|Diet of larval albacore Thunnus alalunga (Bonnaterre, 1788) off Mallorca Island (NW Mediterranean)|
Catalán, I.A.; Alemany, F.; Morillas, A.; Morales-Nin, B. (2007). Diet of larval albacore Thunnus alalunga (Bonnaterre, 1788) off Mallorca Island (NW Mediterranean). Sci. Mar. (Barc.) 71(2): 347-354
In: Scientia Marina (Barcelona). Consejo Superior de Investigaciones Científicas. Institut de Ciènces del Mar: Barcelona. ISSN 0214-8358, more
Diets; Feeding; Larvae; Thunnus alalunga (Bonnaterre, 1788) [WoRMS]; MED, Spain, Balearic I., Majorca [Marine Regions]; Marine
|Authors|| || Top |
- Catalán, I.A.
- Alemany, F.
- Morillas, A.
- Morales-Nin, B., more
These are the first data on the feeding of larval albacore (Thunnus alalunga Bonnaterre, 1788) in the Mediterranean. Specimens were gathered from day-time bongo-hauls conducted over the SW Mallorcan (Balearic Islands) shelf-slope. Ninety eight percent of 101 individuals ranging from 2.65 to 9.4 mm standard length (SL) contained 1 to 15 prey items per gut. Mean number of prey/gut was 3.55 ± 2.19 (SD). A positive correlation was found between larval SL and the number of prey/gut. The analysis of frequency of occurrence (F), numerical frequency (N), weight frequency (W) and the Index of Relative Importance (IRD showed a dominance of copepodites and nauplii in the smallest size-class. As larvae grew, cladocerans and Calanoida copepodites dominated the diet, and cladocerans and copepodites were important in F, N and W. Piscivory was observed after notochord flexion and was important in terms of W. A positive correlation between mean prey size and both SL and lower jaw length (IJL) was observed. The niche breadth (S) did not vary with LJL, but the raw prey size range did. Larger copepodites, the absence of nauplii and the incorporation of fish larv and a larger number of cladocerans in the diet accounted for the increase in mean prey size through increased larval size.