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Helgol Mar Res (2014) 68:271279 DOI 10.1007/s10152-014-0387-2
ORIGINAL ARTICLE
The barred grunt Conodon nobilis (Perciformes: Haemulidae) in shallow areas of a tropical bight: spatial and temporal distribution, body growth and diet
Mara Pombo Mrcia Regina Denadai
Eduardo Bessa Flvia Borges Santos
Vanessa Hermann de Faria Alexander Turra
Received: 2 September 2013 / Revised: 14 January 2014 / Accepted: 12 February 2014 / Published online: 27 February 2014 Springer-Verlag Berlin Heidelberg and AWI 2014
Abstract This study aimed to comprehensively investigate the population biology of Conodon nobilis (Perciformes, Haemulidae) in Caraguatatuba Bight, southeastern Brazil. Monthly trawls were performed from October 2003 through October 2004 in two areas of the bight that are similar to but distant from each other, South and North. For all specimens, the size was measured and the sex and reproductive stage identied. Abundance and size were compared over areas and months. Body growth parameters were parameterized according to the Von Bertalanffy growth function. The stomach contents were identied and quantied. C. nobilis occurred mainly in the North area and showed an erratic pattern of abundance over time. Several
cohorts entered in different periods, but very few large and mature individuals were observed. The results indicate a preference for shallow, ocean-inuenced habitats and some degree of segregation between young and older individuals. The species showed a distribution consistent with an r-strategist species, with high abundance and a high growth constant (K = 0.68 year-1 and Lmax = 34.2 cm). Both the relative length of the digestive tube and the prey items indicated a carnivorous feeding habit; mysids were the main item of the diet throughout the study period, indicating that this grunt is a specialist feeder. Other frequently observed items were amphipods and sh fragments. Ingestion of scales is possibly intentional.
Keywords Spatio-temporal distribution Size
Abundance Body growth Mysida
Introduction
Studies of ichthyofauna communities have been carried out widely in tropical areas, especially concerning the effects of shrimp trawling in coastal areas and the enormous numbers of sh uselessly killed by this activity (Crowder and Murawski 1998; Branco and Verani 2006). Efforts to understand these specic sh populations are rarer, since most community studies target commercially important species. The varied human pressures on coastal areas in addition to shrimp trawling are of great...