haemulidae (grunts) remain quiescent on reefs during the day and migrate to seagrass beds or sand flats at night. Hypothesized advantages of such nocturnal migrations are increased food availability and/or decreased predation risk. Here, we tested predictions of an alternative hypothesis that nocturnal migrations of French grunt, Haemulon flavolineatum (Desmarest, 1823), reduce exposure to blood-feeding gnathiid isopods. The departure of grunts from the reef coincides with increasing gnathiid activity. In field experiments, subadult fish placed in cages and deployed on the reef at night harbored significantly more gnathiids than those placed in the seagrass habitat. However, this was not the case during the day when gnathiid activity in all habitats is low. In another experiment, the timing of return to the reef was determined to coincide with the postdawn decrease in gnathiid activity. Estimates of cumulative gnathiid exposure at two sites revealed that grunts remaining in reef habitat at night would experience an average of 3 and 44 times more gnathiids than if they spent the night in the seagrass bed, and could reach more than 300 gnathiids on a single fish. In a final field experiment, even recently-settled (<2 cm) juvenile grunts were infested by gnathiids, supporting previous laboratory experiments showing that a single third-stage gnathiid will infest and kill grunts of this size. Combined, these findings suggest that nocturnal feeding migrations of French grunts and ecologically similar fishes result in reduced exposure to blood-feeding gnathiid isopods.

69 References.

No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Affiliations: 1: Department of Biological Sciences and Environmental Sciences Program, Arkansas State University, State University, Arkansas 72467, Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa;, Email: [email protected] 2: Department of Biological Sciences and Environmental Sciences Program, Arkansas State University, State University, Arkansas 72467, Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa 3: Department of Biological Sciences and Environmental Sciences Program, Arkansas State University, State University, Arkansas 72467 4: Department of Biological Sciences and Environmental Sciences Program, Arkansas State University, State University, Arkansas 72467, Center for Marine and Environmental Studies, University of the Virgin Islands, 2 Brewers Bay, St. Thomas, US Virgin Islands 00802 5: Center for Marine and Environmental Studies, University of the Virgin Islands, 2 Brewers Bay, St. Thomas, US Virgin Islands 00802

Publication date: 01 April 2017

This article was made available online on 13 September 2016 as a Fast Track article with title: "Nocturnal migration reduces exposure to micropredation in a coral reef fish".

More about this publication?
  • The Bulletin of Marine Science is dedicated to the dissemination of high quality research from the world's oceans. All aspects of marine science are treated by the Bulletin of Marine Science, including papers in marine biology, biological oceanography, fisheries, marine affairs, applied marine physics, marine geology and geophysics, marine and atmospheric chemistry, and meteorology and physical oceanography.
  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • Terms & Conditions
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more