A null model for the analysis of dietary overlap in Macroramphosus spp. at the Great Meteor Seamount (subtropical North-east Atlantic)

• Main Authors: Matthiessen, Birte, Fock, H. O.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2004
• Subjects: Meteor Seamount; North East Atlantic
• Online Access: https://oceanrep.geomar.de/id/eprint/6901/; https://oceanrep.geomar.de/id/eprint/6901/1/Mat-Foc-AFMR-51-2004.pdf

Macroramphosus spp. (Centriscidae, Macroramphosinae) are the most abundant demersal fishes on the Great Meteor Seamount (GMR, subtropical NE Atlantic, 30degrees N, 28.5degrees W). Previous investigations evidenced the existence of two species that differed in morphology and diet. A deep-bodied benthos feeding type (b-type), M. scolopax, could be significantly distinguished from a slender planktivorous type (p-type), M. gracilis. In this study we investigate whether dietary differences are also significant. Based on a novel null model termed ortho-RA3 in accordance with Lawlor (1980), the analysis of dietary overlap revealed significant differences between feeding types for two of three hypotheses that were tested, i.e., between-group differences and within-group differences for M. gracilis. Reasons for the failure of the third hypothesis (within-group differences for M scolopax) are discussed. Our results 4 reinforce the hypothesis of two competing species of snipefishes at GMR