Net tube substrates with inner interstices affecting on the colonization of invertebrates, particularly the food source for fish
2002
Noda, M. (Shimonoseki Univ. of Fisheries, Yamaguchi (Japan)) | Tahara, M. | Katayama, T. | Katayama, K. | Kakimoto, H.
Four different test substrates were compared for the degree of colonization by fish food items over 2 years at four sites in the central Seto Inland Sea. Three substrates were polyethylene net tubes (20 X 25 mm mesh, 15 cm in diameter, 30 cm long) stuffed with either oyster shells, pearl oyster shells, or crushed stones, whereas one substrate was a solid concrete cylinder of the same dimensions. After 24 months of immersion, the net tube substrates offering many complex openings created by an accumulation of materials were colonized by a higher number of species and abundance of decapods and molluscs than the concrete, although cirripedes and ascidians dominated all substrates. A comparison of the monthly temporal changes in total wet weight of the epibenthic animals and the food items showed that in most cases the net tube substrates had higher levels, while the concrete had the lowest level. In particular, decapods tended to colonize in net tube substrates more quickly than the concrete substrates. Differences in the substrates structure may explain the differences between the communities.
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