Effect of diet on otolith composition in Pomatomus saltatrix, an estuarine piscivore

Abstract

To test the hypothesis that elemental composition of otoliths (sagittae) could be influenced by differences in natural prey type, young-of-the-year bluefish Pomatomus saltatrix were captured immediately after their migration from oceanic waters into mid-Atlantic Bight estuaries and fed either shrimp, Crangon septemspinosa and Palaemonetes spp. or fish Menidia menidia under similar temperature and salinity regimes in two separate 60 day experiments. Unlimited rations of fish and shrimp prey were provided in the first experiment which led to differences in bluefish growth rate between the two prey treatments; fish prey was limited in the second experiment to ensure that growth rates of bluefish in the two prey treatments were similar. Concentrations of seven elements in bluefish otoliths were determined using solution-based inductively coupled plasma mass spectrometry (ICPMS). There was no significant effect of diet on five of the seven elements examined (Na, Mg, K, Ca and Mn). The levels of Sr and Ba in the otoliths of shrimp-fed bluefish, however, were significantly higher than fish-fed bluefish in both experiments. Concentrations of Ba in shrimp-fed bluefish otoliths were double that found in fish-fed bluefish. The results suggest that diet can explain some of the variation in otolith chemistry previously attributed to physical and chemical properties of the water. # 2004 The Fisheries Society of the British Isles

Dietary effects on multi-element composition of European eel (Anguilla anguilla) otoliths

“…2). SigniWcant eVects on strontium and barium uptake into otoliths were found in blueWsh, P. saltatrix (Buckel et al 2004) fed on Wsh versus shrimp diets. Contents of Sr and Ba reached values from 110.4 ppm Sr and 0.996 ppm Ba in Wsh to 421.6 ppm Sr and 3.523 ppm Ba in shrimp diet.…”

“…Element composition of biogenic aragonites is thought to depend mainly on physicochemical properties of the surrounding water (Campana 1999). Nevertheless, it has been repeatedly reported that endogenous factors such as diet might have an eVect on the element compositions of Wsh otoliths (Limburg 1995;Farrell and Campana 1996;Gallahar and Kingsford 1996;Buckel et al 2004) as well as cephalopod statoliths (Zumholz et al 2006), since cations entering the inner ear endolymph via the blood circuit can originate either from branchial or intestinal uptake (Campana 1999). Previous investigations on the importance of food on element incorporation into otoliths were highly ambiguous.…”

“…Walther and Thorrold (2006) concluded that Sr and Ba contents in marine Wsh otoliths clearly reXect ambient Sr and Ba concentrations, while Kennedy et al (2000) reported 70% of the Sr isotopic signature in freshwater Atlantic salmon (Salmo salar) otoliths to originate from food. SigniWcant dietary eVects on strontium incorporation have been demonstrated for American shad (Alosa sapidissima) (Limburg 1995) and Black bream (Girella elevata) (Gallahar and Kingsford 1996) and for strontium and barium incorporation in blueWsh (Pomatomus saltatrix) (Buckel et al 2004). No eVects were detected for the uptake of magnesium, potassium, strontium, sodium, and calcium in Red drum (Sciaenops ocellatus) (HoV and Fuiman 1995), for strontium, copper and lead in barramundi (Milton and Chenery 2001), for sodium, magnesium, potassium, calcium and manganese in blueWsh (P. saltatrix) (Buckel et al 2004) and for strontium in Japanese eel (Anguilla japonica) (Lin et al 2007).…”

“…SigniWcant dietary eVects on strontium incorporation have been demonstrated for American shad (Alosa sapidissima) (Limburg 1995) and Black bream (Girella elevata) (Gallahar and Kingsford 1996) and for strontium and barium incorporation in blueWsh (Pomatomus saltatrix) (Buckel et al 2004). No eVects were detected for the uptake of magnesium, potassium, strontium, sodium, and calcium in Red drum (Sciaenops ocellatus) (HoV and Fuiman 1995), for strontium, copper and lead in barramundi (Milton and Chenery 2001), for sodium, magnesium, potassium, calcium and manganese in blueWsh (P. saltatrix) (Buckel et al 2004) and for strontium in Japanese eel (Anguilla japonica) (Lin et al 2007). Lin et al (2007) examined the inXuence of two diVerent diets on strontium contents of A. japonica otoliths.…”

“…DiVerent analytical methods are commonly used for microchemical studies of Wsh otoliths: Synchrotron X-ray Xuorescence analysis (Tsukamoto et al 1998), particle induced X-ray emission (PIXE; Elfman et al 1999), electron probe microanalysis (HoV and Fuiman 1995), solution based inductively coupled plasma mass spectrometry (ICP-MS; Buckel et al 2004) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS; Walther and Thorrold 2006). In the present study, LA-ICP-MS was chosen to measure feed-dependency on the incorporation of 16 elements because of its high precision in multi-element analysis and good spatial resolution.…”