Skip to main content

Free Content Diet of juvenile gag Mycteroperca microlepis from a non-estuarine seagrass bed habitat in the southern Gulf of Mexico

Download Article:
 Download
(PDF 879.33203125 kb)
 

Abstract:

Diet composition, including seasonal and ontogenetic variations, was evaluated in juvenile gag, Mycteroperca microlepis (Goode and Bean, 1880), from a nearshore open marine seagrass bed on the north coast of the Yucatán Peninsula. Stomach contents from 322 juveniles (6.6–36.0 cm total length, TL) were analyzed using percentage frequency of occurrence (%F), percentage number (%N), percentage weight (%W), and a dietary index (Q = %N · %W). Young gag preyed heavily on caridean shrimps (Q = 791, %F = 38), fishes (Q = 327, %F = 13), penaeid shrimps (Q = 287, %F = 16), and unidentified decapods (Q = 114, %F = 26). Dominant prey in stomach contents shifted from caridean shrimps (Q = 1072, %F = 41) during the warm season to fishes (Q = 1392, %F = 21) and penaeid shrimps (Q = 1098, %F = 33) during the cold season. Size-dependent shifts in diet were also observed, particularly when organisms reached a size of ∼17 cm TL. Dominant prey were caridean shrimps (Q = 1186, %F = 45) for gag ≤ 17 cm TL and fishes (Q = 2379, %F = 35) and penaeid shrimps (Q = 1005, %F = 27) for gag > 17 cm tl. Diet composition and ontogenetic changes in juvenile gag diet were similar, independent of nursery habitat (seagrass or oyster shell bed inside or outside of an estuarine system). Gag is therefore best considered an estuarine opportunist, with nursery ground habitat (i.e., seagrass meadows) being the final factor controlling juvenile settlement and growth.

Document Type: Research Article

DOI: https://doi.org/10.5343/bms.2010.1028

Publication date: 2011-01-01

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