Feeding ecology and growth of age 0 year Platichthys flesus(L.) in a vegetated and a bare sand habitat in a nutrient rich fjord

• Published in: Journal of fish biology Vol. 66; no. 2; pp. 531 - 552
• Main Authors: Andersen, B. S., Carl, J. D., Grønkjær, P., Støttrup, J. G.
• Format: Journal Article
• Language: English
• Published: Oxford, UK; Malden, USA Blackwell Science Ltd 01.02.2005; Blackwell
• Subjects: Agnatha. Pisces; Biological and medical sciences; diet; feeding strategy; Fundamental and applied biological sciences. Psychology; growth; juvenile flounder; macroalgae; ontogenetic shift; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Sand; Growth; feeding strategy; Platichthys flesus; Biology; Ecology; Feeding; Freshwater environment; Marine environment; Fjord; Vertebrata; Diet; macroalgae; Pisces; juvenile flounder; Nutrient; Strategy; Habitat; Age; ontogenetic shift
• ISSN: 0022-1112; 1095-8649
• DOI: 10.1111/j.0022-1112.2005.00620.x

A study was carried out to investigate the diet and feeding strategies of age 0 year juvenile flounder Platichthys flesus in two different micro‐tidal habitats in the nutrient enriched Mariager Fjord on the Danish east coast. Juvenile flounder and benthic macrofauna were sampled monthly from June to October 1999 in a bare sand habitat and a habitat covered by filamentous and mat forming macroalgae. The presence of the ‘opportunistic’ macroalgae created a shift in the dominance of surface dwelling prey such as epifaunal amphipods to more infaunal groups such as oligochaetes and polychaetes. The diet of the flounder varied considerably between the two habitats mainly reflecting prey availability relative to their abundance, prey spatial distribution, habitat structure and ontogenetic prey shifts as a function of total length. Flounder in the vegetated site fed on a diverse diet of copepods, polychaetes and oligochaetes, whereas those caught in the bare sand site fed primarily on the amphipod Corophium volutator which was numerically dominant at this site. During the growth season, two diet shifts were observed: from copepods early in the season to macrofauna organisms and, later in the season, the inclusion of more hyperbenthic prey such as Mysidea spp; Idotea spp. and the common goby Pomatoschistus microps.