• DOI:10.1007/BF00004634
• Corpus ID: 34037401

Development and changes at settlement in the barbel structure of the reef fish, Upeneus tragula (Mullidae)

@article{McCormick2004DevelopmentAC,
  title={Development and changes at settlement in the barbel structure of the reef fish, Upeneus tragula (Mullidae)},
  author={Mark I. McCormick},
  journal={Environmental Biology of Fishes},
  year={2004},
  volume={37},
  pages={269-282}
}

• M. McCormick
• Published 1 July 1993
• Environmental Science
• Environmental Biology of Fishes

SynopsisThe development of the sensory barbels of the tropical goatfish, Upeneus tragula (Mullidae), was examined from their first appearance early in planktonic life through to the reef-associated juvenile period. The structure of the barbel was examined histologically and found to represent an outgrowth of the gustatory (taste) system, composed of at least 50% sensory tissue at settlement. Abrupt changes in morphology were found to be coincident with the 6–12 h settlement period: barbels rapidly moved forward along the hyoid arch to abut the dentary; the length of the barbels increased by up to 52%; the epidermal layer increased to comprise 75% of the cross-sectional area; and the mean size of the taste bud cells increased by up to 100%. A strong relationship was found between barbel length and mean taste-bud size. This relationship was used to predict the mean taste-bud sizes for 237 newly-settled fish, collected as 12 samples over two recruitment seasons. Mean taste-bud size varied significantly among samples. Experiments examined whether food availability or temperature of the water within the pelagic phase influenced the size of the barbels at settlement. Food availability influenced the relationship between barbel length and fish size. Slower growing fish had larger barbels relative to fish length than those that grew faster. Temperature did not influence the relationship between barbel length and fish size. Variability in sensory development at settlement, and the factors which influence it, may have important ramifications for the potential success of the fish once on the reef.